Shoulder & Elbow

ABSTRACT

Complex glenoid bone deformities present the treating surgeon with a complex reconstructive challenge. Although glenoid bone loss can be encountered in the primary setting (degenerative, congenital, post-traumatic), severe glenoid bone loss is encountered in most revision total shoulder arthroplasties. Severe glenoid bone loss is treated with various techniques including hemiarthroplasty, eccentric reaming, and glenoid reconstruction with bone autografts and allografts. Despite encouraging short- to mid-term results reported with these reconstruction techniques, the clinical and radiographic outcomes remain inconsistent and the high number of complications is a concern. To overcome this problem, more recently augmented components and patient specific implants were introduced. Using the computer-aided design and computer-aided manufacturing technology patient-specific implants have been created to reconstruct the glenoid vault in cases of severe glenoid bone loss.

In this article we describe a patient specific glenoid implant, its indication, technical aspects and surgical technique, based on the author's experience as well as a review of the current literature on custom glenoid implants.

Continue to: Total shoulder arthroplasty...

Total shoulder arthroplasty (TSA) is an effective operation for providing pain relief and improving function in patients with end-stage degenerative shoulder disease that is nonresponsive to nonoperative treatments.^1-4 With the increasing number of arthroplasties performed, and the expanding indication for shoulder arthroplasty, the number of revision shoulder arthroplasties is also increasing.^5-14 Complex glenoid bone deformities present the treating surgeon with a complex reconstructive challenge. Although glenoid bone loss can be seen in the primary setting (degenerative, congenital, and post-traumatic), severe glenoid bone loss is encountered mostly in revision TSAs.

Historically, patients with severe glenoid bone loss were treated with a hemiarthroplasty.^15-17 However, due to inferior outcomes associated with the use of shoulder hemiarthroplasties compared with TSA in these cases,^18-20 various techniques were developed with the aim of realigning the glenoid axis and securing the implants into the deficient glenoid vault.^21-25 Options have included eccentric reaming, glenoid reconstruction with bone autografts and allografts, and more recently augmented components and patient-specific implants. Studies with eccentric reaming and reconstruction with bone graft during complex shoulder arthroplasty have reported encouraging short- to mid-term results, but the clinical and radiographic outcomes remain inconsistent, and the high number of complications is a concern.^25-28

Complications with these techniques include component loosening, graft resorption, nonunion, failure of graft incorporation, infection, and instability.^25-28

Computer-aided design and computer-aided manufacturing (CAD/CAM) of patient-specific implants have been used successfully by hip arthroplasty surgeons to deal with complex acetabular reconstructions in the setting of severe bone loss. More recently, the same technology has been used to reconstruct the glenoid vault in cases of severe glenoid bone loss.

In this article, we describe a patient-specific glenoid implant, its indication, and both technical aspects and the surgical technique, based on the authors’ experience as well as a review of the current literature on custom glenoid implants.

Continue to: PATIENT-SPECIFIC GLENOID COMPONENT

The Vault Reconstruction System ([VRS], Zimmer Biomet) is a patient-specific glenoid vault reconstruction system developed with the use of CAD/CAM to address severe glenoid bone loss encountered during shoulder arthroplasty. For several years, the VRS was available only as a custom implant according to the US Food and Drug Administration rules, and therefore its use was limited to a few cases per year. Recently, a 510(k) envelope clearance was granted to use the VRS in reverse TSA to address significant glenoid bone defects.

The VRS is made of porous plasma spray titanium to provide high strength and flexibility, and allows for biologic fixation. This system can accommodate a restricted bone loss envelope of about 50 mm × 50 mm × 35 mm according to the previous experience of the manufacturer in the custom scenario, covering 96% of defects previously addressed. One 6.5-mm nonlocking central screw and a minimum of four 4.75-mm nonlocking or locking peripheral screws are required for optimal fixation of the implant in the native scapula. A custom boss can be added in to enhance fixation in the native scapula when the bone is sufficient. To facilitate the surgical procedure, a trial implant, a bone model of the scapula, and a custom boss reaming guide are 3-dimensional (3-D) and printed in sterilizable material. These are all provided as single-use disposable instruments and can be available for surgeons during both the initial plan review and surgery.

PREOPERATIVE PLANNING

Patients undergo a preoperative fine-cut 2-dimensional computed tomography scan of the scapula and adjacent humerus following a predefined protocol with a slice thickness of 2 mm to 3 mm. An accurate 3-D bone model of the scapula is obtained using a 3-D image processing software system (Figure 1). The 3-D scapular model is used to create a patient-specific glenoid implant proposal that is approved by the surgeon (Figure 2). Implant position, orientation, size, screw trajectory, and recommended bone removal, if necessary, are determined to create a more normal glenohumeral center of rotation and to secure a glenoid implant in severely deficient glenoid bone (Figure 3). Once the implant design is approved by the surgeon, the final patient-specific implant is manufactured.

SURGICAL TECHNIQUE

The exposure of the glenoid is a critical step for the successful implantation of the patient-specific glenoid implant. Soft tissue and scar tissue around the glenoid must be removed to allow for optimal fit of the custom-made reaming guide. Also, removal of the entire capsulolabral complex on the anteroinferior rim of the glenoid is essential to both enhance glenoid exposure and to allow a perfect fit of the guide to the pathologic bone stock. Attention should be paid during débridement and/or implant removal in case of revision, to make sure that no excessive bone is removed because the patient-specific guide is referenced to this anatomy. Excessive bone removal can change the orientation of the patient-specific guide and ultimately the fixation of the implant. Once the custom-made patient-specific guide is positioned, a 3.2-mm Steinmann pin is placed through the inserter for temporary fixation. The pin should engage or perforate the medial cortical wall to ensure that the subsequent reamer has a stable cannula over which to ream. After the glenoid is reamed, the final implant can be placed in the ideal position according to the preoperative planning. A central 6.5-mm nonlocking central screw and 4.75-mm nonlocking or locking peripheral screws are required to complete the fixation of the implant in the native scapula. Once the patient-specific glenoid component is positioned and strongly fixed to the bone, the glenosphere can be positioned according to the preoperative planning, and the reverse shoulder arthroplasty can be completed in the usual fashion.

CASE EXAMPLES

A 68-year-old woman underwent a TSA for end-stage osteoarthritis in 2000. The implant failed due to a cuff failure. The patient underwent several surgeries, including an open cuff repair, with no success. She had no active elevation preoperatively. Because of the significant glenoid bone loss, a patient-specific glenoid reconstruction was planned. Within 24 months after this surgery, the patient was able to get her hand to her head and elevate to 90º (Figures 4A-4F).

Continue to: In October 2013...

In October 2013, a 68-year-old man underwent a TSA for end-stage osteoarthritis. After 18 months, the implant failed due to active Propionibacterium acnes infection, which required excisional arthroplasty with insertion of an antibiotic spacer. Significant glenoid bone loss (Figure 5) and global soft-tissue deficiency caused substantial disability and led to an indication for a reverse TSA with a patient-specific glenoid vault reconstruction (Figures 6A-6D) after infection eradication. Within 20 months after this surgery, the patient had resumed a satisfactory range of motion (130º forward elevation, 20º external rotation) and outcome.

DISCUSSION

Although glenoid bone loss is often seen in the primary setting (degenerative, congenital, and post-traumatic), severe glenoid bone loss is encountered in most revision TSAs. The best treatment method for massive glenoid bone defects during complex shoulder arthroplasty remains uncertain. Options have included eccentric reaming, glenoid reconstruction with bone allograft and autograft, and more recently augmented components and patient-specific implants.^21-25 The advent and availability of CAD/CAM technology have enabled shoulder surgeons to create patient-specific metal solutions to these challenging cases. Currently, only a few reports exist in the literature on patient-specific glenoid components in the setting of severe bone loss.^29-32

Chammaa and colleagues²⁹ reported the outcomes of 37 patients with a hip-inspired glenoid component (Total Shoulder Replacement, Stanmore Implants Worldwide). The 5-year results with this implant were promising, with a 16% revision rate and only 1 case of glenoid loosening.

Stoffelen and colleagues³⁰ recently described the successful use of a patient-specific anatomic metal-backed glenoid component for the management of severe glenoid bone loss with excellent results at 2.5 years of follow-up. A different approach was pursued by Gunther and Lynch,³¹ who reported on 7 patients with a custom inset glenoid implant for deficient glenoid vaults. These circular anatomic, custom-made glenoid components were created with the intention of placing the implants partially inside the glenoid vault and relying partially on sclerotic cortical bone. Despite excellent results at 3 years of follow-up, their use is limited to specific defect geometries and cannot be used in cases of extreme bone loss.

CONCLUSION

We have described the use of a patient-specific glenoid component in 2 patients with severe glenoid bone loss. Despite the satisfactory clinical and short-term radiographic results, we acknowledge that longer-term follow-up is needed to confirm the efficacy of this type of reconstruction. We believe that patient-specific glenoid components represent a valuable addition to the armamentarium of shoulder surgeons who address complex glenoid bone deformities.

ABSTRACT

Complex glenoid bone deformities present the treating surgeon with a complex reconstructive challenge. Although glenoid bone loss can be encountered in the primary setting (degenerative, congenital, post-traumatic), severe glenoid bone loss is encountered in most revision total shoulder arthroplasties. Severe glenoid bone loss is treated with various techniques including hemiarthroplasty, eccentric reaming, and glenoid reconstruction with bone autografts and allografts. Despite encouraging short- to mid-term results reported with these reconstruction techniques, the clinical and radiographic outcomes remain inconsistent and the high number of complications is a concern. To overcome this problem, more recently augmented components and patient specific implants were introduced. Using the computer-aided design and computer-aided manufacturing technology patient-specific implants have been created to reconstruct the glenoid vault in cases of severe glenoid bone loss.

In this article we describe a patient specific glenoid implant, its indication, technical aspects and surgical technique, based on the author's experience as well as a review of the current literature on custom glenoid implants.

Continue to: Total shoulder arthroplasty...

Total shoulder arthroplasty (TSA) is an effective operation for providing pain relief and improving function in patients with end-stage degenerative shoulder disease that is nonresponsive to nonoperative treatments.^1-4 With the increasing number of arthroplasties performed, and the expanding indication for shoulder arthroplasty, the number of revision shoulder arthroplasties is also increasing.^5-14 Complex glenoid bone deformities present the treating surgeon with a complex reconstructive challenge. Although glenoid bone loss can be seen in the primary setting (degenerative, congenital, and post-traumatic), severe glenoid bone loss is encountered mostly in revision TSAs.

Historically, patients with severe glenoid bone loss were treated with a hemiarthroplasty.^15-17 However, due to inferior outcomes associated with the use of shoulder hemiarthroplasties compared with TSA in these cases,^18-20 various techniques were developed with the aim of realigning the glenoid axis and securing the implants into the deficient glenoid vault.^21-25 Options have included eccentric reaming, glenoid reconstruction with bone autografts and allografts, and more recently augmented components and patient-specific implants. Studies with eccentric reaming and reconstruction with bone graft during complex shoulder arthroplasty have reported encouraging short- to mid-term results, but the clinical and radiographic outcomes remain inconsistent, and the high number of complications is a concern.^25-28

Complications with these techniques include component loosening, graft resorption, nonunion, failure of graft incorporation, infection, and instability.^25-28

Computer-aided design and computer-aided manufacturing (CAD/CAM) of patient-specific implants have been used successfully by hip arthroplasty surgeons to deal with complex acetabular reconstructions in the setting of severe bone loss. More recently, the same technology has been used to reconstruct the glenoid vault in cases of severe glenoid bone loss.

In this article, we describe a patient-specific glenoid implant, its indication, and both technical aspects and the surgical technique, based on the authors’ experience as well as a review of the current literature on custom glenoid implants.

Continue to: PATIENT-SPECIFIC GLENOID COMPONENT

The Vault Reconstruction System ([VRS], Zimmer Biomet) is a patient-specific glenoid vault reconstruction system developed with the use of CAD/CAM to address severe glenoid bone loss encountered during shoulder arthroplasty. For several years, the VRS was available only as a custom implant according to the US Food and Drug Administration rules, and therefore its use was limited to a few cases per year. Recently, a 510(k) envelope clearance was granted to use the VRS in reverse TSA to address significant glenoid bone defects.

The VRS is made of porous plasma spray titanium to provide high strength and flexibility, and allows for biologic fixation. This system can accommodate a restricted bone loss envelope of about 50 mm × 50 mm × 35 mm according to the previous experience of the manufacturer in the custom scenario, covering 96% of defects previously addressed. One 6.5-mm nonlocking central screw and a minimum of four 4.75-mm nonlocking or locking peripheral screws are required for optimal fixation of the implant in the native scapula. A custom boss can be added in to enhance fixation in the native scapula when the bone is sufficient. To facilitate the surgical procedure, a trial implant, a bone model of the scapula, and a custom boss reaming guide are 3-dimensional (3-D) and printed in sterilizable material. These are all provided as single-use disposable instruments and can be available for surgeons during both the initial plan review and surgery.

PREOPERATIVE PLANNING

Patients undergo a preoperative fine-cut 2-dimensional computed tomography scan of the scapula and adjacent humerus following a predefined protocol with a slice thickness of 2 mm to 3 mm. An accurate 3-D bone model of the scapula is obtained using a 3-D image processing software system (Figure 1). The 3-D scapular model is used to create a patient-specific glenoid implant proposal that is approved by the surgeon (Figure 2). Implant position, orientation, size, screw trajectory, and recommended bone removal, if necessary, are determined to create a more normal glenohumeral center of rotation and to secure a glenoid implant in severely deficient glenoid bone (Figure 3). Once the implant design is approved by the surgeon, the final patient-specific implant is manufactured.

SURGICAL TECHNIQUE

The exposure of the glenoid is a critical step for the successful implantation of the patient-specific glenoid implant. Soft tissue and scar tissue around the glenoid must be removed to allow for optimal fit of the custom-made reaming guide. Also, removal of the entire capsulolabral complex on the anteroinferior rim of the glenoid is essential to both enhance glenoid exposure and to allow a perfect fit of the guide to the pathologic bone stock. Attention should be paid during débridement and/or implant removal in case of revision, to make sure that no excessive bone is removed because the patient-specific guide is referenced to this anatomy. Excessive bone removal can change the orientation of the patient-specific guide and ultimately the fixation of the implant. Once the custom-made patient-specific guide is positioned, a 3.2-mm Steinmann pin is placed through the inserter for temporary fixation. The pin should engage or perforate the medial cortical wall to ensure that the subsequent reamer has a stable cannula over which to ream. After the glenoid is reamed, the final implant can be placed in the ideal position according to the preoperative planning. A central 6.5-mm nonlocking central screw and 4.75-mm nonlocking or locking peripheral screws are required to complete the fixation of the implant in the native scapula. Once the patient-specific glenoid component is positioned and strongly fixed to the bone, the glenosphere can be positioned according to the preoperative planning, and the reverse shoulder arthroplasty can be completed in the usual fashion.

CASE EXAMPLES

A 68-year-old woman underwent a TSA for end-stage osteoarthritis in 2000. The implant failed due to a cuff failure. The patient underwent several surgeries, including an open cuff repair, with no success. She had no active elevation preoperatively. Because of the significant glenoid bone loss, a patient-specific glenoid reconstruction was planned. Within 24 months after this surgery, the patient was able to get her hand to her head and elevate to 90º (Figures 4A-4F).

Continue to: In October 2013...

In October 2013, a 68-year-old man underwent a TSA for end-stage osteoarthritis. After 18 months, the implant failed due to active Propionibacterium acnes infection, which required excisional arthroplasty with insertion of an antibiotic spacer. Significant glenoid bone loss (Figure 5) and global soft-tissue deficiency caused substantial disability and led to an indication for a reverse TSA with a patient-specific glenoid vault reconstruction (Figures 6A-6D) after infection eradication. Within 20 months after this surgery, the patient had resumed a satisfactory range of motion (130º forward elevation, 20º external rotation) and outcome.

DISCUSSION

Although glenoid bone loss is often seen in the primary setting (degenerative, congenital, and post-traumatic), severe glenoid bone loss is encountered in most revision TSAs. The best treatment method for massive glenoid bone defects during complex shoulder arthroplasty remains uncertain. Options have included eccentric reaming, glenoid reconstruction with bone allograft and autograft, and more recently augmented components and patient-specific implants.^21-25 The advent and availability of CAD/CAM technology have enabled shoulder surgeons to create patient-specific metal solutions to these challenging cases. Currently, only a few reports exist in the literature on patient-specific glenoid components in the setting of severe bone loss.^29-32

Chammaa and colleagues²⁹ reported the outcomes of 37 patients with a hip-inspired glenoid component (Total Shoulder Replacement, Stanmore Implants Worldwide). The 5-year results with this implant were promising, with a 16% revision rate and only 1 case of glenoid loosening.

Stoffelen and colleagues³⁰ recently described the successful use of a patient-specific anatomic metal-backed glenoid component for the management of severe glenoid bone loss with excellent results at 2.5 years of follow-up. A different approach was pursued by Gunther and Lynch,³¹ who reported on 7 patients with a custom inset glenoid implant for deficient glenoid vaults. These circular anatomic, custom-made glenoid components were created with the intention of placing the implants partially inside the glenoid vault and relying partially on sclerotic cortical bone. Despite excellent results at 3 years of follow-up, their use is limited to specific defect geometries and cannot be used in cases of extreme bone loss.

CONCLUSION

We have described the use of a patient-specific glenoid component in 2 patients with severe glenoid bone loss. Despite the satisfactory clinical and short-term radiographic results, we acknowledge that longer-term follow-up is needed to confirm the efficacy of this type of reconstruction. We believe that patient-specific glenoid components represent a valuable addition to the armamentarium of shoulder surgeons who address complex glenoid bone deformities.

ABSTRACT

Complex glenoid bone deformities present the treating surgeon with a complex reconstructive challenge. Although glenoid bone loss can be encountered in the primary setting (degenerative, congenital, post-traumatic), severe glenoid bone loss is encountered in most revision total shoulder arthroplasties. Severe glenoid bone loss is treated with various techniques including hemiarthroplasty, eccentric reaming, and glenoid reconstruction with bone autografts and allografts. Despite encouraging short- to mid-term results reported with these reconstruction techniques, the clinical and radiographic outcomes remain inconsistent and the high number of complications is a concern. To overcome this problem, more recently augmented components and patient specific implants were introduced. Using the computer-aided design and computer-aided manufacturing technology patient-specific implants have been created to reconstruct the glenoid vault in cases of severe glenoid bone loss.

In this article we describe a patient specific glenoid implant, its indication, technical aspects and surgical technique, based on the author's experience as well as a review of the current literature on custom glenoid implants.

Continue to: Total shoulder arthroplasty...

Total shoulder arthroplasty (TSA) is an effective operation for providing pain relief and improving function in patients with end-stage degenerative shoulder disease that is nonresponsive to nonoperative treatments.^1-4 With the increasing number of arthroplasties performed, and the expanding indication for shoulder arthroplasty, the number of revision shoulder arthroplasties is also increasing.^5-14 Complex glenoid bone deformities present the treating surgeon with a complex reconstructive challenge. Although glenoid bone loss can be seen in the primary setting (degenerative, congenital, and post-traumatic), severe glenoid bone loss is encountered mostly in revision TSAs.

Historically, patients with severe glenoid bone loss were treated with a hemiarthroplasty.^15-17 However, due to inferior outcomes associated with the use of shoulder hemiarthroplasties compared with TSA in these cases,^18-20 various techniques were developed with the aim of realigning the glenoid axis and securing the implants into the deficient glenoid vault.^21-25 Options have included eccentric reaming, glenoid reconstruction with bone autografts and allografts, and more recently augmented components and patient-specific implants. Studies with eccentric reaming and reconstruction with bone graft during complex shoulder arthroplasty have reported encouraging short- to mid-term results, but the clinical and radiographic outcomes remain inconsistent, and the high number of complications is a concern.^25-28

Complications with these techniques include component loosening, graft resorption, nonunion, failure of graft incorporation, infection, and instability.^25-28

Computer-aided design and computer-aided manufacturing (CAD/CAM) of patient-specific implants have been used successfully by hip arthroplasty surgeons to deal with complex acetabular reconstructions in the setting of severe bone loss. More recently, the same technology has been used to reconstruct the glenoid vault in cases of severe glenoid bone loss.

In this article, we describe a patient-specific glenoid implant, its indication, and both technical aspects and the surgical technique, based on the authors’ experience as well as a review of the current literature on custom glenoid implants.

Continue to: PATIENT-SPECIFIC GLENOID COMPONENT

The Vault Reconstruction System ([VRS], Zimmer Biomet) is a patient-specific glenoid vault reconstruction system developed with the use of CAD/CAM to address severe glenoid bone loss encountered during shoulder arthroplasty. For several years, the VRS was available only as a custom implant according to the US Food and Drug Administration rules, and therefore its use was limited to a few cases per year. Recently, a 510(k) envelope clearance was granted to use the VRS in reverse TSA to address significant glenoid bone defects.

The VRS is made of porous plasma spray titanium to provide high strength and flexibility, and allows for biologic fixation. This system can accommodate a restricted bone loss envelope of about 50 mm × 50 mm × 35 mm according to the previous experience of the manufacturer in the custom scenario, covering 96% of defects previously addressed. One 6.5-mm nonlocking central screw and a minimum of four 4.75-mm nonlocking or locking peripheral screws are required for optimal fixation of the implant in the native scapula. A custom boss can be added in to enhance fixation in the native scapula when the bone is sufficient. To facilitate the surgical procedure, a trial implant, a bone model of the scapula, and a custom boss reaming guide are 3-dimensional (3-D) and printed in sterilizable material. These are all provided as single-use disposable instruments and can be available for surgeons during both the initial plan review and surgery.

PREOPERATIVE PLANNING

Patients undergo a preoperative fine-cut 2-dimensional computed tomography scan of the scapula and adjacent humerus following a predefined protocol with a slice thickness of 2 mm to 3 mm. An accurate 3-D bone model of the scapula is obtained using a 3-D image processing software system (Figure 1). The 3-D scapular model is used to create a patient-specific glenoid implant proposal that is approved by the surgeon (Figure 2). Implant position, orientation, size, screw trajectory, and recommended bone removal, if necessary, are determined to create a more normal glenohumeral center of rotation and to secure a glenoid implant in severely deficient glenoid bone (Figure 3). Once the implant design is approved by the surgeon, the final patient-specific implant is manufactured.

SURGICAL TECHNIQUE

The exposure of the glenoid is a critical step for the successful implantation of the patient-specific glenoid implant. Soft tissue and scar tissue around the glenoid must be removed to allow for optimal fit of the custom-made reaming guide. Also, removal of the entire capsulolabral complex on the anteroinferior rim of the glenoid is essential to both enhance glenoid exposure and to allow a perfect fit of the guide to the pathologic bone stock. Attention should be paid during débridement and/or implant removal in case of revision, to make sure that no excessive bone is removed because the patient-specific guide is referenced to this anatomy. Excessive bone removal can change the orientation of the patient-specific guide and ultimately the fixation of the implant. Once the custom-made patient-specific guide is positioned, a 3.2-mm Steinmann pin is placed through the inserter for temporary fixation. The pin should engage or perforate the medial cortical wall to ensure that the subsequent reamer has a stable cannula over which to ream. After the glenoid is reamed, the final implant can be placed in the ideal position according to the preoperative planning. A central 6.5-mm nonlocking central screw and 4.75-mm nonlocking or locking peripheral screws are required to complete the fixation of the implant in the native scapula. Once the patient-specific glenoid component is positioned and strongly fixed to the bone, the glenosphere can be positioned according to the preoperative planning, and the reverse shoulder arthroplasty can be completed in the usual fashion.

CASE EXAMPLES

A 68-year-old woman underwent a TSA for end-stage osteoarthritis in 2000. The implant failed due to a cuff failure. The patient underwent several surgeries, including an open cuff repair, with no success. She had no active elevation preoperatively. Because of the significant glenoid bone loss, a patient-specific glenoid reconstruction was planned. Within 24 months after this surgery, the patient was able to get her hand to her head and elevate to 90º (Figures 4A-4F).

Continue to: In October 2013...

In October 2013, a 68-year-old man underwent a TSA for end-stage osteoarthritis. After 18 months, the implant failed due to active Propionibacterium acnes infection, which required excisional arthroplasty with insertion of an antibiotic spacer. Significant glenoid bone loss (Figure 5) and global soft-tissue deficiency caused substantial disability and led to an indication for a reverse TSA with a patient-specific glenoid vault reconstruction (Figures 6A-6D) after infection eradication. Within 20 months after this surgery, the patient had resumed a satisfactory range of motion (130º forward elevation, 20º external rotation) and outcome.

DISCUSSION

Although glenoid bone loss is often seen in the primary setting (degenerative, congenital, and post-traumatic), severe glenoid bone loss is encountered in most revision TSAs. The best treatment method for massive glenoid bone defects during complex shoulder arthroplasty remains uncertain. Options have included eccentric reaming, glenoid reconstruction with bone allograft and autograft, and more recently augmented components and patient-specific implants.^21-25 The advent and availability of CAD/CAM technology have enabled shoulder surgeons to create patient-specific metal solutions to these challenging cases. Currently, only a few reports exist in the literature on patient-specific glenoid components in the setting of severe bone loss.^29-32

Chammaa and colleagues²⁹ reported the outcomes of 37 patients with a hip-inspired glenoid component (Total Shoulder Replacement, Stanmore Implants Worldwide). The 5-year results with this implant were promising, with a 16% revision rate and only 1 case of glenoid loosening.

Stoffelen and colleagues³⁰ recently described the successful use of a patient-specific anatomic metal-backed glenoid component for the management of severe glenoid bone loss with excellent results at 2.5 years of follow-up. A different approach was pursued by Gunther and Lynch,³¹ who reported on 7 patients with a custom inset glenoid implant for deficient glenoid vaults. These circular anatomic, custom-made glenoid components were created with the intention of placing the implants partially inside the glenoid vault and relying partially on sclerotic cortical bone. Despite excellent results at 3 years of follow-up, their use is limited to specific defect geometries and cannot be used in cases of extreme bone loss.

CONCLUSION

We have described the use of a patient-specific glenoid component in 2 patients with severe glenoid bone loss. Despite the satisfactory clinical and short-term radiographic results, we acknowledge that longer-term follow-up is needed to confirm the efficacy of this type of reconstruction. We believe that patient-specific glenoid components represent a valuable addition to the armamentarium of shoulder surgeons who address complex glenoid bone deformities.

ABSTRACT

Removal of a cemented glenoid component often leads to massive glenoid bone loss, which makes it difficult to implant a new glenoid baseplate. The purpose of this study was to demonstrate the feasibility of revisions with a completely convertible system and to report clinical and radiographic results of a retrospective review of 13 cases.

Between 2003 and 2011, 104 primary total shoulder arthroplasties (TSAs) were performed with an uncemented glenoid component in our group. Of these patients, 13 (average age, 64 years) were revised to reverse shoulder arthroplasty (RSA) using a modular convertible platform system and were included in this study. Average follow-up after revision was 22 months. Outcome measures included pain, range of motion, Constant-Murley scores, Simple Shoulder Tests, and subjective shoulder values. Active flexion increased significantly from a mean of 93° (range, 30°-120°) to 138° (range, 95°-170°) (P = 0.021), and active external rotation increased significantly from 8° (range, −20°-15°) to 25° (range, −10°-60°). Mean pain scores significantly improved from 4.2 to 13.3 points. The mean Constant Scores improved from 21 (range, 18-32) to 63 (range, 43-90). Subjectively, 12 patients rated their shoulder as better or much better than preoperatively. This retrospective study shows that a complete convertible system facilitates conversion of TSAs to RSAs with excellent pain relief and a significant improvement in shoulder function.

Continue to: Polyethylene glenoid components...

Polyethylene glenoid components are the gold standard in anatomic total shoulder arthroplasty (TSA). However, even though TSA survivorship exceeds 95% at 10-year follow-up,¹ glenoid component loosening remains the main complication and the weak link in these implants. This complication accounts for 25% of all complications related to TSA in the literature.² In most cases, glenoid component loosening is not isolated but combined with a rotator cuff tear, glenohumeral instability, or component malposition.^3-5 Therefore, revision of TSA to reverse shoulder arthroplasty (RSA) often requires the removal of both the humeral stem and glenoid component. Removal of the humeral stem can be challenging and can necessitate removal of the cement and osteotomy of the diaphysis, risking fracture and extensive damage to the soft tissue (Figures 1A, 1B).^6-8 Removal of a cemented glenoid component often leads to massive glenoid bone loss, which makes it difficult to implant a new glenoid baseplate. Allografts and specific designs with a longer post can be mandatory to obtain a stable fixation of the new baseplate.^9-12

We hypothesized that a completely convertible platform system on both the humeral and the glenoid side could facilitate the revision of a failed TSA to a RSA. This would enable the surgeon to leave the humeral stem and the glenoid baseplate in place, avoiding the difficulty of stem removal and the reimplantation of a glenoid component, especially in osteoporotic glenoid bone and elderly patients. The revision procedure would then only consist of replacing the humeral head by a metallic tray and polyethylene bearing on the humeral side and by impacting a glenosphere on the glenoid baseplate (Figures 2A, 2B).

The purpose of this study was to demonstrate the feasibility of revisions with this completely convertible system and to report clinical and radiographic results of a retrospective review of 13 cases.

MATERIALS AND METHODS

PATIENT SELECTION

Between 2003 and 2011, 104 primary TSAs were performed with an uncemented glenoid component in our group. Of these patients, 18 underwent revision (17.3%). Among these 18 patients, 13 were revised to RSA using a modular convertible platform system and were included in this study, while 5 patients were revised to another TSA (2 dissociations of the polyethylene glenoid implant, 2 excessively low implantations of the glenoid baseplate, and 1 glenoid loosening). The mean age of the 13 patients (9 women, 4 men) included in this retrospective study at the time of revision was 64 years (range, 50-75 years). The reasons for revision surgery were rotator cuff tear (5, among which 2 were posterosuperior tears, and 3 were tears of the subscapularis), dislocations (5 posterior and 1 anterior, among which 4 had a B2 or C glenoid), suprascapular nerve paralysis (1), and dissociation of the polyethylene (1). The initial TSA was indicated for primary osteoarthritis with a normal cuff (9), primary osteoarthritis with a reparable cuff tear (2), posttraumatic osteoarthritis (1), and chronic dislocation (1). The right dominant shoulder was involved in 10 cases. The mean time interval between the primary TSA and the revision was 15 months (range, 1-61 months).

OPERATIVE TECHNIQUE

PREOPERATIVE PLANNING

Revision of a failed TSA is always a difficult challenge, and evaluation of bone loss on both the humeral and the glenoid sides, as well as the status of the cuff, is mandatory, even with a completely convertible arthroplasty system. The surgeon must be prepared to remove the humeral stem in case reduction of the joint is impossible. We systematically performed standard radiographs (anteroposterior, axillary, and outlet views) and computed tomography (CT) scans in order to assess both the version and positioning, as well as potential signs of loosening of the implants and the status of the cuff (continuity, degree of muscle trophicity, and fatty infiltration). A preoperative leucocyte count, sedimentation rate, and C-reactive protein rates were requested in every revision case, even if a mechanical etiology was strongly suspected.

Continue to: REVISION PROCEDURE

All the implants that had been used in the primary TSAs were Arrow Universal Shoulder Prostheses (FH Orthopedics). All revisions were performed through the previous deltopectoral approach in the beach chair position under general anesthesia with an interscalene block. Adhesions of the deep part of the deltoid were carefully released. The conjoint tendon was released, and the location of the musculocutaneous and axillary nerves was identified before any retractor was placed. In the 10 cases where the subscapularis was intact, it was peeled off the medial border of the bicipital groove to obtain sufficient length for a tension-free reinsertion.

The anatomical head of the humeral implant was disconnected from the stem and removed. All stems were found to be well fixed; there were no cases of loosening or evidence of infection. A circumferential capsular release was systematically carried out. The polyethylene glenoid onlay was then unlocked from the baseplate.

The quality of the fixation of the glenoid baseplate was systematically evaluated; no screw was found to be loose, and the fixation of all baseplates was stable. Therefore, there was no need to revise the glenoid baseplate, even when its position was considered excessively retroverted (Glenoid B2) or high. A glenosphere was impacted on the baseplate, and a polyethylene humeral bearing was then implanted on the humeral stem. The thinnest polyethylene bearing available (number 0) was chosen in all cases, and a size 36 glenosphere was chosen in 12 out of 13 cases. Intraoperative stability of the implant was satisfactory, and no impingement was found posteriorly, anteriorly, or inferiorly.

In one case, the humeral stem was a first-generation humeral implant which was not compatible with the new-generation humeral bearing, and the humeral stem had to be replaced.

In 2 cases, reduction of the RSA was either impossible or felt to be too tight, even after extensive soft-tissue release and resection of the remaining supraspinatus. The main reason for this was an excessively proud humeral stem because of an onlay polyethylene humeral bearing instead of an inlay design. However, removal of the uncemented humeral stem was always possible with no osteotomy or cortical window of the humeral shaft as the humeral stem has been designed with a bone ingrowth surface only on the metaphyseal part with a smooth surface on diaphyseal part. After removal of the stem, a small amount of humeral metaphysis was cut, and a new humeral stem was press-fit in a lower position. This allowed restoration of an appropriate tension of the soft tissue and, therefore, an easier reduction. The subscapularis was medialized and reinserted transosseously when possible with a double-row repair. In 3 cases, the subscapularis was torn and retracted at the level of the glenoid, or impossible to identify to allow its reinsertion.

Continue to: According to our infectious disease department...

According to our infectious disease department, we made a minimum of 5 cultures for each revision case looking for a possible low-grade infection. All cultures in our group are held for 14 days to assess for Propionibacterium acnes.

POSTOPERATIVE MANAGEMENT

A shoulder splint in neutral rotation was used for the first 4 weeks. Passive range of motion (ROM) was started immediately with pendulum exercises and passive anterior elevation. Active assisted and active ROM were allowed after 4 weeks, and physiotherapy was continued for 6 months. Elderly patients were referred to a center of rehabilitation. We found only 1 or 2 positive cultures (Propionibacterium acnes) for 4 patients, and we decided to consider them as a contamination. None of the patients were treated with antibiotics.

CLINICAL AND RADIOLOGICAL ASSESSMENT

Clinical evaluation included pre- and postoperative pain scores (visual analog scale [VAS]), ROM, the Constant-Murley¹³ score, the Simple Shoulder Test (SST),¹⁴ and the subjective shoulder value.¹⁵ Subjective satisfaction was assessed by asking the patients at follow-up how they felt compared with before surgery and was graded using a 4-point scale: 1, much better; 2, better; 3, the same; and 4, worse. Radiographic evaluation was performed on pre- and postoperative standard anteroposterior, outlet, and axillary views. Radiographs were reviewed to determine the presence of glenohumeral subluxation, periprosthetic lucency, component shift in position, and scapular notching.

STATISTICAL ANALYSIS

Descriptive statistics are reported as mean (range) for continuous measures and number (percentage) for discrete variables. The Wilcoxon signed-rank test was used for preoperative vs postoperative changes. The alpha level for all tests was set at 0.05 for statistical significance.

RESULTS

CLINICAL OUTCOME

At a mean of 22 months (range, 7-38 months) follow-up after revision, active ROM was significantly improved. Active flexion increased significantly from a mean of 93° (range, 30°-120°) to 138° (range, 95°-170°) (P = 0.021). Active external rotation with the elbow on the side increased significantly from 8° (range, −20°-15°) to 25° (range, −10°-60°) (P = 0.034), and increased with the arm held at 90° abduction from 13° (range, 0°-20°) to 49° (range, 0°-80°) (P = 0.025). Mean pain scores improved from 4.2 to 13.3 points (P < 0.001). VAS improved significantly from 9 to 1 (P < 0.0001). The mean Constant Scores improved from 21 (range, 18-32) to 63 (range, 43-90) (P = 0.006). The final SST was 7 per 12. Subjectively, 4 patients rated their shoulder as much better, 8 as better, and 1 as the same as preoperatively. No intra- or postoperative complications, including infections, were observed. The mean duration of the procedure was 60 minutes (range, 30-75 minutes).

Continue to: RADIOLOGICAL OUTCOME

No periprosthetic lucency or shift in component was observed at the last follow-up. There was no scapular notching. No resorption of the tuberosities, and no fractures of the acromion or the scapular spine were observed.

DISCUSSION

In this retrospective study, failure of TSA with a metal-backed glenoid implant was successfully revised to RSA. In 10 patients, the use of a universal platform system allowed an easier conversion without removal of the humeral stem or the glenoid component (Figures 3A-3D). Twelve of the 13 patients were satisfied or very satisfied at the last follow-up. None of the patients were in pain, and the mean Constant score was 63. In all the cases, the glenoid baseplate was not changed. In 3 cases the humeral stem was changed without any fracture of the tuberosities of need for an osteotomy. This greatly simplified the revision procedure, as glenoid revisions can be very challenging. Indeed, it is often difficult to assess precisely preoperatively the remaining glenoid bone stock after removal of the glenoid component and the cement. Many therapeutic options to deal with glenoid loosening have been reported in the literature: glenoid bone reconstruction after glenoid component removal and revision to a hemiarthroplasty (HA),^10,16-18 glenoid bone reconstruction after glenoid component removal and revision to a new TSA with a cemented glenoid implant,^16,17,19,20 and glenoid reconstruction after glenoid component removal and revision to a RSA.^12,21 These authors reported that glenoid reconstruction frequently necessitates an iliac bone graft associated with a special design of the baseplate with a long post fixed into the native glenoid bone. However, sometimes implantation of an uncemented glenoid component can be unstable with a high risk of early mobilization of the implant, and 2 steps may be necessary. Conversion to a HA,^10,16-18 or a TSA^16,17,19,20 with a new cemented implant have both been associated with poor clinical outcome, with a high rate of recurrent glenoid loosening for the TSAs.

In our retrospective study, we reported no intra- or postoperative complications. Flury and colleagues²² reported a complication rate of 38% in 21 patients after conversion from a TSA to a RSA with a mean follow-up of 46 months. They removed all the components of the prosthesis with a crack or fracture of the humerus and/or the glenoid. Ortmaier and colleagues²³ reported a rate of complication of 22.7% during the conversion of TSA to RSA. They did an osteotomy of the humeral diaphysis to extract the stem in 40% of cases and had to remove the glenoid cement in 86% of cases with severe damage of the glenoid bone in 10% of cases. Fewer complications were found in our study, as we did not need any procedure such as humeral osteotomy, cerclage, bone grafting, and/or reconstruction of the glenoid. The short operative time and the absence of extensive soft-tissue dissection, thanks to a standard deltopectoral approach, could explain the absence of infection in our series.

Other authors shared our strategy of a universal convertible system and reported their results in the literature. Castagna and colleagues²⁴ in 2013 reported the clinical and radiological results of conversions of HA or TSA to RSA using a modular, convertible system (SMR Shoulder System, Lima Corporate). In their series, only 8 cases of TSAs were converted to RSA. They preserved, in each case, the humeral stem and the glenoid baseplate. There were no intra- or postoperative complications. The mean VAS score decreased from 8 to 2. Weber-Spickschen and colleague²⁵ reported recently in 2015 the same experience with the same system (SMR Shoulder System). They reviewed 15 conversions of TSAs to RSAs without any removal of the implants at a mean 43-month follow-up. They reported excellent pain relief (VAS decreased from 8 to 1) and improvement in shoulder function with a low rate of complications.

Kany and colleagues²⁶ in 2015 had already reported the advantages of a shoulder platform system for revisions. In their series, the authors included cases of failure of HAs and TSAs with loose cemented glenoids and metal-backed glenoids. The clinical and radiological results were similar, with a final Constant score of 60 (range, 42-85) and a similar rate of humeral stems which had to be changed (24%). These stems were replaced either because they were too proud or because there was not enough space to add an onlay polyethylene socket.

Continue to: Despite the encouraging results...

Despite the encouraging results reported in this study, there are some limitations. Firstly, no control group was used. Attempting to address this issue, we compared our results with the literature. Secondly, the number of patients in our study was small. Finally, the follow-up duration (mean 22 months) did not provide long-term outcomes.

CONCLUSION

This retrospective study shows that a complete convertible system facilitates conversion of TSAs to RSAs with excellent pain relief and a significant improvement in shoulder function. A platform system on both the humeral and the glenoid side reduces the operative time of the conversion with a low risk of complications.

ABSTRACT

Removal of a cemented glenoid component often leads to massive glenoid bone loss, which makes it difficult to implant a new glenoid baseplate. The purpose of this study was to demonstrate the feasibility of revisions with a completely convertible system and to report clinical and radiographic results of a retrospective review of 13 cases.

Between 2003 and 2011, 104 primary total shoulder arthroplasties (TSAs) were performed with an uncemented glenoid component in our group. Of these patients, 13 (average age, 64 years) were revised to reverse shoulder arthroplasty (RSA) using a modular convertible platform system and were included in this study. Average follow-up after revision was 22 months. Outcome measures included pain, range of motion, Constant-Murley scores, Simple Shoulder Tests, and subjective shoulder values. Active flexion increased significantly from a mean of 93° (range, 30°-120°) to 138° (range, 95°-170°) (P = 0.021), and active external rotation increased significantly from 8° (range, −20°-15°) to 25° (range, −10°-60°). Mean pain scores significantly improved from 4.2 to 13.3 points. The mean Constant Scores improved from 21 (range, 18-32) to 63 (range, 43-90). Subjectively, 12 patients rated their shoulder as better or much better than preoperatively. This retrospective study shows that a complete convertible system facilitates conversion of TSAs to RSAs with excellent pain relief and a significant improvement in shoulder function.

Continue to: Polyethylene glenoid components...

Polyethylene glenoid components are the gold standard in anatomic total shoulder arthroplasty (TSA). However, even though TSA survivorship exceeds 95% at 10-year follow-up,¹ glenoid component loosening remains the main complication and the weak link in these implants. This complication accounts for 25% of all complications related to TSA in the literature.² In most cases, glenoid component loosening is not isolated but combined with a rotator cuff tear, glenohumeral instability, or component malposition.^3-5 Therefore, revision of TSA to reverse shoulder arthroplasty (RSA) often requires the removal of both the humeral stem and glenoid component. Removal of the humeral stem can be challenging and can necessitate removal of the cement and osteotomy of the diaphysis, risking fracture and extensive damage to the soft tissue (Figures 1A, 1B).^6-8 Removal of a cemented glenoid component often leads to massive glenoid bone loss, which makes it difficult to implant a new glenoid baseplate. Allografts and specific designs with a longer post can be mandatory to obtain a stable fixation of the new baseplate.^9-12

We hypothesized that a completely convertible platform system on both the humeral and the glenoid side could facilitate the revision of a failed TSA to a RSA. This would enable the surgeon to leave the humeral stem and the glenoid baseplate in place, avoiding the difficulty of stem removal and the reimplantation of a glenoid component, especially in osteoporotic glenoid bone and elderly patients. The revision procedure would then only consist of replacing the humeral head by a metallic tray and polyethylene bearing on the humeral side and by impacting a glenosphere on the glenoid baseplate (Figures 2A, 2B).

The purpose of this study was to demonstrate the feasibility of revisions with this completely convertible system and to report clinical and radiographic results of a retrospective review of 13 cases.

MATERIALS AND METHODS

PATIENT SELECTION

Between 2003 and 2011, 104 primary TSAs were performed with an uncemented glenoid component in our group. Of these patients, 18 underwent revision (17.3%). Among these 18 patients, 13 were revised to RSA using a modular convertible platform system and were included in this study, while 5 patients were revised to another TSA (2 dissociations of the polyethylene glenoid implant, 2 excessively low implantations of the glenoid baseplate, and 1 glenoid loosening). The mean age of the 13 patients (9 women, 4 men) included in this retrospective study at the time of revision was 64 years (range, 50-75 years). The reasons for revision surgery were rotator cuff tear (5, among which 2 were posterosuperior tears, and 3 were tears of the subscapularis), dislocations (5 posterior and 1 anterior, among which 4 had a B2 or C glenoid), suprascapular nerve paralysis (1), and dissociation of the polyethylene (1). The initial TSA was indicated for primary osteoarthritis with a normal cuff (9), primary osteoarthritis with a reparable cuff tear (2), posttraumatic osteoarthritis (1), and chronic dislocation (1). The right dominant shoulder was involved in 10 cases. The mean time interval between the primary TSA and the revision was 15 months (range, 1-61 months).

OPERATIVE TECHNIQUE

PREOPERATIVE PLANNING

Revision of a failed TSA is always a difficult challenge, and evaluation of bone loss on both the humeral and the glenoid sides, as well as the status of the cuff, is mandatory, even with a completely convertible arthroplasty system. The surgeon must be prepared to remove the humeral stem in case reduction of the joint is impossible. We systematically performed standard radiographs (anteroposterior, axillary, and outlet views) and computed tomography (CT) scans in order to assess both the version and positioning, as well as potential signs of loosening of the implants and the status of the cuff (continuity, degree of muscle trophicity, and fatty infiltration). A preoperative leucocyte count, sedimentation rate, and C-reactive protein rates were requested in every revision case, even if a mechanical etiology was strongly suspected.

Continue to: REVISION PROCEDURE

All the implants that had been used in the primary TSAs were Arrow Universal Shoulder Prostheses (FH Orthopedics). All revisions were performed through the previous deltopectoral approach in the beach chair position under general anesthesia with an interscalene block. Adhesions of the deep part of the deltoid were carefully released. The conjoint tendon was released, and the location of the musculocutaneous and axillary nerves was identified before any retractor was placed. In the 10 cases where the subscapularis was intact, it was peeled off the medial border of the bicipital groove to obtain sufficient length for a tension-free reinsertion.

The anatomical head of the humeral implant was disconnected from the stem and removed. All stems were found to be well fixed; there were no cases of loosening or evidence of infection. A circumferential capsular release was systematically carried out. The polyethylene glenoid onlay was then unlocked from the baseplate.

The quality of the fixation of the glenoid baseplate was systematically evaluated; no screw was found to be loose, and the fixation of all baseplates was stable. Therefore, there was no need to revise the glenoid baseplate, even when its position was considered excessively retroverted (Glenoid B2) or high. A glenosphere was impacted on the baseplate, and a polyethylene humeral bearing was then implanted on the humeral stem. The thinnest polyethylene bearing available (number 0) was chosen in all cases, and a size 36 glenosphere was chosen in 12 out of 13 cases. Intraoperative stability of the implant was satisfactory, and no impingement was found posteriorly, anteriorly, or inferiorly.

In one case, the humeral stem was a first-generation humeral implant which was not compatible with the new-generation humeral bearing, and the humeral stem had to be replaced.

In 2 cases, reduction of the RSA was either impossible or felt to be too tight, even after extensive soft-tissue release and resection of the remaining supraspinatus. The main reason for this was an excessively proud humeral stem because of an onlay polyethylene humeral bearing instead of an inlay design. However, removal of the uncemented humeral stem was always possible with no osteotomy or cortical window of the humeral shaft as the humeral stem has been designed with a bone ingrowth surface only on the metaphyseal part with a smooth surface on diaphyseal part. After removal of the stem, a small amount of humeral metaphysis was cut, and a new humeral stem was press-fit in a lower position. This allowed restoration of an appropriate tension of the soft tissue and, therefore, an easier reduction. The subscapularis was medialized and reinserted transosseously when possible with a double-row repair. In 3 cases, the subscapularis was torn and retracted at the level of the glenoid, or impossible to identify to allow its reinsertion.

Continue to: According to our infectious disease department...

According to our infectious disease department, we made a minimum of 5 cultures for each revision case looking for a possible low-grade infection. All cultures in our group are held for 14 days to assess for Propionibacterium acnes.

POSTOPERATIVE MANAGEMENT

A shoulder splint in neutral rotation was used for the first 4 weeks. Passive range of motion (ROM) was started immediately with pendulum exercises and passive anterior elevation. Active assisted and active ROM were allowed after 4 weeks, and physiotherapy was continued for 6 months. Elderly patients were referred to a center of rehabilitation. We found only 1 or 2 positive cultures (Propionibacterium acnes) for 4 patients, and we decided to consider them as a contamination. None of the patients were treated with antibiotics.

CLINICAL AND RADIOLOGICAL ASSESSMENT

Clinical evaluation included pre- and postoperative pain scores (visual analog scale [VAS]), ROM, the Constant-Murley¹³ score, the Simple Shoulder Test (SST),¹⁴ and the subjective shoulder value.¹⁵ Subjective satisfaction was assessed by asking the patients at follow-up how they felt compared with before surgery and was graded using a 4-point scale: 1, much better; 2, better; 3, the same; and 4, worse. Radiographic evaluation was performed on pre- and postoperative standard anteroposterior, outlet, and axillary views. Radiographs were reviewed to determine the presence of glenohumeral subluxation, periprosthetic lucency, component shift in position, and scapular notching.

STATISTICAL ANALYSIS

Descriptive statistics are reported as mean (range) for continuous measures and number (percentage) for discrete variables. The Wilcoxon signed-rank test was used for preoperative vs postoperative changes. The alpha level for all tests was set at 0.05 for statistical significance.

RESULTS

CLINICAL OUTCOME

At a mean of 22 months (range, 7-38 months) follow-up after revision, active ROM was significantly improved. Active flexion increased significantly from a mean of 93° (range, 30°-120°) to 138° (range, 95°-170°) (P = 0.021). Active external rotation with the elbow on the side increased significantly from 8° (range, −20°-15°) to 25° (range, −10°-60°) (P = 0.034), and increased with the arm held at 90° abduction from 13° (range, 0°-20°) to 49° (range, 0°-80°) (P = 0.025). Mean pain scores improved from 4.2 to 13.3 points (P < 0.001). VAS improved significantly from 9 to 1 (P < 0.0001). The mean Constant Scores improved from 21 (range, 18-32) to 63 (range, 43-90) (P = 0.006). The final SST was 7 per 12. Subjectively, 4 patients rated their shoulder as much better, 8 as better, and 1 as the same as preoperatively. No intra- or postoperative complications, including infections, were observed. The mean duration of the procedure was 60 minutes (range, 30-75 minutes).

Continue to: RADIOLOGICAL OUTCOME

No periprosthetic lucency or shift in component was observed at the last follow-up. There was no scapular notching. No resorption of the tuberosities, and no fractures of the acromion or the scapular spine were observed.

DISCUSSION

In this retrospective study, failure of TSA with a metal-backed glenoid implant was successfully revised to RSA. In 10 patients, the use of a universal platform system allowed an easier conversion without removal of the humeral stem or the glenoid component (Figures 3A-3D). Twelve of the 13 patients were satisfied or very satisfied at the last follow-up. None of the patients were in pain, and the mean Constant score was 63. In all the cases, the glenoid baseplate was not changed. In 3 cases the humeral stem was changed without any fracture of the tuberosities of need for an osteotomy. This greatly simplified the revision procedure, as glenoid revisions can be very challenging. Indeed, it is often difficult to assess precisely preoperatively the remaining glenoid bone stock after removal of the glenoid component and the cement. Many therapeutic options to deal with glenoid loosening have been reported in the literature: glenoid bone reconstruction after glenoid component removal and revision to a hemiarthroplasty (HA),^10,16-18 glenoid bone reconstruction after glenoid component removal and revision to a new TSA with a cemented glenoid implant,^16,17,19,20 and glenoid reconstruction after glenoid component removal and revision to a RSA.^12,21 These authors reported that glenoid reconstruction frequently necessitates an iliac bone graft associated with a special design of the baseplate with a long post fixed into the native glenoid bone. However, sometimes implantation of an uncemented glenoid component can be unstable with a high risk of early mobilization of the implant, and 2 steps may be necessary. Conversion to a HA,^10,16-18 or a TSA^16,17,19,20 with a new cemented implant have both been associated with poor clinical outcome, with a high rate of recurrent glenoid loosening for the TSAs.

In our retrospective study, we reported no intra- or postoperative complications. Flury and colleagues²² reported a complication rate of 38% in 21 patients after conversion from a TSA to a RSA with a mean follow-up of 46 months. They removed all the components of the prosthesis with a crack or fracture of the humerus and/or the glenoid. Ortmaier and colleagues²³ reported a rate of complication of 22.7% during the conversion of TSA to RSA. They did an osteotomy of the humeral diaphysis to extract the stem in 40% of cases and had to remove the glenoid cement in 86% of cases with severe damage of the glenoid bone in 10% of cases. Fewer complications were found in our study, as we did not need any procedure such as humeral osteotomy, cerclage, bone grafting, and/or reconstruction of the glenoid. The short operative time and the absence of extensive soft-tissue dissection, thanks to a standard deltopectoral approach, could explain the absence of infection in our series.

Other authors shared our strategy of a universal convertible system and reported their results in the literature. Castagna and colleagues²⁴ in 2013 reported the clinical and radiological results of conversions of HA or TSA to RSA using a modular, convertible system (SMR Shoulder System, Lima Corporate). In their series, only 8 cases of TSAs were converted to RSA. They preserved, in each case, the humeral stem and the glenoid baseplate. There were no intra- or postoperative complications. The mean VAS score decreased from 8 to 2. Weber-Spickschen and colleague²⁵ reported recently in 2015 the same experience with the same system (SMR Shoulder System). They reviewed 15 conversions of TSAs to RSAs without any removal of the implants at a mean 43-month follow-up. They reported excellent pain relief (VAS decreased from 8 to 1) and improvement in shoulder function with a low rate of complications.

Kany and colleagues²⁶ in 2015 had already reported the advantages of a shoulder platform system for revisions. In their series, the authors included cases of failure of HAs and TSAs with loose cemented glenoids and metal-backed glenoids. The clinical and radiological results were similar, with a final Constant score of 60 (range, 42-85) and a similar rate of humeral stems which had to be changed (24%). These stems were replaced either because they were too proud or because there was not enough space to add an onlay polyethylene socket.

Continue to: Despite the encouraging results...

Despite the encouraging results reported in this study, there are some limitations. Firstly, no control group was used. Attempting to address this issue, we compared our results with the literature. Secondly, the number of patients in our study was small. Finally, the follow-up duration (mean 22 months) did not provide long-term outcomes.

CONCLUSION

This retrospective study shows that a complete convertible system facilitates conversion of TSAs to RSAs with excellent pain relief and a significant improvement in shoulder function. A platform system on both the humeral and the glenoid side reduces the operative time of the conversion with a low risk of complications.

ABSTRACT

Removal of a cemented glenoid component often leads to massive glenoid bone loss, which makes it difficult to implant a new glenoid baseplate. The purpose of this study was to demonstrate the feasibility of revisions with a completely convertible system and to report clinical and radiographic results of a retrospective review of 13 cases.

Between 2003 and 2011, 104 primary total shoulder arthroplasties (TSAs) were performed with an uncemented glenoid component in our group. Of these patients, 13 (average age, 64 years) were revised to reverse shoulder arthroplasty (RSA) using a modular convertible platform system and were included in this study. Average follow-up after revision was 22 months. Outcome measures included pain, range of motion, Constant-Murley scores, Simple Shoulder Tests, and subjective shoulder values. Active flexion increased significantly from a mean of 93° (range, 30°-120°) to 138° (range, 95°-170°) (P = 0.021), and active external rotation increased significantly from 8° (range, −20°-15°) to 25° (range, −10°-60°). Mean pain scores significantly improved from 4.2 to 13.3 points. The mean Constant Scores improved from 21 (range, 18-32) to 63 (range, 43-90). Subjectively, 12 patients rated their shoulder as better or much better than preoperatively. This retrospective study shows that a complete convertible system facilitates conversion of TSAs to RSAs with excellent pain relief and a significant improvement in shoulder function.

Continue to: Polyethylene glenoid components...

Polyethylene glenoid components are the gold standard in anatomic total shoulder arthroplasty (TSA). However, even though TSA survivorship exceeds 95% at 10-year follow-up,¹ glenoid component loosening remains the main complication and the weak link in these implants. This complication accounts for 25% of all complications related to TSA in the literature.² In most cases, glenoid component loosening is not isolated but combined with a rotator cuff tear, glenohumeral instability, or component malposition.^3-5 Therefore, revision of TSA to reverse shoulder arthroplasty (RSA) often requires the removal of both the humeral stem and glenoid component. Removal of the humeral stem can be challenging and can necessitate removal of the cement and osteotomy of the diaphysis, risking fracture and extensive damage to the soft tissue (Figures 1A, 1B).^6-8 Removal of a cemented glenoid component often leads to massive glenoid bone loss, which makes it difficult to implant a new glenoid baseplate. Allografts and specific designs with a longer post can be mandatory to obtain a stable fixation of the new baseplate.^9-12

We hypothesized that a completely convertible platform system on both the humeral and the glenoid side could facilitate the revision of a failed TSA to a RSA. This would enable the surgeon to leave the humeral stem and the glenoid baseplate in place, avoiding the difficulty of stem removal and the reimplantation of a glenoid component, especially in osteoporotic glenoid bone and elderly patients. The revision procedure would then only consist of replacing the humeral head by a metallic tray and polyethylene bearing on the humeral side and by impacting a glenosphere on the glenoid baseplate (Figures 2A, 2B).

The purpose of this study was to demonstrate the feasibility of revisions with this completely convertible system and to report clinical and radiographic results of a retrospective review of 13 cases.

MATERIALS AND METHODS

PATIENT SELECTION

Between 2003 and 2011, 104 primary TSAs were performed with an uncemented glenoid component in our group. Of these patients, 18 underwent revision (17.3%). Among these 18 patients, 13 were revised to RSA using a modular convertible platform system and were included in this study, while 5 patients were revised to another TSA (2 dissociations of the polyethylene glenoid implant, 2 excessively low implantations of the glenoid baseplate, and 1 glenoid loosening). The mean age of the 13 patients (9 women, 4 men) included in this retrospective study at the time of revision was 64 years (range, 50-75 years). The reasons for revision surgery were rotator cuff tear (5, among which 2 were posterosuperior tears, and 3 were tears of the subscapularis), dislocations (5 posterior and 1 anterior, among which 4 had a B2 or C glenoid), suprascapular nerve paralysis (1), and dissociation of the polyethylene (1). The initial TSA was indicated for primary osteoarthritis with a normal cuff (9), primary osteoarthritis with a reparable cuff tear (2), posttraumatic osteoarthritis (1), and chronic dislocation (1). The right dominant shoulder was involved in 10 cases. The mean time interval between the primary TSA and the revision was 15 months (range, 1-61 months).

OPERATIVE TECHNIQUE

PREOPERATIVE PLANNING

Revision of a failed TSA is always a difficult challenge, and evaluation of bone loss on both the humeral and the glenoid sides, as well as the status of the cuff, is mandatory, even with a completely convertible arthroplasty system. The surgeon must be prepared to remove the humeral stem in case reduction of the joint is impossible. We systematically performed standard radiographs (anteroposterior, axillary, and outlet views) and computed tomography (CT) scans in order to assess both the version and positioning, as well as potential signs of loosening of the implants and the status of the cuff (continuity, degree of muscle trophicity, and fatty infiltration). A preoperative leucocyte count, sedimentation rate, and C-reactive protein rates were requested in every revision case, even if a mechanical etiology was strongly suspected.

Continue to: REVISION PROCEDURE

All the implants that had been used in the primary TSAs were Arrow Universal Shoulder Prostheses (FH Orthopedics). All revisions were performed through the previous deltopectoral approach in the beach chair position under general anesthesia with an interscalene block. Adhesions of the deep part of the deltoid were carefully released. The conjoint tendon was released, and the location of the musculocutaneous and axillary nerves was identified before any retractor was placed. In the 10 cases where the subscapularis was intact, it was peeled off the medial border of the bicipital groove to obtain sufficient length for a tension-free reinsertion.

The anatomical head of the humeral implant was disconnected from the stem and removed. All stems were found to be well fixed; there were no cases of loosening or evidence of infection. A circumferential capsular release was systematically carried out. The polyethylene glenoid onlay was then unlocked from the baseplate.

The quality of the fixation of the glenoid baseplate was systematically evaluated; no screw was found to be loose, and the fixation of all baseplates was stable. Therefore, there was no need to revise the glenoid baseplate, even when its position was considered excessively retroverted (Glenoid B2) or high. A glenosphere was impacted on the baseplate, and a polyethylene humeral bearing was then implanted on the humeral stem. The thinnest polyethylene bearing available (number 0) was chosen in all cases, and a size 36 glenosphere was chosen in 12 out of 13 cases. Intraoperative stability of the implant was satisfactory, and no impingement was found posteriorly, anteriorly, or inferiorly.

In one case, the humeral stem was a first-generation humeral implant which was not compatible with the new-generation humeral bearing, and the humeral stem had to be replaced.

In 2 cases, reduction of the RSA was either impossible or felt to be too tight, even after extensive soft-tissue release and resection of the remaining supraspinatus. The main reason for this was an excessively proud humeral stem because of an onlay polyethylene humeral bearing instead of an inlay design. However, removal of the uncemented humeral stem was always possible with no osteotomy or cortical window of the humeral shaft as the humeral stem has been designed with a bone ingrowth surface only on the metaphyseal part with a smooth surface on diaphyseal part. After removal of the stem, a small amount of humeral metaphysis was cut, and a new humeral stem was press-fit in a lower position. This allowed restoration of an appropriate tension of the soft tissue and, therefore, an easier reduction. The subscapularis was medialized and reinserted transosseously when possible with a double-row repair. In 3 cases, the subscapularis was torn and retracted at the level of the glenoid, or impossible to identify to allow its reinsertion.

Continue to: According to our infectious disease department...

According to our infectious disease department, we made a minimum of 5 cultures for each revision case looking for a possible low-grade infection. All cultures in our group are held for 14 days to assess for Propionibacterium acnes.

POSTOPERATIVE MANAGEMENT

A shoulder splint in neutral rotation was used for the first 4 weeks. Passive range of motion (ROM) was started immediately with pendulum exercises and passive anterior elevation. Active assisted and active ROM were allowed after 4 weeks, and physiotherapy was continued for 6 months. Elderly patients were referred to a center of rehabilitation. We found only 1 or 2 positive cultures (Propionibacterium acnes) for 4 patients, and we decided to consider them as a contamination. None of the patients were treated with antibiotics.

CLINICAL AND RADIOLOGICAL ASSESSMENT

Clinical evaluation included pre- and postoperative pain scores (visual analog scale [VAS]), ROM, the Constant-Murley¹³ score, the Simple Shoulder Test (SST),¹⁴ and the subjective shoulder value.¹⁵ Subjective satisfaction was assessed by asking the patients at follow-up how they felt compared with before surgery and was graded using a 4-point scale: 1, much better; 2, better; 3, the same; and 4, worse. Radiographic evaluation was performed on pre- and postoperative standard anteroposterior, outlet, and axillary views. Radiographs were reviewed to determine the presence of glenohumeral subluxation, periprosthetic lucency, component shift in position, and scapular notching.

STATISTICAL ANALYSIS

Descriptive statistics are reported as mean (range) for continuous measures and number (percentage) for discrete variables. The Wilcoxon signed-rank test was used for preoperative vs postoperative changes. The alpha level for all tests was set at 0.05 for statistical significance.

RESULTS

CLINICAL OUTCOME

At a mean of 22 months (range, 7-38 months) follow-up after revision, active ROM was significantly improved. Active flexion increased significantly from a mean of 93° (range, 30°-120°) to 138° (range, 95°-170°) (P = 0.021). Active external rotation with the elbow on the side increased significantly from 8° (range, −20°-15°) to 25° (range, −10°-60°) (P = 0.034), and increased with the arm held at 90° abduction from 13° (range, 0°-20°) to 49° (range, 0°-80°) (P = 0.025). Mean pain scores improved from 4.2 to 13.3 points (P < 0.001). VAS improved significantly from 9 to 1 (P < 0.0001). The mean Constant Scores improved from 21 (range, 18-32) to 63 (range, 43-90) (P = 0.006). The final SST was 7 per 12. Subjectively, 4 patients rated their shoulder as much better, 8 as better, and 1 as the same as preoperatively. No intra- or postoperative complications, including infections, were observed. The mean duration of the procedure was 60 minutes (range, 30-75 minutes).

Continue to: RADIOLOGICAL OUTCOME

No periprosthetic lucency or shift in component was observed at the last follow-up. There was no scapular notching. No resorption of the tuberosities, and no fractures of the acromion or the scapular spine were observed.

DISCUSSION

In this retrospective study, failure of TSA with a metal-backed glenoid implant was successfully revised to RSA. In 10 patients, the use of a universal platform system allowed an easier conversion without removal of the humeral stem or the glenoid component (Figures 3A-3D). Twelve of the 13 patients were satisfied or very satisfied at the last follow-up. None of the patients were in pain, and the mean Constant score was 63. In all the cases, the glenoid baseplate was not changed. In 3 cases the humeral stem was changed without any fracture of the tuberosities of need for an osteotomy. This greatly simplified the revision procedure, as glenoid revisions can be very challenging. Indeed, it is often difficult to assess precisely preoperatively the remaining glenoid bone stock after removal of the glenoid component and the cement. Many therapeutic options to deal with glenoid loosening have been reported in the literature: glenoid bone reconstruction after glenoid component removal and revision to a hemiarthroplasty (HA),^10,16-18 glenoid bone reconstruction after glenoid component removal and revision to a new TSA with a cemented glenoid implant,^16,17,19,20 and glenoid reconstruction after glenoid component removal and revision to a RSA.^12,21 These authors reported that glenoid reconstruction frequently necessitates an iliac bone graft associated with a special design of the baseplate with a long post fixed into the native glenoid bone. However, sometimes implantation of an uncemented glenoid component can be unstable with a high risk of early mobilization of the implant, and 2 steps may be necessary. Conversion to a HA,^10,16-18 or a TSA^16,17,19,20 with a new cemented implant have both been associated with poor clinical outcome, with a high rate of recurrent glenoid loosening for the TSAs.

In our retrospective study, we reported no intra- or postoperative complications. Flury and colleagues²² reported a complication rate of 38% in 21 patients after conversion from a TSA to a RSA with a mean follow-up of 46 months. They removed all the components of the prosthesis with a crack or fracture of the humerus and/or the glenoid. Ortmaier and colleagues²³ reported a rate of complication of 22.7% during the conversion of TSA to RSA. They did an osteotomy of the humeral diaphysis to extract the stem in 40% of cases and had to remove the glenoid cement in 86% of cases with severe damage of the glenoid bone in 10% of cases. Fewer complications were found in our study, as we did not need any procedure such as humeral osteotomy, cerclage, bone grafting, and/or reconstruction of the glenoid. The short operative time and the absence of extensive soft-tissue dissection, thanks to a standard deltopectoral approach, could explain the absence of infection in our series.

Other authors shared our strategy of a universal convertible system and reported their results in the literature. Castagna and colleagues²⁴ in 2013 reported the clinical and radiological results of conversions of HA or TSA to RSA using a modular, convertible system (SMR Shoulder System, Lima Corporate). In their series, only 8 cases of TSAs were converted to RSA. They preserved, in each case, the humeral stem and the glenoid baseplate. There were no intra- or postoperative complications. The mean VAS score decreased from 8 to 2. Weber-Spickschen and colleague²⁵ reported recently in 2015 the same experience with the same system (SMR Shoulder System). They reviewed 15 conversions of TSAs to RSAs without any removal of the implants at a mean 43-month follow-up. They reported excellent pain relief (VAS decreased from 8 to 1) and improvement in shoulder function with a low rate of complications.

Kany and colleagues²⁶ in 2015 had already reported the advantages of a shoulder platform system for revisions. In their series, the authors included cases of failure of HAs and TSAs with loose cemented glenoids and metal-backed glenoids. The clinical and radiological results were similar, with a final Constant score of 60 (range, 42-85) and a similar rate of humeral stems which had to be changed (24%). These stems were replaced either because they were too proud or because there was not enough space to add an onlay polyethylene socket.

Continue to: Despite the encouraging results...

Despite the encouraging results reported in this study, there are some limitations. Firstly, no control group was used. Attempting to address this issue, we compared our results with the literature. Secondly, the number of patients in our study was small. Finally, the follow-up duration (mean 22 months) did not provide long-term outcomes.

CONCLUSION

This retrospective study shows that a complete convertible system facilitates conversion of TSAs to RSAs with excellent pain relief and a significant improvement in shoulder function. A platform system on both the humeral and the glenoid side reduces the operative time of the conversion with a low risk of complications.

ABSTRACT

Proper reconstruction of proximal humeral anatomy is of primary importance to maximize patient outcomes after total shoulder arthroplasty. This article describes a new arthroplasty technique, where a fixed multiplanar bone resection is made and a novel implant, which is designed to precisely match the bone resection, is inserted. 

Continue to: The success of total shoulder arthroplasty...

The success of total shoulder arthroplasty (TSA) is largely dependent on how accurate the proximal humeral anatomy is reconstructed and the glenohumeral relationships are restored.^1-4 Numerous studies have demonstrated a relationship of worse clinical outcomes and implant failure with nonanatomic implant placement.^5-8 The majority of arthroplasty systems rely on surgeon-dependent decision-making to determine the location of the border of the articular surface and, ultimately, the amount and location of bone to be resected. Even in experienced hands, the ability to reproducibly restore the joint line is inconsistent.³

In contrast, the majority of total knee arthroplasty (TKA) systems have been designed with instrumentation that guides the surgeon precisely regarding where and how much femoral bone must be resected, and the corresponding implant is designed with the same thickness to preserve the location of the joint line. Cutting block instrumentation rather than freehand cuts enables reproducibility of TKA while being performed for an estimated 700,000 times annually in the US.⁹

To achieve similar high levels of reproducibility in shoulder arthroplasty, a new technique was developed based on the principle of providing instrumentation to assist the surgeon in accurately restoring the proximal humeral joint line. This technical article describes the technique of using a multiplanar instrumented cutting system and matching implants to perform TSA. The technique shown was previously studied and was found to allow surgeons to recreate the original anatomy of the humerus with very high precision.¹⁰

The humeral prosthesis described in this article has an articular surface that is slightly elliptical to more closely match the actual shape of the humerus bone.¹¹ Biomechanical studies have demonstrated that implants designed with a nonspherical shape have more similar motion and kinematics to those of the native humeral head.¹² The undersurface of the implant has a concave four-plane geometry that matches with the bone cuts created by the cutting guides (Figures 1, 2). 

This provides rotation stability, and the implant rests on the strong subchondral bone of the proximal humerus proximal to the anatomic neck rather than relying on metaphyseal bone or canal fixation, as recommended by Aldoiusti.¹³ It also allows optimal implant placement with complete freedom with respect to inclination, version, and medial/posterior offset from the humeral canal. 

Continue to: The implant respects the relationship...

The implant respects the relationship of the rotator cuff insertion and has a recessed superior margin to keep both the implant and the saw blade 3 mm to 5 mm away from the supraspinatus fibers to protect the rotator cuff from iatrogenic injury.

TECHNIQUE

The technique described in this article uses the Catalyst CSR Total Shoulder System (Catalyst OrthoScience), which was cleared to treat arthritis of the shoulder by the US Food and Drug Administration in May 2016.

A standard deltopectoral incision is made, and the surgeon dissects the interval between the pectoralis major medially and the deltoid laterally. The subscapularis can be incised by tenotomy; alternatively, the surgeon can perform a subscapularis peel or a lesser tuberosity osteotomy using this technique.

Once the glenohumeral joint is exposed, the surgeon delivers the humeral head anteriorly. A preferred method is to place a Darrach retractor between the humeral head and the glenoid, and a cobra or a second Darrach retractor behind the superolateral humeral head superficial to the supraspinatus tendon. By simultaneously pressing on both retractors and externally rotating the patient’s arm, the humeral head is delivered anteriorly. Osteophytes on the anterior and inferior edge of the humeral head are generously removed at this time using a rongeur.

Using a pin guide, the long 3.2-mm guidewire pin is drilled under power into the center of the articular surface. The pin guide is then removed, leaving the pin in the center of the humerus (Figure 3).

Continue to: Next, the surgeon...

Next, the surgeon slides the cannulated reamer over the long guidewire pin and under power removes a small portion of the humeral head subchondral bone until the surgeon feels and observes that the reamer is no longer removing bone (Figure 4). The patent-pending reamer design prevents the surgeon from removing more than a few millimeters of bone, after which point the reamer spins on the surface of the bone without resecting further.

The surgeon is aware that the reamer has achieved its desired depth when it is no longer creating new bone shavings, and the surgeon can hear and feel that the reamer is spinning and no longer cutting. Then the surgeon removes the reamer.

The surgeon places the first humeral cut guide over the long guidewire pin, oriented superiorly-inferiorly and secures the guide using 4 short pins, and the long pin is removed. The surgeon uses an oscillating saw to cut the anterior and posterior plane cuts through the saw captures in the cut guide (Figure 5). The humeral cut guide and short pins are removed (Figure 6).

The surgeon then applies the second humeral cut guide to the proximal humerus and secures it using 2 short pins. The surgeon then uses the 6-mm drill to drill the 4 holes for the pegs of the implant. The top portion of the guide is removed, and the surgeon makes the superior and inferior cuts along the top and bottom surfaces of the guide using an oscillating saw (Figure 7).

The surgeon then uses a rongeur to slightly round the edges of the 4 corners at the periphery of the humerus. The second humeral cut guide and short pins are removed (Figure 8).

Continue to: Next, the surgeon trials...

Next, the surgeon trials humeral implants to determine the correct implant size (Figure 9). Once the proper humeral size is chosen, the trial is removed and the humeral cover is placed over the prepared humeral head. The surgeon then proceeds to glenoid preparation (Figure 10), which is easily accessible and facilitated by angled planar cuts on the humeral head. Glenoid technique will be discussed in a subsequent article.

After glenoid preparation and insertion, the humerus is delivered anteriorly. The proximal humerus is washed and dried, and cement is applied to the peg holes in the humerus bone and the underside of the humeral implant. The implant is then inserted using the humeral impactor to apply pressure and assure that the implant is fully seated. Once the humeral cement is hardened, the glenohumeral joint is irrigated and closure begins. Postoperative radiograph is shown in Figure 11.

DISCUSSION

Numerous authors have demonstrated that accurate implant placement is crucial for restoring normal glenoid kinematics and motion,^1-4 while some authors have reported worsening clinical outcomes and higher rates of pain and implant loosening when the implants were not placed anatomically.^5-8 This is such an important concept that it essentially was the primary inspiration for creating this TSA system. In addition, the system utilizes a nonspherical, elliptical humeral head that more closely matches the anatomy of the proximal humerus,^14,15 and this type of shape has shown improved biomechanics in laboratory testing.¹²

Good results have been demonstrated in restoring the normal anatomy using stemmed devices on the radiographic analysis of cadavers.¹⁶ The creation of stemmed implants with variable inclination and offset has improved computer models¹⁷ compared with previous studies,¹⁸ with the exception of scenarios with extreme offset. 

In theory, resurfacing implants and implants without a canal stem should have a better implant placement than that with stemmed implants; however, the ability to restore the center of rotation was even worse for resurfacing prostheses, with 65% of all implants being measured as outliers postoperatively in one study.¹⁹ Most of the resurfacing implants and their instrumentation techniques offer little to help the surgeon control for implant height. The depth of the reaming is variable, not calibrated, and not correlated with the implant size, frequently leading to overstuffing after surgery. Second, the use of spherical prostheses forces the surgeon to choose between matching the superior-inferior humeral size, leading to overhang of the implant, or matching the anteroposterior, leading to frequent undersizing in the coronal plane. The nonspherical, elliptical head shape can potentially simplify implant selection.

In summary, new techniques have been developed in an attempt to achieve increased consistency and precision in TSA. By more accurately reproducing the proximal humeral anatomy, it is proposed that clinical outcomes in terms of the range of motion and patient satisfaction may also be improved through newer techniques. Cadaver studies have validated the anatomic precision of this technique.¹⁰ Clinical data comprising of patient-reported outcome measures and radiographic outcome studies are currently underway for this arthroplasty system.

ABSTRACT

Proper reconstruction of proximal humeral anatomy is of primary importance to maximize patient outcomes after total shoulder arthroplasty. This article describes a new arthroplasty technique, where a fixed multiplanar bone resection is made and a novel implant, which is designed to precisely match the bone resection, is inserted. 

Continue to: The success of total shoulder arthroplasty...

The success of total shoulder arthroplasty (TSA) is largely dependent on how accurate the proximal humeral anatomy is reconstructed and the glenohumeral relationships are restored.^1-4 Numerous studies have demonstrated a relationship of worse clinical outcomes and implant failure with nonanatomic implant placement.^5-8 The majority of arthroplasty systems rely on surgeon-dependent decision-making to determine the location of the border of the articular surface and, ultimately, the amount and location of bone to be resected. Even in experienced hands, the ability to reproducibly restore the joint line is inconsistent.³

In contrast, the majority of total knee arthroplasty (TKA) systems have been designed with instrumentation that guides the surgeon precisely regarding where and how much femoral bone must be resected, and the corresponding implant is designed with the same thickness to preserve the location of the joint line. Cutting block instrumentation rather than freehand cuts enables reproducibility of TKA while being performed for an estimated 700,000 times annually in the US.⁹

To achieve similar high levels of reproducibility in shoulder arthroplasty, a new technique was developed based on the principle of providing instrumentation to assist the surgeon in accurately restoring the proximal humeral joint line. This technical article describes the technique of using a multiplanar instrumented cutting system and matching implants to perform TSA. The technique shown was previously studied and was found to allow surgeons to recreate the original anatomy of the humerus with very high precision.¹⁰

The humeral prosthesis described in this article has an articular surface that is slightly elliptical to more closely match the actual shape of the humerus bone.¹¹ Biomechanical studies have demonstrated that implants designed with a nonspherical shape have more similar motion and kinematics to those of the native humeral head.¹² The undersurface of the implant has a concave four-plane geometry that matches with the bone cuts created by the cutting guides (Figures 1, 2). 

This provides rotation stability, and the implant rests on the strong subchondral bone of the proximal humerus proximal to the anatomic neck rather than relying on metaphyseal bone or canal fixation, as recommended by Aldoiusti.¹³ It also allows optimal implant placement with complete freedom with respect to inclination, version, and medial/posterior offset from the humeral canal. 

Continue to: The implant respects the relationship...

The implant respects the relationship of the rotator cuff insertion and has a recessed superior margin to keep both the implant and the saw blade 3 mm to 5 mm away from the supraspinatus fibers to protect the rotator cuff from iatrogenic injury.

TECHNIQUE

The technique described in this article uses the Catalyst CSR Total Shoulder System (Catalyst OrthoScience), which was cleared to treat arthritis of the shoulder by the US Food and Drug Administration in May 2016.

A standard deltopectoral incision is made, and the surgeon dissects the interval between the pectoralis major medially and the deltoid laterally. The subscapularis can be incised by tenotomy; alternatively, the surgeon can perform a subscapularis peel or a lesser tuberosity osteotomy using this technique.

Once the glenohumeral joint is exposed, the surgeon delivers the humeral head anteriorly. A preferred method is to place a Darrach retractor between the humeral head and the glenoid, and a cobra or a second Darrach retractor behind the superolateral humeral head superficial to the supraspinatus tendon. By simultaneously pressing on both retractors and externally rotating the patient’s arm, the humeral head is delivered anteriorly. Osteophytes on the anterior and inferior edge of the humeral head are generously removed at this time using a rongeur.

Using a pin guide, the long 3.2-mm guidewire pin is drilled under power into the center of the articular surface. The pin guide is then removed, leaving the pin in the center of the humerus (Figure 3).

Continue to: Next, the surgeon...

Next, the surgeon slides the cannulated reamer over the long guidewire pin and under power removes a small portion of the humeral head subchondral bone until the surgeon feels and observes that the reamer is no longer removing bone (Figure 4). The patent-pending reamer design prevents the surgeon from removing more than a few millimeters of bone, after which point the reamer spins on the surface of the bone without resecting further.

The surgeon is aware that the reamer has achieved its desired depth when it is no longer creating new bone shavings, and the surgeon can hear and feel that the reamer is spinning and no longer cutting. Then the surgeon removes the reamer.

The surgeon places the first humeral cut guide over the long guidewire pin, oriented superiorly-inferiorly and secures the guide using 4 short pins, and the long pin is removed. The surgeon uses an oscillating saw to cut the anterior and posterior plane cuts through the saw captures in the cut guide (Figure 5). The humeral cut guide and short pins are removed (Figure 6).

The surgeon then applies the second humeral cut guide to the proximal humerus and secures it using 2 short pins. The surgeon then uses the 6-mm drill to drill the 4 holes for the pegs of the implant. The top portion of the guide is removed, and the surgeon makes the superior and inferior cuts along the top and bottom surfaces of the guide using an oscillating saw (Figure 7).

The surgeon then uses a rongeur to slightly round the edges of the 4 corners at the periphery of the humerus. The second humeral cut guide and short pins are removed (Figure 8).

Continue to: Next, the surgeon trials...

Next, the surgeon trials humeral implants to determine the correct implant size (Figure 9). Once the proper humeral size is chosen, the trial is removed and the humeral cover is placed over the prepared humeral head. The surgeon then proceeds to glenoid preparation (Figure 10), which is easily accessible and facilitated by angled planar cuts on the humeral head. Glenoid technique will be discussed in a subsequent article.

After glenoid preparation and insertion, the humerus is delivered anteriorly. The proximal humerus is washed and dried, and cement is applied to the peg holes in the humerus bone and the underside of the humeral implant. The implant is then inserted using the humeral impactor to apply pressure and assure that the implant is fully seated. Once the humeral cement is hardened, the glenohumeral joint is irrigated and closure begins. Postoperative radiograph is shown in Figure 11.

DISCUSSION

Numerous authors have demonstrated that accurate implant placement is crucial for restoring normal glenoid kinematics and motion,^1-4 while some authors have reported worsening clinical outcomes and higher rates of pain and implant loosening when the implants were not placed anatomically.^5-8 This is such an important concept that it essentially was the primary inspiration for creating this TSA system. In addition, the system utilizes a nonspherical, elliptical humeral head that more closely matches the anatomy of the proximal humerus,^14,15 and this type of shape has shown improved biomechanics in laboratory testing.¹²

Good results have been demonstrated in restoring the normal anatomy using stemmed devices on the radiographic analysis of cadavers.¹⁶ The creation of stemmed implants with variable inclination and offset has improved computer models¹⁷ compared with previous studies,¹⁸ with the exception of scenarios with extreme offset. 

In theory, resurfacing implants and implants without a canal stem should have a better implant placement than that with stemmed implants; however, the ability to restore the center of rotation was even worse for resurfacing prostheses, with 65% of all implants being measured as outliers postoperatively in one study.¹⁹ Most of the resurfacing implants and their instrumentation techniques offer little to help the surgeon control for implant height. The depth of the reaming is variable, not calibrated, and not correlated with the implant size, frequently leading to overstuffing after surgery. Second, the use of spherical prostheses forces the surgeon to choose between matching the superior-inferior humeral size, leading to overhang of the implant, or matching the anteroposterior, leading to frequent undersizing in the coronal plane. The nonspherical, elliptical head shape can potentially simplify implant selection.

In summary, new techniques have been developed in an attempt to achieve increased consistency and precision in TSA. By more accurately reproducing the proximal humeral anatomy, it is proposed that clinical outcomes in terms of the range of motion and patient satisfaction may also be improved through newer techniques. Cadaver studies have validated the anatomic precision of this technique.¹⁰ Clinical data comprising of patient-reported outcome measures and radiographic outcome studies are currently underway for this arthroplasty system.

ABSTRACT

Proper reconstruction of proximal humeral anatomy is of primary importance to maximize patient outcomes after total shoulder arthroplasty. This article describes a new arthroplasty technique, where a fixed multiplanar bone resection is made and a novel implant, which is designed to precisely match the bone resection, is inserted. 

Continue to: The success of total shoulder arthroplasty...

The success of total shoulder arthroplasty (TSA) is largely dependent on how accurate the proximal humeral anatomy is reconstructed and the glenohumeral relationships are restored.^1-4 Numerous studies have demonstrated a relationship of worse clinical outcomes and implant failure with nonanatomic implant placement.^5-8 The majority of arthroplasty systems rely on surgeon-dependent decision-making to determine the location of the border of the articular surface and, ultimately, the amount and location of bone to be resected. Even in experienced hands, the ability to reproducibly restore the joint line is inconsistent.³

In contrast, the majority of total knee arthroplasty (TKA) systems have been designed with instrumentation that guides the surgeon precisely regarding where and how much femoral bone must be resected, and the corresponding implant is designed with the same thickness to preserve the location of the joint line. Cutting block instrumentation rather than freehand cuts enables reproducibility of TKA while being performed for an estimated 700,000 times annually in the US.⁹

To achieve similar high levels of reproducibility in shoulder arthroplasty, a new technique was developed based on the principle of providing instrumentation to assist the surgeon in accurately restoring the proximal humeral joint line. This technical article describes the technique of using a multiplanar instrumented cutting system and matching implants to perform TSA. The technique shown was previously studied and was found to allow surgeons to recreate the original anatomy of the humerus with very high precision.¹⁰

The humeral prosthesis described in this article has an articular surface that is slightly elliptical to more closely match the actual shape of the humerus bone.¹¹ Biomechanical studies have demonstrated that implants designed with a nonspherical shape have more similar motion and kinematics to those of the native humeral head.¹² The undersurface of the implant has a concave four-plane geometry that matches with the bone cuts created by the cutting guides (Figures 1, 2). 

This provides rotation stability, and the implant rests on the strong subchondral bone of the proximal humerus proximal to the anatomic neck rather than relying on metaphyseal bone or canal fixation, as recommended by Aldoiusti.¹³ It also allows optimal implant placement with complete freedom with respect to inclination, version, and medial/posterior offset from the humeral canal. 

Continue to: The implant respects the relationship...

The implant respects the relationship of the rotator cuff insertion and has a recessed superior margin to keep both the implant and the saw blade 3 mm to 5 mm away from the supraspinatus fibers to protect the rotator cuff from iatrogenic injury.

TECHNIQUE

The technique described in this article uses the Catalyst CSR Total Shoulder System (Catalyst OrthoScience), which was cleared to treat arthritis of the shoulder by the US Food and Drug Administration in May 2016.

A standard deltopectoral incision is made, and the surgeon dissects the interval between the pectoralis major medially and the deltoid laterally. The subscapularis can be incised by tenotomy; alternatively, the surgeon can perform a subscapularis peel or a lesser tuberosity osteotomy using this technique.

Once the glenohumeral joint is exposed, the surgeon delivers the humeral head anteriorly. A preferred method is to place a Darrach retractor between the humeral head and the glenoid, and a cobra or a second Darrach retractor behind the superolateral humeral head superficial to the supraspinatus tendon. By simultaneously pressing on both retractors and externally rotating the patient’s arm, the humeral head is delivered anteriorly. Osteophytes on the anterior and inferior edge of the humeral head are generously removed at this time using a rongeur.

Using a pin guide, the long 3.2-mm guidewire pin is drilled under power into the center of the articular surface. The pin guide is then removed, leaving the pin in the center of the humerus (Figure 3).

Continue to: Next, the surgeon...

Next, the surgeon slides the cannulated reamer over the long guidewire pin and under power removes a small portion of the humeral head subchondral bone until the surgeon feels and observes that the reamer is no longer removing bone (Figure 4). The patent-pending reamer design prevents the surgeon from removing more than a few millimeters of bone, after which point the reamer spins on the surface of the bone without resecting further.

The surgeon is aware that the reamer has achieved its desired depth when it is no longer creating new bone shavings, and the surgeon can hear and feel that the reamer is spinning and no longer cutting. Then the surgeon removes the reamer.

The surgeon places the first humeral cut guide over the long guidewire pin, oriented superiorly-inferiorly and secures the guide using 4 short pins, and the long pin is removed. The surgeon uses an oscillating saw to cut the anterior and posterior plane cuts through the saw captures in the cut guide (Figure 5). The humeral cut guide and short pins are removed (Figure 6).

The surgeon then applies the second humeral cut guide to the proximal humerus and secures it using 2 short pins. The surgeon then uses the 6-mm drill to drill the 4 holes for the pegs of the implant. The top portion of the guide is removed, and the surgeon makes the superior and inferior cuts along the top and bottom surfaces of the guide using an oscillating saw (Figure 7).

The surgeon then uses a rongeur to slightly round the edges of the 4 corners at the periphery of the humerus. The second humeral cut guide and short pins are removed (Figure 8).

Continue to: Next, the surgeon trials...

Next, the surgeon trials humeral implants to determine the correct implant size (Figure 9). Once the proper humeral size is chosen, the trial is removed and the humeral cover is placed over the prepared humeral head. The surgeon then proceeds to glenoid preparation (Figure 10), which is easily accessible and facilitated by angled planar cuts on the humeral head. Glenoid technique will be discussed in a subsequent article.

After glenoid preparation and insertion, the humerus is delivered anteriorly. The proximal humerus is washed and dried, and cement is applied to the peg holes in the humerus bone and the underside of the humeral implant. The implant is then inserted using the humeral impactor to apply pressure and assure that the implant is fully seated. Once the humeral cement is hardened, the glenohumeral joint is irrigated and closure begins. Postoperative radiograph is shown in Figure 11.

DISCUSSION

Numerous authors have demonstrated that accurate implant placement is crucial for restoring normal glenoid kinematics and motion,^1-4 while some authors have reported worsening clinical outcomes and higher rates of pain and implant loosening when the implants were not placed anatomically.^5-8 This is such an important concept that it essentially was the primary inspiration for creating this TSA system. In addition, the system utilizes a nonspherical, elliptical humeral head that more closely matches the anatomy of the proximal humerus,^14,15 and this type of shape has shown improved biomechanics in laboratory testing.¹²

Good results have been demonstrated in restoring the normal anatomy using stemmed devices on the radiographic analysis of cadavers.¹⁶ The creation of stemmed implants with variable inclination and offset has improved computer models¹⁷ compared with previous studies,¹⁸ with the exception of scenarios with extreme offset. 

In theory, resurfacing implants and implants without a canal stem should have a better implant placement than that with stemmed implants; however, the ability to restore the center of rotation was even worse for resurfacing prostheses, with 65% of all implants being measured as outliers postoperatively in one study.¹⁹ Most of the resurfacing implants and their instrumentation techniques offer little to help the surgeon control for implant height. The depth of the reaming is variable, not calibrated, and not correlated with the implant size, frequently leading to overstuffing after surgery. Second, the use of spherical prostheses forces the surgeon to choose between matching the superior-inferior humeral size, leading to overhang of the implant, or matching the anteroposterior, leading to frequent undersizing in the coronal plane. The nonspherical, elliptical head shape can potentially simplify implant selection.

In summary, new techniques have been developed in an attempt to achieve increased consistency and precision in TSA. By more accurately reproducing the proximal humeral anatomy, it is proposed that clinical outcomes in terms of the range of motion and patient satisfaction may also be improved through newer techniques. Cadaver studies have validated the anatomic precision of this technique.¹⁰ Clinical data comprising of patient-reported outcome measures and radiographic outcome studies are currently underway for this arthroplasty system.

ABSTRACT

In a previous study, compared with throwing athletes with superior labral anterior posterior (SLAP) tears, those with concomitant SLAP tears and rotator cuff tears (RCTs) had significantly poorer outcome scores and return to play. Posterior shoulder instability also occurs in throwing athletes, but no studies currently exist regarding outcomes of these patients with concomitant RCTs.

The authors hypothesized that throwing athletes treated with arthroscopic capsulolabral repair for posterior shoulder instability with coexistent rotator cuff pathology would have poorer outcome scores and return to play.

Fifty-six consecutive throwing athletes with unidirectional posterior shoulder instability underwent arthroscopic capsulolabral repair. Preoperative and postoperative patient-centered outcomes of pain, stability, function, range of motion, strength, and American Shoulder and Elbow Surgeons Shoulder (ASES) scores, as well as return to play, were evaluated. Patients with and without rotator cuff pathology were compared.

Forty-three percent (24/56) of throwing athletes had rotator cuff pathology in addition to posterior capsulolabral pathology. All RCTs were débrided. At a mean of 3 years, there were no differences in preoperative and postoperative patient-centered outcomes between those with and without RCTs. Return-to-play rates showed no between-group differences; 92% (22/24) of athletes with concomitant RCTs returned to sport (P = .414) and 67% (16/24) returned to the same level (P = .430).

Arthroscopic capsulolabral reconstruction is successful in throwing athletes with RCTs treated with arthroscopic débridement. Unlike the previous study evaluating throwers outcomes after surgical treatment for concomitant SLAP tears and RCTs, the authors found no difference in patient-reported outcome measures or return to play for throwing athletes with concomitant posterior shoulder instability and RCTs. In throwing athletes with concomitant posterior instability and RCTs, arthroscopic posterior capsulolabral repair with rotator cuff débridement is successful.

Continue to: Posterior shoulder instability...

Posterior shoulder instability is an important and increasingly recognized pathology among throwers. Like the superior labrum, the posterior capsulolabral complex is also susceptible to injury during the throwing motion; the posterior labrum being most at risk during the late cocking and follow-through phases. Recent studies have found that arthroscopic capsulolabral reconstruction in posterior shoulder instability is successful in allowing athletes to return to their preinjury sports activities, with 2 studies detailing outcomes in throwing athletes.^1-4 However, superior labral anterior posterior (SLAP) tears are common in throwing athletes and have been treated with varying and limited success. Further, in a study of outcomes of arthroscopic repair of SLAP lesions, Neri and colleagues⁵ found that, compared with throwing athletes with SLAP tears, throwing athletes with concomitant SLAP tears and partial-thickness rotator cuff tears (RCTs) had significantly poorer outcomes and return-to-play rates after surgical repair.

The purpose of this study was to determine outcome scores and return to play of throwing athletes treated with arthroscopic capsulolabral repair for posterior shoulder instability with coexistent RCTs and to compare them with outcome scores as well as return to play of throwing athletes with isolated posterior shoulder instability. It was hypothesized that throwing athletes with a combination of posterior shoulder instability and RCT would have poorer outcomes and poorer return to play after surgery.⁵

METHODS

PATIENT SELECTION

After Institutional Review Board approval, informed consent was obtained, and consecutive throwing athletes who underwent arthroscopic posterior capsulolabral reconstruction for posterior shoulder instability were followed in the perioperative period. Inclusion criteria were throwing athletes participating in competitive sports at the high school, collegiate, or professional level, minimum 1-year follow-up, presence of unidirectional posterior instability, and absence of symptoms of instability in any direction other than posterior. Patients with inferior instability, SLAP pathology on examination and on magnetic resonance imaging, multidirectional instability, or habitual or psychogenic voluntary shoulder subluxations were excluded. Patients with diagnoses of both posterior shoulder instability and impingement treated with subacromial decompression and distal clavicle resection were also excluded.

After this cohort was identified, patient records were reviewed for pertinent operative data, such as procedure, complications, and evidence of RCT by operative report and arthroscopic photographs. A partial RCT was defined as a tear of 10% to 50%; those with rotator cuff fraying were determined not to be significant.

PATIENT EVALUATION

Surgeries were performed between January 1998 and December 2009 by the senior author (JPB). All patients were followed with clinical examinations, radiographs, and subjective grading scales. Recorded patient demographic data included age, sex, sport, position, competition level, and follow-up duration.

Continue to: All patients had...

All patients had symptomatic posterior shoulder instability, including posterior shoulder pain, clicking, a sensation of subluxation, or instability/apprehension with motion. Each athlete’s shoulder was palpated for tenderness and tested for impingement. Specific posterior glenohumeral instability tests, including the Kim test,⁶ the circumduction test, the jerk test,⁷ the posterior load-and-shift test,⁸ and the posterior stress test,⁹ were performed on all patients. Patients with multidirectional instability on the sulcus test, as well as provocative tests indicating SLAP pathology, such as the Crank test and the active compression test, were not included. Standard radiography and magnetic resonance arthrography (MRA) were performed to further narrow inclusion and exclusion criteria.

Both before surgery and at latest follow-up, patient outcomes were evaluated using the American Shoulder and Elbow Surgeons (ASES) score (range, 0-100) which combines a subjective functional scale measuring activities of daily living (0-3 for each of 10 tasks, with a total of 0-30) and a subjective pain scale (0-10, with 10 being worst pain). Values >80 were described as excellent, and failures were defined as scores <60 after surgery.¹⁰ A subjective stability scale (0-10, with 0 indicating completely stable and 10 completely unstable), strength scale (0-3, with 0 indicating none, 1 markedly decreased, 2 slightly decreased, and 3 normal), and ROM scale (0-3, with 0 indicating poor, 1 limited, 2 satisfactory, and 3 full) were evaluated both before surgery and at the latest follow-up. A stability score >5 after surgery was defined as a failure.^1,2,11 Patients were also asked if, based on their current state, they would undergo surgery again. Intraoperative findings and specific surgical procedures performed were correlated with the aforementioned subjective and objective outcome scores.

OPERATIVE TREATMENT

Throwing athletes who met inclusion criteria and failed nonoperative management underwent surgery by the senior author (JPB). Each patient was examined under anesthesia and, with the patient in the lateral decubitus position, a diagnostic arthroscopy was performed to identify posterior capsulolabral complex pathology, including a patulous capsule, capsular tears, labral fraying, and labral tears. A careful examination for rotator cuff pathology was also performed. Based on preoperative clinical examination, MRA, examination under anesthesia, pathologic findings at diagnostic arthroscopic surgery, and surgeon experience, capsulolabral plication was performed with or without suture anchors.^2,5 After capsulolabral repair, the capsule was evaluated for residual laxity, and additional plication sutures were placed, as indicated, with care to avoid overconstraint in these throwing athletes.¹ Posterior glenohumeral stability restoration was judged by removing traction and performing posterior load-and-shift and posterior stress tests. Any RCT with <50% thickness was débrided. Postoperative care and rehabilitation were carried out as previously described and were not altered by the presence or absence of a RCT.³

STATISTICAL ANALYSIS

Preoperative and latest follow-up ASES scores, stability scores, functional scores, and pain-level findings were compared using paired-samples Comparisons between groups, including throwing athletes with and without rotator cuff pathology, were done using the Student t test. Outcome comparisons between multiple groups, which included intraoperative findings and surgical fixation methods, were analyzed with c² modeling for nonparametric data. Statistical significance was set at P < .05. A power analysis found that this study was able to detect a meaningful difference of 10 ASES points.

RESULTS

PATIENT DEMOGRAPHIC CHARACTERISTICS

Of the 56 throwing athletes who met the inclusion criteria, 24 were found to have rotator cuff pathology in addition to posterior capsulolabral pathology, while 32 were found to have capsulolabral pathology alone. Demographic data are listed in Table 1. Mean age was 20.1 years for patients with rotator cuff pathology and 17.8 years for patients without RCTs. All 24 athletes with rotator cuff pathology were treated with arthroscopic débridement. Mean follow-up was 38.6 months (range, 16.5-63.6 months) for patients with RCTs and 39.1 months (range, 12-98.8 months) for patients without RCTs. No significant difference was found in age, sports level, or follow-up between groups.

Table 1. Demographic Data for Athletes With Posterior Instability With and Without Rotator Cuff Tears (N = 56 Shoulders)^a

^aThe majority of athletes were males in high school and their mean follow-up was 3 years.

Continue to: Outcomes

Table 2 lists the preoperative and postoperative scores for shoulder performance in throwing athletes with posterior shoulder instability, with and without RCTs.

Table 2. Preoperative and Postoperative Scores for Shoulder Performance in Throwing Athletes With Posterior Shoulder Instability With and Without Rotator Cuff Tears^a

^aThere was no difference in ASES, stability, pain, or functional scores between athletes with posterior instability alone compared with patients with concomitant rotator cuff tears.

Abbreviation: ASES, American Shoulder and Elbow Surgeons.

ASES Scores. Mean preoperative ASES scores for patients with RCTs improved significantly (t = –13.8, P < .001), as did those for patients without rotator cuff pathology (t = –8.9, P < .001). No significant differences in ASES score were found between patients with and without rotator cuff pathology before or after surgery (t = 1.9, P = .07; t = .58, P = .06). In addition, 70.8% (17/24) of throwing athletes with rotator cuff pathology had an excellent postoperative outcome (ASES score >80), and 29.2% (7/24) had a satisfactory outcome (ASES score, 60-80). Thus, 100% of those with concomitant posterior shoulder instability and RCTs had a good or excellent outcome after surgical intervention. In those without rotator cuff pathology, 78.1% (25/32) had an excellent outcome, 12.5% (4/32) had a satisfactory outcome, and 9.4% (3/32) had a poor outcome. Thus, 91% of those without rotator cuff pathology had a good or excellent outcome after surgery.

Stability. Preoperative stability scores improved significantly after surgery in both groups (t = 7.2, P < .001; t = 10.5, P < .001). There were no statistical differences between preoperative or postoperative stability scores in those with or without rotator cuff pathology (t = 1.7, P = .095; t = .03, P = .975). Of throwing athletes with RCTs, 54.2% (13/24) had an excellent outcome, 33.3% (8/24) a good outcome, and 12.5% (3/24) a satisfactory outcome. Thus, 87.5% (21/24) of those with RCTs had a good or excellent outcome in terms of stability. In those without rotator cuff pathology, 46.9% (15/32) had excellent stability, 46.9% (15/32) had good stability, and 3.1% (1/32) had satisfactory stability after surgery. Thus, 93.8% (30/32) of throwing athletes without rotator cuff pathology had good or excellent stability after surgery.

Pain. Mean preoperative pain scores for those with and without rotator cuff pathology improved significantly (t = 13.4, P < .001; t = 7.1, P < .001). There was no statistical difference in preoperative or postoperative pain scores between those with and without rotator cuff pathology (t = 1.99, P = .051; t = .49, P = .627).

Function. Mean preoperative function scores for both groups improved significantly (t = 7.7, P < .001; t = 8.0, P < .001). There was no difference in improvement in functional scores between the two groups before or after surgery (t = .36, P = .721; t = .5, P = .622).

Continue to: ROM

ROM. Of those with rotator cuff pathology, 54% (13/24) had normal ROM, 42% (10/24) had satisfactory ROM, and 4% (1/24) had limited ROM. In throwing athletes without rotator cuff pathology, 34% (11/32) had normal ROM, 53.1% (17/32) had satisfactory ROM, and 9% (3/32) had limited ROM after surgery. There was no significant difference in ROM between the groups (c² = 2.7, P = .260).

Strength. Of those with RCTs, 67% (16/24) reported normal strength, 29% (7/24) slightly decreased strength, and 4% (1/24) markedly decreased strength. Of those throwing athletes without rotator cuff pathology, 50% (16/32) had normal strength, 41% (13/32) had slightly decreased strength, and 9% (3/32) had markedly decreased strength. No statistical difference was noted between the two groups (c² = 1.7, P = .429).

Return to Sport. Of those with RCTs, 92% (22/24) returned to sport while 84% (27/32) of throwing athletes without RCTs returned to sport. There was no difference between the two groups (c² = .667, P = .414). Sixty-seven percent (16/24) of those with RCTs and 56% (18/32) of those without RCTs returned to the same level of sport. No statistical difference was found in return to play between throwing athletes with and without rotator cuff pathology (c² = .624, P = .430).

Failures. According to ASES scores, no throwers with RCTs failed, while 9.4% (3/32) with posterior instability alone failed. Regarding stability, 8.3% (2/24) of athletes with RCTs failed, while 6.3% (2/32) with posterior instability alone failed. 

SURGICAL FINDINGS AND PROCEDURES

Of the 24 throwing athletes with rotator cuff pathology, 92% (22/24) had labral tears, while 78% (25/32) of those without RCTs had labral tears. The majority of RCTs were in the posterior supraspinatus and anterior infraspinatus regions. This was not significantly different between groups (c² = 1.86, P = .172). All labral pathology was posterior-inferior, and all RCTs were <50% thickness, and therefore were débrided. Fifty-four percent (13/24) of those with RCTs had a patulous capsule and 63% (20/32) of throwing athletes without rotator cuff pathology had a patulous capsule. There was no significant difference between groups (c² = .393, P = .530). Of those with RCTs, 92% (22/24) had surgical fixation with anchors, while 78% (25/32) of those without rotator cuff pathology underwent repair with anchor fixation. There was no statistically significant difference in anchor use between groups (c² = 1.86, P = .172).

Continue to: Discussion

Throwing athletes with and without RCTs had similar rates of recovery and return to play after arthroscopic capsular labral repair, with rotator cuff débridement if a tear was present. The mean follow-up was 3.2 years. Further, there was no difference in return to play (92% vs 84%), ASES score, stability, pain, function, ROM, or strength between the 2 groups before or after surgery. In this cohort of 56 patients, 24 throwing athletes (43%) were found to have RCTs.

Return-to-play rates showed no between-group differences; 92% (22/24) of athletes with concomitant RCTs returned to sport, and 67% (16/24) returned to the same level. Eight percent of throwing athletes with RCTs were unable to return to sport after surgery. These return-to-play rates are an improvement over most previously reported rates in throwing athletes and in posterior shoulder instability in general.^1-4,11 When these athletes are compared with their counterparts with combined SLAP tears and RCTs, return-to-play rates are notably higher. There may be discrepancies in interpreting return-to-play between the two studies, but in the current study, 67% of those with concomitant RCTs achieved return to preinjury level of play. This is 10% higher than the rate reported in athletes with SLAP tears alone (57%) and even higher than in those with concomitant SLAP and RCTs. It is also essential to note that a number of this cohort’s athletes who did not return to play did so for factors (eg, graduation) unrelated to the shoulder. However, the study by Neri and colleagues⁵ included professional athletes who likely all attempted to return to play and, if unable to perform at the same level, likely were unable to continue their professional career.⁵

All patients with RCTs had a good or excellent outcome (ASES score), and 70.8% had an excellent outcome. Similarly, 97% of those without rotator cuff pathology had a good or excellent outcome, and 81.3% had an excellent outcome. There was no significant difference between the two groups. These results parallel those of Neri and colleagues’⁵ study of SLAP tears with RCTs, where 96% (22/23) of throwing athletes had a good or excellent outcome. Despite these high outcome scores in patients with SLAP tears, only 57% were able to return to elite pitching.⁵ In the current study, pain was slightly higher for those with rotator cuff pathology before surgery—a finding consistent with pain frequently being found in patients with isolated partial-thickness RCTs. Their postoperative pain scores were actually lower on average than those of patients without RCTs, which suggests simple débridement of undersurface tears adequately addressed the pathology. The authors theorize that the main pain generator in this population may be posterior instability, and that the rotator cuff has less of an influence. In the SLAP population, the main pain generator likely is the RCT.

Failures by ASES score or strength were fairly rare in this cohort. Many patients opted to have revision surgery because of continued instability, pain, decreased function, or reinjury. One potential cause of failure in this cohort is inadequate capsular shift. However, capsular plication in throwing athletes is difficult to address, as overtensioning the repair can lead to the inability to adequately perform overhead activites.^3,4 This cannot be overemphasized, particularly with pitchers.

Partial-thickness RCTs, particularly those on the articular side, are common in throwing athletes because of high tensile and compressive loads.¹² Despite the known risk of RCTs with posterior shoulder instability in throwing athletes, the authors are unaware of reports of the incidence or treatment of this pathology. RCTs in this posterior instability group likely represent a pathology other than internal impingement. The high proportion of throwing athletes with RCTs in this study (43%) indicates a need for close evaluation of rotator cuff pathology in young throwing athletes. Ide et al found that 75% of patients with SLAP tears had partial articular-sided RCTs.¹³ In the current study, all RCTs were small partial tears, and arthroscopic débridement was performed. It is unknown whether repair of these RCTs would impact return to play. However, rotator cuff repair in this population has been shown to have poor outcomes. Tear thickness typically is used to determine treatment, with débridement performed if <50% tendon thickness is affected. More recently, many have advocated having greater tendon involvement in throwers before repair, because of poor outcomes. Although studies are limited, tear size does seem to correlate with outcomes.¹⁴

Continue to: Study Limitations

Limitations of this study include its small number of professional throwing athletes, with the majority being high school athletes. Further, although ASES scores are consistently used in posterior shoulder instability studies, these scores are influenced highly by pain scores, and some argue that other scoring systems may provide more useful information. However, none of the more modern scoring systems have been studied extensively in posterior glenohumeral instability. Further, because the authors used the present scoring systems previously,^1-4 they were continued to be used for comparison and consistency. Outcomes such as ROM and strength may carry more weight if measured and documented by clinical examination. Further testing, such as clinical evaluation of the jerk test or the posterior load-and-shift test, and their comparison before and after surgery may provide more objective data.

CONCLUSION

Arthroscopic capsulolabral reconstruction is successful in throwing athletes with RCTs treated with arthroscopic débridement. Unlike a previous study of throwing athletes’ outcomes after surgery for concomitant SLAP tears and RCTs,⁵ this study of throwing athletes with concomitant posterior shoulder instability and RCTs found no difference in patient-reported outcome measures or return to play. In throwing athletes with posterior instability and RCTs, arthroscopic posterior capsulolabral repair with rotator cuff débridement is successful.

ABSTRACT

In a previous study, compared with throwing athletes with superior labral anterior posterior (SLAP) tears, those with concomitant SLAP tears and rotator cuff tears (RCTs) had significantly poorer outcome scores and return to play. Posterior shoulder instability also occurs in throwing athletes, but no studies currently exist regarding outcomes of these patients with concomitant RCTs.

The authors hypothesized that throwing athletes treated with arthroscopic capsulolabral repair for posterior shoulder instability with coexistent rotator cuff pathology would have poorer outcome scores and return to play.

Fifty-six consecutive throwing athletes with unidirectional posterior shoulder instability underwent arthroscopic capsulolabral repair. Preoperative and postoperative patient-centered outcomes of pain, stability, function, range of motion, strength, and American Shoulder and Elbow Surgeons Shoulder (ASES) scores, as well as return to play, were evaluated. Patients with and without rotator cuff pathology were compared.

Forty-three percent (24/56) of throwing athletes had rotator cuff pathology in addition to posterior capsulolabral pathology. All RCTs were débrided. At a mean of 3 years, there were no differences in preoperative and postoperative patient-centered outcomes between those with and without RCTs. Return-to-play rates showed no between-group differences; 92% (22/24) of athletes with concomitant RCTs returned to sport (P = .414) and 67% (16/24) returned to the same level (P = .430).

Arthroscopic capsulolabral reconstruction is successful in throwing athletes with RCTs treated with arthroscopic débridement. Unlike the previous study evaluating throwers outcomes after surgical treatment for concomitant SLAP tears and RCTs, the authors found no difference in patient-reported outcome measures or return to play for throwing athletes with concomitant posterior shoulder instability and RCTs. In throwing athletes with concomitant posterior instability and RCTs, arthroscopic posterior capsulolabral repair with rotator cuff débridement is successful.

Continue to: Posterior shoulder instability...

Posterior shoulder instability is an important and increasingly recognized pathology among throwers. Like the superior labrum, the posterior capsulolabral complex is also susceptible to injury during the throwing motion; the posterior labrum being most at risk during the late cocking and follow-through phases. Recent studies have found that arthroscopic capsulolabral reconstruction in posterior shoulder instability is successful in allowing athletes to return to their preinjury sports activities, with 2 studies detailing outcomes in throwing athletes.^1-4 However, superior labral anterior posterior (SLAP) tears are common in throwing athletes and have been treated with varying and limited success. Further, in a study of outcomes of arthroscopic repair of SLAP lesions, Neri and colleagues⁵ found that, compared with throwing athletes with SLAP tears, throwing athletes with concomitant SLAP tears and partial-thickness rotator cuff tears (RCTs) had significantly poorer outcomes and return-to-play rates after surgical repair.

The purpose of this study was to determine outcome scores and return to play of throwing athletes treated with arthroscopic capsulolabral repair for posterior shoulder instability with coexistent RCTs and to compare them with outcome scores as well as return to play of throwing athletes with isolated posterior shoulder instability. It was hypothesized that throwing athletes with a combination of posterior shoulder instability and RCT would have poorer outcomes and poorer return to play after surgery.⁵

METHODS

PATIENT SELECTION

After Institutional Review Board approval, informed consent was obtained, and consecutive throwing athletes who underwent arthroscopic posterior capsulolabral reconstruction for posterior shoulder instability were followed in the perioperative period. Inclusion criteria were throwing athletes participating in competitive sports at the high school, collegiate, or professional level, minimum 1-year follow-up, presence of unidirectional posterior instability, and absence of symptoms of instability in any direction other than posterior. Patients with inferior instability, SLAP pathology on examination and on magnetic resonance imaging, multidirectional instability, or habitual or psychogenic voluntary shoulder subluxations were excluded. Patients with diagnoses of both posterior shoulder instability and impingement treated with subacromial decompression and distal clavicle resection were also excluded.

After this cohort was identified, patient records were reviewed for pertinent operative data, such as procedure, complications, and evidence of RCT by operative report and arthroscopic photographs. A partial RCT was defined as a tear of 10% to 50%; those with rotator cuff fraying were determined not to be significant.

PATIENT EVALUATION

Surgeries were performed between January 1998 and December 2009 by the senior author (JPB). All patients were followed with clinical examinations, radiographs, and subjective grading scales. Recorded patient demographic data included age, sex, sport, position, competition level, and follow-up duration.

Continue to: All patients had...

All patients had symptomatic posterior shoulder instability, including posterior shoulder pain, clicking, a sensation of subluxation, or instability/apprehension with motion. Each athlete’s shoulder was palpated for tenderness and tested for impingement. Specific posterior glenohumeral instability tests, including the Kim test,⁶ the circumduction test, the jerk test,⁷ the posterior load-and-shift test,⁸ and the posterior stress test,⁹ were performed on all patients. Patients with multidirectional instability on the sulcus test, as well as provocative tests indicating SLAP pathology, such as the Crank test and the active compression test, were not included. Standard radiography and magnetic resonance arthrography (MRA) were performed to further narrow inclusion and exclusion criteria.

Both before surgery and at latest follow-up, patient outcomes were evaluated using the American Shoulder and Elbow Surgeons (ASES) score (range, 0-100) which combines a subjective functional scale measuring activities of daily living (0-3 for each of 10 tasks, with a total of 0-30) and a subjective pain scale (0-10, with 10 being worst pain). Values >80 were described as excellent, and failures were defined as scores <60 after surgery.¹⁰ A subjective stability scale (0-10, with 0 indicating completely stable and 10 completely unstable), strength scale (0-3, with 0 indicating none, 1 markedly decreased, 2 slightly decreased, and 3 normal), and ROM scale (0-3, with 0 indicating poor, 1 limited, 2 satisfactory, and 3 full) were evaluated both before surgery and at the latest follow-up. A stability score >5 after surgery was defined as a failure.^1,2,11 Patients were also asked if, based on their current state, they would undergo surgery again. Intraoperative findings and specific surgical procedures performed were correlated with the aforementioned subjective and objective outcome scores.

OPERATIVE TREATMENT

Throwing athletes who met inclusion criteria and failed nonoperative management underwent surgery by the senior author (JPB). Each patient was examined under anesthesia and, with the patient in the lateral decubitus position, a diagnostic arthroscopy was performed to identify posterior capsulolabral complex pathology, including a patulous capsule, capsular tears, labral fraying, and labral tears. A careful examination for rotator cuff pathology was also performed. Based on preoperative clinical examination, MRA, examination under anesthesia, pathologic findings at diagnostic arthroscopic surgery, and surgeon experience, capsulolabral plication was performed with or without suture anchors.^2,5 After capsulolabral repair, the capsule was evaluated for residual laxity, and additional plication sutures were placed, as indicated, with care to avoid overconstraint in these throwing athletes.¹ Posterior glenohumeral stability restoration was judged by removing traction and performing posterior load-and-shift and posterior stress tests. Any RCT with <50% thickness was débrided. Postoperative care and rehabilitation were carried out as previously described and were not altered by the presence or absence of a RCT.³

STATISTICAL ANALYSIS

Preoperative and latest follow-up ASES scores, stability scores, functional scores, and pain-level findings were compared using paired-samples Comparisons between groups, including throwing athletes with and without rotator cuff pathology, were done using the Student t test. Outcome comparisons between multiple groups, which included intraoperative findings and surgical fixation methods, were analyzed with c² modeling for nonparametric data. Statistical significance was set at P < .05. A power analysis found that this study was able to detect a meaningful difference of 10 ASES points.

RESULTS

PATIENT DEMOGRAPHIC CHARACTERISTICS

Of the 56 throwing athletes who met the inclusion criteria, 24 were found to have rotator cuff pathology in addition to posterior capsulolabral pathology, while 32 were found to have capsulolabral pathology alone. Demographic data are listed in Table 1. Mean age was 20.1 years for patients with rotator cuff pathology and 17.8 years for patients without RCTs. All 24 athletes with rotator cuff pathology were treated with arthroscopic débridement. Mean follow-up was 38.6 months (range, 16.5-63.6 months) for patients with RCTs and 39.1 months (range, 12-98.8 months) for patients without RCTs. No significant difference was found in age, sports level, or follow-up between groups.

Table 1. Demographic Data for Athletes With Posterior Instability With and Without Rotator Cuff Tears (N = 56 Shoulders)^a

^aThe majority of athletes were males in high school and their mean follow-up was 3 years.

Continue to: Outcomes

Table 2 lists the preoperative and postoperative scores for shoulder performance in throwing athletes with posterior shoulder instability, with and without RCTs.

Table 2. Preoperative and Postoperative Scores for Shoulder Performance in Throwing Athletes With Posterior Shoulder Instability With and Without Rotator Cuff Tears^a

^aThere was no difference in ASES, stability, pain, or functional scores between athletes with posterior instability alone compared with patients with concomitant rotator cuff tears.

Abbreviation: ASES, American Shoulder and Elbow Surgeons.

ASES Scores. Mean preoperative ASES scores for patients with RCTs improved significantly (t = –13.8, P < .001), as did those for patients without rotator cuff pathology (t = –8.9, P < .001). No significant differences in ASES score were found between patients with and without rotator cuff pathology before or after surgery (t = 1.9, P = .07; t = .58, P = .06). In addition, 70.8% (17/24) of throwing athletes with rotator cuff pathology had an excellent postoperative outcome (ASES score >80), and 29.2% (7/24) had a satisfactory outcome (ASES score, 60-80). Thus, 100% of those with concomitant posterior shoulder instability and RCTs had a good or excellent outcome after surgical intervention. In those without rotator cuff pathology, 78.1% (25/32) had an excellent outcome, 12.5% (4/32) had a satisfactory outcome, and 9.4% (3/32) had a poor outcome. Thus, 91% of those without rotator cuff pathology had a good or excellent outcome after surgery.

Stability. Preoperative stability scores improved significantly after surgery in both groups (t = 7.2, P < .001; t = 10.5, P < .001). There were no statistical differences between preoperative or postoperative stability scores in those with or without rotator cuff pathology (t = 1.7, P = .095; t = .03, P = .975). Of throwing athletes with RCTs, 54.2% (13/24) had an excellent outcome, 33.3% (8/24) a good outcome, and 12.5% (3/24) a satisfactory outcome. Thus, 87.5% (21/24) of those with RCTs had a good or excellent outcome in terms of stability. In those without rotator cuff pathology, 46.9% (15/32) had excellent stability, 46.9% (15/32) had good stability, and 3.1% (1/32) had satisfactory stability after surgery. Thus, 93.8% (30/32) of throwing athletes without rotator cuff pathology had good or excellent stability after surgery.

Pain. Mean preoperative pain scores for those with and without rotator cuff pathology improved significantly (t = 13.4, P < .001; t = 7.1, P < .001). There was no statistical difference in preoperative or postoperative pain scores between those with and without rotator cuff pathology (t = 1.99, P = .051; t = .49, P = .627).

Function. Mean preoperative function scores for both groups improved significantly (t = 7.7, P < .001; t = 8.0, P < .001). There was no difference in improvement in functional scores between the two groups before or after surgery (t = .36, P = .721; t = .5, P = .622).

Continue to: ROM

ROM. Of those with rotator cuff pathology, 54% (13/24) had normal ROM, 42% (10/24) had satisfactory ROM, and 4% (1/24) had limited ROM. In throwing athletes without rotator cuff pathology, 34% (11/32) had normal ROM, 53.1% (17/32) had satisfactory ROM, and 9% (3/32) had limited ROM after surgery. There was no significant difference in ROM between the groups (c² = 2.7, P = .260).

Strength. Of those with RCTs, 67% (16/24) reported normal strength, 29% (7/24) slightly decreased strength, and 4% (1/24) markedly decreased strength. Of those throwing athletes without rotator cuff pathology, 50% (16/32) had normal strength, 41% (13/32) had slightly decreased strength, and 9% (3/32) had markedly decreased strength. No statistical difference was noted between the two groups (c² = 1.7, P = .429).

Return to Sport. Of those with RCTs, 92% (22/24) returned to sport while 84% (27/32) of throwing athletes without RCTs returned to sport. There was no difference between the two groups (c² = .667, P = .414). Sixty-seven percent (16/24) of those with RCTs and 56% (18/32) of those without RCTs returned to the same level of sport. No statistical difference was found in return to play between throwing athletes with and without rotator cuff pathology (c² = .624, P = .430).

Failures. According to ASES scores, no throwers with RCTs failed, while 9.4% (3/32) with posterior instability alone failed. Regarding stability, 8.3% (2/24) of athletes with RCTs failed, while 6.3% (2/32) with posterior instability alone failed. 

SURGICAL FINDINGS AND PROCEDURES

Of the 24 throwing athletes with rotator cuff pathology, 92% (22/24) had labral tears, while 78% (25/32) of those without RCTs had labral tears. The majority of RCTs were in the posterior supraspinatus and anterior infraspinatus regions. This was not significantly different between groups (c² = 1.86, P = .172). All labral pathology was posterior-inferior, and all RCTs were <50% thickness, and therefore were débrided. Fifty-four percent (13/24) of those with RCTs had a patulous capsule and 63% (20/32) of throwing athletes without rotator cuff pathology had a patulous capsule. There was no significant difference between groups (c² = .393, P = .530). Of those with RCTs, 92% (22/24) had surgical fixation with anchors, while 78% (25/32) of those without rotator cuff pathology underwent repair with anchor fixation. There was no statistically significant difference in anchor use between groups (c² = 1.86, P = .172).

Continue to: Discussion

Throwing athletes with and without RCTs had similar rates of recovery and return to play after arthroscopic capsular labral repair, with rotator cuff débridement if a tear was present. The mean follow-up was 3.2 years. Further, there was no difference in return to play (92% vs 84%), ASES score, stability, pain, function, ROM, or strength between the 2 groups before or after surgery. In this cohort of 56 patients, 24 throwing athletes (43%) were found to have RCTs.

Return-to-play rates showed no between-group differences; 92% (22/24) of athletes with concomitant RCTs returned to sport, and 67% (16/24) returned to the same level. Eight percent of throwing athletes with RCTs were unable to return to sport after surgery. These return-to-play rates are an improvement over most previously reported rates in throwing athletes and in posterior shoulder instability in general.^1-4,11 When these athletes are compared with their counterparts with combined SLAP tears and RCTs, return-to-play rates are notably higher. There may be discrepancies in interpreting return-to-play between the two studies, but in the current study, 67% of those with concomitant RCTs achieved return to preinjury level of play. This is 10% higher than the rate reported in athletes with SLAP tears alone (57%) and even higher than in those with concomitant SLAP and RCTs. It is also essential to note that a number of this cohort’s athletes who did not return to play did so for factors (eg, graduation) unrelated to the shoulder. However, the study by Neri and colleagues⁵ included professional athletes who likely all attempted to return to play and, if unable to perform at the same level, likely were unable to continue their professional career.⁵

All patients with RCTs had a good or excellent outcome (ASES score), and 70.8% had an excellent outcome. Similarly, 97% of those without rotator cuff pathology had a good or excellent outcome, and 81.3% had an excellent outcome. There was no significant difference between the two groups. These results parallel those of Neri and colleagues’⁵ study of SLAP tears with RCTs, where 96% (22/23) of throwing athletes had a good or excellent outcome. Despite these high outcome scores in patients with SLAP tears, only 57% were able to return to elite pitching.⁵ In the current study, pain was slightly higher for those with rotator cuff pathology before surgery—a finding consistent with pain frequently being found in patients with isolated partial-thickness RCTs. Their postoperative pain scores were actually lower on average than those of patients without RCTs, which suggests simple débridement of undersurface tears adequately addressed the pathology. The authors theorize that the main pain generator in this population may be posterior instability, and that the rotator cuff has less of an influence. In the SLAP population, the main pain generator likely is the RCT.

Failures by ASES score or strength were fairly rare in this cohort. Many patients opted to have revision surgery because of continued instability, pain, decreased function, or reinjury. One potential cause of failure in this cohort is inadequate capsular shift. However, capsular plication in throwing athletes is difficult to address, as overtensioning the repair can lead to the inability to adequately perform overhead activites.^3,4 This cannot be overemphasized, particularly with pitchers.

Partial-thickness RCTs, particularly those on the articular side, are common in throwing athletes because of high tensile and compressive loads.¹² Despite the known risk of RCTs with posterior shoulder instability in throwing athletes, the authors are unaware of reports of the incidence or treatment of this pathology. RCTs in this posterior instability group likely represent a pathology other than internal impingement. The high proportion of throwing athletes with RCTs in this study (43%) indicates a need for close evaluation of rotator cuff pathology in young throwing athletes. Ide et al found that 75% of patients with SLAP tears had partial articular-sided RCTs.¹³ In the current study, all RCTs were small partial tears, and arthroscopic débridement was performed. It is unknown whether repair of these RCTs would impact return to play. However, rotator cuff repair in this population has been shown to have poor outcomes. Tear thickness typically is used to determine treatment, with débridement performed if <50% tendon thickness is affected. More recently, many have advocated having greater tendon involvement in throwers before repair, because of poor outcomes. Although studies are limited, tear size does seem to correlate with outcomes.¹⁴

Continue to: Study Limitations

Limitations of this study include its small number of professional throwing athletes, with the majority being high school athletes. Further, although ASES scores are consistently used in posterior shoulder instability studies, these scores are influenced highly by pain scores, and some argue that other scoring systems may provide more useful information. However, none of the more modern scoring systems have been studied extensively in posterior glenohumeral instability. Further, because the authors used the present scoring systems previously,^1-4 they were continued to be used for comparison and consistency. Outcomes such as ROM and strength may carry more weight if measured and documented by clinical examination. Further testing, such as clinical evaluation of the jerk test or the posterior load-and-shift test, and their comparison before and after surgery may provide more objective data.

CONCLUSION

Arthroscopic capsulolabral reconstruction is successful in throwing athletes with RCTs treated with arthroscopic débridement. Unlike a previous study of throwing athletes’ outcomes after surgery for concomitant SLAP tears and RCTs,⁵ this study of throwing athletes with concomitant posterior shoulder instability and RCTs found no difference in patient-reported outcome measures or return to play. In throwing athletes with posterior instability and RCTs, arthroscopic posterior capsulolabral repair with rotator cuff débridement is successful.

ABSTRACT

In a previous study, compared with throwing athletes with superior labral anterior posterior (SLAP) tears, those with concomitant SLAP tears and rotator cuff tears (RCTs) had significantly poorer outcome scores and return to play. Posterior shoulder instability also occurs in throwing athletes, but no studies currently exist regarding outcomes of these patients with concomitant RCTs.

The authors hypothesized that throwing athletes treated with arthroscopic capsulolabral repair for posterior shoulder instability with coexistent rotator cuff pathology would have poorer outcome scores and return to play.

Fifty-six consecutive throwing athletes with unidirectional posterior shoulder instability underwent arthroscopic capsulolabral repair. Preoperative and postoperative patient-centered outcomes of pain, stability, function, range of motion, strength, and American Shoulder and Elbow Surgeons Shoulder (ASES) scores, as well as return to play, were evaluated. Patients with and without rotator cuff pathology were compared.

Forty-three percent (24/56) of throwing athletes had rotator cuff pathology in addition to posterior capsulolabral pathology. All RCTs were débrided. At a mean of 3 years, there were no differences in preoperative and postoperative patient-centered outcomes between those with and without RCTs. Return-to-play rates showed no between-group differences; 92% (22/24) of athletes with concomitant RCTs returned to sport (P = .414) and 67% (16/24) returned to the same level (P = .430).

Arthroscopic capsulolabral reconstruction is successful in throwing athletes with RCTs treated with arthroscopic débridement. Unlike the previous study evaluating throwers outcomes after surgical treatment for concomitant SLAP tears and RCTs, the authors found no difference in patient-reported outcome measures or return to play for throwing athletes with concomitant posterior shoulder instability and RCTs. In throwing athletes with concomitant posterior instability and RCTs, arthroscopic posterior capsulolabral repair with rotator cuff débridement is successful.

Continue to: Posterior shoulder instability...

Posterior shoulder instability is an important and increasingly recognized pathology among throwers. Like the superior labrum, the posterior capsulolabral complex is also susceptible to injury during the throwing motion; the posterior labrum being most at risk during the late cocking and follow-through phases. Recent studies have found that arthroscopic capsulolabral reconstruction in posterior shoulder instability is successful in allowing athletes to return to their preinjury sports activities, with 2 studies detailing outcomes in throwing athletes.^1-4 However, superior labral anterior posterior (SLAP) tears are common in throwing athletes and have been treated with varying and limited success. Further, in a study of outcomes of arthroscopic repair of SLAP lesions, Neri and colleagues⁵ found that, compared with throwing athletes with SLAP tears, throwing athletes with concomitant SLAP tears and partial-thickness rotator cuff tears (RCTs) had significantly poorer outcomes and return-to-play rates after surgical repair.

The purpose of this study was to determine outcome scores and return to play of throwing athletes treated with arthroscopic capsulolabral repair for posterior shoulder instability with coexistent RCTs and to compare them with outcome scores as well as return to play of throwing athletes with isolated posterior shoulder instability. It was hypothesized that throwing athletes with a combination of posterior shoulder instability and RCT would have poorer outcomes and poorer return to play after surgery.⁵

METHODS

PATIENT SELECTION

After Institutional Review Board approval, informed consent was obtained, and consecutive throwing athletes who underwent arthroscopic posterior capsulolabral reconstruction for posterior shoulder instability were followed in the perioperative period. Inclusion criteria were throwing athletes participating in competitive sports at the high school, collegiate, or professional level, minimum 1-year follow-up, presence of unidirectional posterior instability, and absence of symptoms of instability in any direction other than posterior. Patients with inferior instability, SLAP pathology on examination and on magnetic resonance imaging, multidirectional instability, or habitual or psychogenic voluntary shoulder subluxations were excluded. Patients with diagnoses of both posterior shoulder instability and impingement treated with subacromial decompression and distal clavicle resection were also excluded.

After this cohort was identified, patient records were reviewed for pertinent operative data, such as procedure, complications, and evidence of RCT by operative report and arthroscopic photographs. A partial RCT was defined as a tear of 10% to 50%; those with rotator cuff fraying were determined not to be significant.

PATIENT EVALUATION

Surgeries were performed between January 1998 and December 2009 by the senior author (JPB). All patients were followed with clinical examinations, radiographs, and subjective grading scales. Recorded patient demographic data included age, sex, sport, position, competition level, and follow-up duration.

Continue to: All patients had...

All patients had symptomatic posterior shoulder instability, including posterior shoulder pain, clicking, a sensation of subluxation, or instability/apprehension with motion. Each athlete’s shoulder was palpated for tenderness and tested for impingement. Specific posterior glenohumeral instability tests, including the Kim test,⁶ the circumduction test, the jerk test,⁷ the posterior load-and-shift test,⁸ and the posterior stress test,⁹ were performed on all patients. Patients with multidirectional instability on the sulcus test, as well as provocative tests indicating SLAP pathology, such as the Crank test and the active compression test, were not included. Standard radiography and magnetic resonance arthrography (MRA) were performed to further narrow inclusion and exclusion criteria.

Both before surgery and at latest follow-up, patient outcomes were evaluated using the American Shoulder and Elbow Surgeons (ASES) score (range, 0-100) which combines a subjective functional scale measuring activities of daily living (0-3 for each of 10 tasks, with a total of 0-30) and a subjective pain scale (0-10, with 10 being worst pain). Values >80 were described as excellent, and failures were defined as scores <60 after surgery.¹⁰ A subjective stability scale (0-10, with 0 indicating completely stable and 10 completely unstable), strength scale (0-3, with 0 indicating none, 1 markedly decreased, 2 slightly decreased, and 3 normal), and ROM scale (0-3, with 0 indicating poor, 1 limited, 2 satisfactory, and 3 full) were evaluated both before surgery and at the latest follow-up. A stability score >5 after surgery was defined as a failure.^1,2,11 Patients were also asked if, based on their current state, they would undergo surgery again. Intraoperative findings and specific surgical procedures performed were correlated with the aforementioned subjective and objective outcome scores.

OPERATIVE TREATMENT

Throwing athletes who met inclusion criteria and failed nonoperative management underwent surgery by the senior author (JPB). Each patient was examined under anesthesia and, with the patient in the lateral decubitus position, a diagnostic arthroscopy was performed to identify posterior capsulolabral complex pathology, including a patulous capsule, capsular tears, labral fraying, and labral tears. A careful examination for rotator cuff pathology was also performed. Based on preoperative clinical examination, MRA, examination under anesthesia, pathologic findings at diagnostic arthroscopic surgery, and surgeon experience, capsulolabral plication was performed with or without suture anchors.^2,5 After capsulolabral repair, the capsule was evaluated for residual laxity, and additional plication sutures were placed, as indicated, with care to avoid overconstraint in these throwing athletes.¹ Posterior glenohumeral stability restoration was judged by removing traction and performing posterior load-and-shift and posterior stress tests. Any RCT with <50% thickness was débrided. Postoperative care and rehabilitation were carried out as previously described and were not altered by the presence or absence of a RCT.³

STATISTICAL ANALYSIS

Preoperative and latest follow-up ASES scores, stability scores, functional scores, and pain-level findings were compared using paired-samples Comparisons between groups, including throwing athletes with and without rotator cuff pathology, were done using the Student t test. Outcome comparisons between multiple groups, which included intraoperative findings and surgical fixation methods, were analyzed with c² modeling for nonparametric data. Statistical significance was set at P < .05. A power analysis found that this study was able to detect a meaningful difference of 10 ASES points.

RESULTS

PATIENT DEMOGRAPHIC CHARACTERISTICS

Of the 56 throwing athletes who met the inclusion criteria, 24 were found to have rotator cuff pathology in addition to posterior capsulolabral pathology, while 32 were found to have capsulolabral pathology alone. Demographic data are listed in Table 1. Mean age was 20.1 years for patients with rotator cuff pathology and 17.8 years for patients without RCTs. All 24 athletes with rotator cuff pathology were treated with arthroscopic débridement. Mean follow-up was 38.6 months (range, 16.5-63.6 months) for patients with RCTs and 39.1 months (range, 12-98.8 months) for patients without RCTs. No significant difference was found in age, sports level, or follow-up between groups.

Table 1. Demographic Data for Athletes With Posterior Instability With and Without Rotator Cuff Tears (N = 56 Shoulders)^a

^aThe majority of athletes were males in high school and their mean follow-up was 3 years.

Continue to: Outcomes

Table 2 lists the preoperative and postoperative scores for shoulder performance in throwing athletes with posterior shoulder instability, with and without RCTs.

Table 2. Preoperative and Postoperative Scores for Shoulder Performance in Throwing Athletes With Posterior Shoulder Instability With and Without Rotator Cuff Tears^a

^aThere was no difference in ASES, stability, pain, or functional scores between athletes with posterior instability alone compared with patients with concomitant rotator cuff tears.

Abbreviation: ASES, American Shoulder and Elbow Surgeons.

ASES Scores. Mean preoperative ASES scores for patients with RCTs improved significantly (t = –13.8, P < .001), as did those for patients without rotator cuff pathology (t = –8.9, P < .001). No significant differences in ASES score were found between patients with and without rotator cuff pathology before or after surgery (t = 1.9, P = .07; t = .58, P = .06). In addition, 70.8% (17/24) of throwing athletes with rotator cuff pathology had an excellent postoperative outcome (ASES score >80), and 29.2% (7/24) had a satisfactory outcome (ASES score, 60-80). Thus, 100% of those with concomitant posterior shoulder instability and RCTs had a good or excellent outcome after surgical intervention. In those without rotator cuff pathology, 78.1% (25/32) had an excellent outcome, 12.5% (4/32) had a satisfactory outcome, and 9.4% (3/32) had a poor outcome. Thus, 91% of those without rotator cuff pathology had a good or excellent outcome after surgery.

Stability. Preoperative stability scores improved significantly after surgery in both groups (t = 7.2, P < .001; t = 10.5, P < .001). There were no statistical differences between preoperative or postoperative stability scores in those with or without rotator cuff pathology (t = 1.7, P = .095; t = .03, P = .975). Of throwing athletes with RCTs, 54.2% (13/24) had an excellent outcome, 33.3% (8/24) a good outcome, and 12.5% (3/24) a satisfactory outcome. Thus, 87.5% (21/24) of those with RCTs had a good or excellent outcome in terms of stability. In those without rotator cuff pathology, 46.9% (15/32) had excellent stability, 46.9% (15/32) had good stability, and 3.1% (1/32) had satisfactory stability after surgery. Thus, 93.8% (30/32) of throwing athletes without rotator cuff pathology had good or excellent stability after surgery.

Pain. Mean preoperative pain scores for those with and without rotator cuff pathology improved significantly (t = 13.4, P < .001; t = 7.1, P < .001). There was no statistical difference in preoperative or postoperative pain scores between those with and without rotator cuff pathology (t = 1.99, P = .051; t = .49, P = .627).

Function. Mean preoperative function scores for both groups improved significantly (t = 7.7, P < .001; t = 8.0, P < .001). There was no difference in improvement in functional scores between the two groups before or after surgery (t = .36, P = .721; t = .5, P = .622).

Continue to: ROM

ROM. Of those with rotator cuff pathology, 54% (13/24) had normal ROM, 42% (10/24) had satisfactory ROM, and 4% (1/24) had limited ROM. In throwing athletes without rotator cuff pathology, 34% (11/32) had normal ROM, 53.1% (17/32) had satisfactory ROM, and 9% (3/32) had limited ROM after surgery. There was no significant difference in ROM between the groups (c² = 2.7, P = .260).

Strength. Of those with RCTs, 67% (16/24) reported normal strength, 29% (7/24) slightly decreased strength, and 4% (1/24) markedly decreased strength. Of those throwing athletes without rotator cuff pathology, 50% (16/32) had normal strength, 41% (13/32) had slightly decreased strength, and 9% (3/32) had markedly decreased strength. No statistical difference was noted between the two groups (c² = 1.7, P = .429).

Return to Sport. Of those with RCTs, 92% (22/24) returned to sport while 84% (27/32) of throwing athletes without RCTs returned to sport. There was no difference between the two groups (c² = .667, P = .414). Sixty-seven percent (16/24) of those with RCTs and 56% (18/32) of those without RCTs returned to the same level of sport. No statistical difference was found in return to play between throwing athletes with and without rotator cuff pathology (c² = .624, P = .430).

Failures. According to ASES scores, no throwers with RCTs failed, while 9.4% (3/32) with posterior instability alone failed. Regarding stability, 8.3% (2/24) of athletes with RCTs failed, while 6.3% (2/32) with posterior instability alone failed. 

SURGICAL FINDINGS AND PROCEDURES

Of the 24 throwing athletes with rotator cuff pathology, 92% (22/24) had labral tears, while 78% (25/32) of those without RCTs had labral tears. The majority of RCTs were in the posterior supraspinatus and anterior infraspinatus regions. This was not significantly different between groups (c² = 1.86, P = .172). All labral pathology was posterior-inferior, and all RCTs were <50% thickness, and therefore were débrided. Fifty-four percent (13/24) of those with RCTs had a patulous capsule and 63% (20/32) of throwing athletes without rotator cuff pathology had a patulous capsule. There was no significant difference between groups (c² = .393, P = .530). Of those with RCTs, 92% (22/24) had surgical fixation with anchors, while 78% (25/32) of those without rotator cuff pathology underwent repair with anchor fixation. There was no statistically significant difference in anchor use between groups (c² = 1.86, P = .172).

Continue to: Discussion

Throwing athletes with and without RCTs had similar rates of recovery and return to play after arthroscopic capsular labral repair, with rotator cuff débridement if a tear was present. The mean follow-up was 3.2 years. Further, there was no difference in return to play (92% vs 84%), ASES score, stability, pain, function, ROM, or strength between the 2 groups before or after surgery. In this cohort of 56 patients, 24 throwing athletes (43%) were found to have RCTs.

Return-to-play rates showed no between-group differences; 92% (22/24) of athletes with concomitant RCTs returned to sport, and 67% (16/24) returned to the same level. Eight percent of throwing athletes with RCTs were unable to return to sport after surgery. These return-to-play rates are an improvement over most previously reported rates in throwing athletes and in posterior shoulder instability in general.^1-4,11 When these athletes are compared with their counterparts with combined SLAP tears and RCTs, return-to-play rates are notably higher. There may be discrepancies in interpreting return-to-play between the two studies, but in the current study, 67% of those with concomitant RCTs achieved return to preinjury level of play. This is 10% higher than the rate reported in athletes with SLAP tears alone (57%) and even higher than in those with concomitant SLAP and RCTs. It is also essential to note that a number of this cohort’s athletes who did not return to play did so for factors (eg, graduation) unrelated to the shoulder. However, the study by Neri and colleagues⁵ included professional athletes who likely all attempted to return to play and, if unable to perform at the same level, likely were unable to continue their professional career.⁵

All patients with RCTs had a good or excellent outcome (ASES score), and 70.8% had an excellent outcome. Similarly, 97% of those without rotator cuff pathology had a good or excellent outcome, and 81.3% had an excellent outcome. There was no significant difference between the two groups. These results parallel those of Neri and colleagues’⁵ study of SLAP tears with RCTs, where 96% (22/23) of throwing athletes had a good or excellent outcome. Despite these high outcome scores in patients with SLAP tears, only 57% were able to return to elite pitching.⁵ In the current study, pain was slightly higher for those with rotator cuff pathology before surgery—a finding consistent with pain frequently being found in patients with isolated partial-thickness RCTs. Their postoperative pain scores were actually lower on average than those of patients without RCTs, which suggests simple débridement of undersurface tears adequately addressed the pathology. The authors theorize that the main pain generator in this population may be posterior instability, and that the rotator cuff has less of an influence. In the SLAP population, the main pain generator likely is the RCT.

Failures by ASES score or strength were fairly rare in this cohort. Many patients opted to have revision surgery because of continued instability, pain, decreased function, or reinjury. One potential cause of failure in this cohort is inadequate capsular shift. However, capsular plication in throwing athletes is difficult to address, as overtensioning the repair can lead to the inability to adequately perform overhead activites.^3,4 This cannot be overemphasized, particularly with pitchers.

Partial-thickness RCTs, particularly those on the articular side, are common in throwing athletes because of high tensile and compressive loads.¹² Despite the known risk of RCTs with posterior shoulder instability in throwing athletes, the authors are unaware of reports of the incidence or treatment of this pathology. RCTs in this posterior instability group likely represent a pathology other than internal impingement. The high proportion of throwing athletes with RCTs in this study (43%) indicates a need for close evaluation of rotator cuff pathology in young throwing athletes. Ide et al found that 75% of patients with SLAP tears had partial articular-sided RCTs.¹³ In the current study, all RCTs were small partial tears, and arthroscopic débridement was performed. It is unknown whether repair of these RCTs would impact return to play. However, rotator cuff repair in this population has been shown to have poor outcomes. Tear thickness typically is used to determine treatment, with débridement performed if <50% tendon thickness is affected. More recently, many have advocated having greater tendon involvement in throwers before repair, because of poor outcomes. Although studies are limited, tear size does seem to correlate with outcomes.¹⁴

Continue to: Study Limitations

Limitations of this study include its small number of professional throwing athletes, with the majority being high school athletes. Further, although ASES scores are consistently used in posterior shoulder instability studies, these scores are influenced highly by pain scores, and some argue that other scoring systems may provide more useful information. However, none of the more modern scoring systems have been studied extensively in posterior glenohumeral instability. Further, because the authors used the present scoring systems previously,^1-4 they were continued to be used for comparison and consistency. Outcomes such as ROM and strength may carry more weight if measured and documented by clinical examination. Further testing, such as clinical evaluation of the jerk test or the posterior load-and-shift test, and their comparison before and after surgery may provide more objective data.

CONCLUSION

Arthroscopic capsulolabral reconstruction is successful in throwing athletes with RCTs treated with arthroscopic débridement. Unlike a previous study of throwing athletes’ outcomes after surgery for concomitant SLAP tears and RCTs,⁵ this study of throwing athletes with concomitant posterior shoulder instability and RCTs found no difference in patient-reported outcome measures or return to play. In throwing athletes with posterior instability and RCTs, arthroscopic posterior capsulolabral repair with rotator cuff débridement is successful.

Over the past few decades, there has been a dramatic increase in the number of shoulder arthroplasties performed around the world. This increase is the result of an aging and increasingly more active population, better implant technology, and the advent of reverse shoulder arthroplasty (RSA) for rotator cuff arthropathy. Additionally, as the indications for RSA have expanded to include pathologies such as rotator cuff insufficiency, chronic instabilities, trauma, and tumors, the number of arthroplasties will continue to increase. Although the results of most arthroplasties are good and predictable, any glenoid and/or humeral bone deficiencies can have detrimental effects on the clinical outcomes of these procedures. Bone loss becomes more of a problem in revision cases, and, as the number of primary arthroplasties increases, it follows that the number of revision procedures will also increase.

Many of the disease- or procedure-specific processes indicated for shoulder arthroplasty have predictable patterns of bone loss, especially on the glenoid side. Walch and colleagues¹ and Bercik and colleagues² made us aware that many patients with primary osteoarthritis have significant glenoid bone deformity. Similarly, there have been a number of first- and second-generation classification systems for delineating glenoid deformity in rotator cuff tear arthropathy and in revision settings. In revision settings, both glenoid and humeral bone deficiencies can occur as a result of implant removal, iatrogenic fracture, and even infection. Each of these bone loss patterns must be recognized and treated appropriately for the best surgical outcome.

The articles in this month of The American Journal of Orthopedics address the most up-to-date concepts and solutions regarding both humeral and glenoid bone loss in shoulder arthroplasty of all types.

HUMERAL BONE LOSS

Humeral bone loss is typically encountered in proximal humerus fractures, in revision surgery necessitating humeral component removal, and, less commonly, in tumors and infection.

In many displaced proximal humeral fractures indicated for shoulder arthroplasty, the bone is comminuted with displacement of the lesser and greater tuberosities. In these situations, failure of tuberosity healing may result in loss of rotator cuff function with loss of elevation, rotation, and even instability. Humeral shortening can also occur as a result of bone loss and can compromise deltoid function by loss of proper muscle tension, leading to instability, dysfunction, or both. In addition to possible instability, humeral shortening with metaphyseal bone loss can adversely affect long-term fixation of the humeral component, leading to stem loosening or failure. Cuff and colleagues³ showed significantly more rotational micromotion in cases lacking metaphyseal support, leading to aseptic loosening of the humeral stem.

Humeral bone loss can also result from humeral stem component removal in revision shoulder arthroplasty for infection, component failure or loosening, and even periprosthetic fracture resulting from surgery or trauma.

For the surgeon, humeral bone loss can create a complex set of circumstances related to rotator cuff attachment failure, soft-tissue balancing effects, and component fixation issues. Any such issue must be recognized and addressed for best outcomes. Best results can be obtained with preoperative imaging, planning, use of bone graft techniques, proximal humeral allografts, and, more recently, modular and patient-specific implants. All of these issues are discussed comprehensively in the articles this month.

Continue to: GLENOID BONE LOSS

Proper glenoid component placement with durable fixation is crucial for success in anatomical total shoulder arthroplasty and RSA. Glenoid bone deformity and loss can result from intrinsic deformity characteristics seen in primary osteoarthritis, cuff tear arthropathy, or glenoid component removal in revision situations and infection. These bone deformity complications can be extremely difficult to treat and in some cases lead to catastrophic failure of the index arthroplasty.

We are now aware that one key to success in the face of moderate to severe deformity is proper recognition. Newer imaging techniques, including 2-dimensional (2-D) computed tomography (CT) and 3-dimensional (3-D) modeling and surgical planning software tools, which are outlined in an upcoming article, have given surgeons important new instruments that can help in treating these difficult cases.

Glenoid bone deformity in primary osteoarthritis was well delineated in the 1999 seminal study of CT changes by Walch and colleagues.¹ The Walch classification system, which characterized glenoid morphology based on 2-D CT findings, was recently upgraded, based on 3-D imaging technology, to include Walch B3 and D patterns (Figure 1).² Recognition of certain primary deformities in osteoarthritis has led to increased use of RSA in some cases of Walch B2, B3, and C deformities with substantial glenoid retroversion and/or humeral head subluxation.⁴

In cases of rotator cuff tear arthropathy, glenoid bone deformities are well described with several classification systems based on degree and dimension of bone insufficiency. The Hamada classification system defines the degree of medial glenoid erosion and superior bone loss, as well as acetabularization of the acromion in 5 grades; ⁵ Rispoli and colleagues⁶ defined and graded the degree of medicalization of the glenohumeral joint based on degree of subchondral plate erosion; and Visotsky and colleagues⁷ based their classification system on wear patterns of bone loss, alignment, and concomitant soft-tissue insufficiencies leading to instability and rotation loss.

In severe glenoid bone deficiency after glenoid component removal, Antuna and colleagues⁸ described the classic findings related to medial bone loss, anterior and posterior wall failure, and combinations thereof.

Continue to: All these classification systems...

All these classification systems are based on the 2-D appearance of the glenoid and should be considered cautiously. The glenoid is a complex 3-D structure that can be affected by any number of disease processes, trauma, and surgical intervention. Using more modern CT techniques and 3-D imaging, we now know that many deformities previously classified as unidirectional are, instead, complex and multidirectional.

Frankle and colleagues⁹ developed a classification based more 3-D CT models which has further classified severe glenoid vault deformities in relation to direction and degree of bone loss (Figures 2A-2E). Using this system, they were better able to determine degree and direction of deformity than in previous 2-D evaluations, and they were able to determine the amount of glenoid vault bone available for baseplate fixation. Scalise and colleagues¹⁰ further defined the influence of such 3-D planning in total shoulder arthroplasty.

With knowledge of these classification systems and use of contemporary imaging systems, shoulder arthroplasty in cases of severe glenoid deficiency can be more successful. Potentially, we can improve outcomes even more in the more severe cases of bone loss with use of patient-specific planning tools, including the guides and patient-specific implants that are now readily available with many implant systems.¹¹

Preoperative planning tools, bone-grafting techniques, augmented and specialized glenoid and humeral implants, and patient-specific implants are discussed this month to give our readers a comprehensive review of the latest concepts in shoulder arthroplasty in cases of significant bone loss or deformity.

This month of The American Journal of Orthopedics presents the most current and cutting-edge solutions for humeral and glenoid bone deformities and deficiencies in contemporary shoulder arthroplasties.

Over the past few decades, there has been a dramatic increase in the number of shoulder arthroplasties performed around the world. This increase is the result of an aging and increasingly more active population, better implant technology, and the advent of reverse shoulder arthroplasty (RSA) for rotator cuff arthropathy. Additionally, as the indications for RSA have expanded to include pathologies such as rotator cuff insufficiency, chronic instabilities, trauma, and tumors, the number of arthroplasties will continue to increase. Although the results of most arthroplasties are good and predictable, any glenoid and/or humeral bone deficiencies can have detrimental effects on the clinical outcomes of these procedures. Bone loss becomes more of a problem in revision cases, and, as the number of primary arthroplasties increases, it follows that the number of revision procedures will also increase.

Many of the disease- or procedure-specific processes indicated for shoulder arthroplasty have predictable patterns of bone loss, especially on the glenoid side. Walch and colleagues¹ and Bercik and colleagues² made us aware that many patients with primary osteoarthritis have significant glenoid bone deformity. Similarly, there have been a number of first- and second-generation classification systems for delineating glenoid deformity in rotator cuff tear arthropathy and in revision settings. In revision settings, both glenoid and humeral bone deficiencies can occur as a result of implant removal, iatrogenic fracture, and even infection. Each of these bone loss patterns must be recognized and treated appropriately for the best surgical outcome.

The articles in this month of The American Journal of Orthopedics address the most up-to-date concepts and solutions regarding both humeral and glenoid bone loss in shoulder arthroplasty of all types.

HUMERAL BONE LOSS

Humeral bone loss is typically encountered in proximal humerus fractures, in revision surgery necessitating humeral component removal, and, less commonly, in tumors and infection.

In many displaced proximal humeral fractures indicated for shoulder arthroplasty, the bone is comminuted with displacement of the lesser and greater tuberosities. In these situations, failure of tuberosity healing may result in loss of rotator cuff function with loss of elevation, rotation, and even instability. Humeral shortening can also occur as a result of bone loss and can compromise deltoid function by loss of proper muscle tension, leading to instability, dysfunction, or both. In addition to possible instability, humeral shortening with metaphyseal bone loss can adversely affect long-term fixation of the humeral component, leading to stem loosening or failure. Cuff and colleagues³ showed significantly more rotational micromotion in cases lacking metaphyseal support, leading to aseptic loosening of the humeral stem.

Humeral bone loss can also result from humeral stem component removal in revision shoulder arthroplasty for infection, component failure or loosening, and even periprosthetic fracture resulting from surgery or trauma.

For the surgeon, humeral bone loss can create a complex set of circumstances related to rotator cuff attachment failure, soft-tissue balancing effects, and component fixation issues. Any such issue must be recognized and addressed for best outcomes. Best results can be obtained with preoperative imaging, planning, use of bone graft techniques, proximal humeral allografts, and, more recently, modular and patient-specific implants. All of these issues are discussed comprehensively in the articles this month.

Continue to: GLENOID BONE LOSS

Proper glenoid component placement with durable fixation is crucial for success in anatomical total shoulder arthroplasty and RSA. Glenoid bone deformity and loss can result from intrinsic deformity characteristics seen in primary osteoarthritis, cuff tear arthropathy, or glenoid component removal in revision situations and infection. These bone deformity complications can be extremely difficult to treat and in some cases lead to catastrophic failure of the index arthroplasty.

We are now aware that one key to success in the face of moderate to severe deformity is proper recognition. Newer imaging techniques, including 2-dimensional (2-D) computed tomography (CT) and 3-dimensional (3-D) modeling and surgical planning software tools, which are outlined in an upcoming article, have given surgeons important new instruments that can help in treating these difficult cases.

Glenoid bone deformity in primary osteoarthritis was well delineated in the 1999 seminal study of CT changes by Walch and colleagues.¹ The Walch classification system, which characterized glenoid morphology based on 2-D CT findings, was recently upgraded, based on 3-D imaging technology, to include Walch B3 and D patterns (Figure 1).² Recognition of certain primary deformities in osteoarthritis has led to increased use of RSA in some cases of Walch B2, B3, and C deformities with substantial glenoid retroversion and/or humeral head subluxation.⁴

In cases of rotator cuff tear arthropathy, glenoid bone deformities are well described with several classification systems based on degree and dimension of bone insufficiency. The Hamada classification system defines the degree of medial glenoid erosion and superior bone loss, as well as acetabularization of the acromion in 5 grades; ⁵ Rispoli and colleagues⁶ defined and graded the degree of medicalization of the glenohumeral joint based on degree of subchondral plate erosion; and Visotsky and colleagues⁷ based their classification system on wear patterns of bone loss, alignment, and concomitant soft-tissue insufficiencies leading to instability and rotation loss.

In severe glenoid bone deficiency after glenoid component removal, Antuna and colleagues⁸ described the classic findings related to medial bone loss, anterior and posterior wall failure, and combinations thereof.

Continue to: All these classification systems...

All these classification systems are based on the 2-D appearance of the glenoid and should be considered cautiously. The glenoid is a complex 3-D structure that can be affected by any number of disease processes, trauma, and surgical intervention. Using more modern CT techniques and 3-D imaging, we now know that many deformities previously classified as unidirectional are, instead, complex and multidirectional.

Frankle and colleagues⁹ developed a classification based more 3-D CT models which has further classified severe glenoid vault deformities in relation to direction and degree of bone loss (Figures 2A-2E). Using this system, they were better able to determine degree and direction of deformity than in previous 2-D evaluations, and they were able to determine the amount of glenoid vault bone available for baseplate fixation. Scalise and colleagues¹⁰ further defined the influence of such 3-D planning in total shoulder arthroplasty.

With knowledge of these classification systems and use of contemporary imaging systems, shoulder arthroplasty in cases of severe glenoid deficiency can be more successful. Potentially, we can improve outcomes even more in the more severe cases of bone loss with use of patient-specific planning tools, including the guides and patient-specific implants that are now readily available with many implant systems.¹¹

Preoperative planning tools, bone-grafting techniques, augmented and specialized glenoid and humeral implants, and patient-specific implants are discussed this month to give our readers a comprehensive review of the latest concepts in shoulder arthroplasty in cases of significant bone loss or deformity.

This month of The American Journal of Orthopedics presents the most current and cutting-edge solutions for humeral and glenoid bone deformities and deficiencies in contemporary shoulder arthroplasties.

Over the past few decades, there has been a dramatic increase in the number of shoulder arthroplasties performed around the world. This increase is the result of an aging and increasingly more active population, better implant technology, and the advent of reverse shoulder arthroplasty (RSA) for rotator cuff arthropathy. Additionally, as the indications for RSA have expanded to include pathologies such as rotator cuff insufficiency, chronic instabilities, trauma, and tumors, the number of arthroplasties will continue to increase. Although the results of most arthroplasties are good and predictable, any glenoid and/or humeral bone deficiencies can have detrimental effects on the clinical outcomes of these procedures. Bone loss becomes more of a problem in revision cases, and, as the number of primary arthroplasties increases, it follows that the number of revision procedures will also increase.

Many of the disease- or procedure-specific processes indicated for shoulder arthroplasty have predictable patterns of bone loss, especially on the glenoid side. Walch and colleagues¹ and Bercik and colleagues² made us aware that many patients with primary osteoarthritis have significant glenoid bone deformity. Similarly, there have been a number of first- and second-generation classification systems for delineating glenoid deformity in rotator cuff tear arthropathy and in revision settings. In revision settings, both glenoid and humeral bone deficiencies can occur as a result of implant removal, iatrogenic fracture, and even infection. Each of these bone loss patterns must be recognized and treated appropriately for the best surgical outcome.

The articles in this month of The American Journal of Orthopedics address the most up-to-date concepts and solutions regarding both humeral and glenoid bone loss in shoulder arthroplasty of all types.

HUMERAL BONE LOSS

Humeral bone loss is typically encountered in proximal humerus fractures, in revision surgery necessitating humeral component removal, and, less commonly, in tumors and infection.

In many displaced proximal humeral fractures indicated for shoulder arthroplasty, the bone is comminuted with displacement of the lesser and greater tuberosities. In these situations, failure of tuberosity healing may result in loss of rotator cuff function with loss of elevation, rotation, and even instability. Humeral shortening can also occur as a result of bone loss and can compromise deltoid function by loss of proper muscle tension, leading to instability, dysfunction, or both. In addition to possible instability, humeral shortening with metaphyseal bone loss can adversely affect long-term fixation of the humeral component, leading to stem loosening or failure. Cuff and colleagues³ showed significantly more rotational micromotion in cases lacking metaphyseal support, leading to aseptic loosening of the humeral stem.

Humeral bone loss can also result from humeral stem component removal in revision shoulder arthroplasty for infection, component failure or loosening, and even periprosthetic fracture resulting from surgery or trauma.

For the surgeon, humeral bone loss can create a complex set of circumstances related to rotator cuff attachment failure, soft-tissue balancing effects, and component fixation issues. Any such issue must be recognized and addressed for best outcomes. Best results can be obtained with preoperative imaging, planning, use of bone graft techniques, proximal humeral allografts, and, more recently, modular and patient-specific implants. All of these issues are discussed comprehensively in the articles this month.

Continue to: GLENOID BONE LOSS

Proper glenoid component placement with durable fixation is crucial for success in anatomical total shoulder arthroplasty and RSA. Glenoid bone deformity and loss can result from intrinsic deformity characteristics seen in primary osteoarthritis, cuff tear arthropathy, or glenoid component removal in revision situations and infection. These bone deformity complications can be extremely difficult to treat and in some cases lead to catastrophic failure of the index arthroplasty.

We are now aware that one key to success in the face of moderate to severe deformity is proper recognition. Newer imaging techniques, including 2-dimensional (2-D) computed tomography (CT) and 3-dimensional (3-D) modeling and surgical planning software tools, which are outlined in an upcoming article, have given surgeons important new instruments that can help in treating these difficult cases.

Glenoid bone deformity in primary osteoarthritis was well delineated in the 1999 seminal study of CT changes by Walch and colleagues.¹ The Walch classification system, which characterized glenoid morphology based on 2-D CT findings, was recently upgraded, based on 3-D imaging technology, to include Walch B3 and D patterns (Figure 1).² Recognition of certain primary deformities in osteoarthritis has led to increased use of RSA in some cases of Walch B2, B3, and C deformities with substantial glenoid retroversion and/or humeral head subluxation.⁴

In cases of rotator cuff tear arthropathy, glenoid bone deformities are well described with several classification systems based on degree and dimension of bone insufficiency. The Hamada classification system defines the degree of medial glenoid erosion and superior bone loss, as well as acetabularization of the acromion in 5 grades; ⁵ Rispoli and colleagues⁶ defined and graded the degree of medicalization of the glenohumeral joint based on degree of subchondral plate erosion; and Visotsky and colleagues⁷ based their classification system on wear patterns of bone loss, alignment, and concomitant soft-tissue insufficiencies leading to instability and rotation loss.

In severe glenoid bone deficiency after glenoid component removal, Antuna and colleagues⁸ described the classic findings related to medial bone loss, anterior and posterior wall failure, and combinations thereof.

Continue to: All these classification systems...

All these classification systems are based on the 2-D appearance of the glenoid and should be considered cautiously. The glenoid is a complex 3-D structure that can be affected by any number of disease processes, trauma, and surgical intervention. Using more modern CT techniques and 3-D imaging, we now know that many deformities previously classified as unidirectional are, instead, complex and multidirectional.

Frankle and colleagues⁹ developed a classification based more 3-D CT models which has further classified severe glenoid vault deformities in relation to direction and degree of bone loss (Figures 2A-2E). Using this system, they were better able to determine degree and direction of deformity than in previous 2-D evaluations, and they were able to determine the amount of glenoid vault bone available for baseplate fixation. Scalise and colleagues¹⁰ further defined the influence of such 3-D planning in total shoulder arthroplasty.

With knowledge of these classification systems and use of contemporary imaging systems, shoulder arthroplasty in cases of severe glenoid deficiency can be more successful. Potentially, we can improve outcomes even more in the more severe cases of bone loss with use of patient-specific planning tools, including the guides and patient-specific implants that are now readily available with many implant systems.¹¹

Preoperative planning tools, bone-grafting techniques, augmented and specialized glenoid and humeral implants, and patient-specific implants are discussed this month to give our readers a comprehensive review of the latest concepts in shoulder arthroplasty in cases of significant bone loss or deformity.

This month of The American Journal of Orthopedics presents the most current and cutting-edge solutions for humeral and glenoid bone deformities and deficiencies in contemporary shoulder arthroplasties.

Take-Home Points

• Fractures of the greater tuberosity are often mismanaged.
• Comprehension of greater tuberosity fractures involves classification into nonoperative and operative treatment, displacement >5mm or <5 mm, and open vs arthroscopic surgery.
• Nearly a third of patients may suffer concomitant anterior glenohumeral instability.
• Stiffness is the most common postoperative complication.
• Surgery is associated with high patient satisfaction and low rates of complications and reoperations.

Although proximal humerus fractures are common in the elderly, isolated fractures of the greater tuberosity occur less often. Management depends on several factors, including fracture pattern and displacement.^1,2 Nondisplaced fractures are often successfully managed with sling immobilization and early range of motion.^3,4 Although surgical intervention improves outcomes in displaced greater tuberosity fractures, the ideal surgical treatment is less clear.⁵

Displaced greater tuberosity fractures may require surgery for prevention of subacromial impingement and range-of-motion deficits.² Superior fracture displacement results in decreased shoulder abduction, and posterior displacement can limit external rotation.⁶ Although the greater tuberosity can displace in any direction, posterosuperior displacement has the worst outcomes.¹ The exact surgery-warranting displacement amount ranges from 3 mm to 10 mm but is yet to be clearly elucidated.^5,6 Less displacement is tolerated by young overhead athletes, and more displacement by older less active patients.^5,7,8 Surgical options for isolated greater tuberosity fractures include fragment excision, open reduction and internal fixation (ORIF), closed reduction with percutaneous fixation, and arthroscopically assisted reduction with internal fixation.^3,9,10

We conducted a study to determine the management patterns for isolated greater tuberosity fractures. We hypothesized that greater tuberosity fractures displaced <5 mm may be managed nonoperatively and that greater tuberosity fractures displaced >5 mm require surgical fixation.

Methods

Search Strategy

We performed this systematic review according to the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) checklist¹¹ and registered it (CRD42014010691) with the PROSPERO international prospective register of systematic reviews. Literature searches using the PubMed/Medline database and the Cochrane Central Register of Clinical Trials were completed in August 2014. There were no date or year restrictions. Key words were used to capture all English- language studies with level I to IV evidence (Oxford Centre for Evidence-Based Medicine) and reported clinical or radiographic outcomes. Initial exclusion criteria were cadaveric, biomechanical, histologic, and kinematic results. An electronic search algorithm with key words and a series of NOT phrases was designed to match our exclusion criteria: 

((((((((((((((((((((((((((((((((((((((((((((((((((greater[Title/Abstract]) AND tuberosity [Title/Abstract] OR tubercle [Title/Abstract]) AND fracture[Title/Abstract]) AND proximal[Title/Abstract] AND (English[lang]))) NOT intramedullary[Title] AND (English[lang]))) NOT nonunion[Title] AND (English[lang]))) NOT malunion[Title] AND (English[lang]))) NOT biomechanical[Title/Abstract] AND (English[lang]))) NOT cadaveric[Title/Abstract] AND (English[lang]))) NOT cadaver[Title/Abstract] AND (English[lang]))) NOT ((basic[Title/Abstract]) AND science[Title/Abstract] AND (English[lang])) AND (English[lang]))) NOT revision[Title] AND (English[lang]))) NOT pediatric[Title] AND (English[lang]))) NOT physeal[Title] AND (English[lang]))) NOT children[Title] AND (English[lang]))) NOT instability[Title] AND (English[lang]))) NOT imaging[Title])) NOT salter[Title])) NOT physis[Title])) NOT shaft[Title])) NOT distal[Title])) NOT clavicle[Title])) NOT scapula[Title])) NOT ((diaphysis[Title]) AND diaphyseal[Title]))) NOT infection[Title])) NOT laboratory[Title/Abstract])) NOT metastatic[Title/Abstract])) NOT (((((((malignancy[Title/Abstract]) OR malignant[Title/Abstract]) OR tumor[Title/Abstract]) OR oncologic[Title/Abstract]) OR cyst[Title/Abstract]) OR aneurysmal[Title/Abstract]) OR unicameral[Title/Abstract]).

Study Selection

We extracted data from the 13 studies that met the eligibility criteria. Details of study design, sample size, and patient demographics, including age, sex, and hand dominance, were recorded, as were mechanism of injury and concomitant anterior shoulder instability. To capture the most patients, we noted radiographic fracture displacement categorically rather than continuously; patients were divided into 2 displacement groups (<5 mm, >5 mm). Most studies did not define degree of comminution or specific direction of displacement per fracture, so these variables were not included in the data analysis. Nonoperative management and operative management were studied. We abstracted surgical factors, such as approach, method, fixation type (screws or sutures), and technique (suture anchors or transosseous tunnels). Clinical outcomes included physical examination findings, functional assessment results (patient satisfaction; Constant and University of California Los Angeles [UCLA] shoulder scores), and the number of revisions. Radiologic outcomes, retrieved from radiographs or computed tomography scans, focused on loss of reduction (as determined by the respective authors), malunion, nonunion, and heterotopic ossification. Each study’s methodologic quality and bias were evaluated with the 15-item Modified Coleman Methodology Score (MCMS), which was described by Cowan and colleagues.²³ The MCMS has been used to assess randomized and nonrandomized patient trials.^24,25 Its scaled potential score ranges from 0 to 100 (85-100, excellent; 70-84, good; 55-69, fair; <55, poor).

Statistical Analysis

We report our data as weighted means (SDs). A mean was calculated for each study that reported a respective data point, and each mean was then weighed according to its study sample size. This calculation was performed by multiplying a study’s individual mean by the number of patients enrolled in that study and dividing the sum of these weighted data points by the number of eligible patients in all relevant studies. The result was that the nonweighted means from studies with smaller sample sizes did not carry as much weight as the nonweighted means from larger studies. We compared 3 paired groups: treatment type (nonoperative vs operative), fracture displacement amount (<5 mm vs >5 mm), and surgery type (open vs arthroscopic). Regarding all patient, surgery, and outcomes data, unpaired Student t tests were used for continuous variables and 2-tailed Fisher exact tests for categorical variables with α = 0.05 (SPSS Version 18; IBM).

Results

Postoperative physical examination findings were underreported so that surgical groups could be compared. Of all the surgical studies, 4 reported postoperative forward elevation (mean, 160°; SD, 9.8°) and external rotation (mean, 46.4°; SD 26.3°).^14,15,18,22 No malunions and only 1 nonunion were reported in all 13 studies. No deaths or other serious medical complications were reported. Patients with anterior instability more often underwent surgery than were treated nonoperatively (39.2% vs 12.0%; P < .01) and more often had fractures displaced >5 mm than <5 mm (44.3% vs 14.5%; P < .01).

Fisher exact tests were used to perform isolated comparisons of screws and sutures as well as suture anchors and transosseous tunnels. Patients with screw fixation were significantly (P = .051) less likely to require reoperation (0/56; 0%) than patients with suture fixation (8/100; 8.0%). Screw fixation also led to significantly less stiffness (0% vs 12.0%; P < .01) but trended toward a higher rate of superficial infection (3.6% vs 0%; P = .13). There was no statistical difference in nerve injury rates between screws and sutures (1.8% vs 3.0%; P = 1.0). There were no significant differences in reoperations, stiffness, superficial infections, or nerve injuries between suture anchor and transosseous tunnel constructs.

For all 13 studies, mean (SD) MCMS was 41.1 (8.6).

Discussion

Five percent of all fractures involve the proximal humerus, and 20% of proximal humerus fractures are isolated greater tuberosity fractures.^26,27 In his classic 1970 article, Neer⁶ formulated the 4-part proximal humerus fracture classification and defined greater tuberosity fracture “parts” using the same criteria as for other fracture “parts.” Neer⁶ recommended nonoperative management for isolated greater tuberosity fractures displaced <1 cm but did not present evidence corroborating his recommendation. More recent cutoffs for nonoperative management include 5 mm (general population) and 3 mm (athletes).^7,17

In the present systematic review of greater tuberosity fractures, 3 separate comparisons were made: treatment type (nonoperative vs operative), fracture displacement amount (<5 mm vs >5 mm), and surgery type (open vs arthroscopic).

Treatment Type. Only 4 studies reported data on nonoperative treatment outcomes.^5,12,16,17 Of these 4 studies, 2 found successful outcomes for fractures displaced <5 mm.^12,17 Platzer and colleagues¹⁷ found good or excellent results in 97% of 135 shoulders after 4 years. Good results were defined with shoulder scores of ≥80 (Constant), <8 (Vienna), and >28 (UCLA), and excellent results were defined with maximum scores on 2 of the 3 systems. Platzer and colleagues¹⁷ also found nonsignificantly worse shoulder scores with superior displacement of 3 mm to 5 mm and recommended surgery for overhead athletes in this group. Rath and colleagues¹² described a successful 3-phase rehabilitation protocol of sling immobilization for 3 weeks, pendulum exercises for 3 weeks, and active exercises thereafter. By an average of 31 months, patient satisfaction scores improved to 9.5 from 4.2 (10-point scale), though the authors cautioned that pain and decreased motion lasted 8 months on average. Conservative treatment was far less successful in the 2 studies of fractures displaced >5 mm.^5,16 Keene and colleagues¹⁶ reported unsatisfactory results in all 4 patients with fractures displaced >1.5 cm. In a study separate from their 2005 analysis,¹⁷ Platzer and colleagues⁵ in 2008 evaluated displaced fractures and found function and patient satisfaction were inferior after nonoperative treatment than after surgery. The studies by Keene and colleagues¹⁶ and Platzer and colleagues⁵ support the finding of an overall lower patient satisfaction rate in nonoperative patients.

Fracture Displacement Amount. Only 2 arthroscopic studies and no open studies addressed surgery for fractures displaced <5 mm. Fewer than 16% of these fractures were managed operatively, and <1% required reoperation. By contrast, almost all fractures displaced >5 mm were managed operatively, and 3.6% required reoperation. Radiographic loss of reduction was more common in fractures displaced <5 mm, primarily because they were managed without fixation. Radiographic loss of reduction was reported in only 9 operatively treated patients, none of whom was symptomatic enough to require another surgery.⁵ Reoperations were most commonly performed for stiffness, which itself was significantly more common in fractures displaced >5 mm. Bhatia and colleagues¹⁴ reported the highest reoperation rate (14.3%; 3/21), but they studied more complex, comminuted fractures of the greater tuberosity. Two of their 3 reoperations were biceps tenodeses for inflamed, stiff tenosynovitis, and the third patient had a foreign body giant cell reaction to suture material. Fewer than 1% of patients with operatively managed displaced fractures required revision ORIF, and <2% developed a superficial infection or postoperative nerve palsy.^19,22 For displaced greater tuberosity fractures, surgery is highly successful overall, complication rates are very low, and 90% of patients report being satisfied.

Surgery Type. Patients were divided into 2 groups. In the nonarthroscopic group, open and percutaneous approaches were used. All studies that described a percutaneous approach used screw fixation^5,21; in addition, 32 patients were treated with screws through an open approach.^2,5 The other open and arthroscopic studies used suture fixation. Interestingly, no studies reported on clinical outcomes of fragment excision. There were no statistically significant differences in rates of reoperation, stiffness, infection, or neurologic injury between the arthroscopic and nonarthroscopic groups. Patient satisfaction scores were slightly higher in the nonarthroscopic group (91.0% vs 87.8%), but the difference was not statistically significant.

With surgical techniques isolated, there were no significant differences between suture anchors and transosseous tunnel constructs, but screws performed significantly better than suture techniques. Compared with suture fixation, screw fixation led to significantly fewer cases of stiffness and reoperation, which suggests surgeons need to give screws more consideration in the operative management of these fractures. However, the number of patients treated with screws was smaller than the number treated with suture fixation; it is possible the differences between these cohorts would be eliminated if there were more patients in the screw cohort. In addition, screw fixation was universally performed with an open or percutaneous approach and trended toward a higher infection rate. As screw and suture techniques have low rates of complications and reoperations, we recommend leaving fixation choice to the surgeon.

Anterior shoulder instability has been associated with greater tuberosity fractures.^1,8,19 The supraspinatus, infraspinatus, and teres minor muscles all insert into the greater tuberosity and resist anterior translation of the proximal humerus. Loss of this dynamic muscle stabilization is amplified by tuberosity fracture displacement: Anterior shoulder instability was significantly more common in fractures displaced >5 mm (44.3%) vs <5 mm (14.5%). In turn, glenohumeral instability was more common in patients treated with surgery, specifically open surgery, because displaced fractures may not be as easily accessed with arthroscopic techniques. No studies reported concomitant labral repair or capsular plication techniques.

This systematic review was limited by the studies analyzed. All but 1 study⁵ had level IV evidence. Mean (SD) MCMS was 41.8 (8.6). Any MCMS score <54 indicates a poor methodology level, but this scoring system is designed for randomized controlled trials,²³ and there were none in this study. Physical examination findings, such as range of motion, were underreported. In addition, radiographic parameters were not consistently described but rather were determined by the respective authors’ subjective interpretations of malunion, nonunion, and loss of reduction. Publication bias is present in that we excluded non- English language studies and medical conference abstracts and may have omitted potentially eligible studies not discoverable with our search methodology. Performance bias is a factor in any systematic review with multiple surgeons and wide variation in surgical technique.

Conclusion

Greater tuberosity fractures displaced <5 mm may be safely managed nonoperatively, as there are no reports of nonoperatively managed fractures that subsequently required surgery. Nonoperative treatment was initially associated with low patient satisfaction, but only because displaced fractures were conservatively managed in early studies.^5,16 Fractures displaced >5 mm respond well to operative fixation with screws, suture anchors, or transosseous suture tunnels. Stiffness is the most common postoperative complication (<6%), followed by heterotopic ossification, transient neurapraxias, and superficial infection. There are no discernible differences in outcome between open and arthroscopic techniques, but screw fixation may lead to significantly fewer cases of stiffness and reoperation in comparison with suture constructs.

Take-Home Points

• Fractures of the greater tuberosity are often mismanaged.
• Comprehension of greater tuberosity fractures involves classification into nonoperative and operative treatment, displacement >5mm or <5 mm, and open vs arthroscopic surgery.
• Nearly a third of patients may suffer concomitant anterior glenohumeral instability.
• Stiffness is the most common postoperative complication.
• Surgery is associated with high patient satisfaction and low rates of complications and reoperations.

Although proximal humerus fractures are common in the elderly, isolated fractures of the greater tuberosity occur less often. Management depends on several factors, including fracture pattern and displacement.^1,2 Nondisplaced fractures are often successfully managed with sling immobilization and early range of motion.^3,4 Although surgical intervention improves outcomes in displaced greater tuberosity fractures, the ideal surgical treatment is less clear.⁵

Displaced greater tuberosity fractures may require surgery for prevention of subacromial impingement and range-of-motion deficits.² Superior fracture displacement results in decreased shoulder abduction, and posterior displacement can limit external rotation.⁶ Although the greater tuberosity can displace in any direction, posterosuperior displacement has the worst outcomes.¹ The exact surgery-warranting displacement amount ranges from 3 mm to 10 mm but is yet to be clearly elucidated.^5,6 Less displacement is tolerated by young overhead athletes, and more displacement by older less active patients.^5,7,8 Surgical options for isolated greater tuberosity fractures include fragment excision, open reduction and internal fixation (ORIF), closed reduction with percutaneous fixation, and arthroscopically assisted reduction with internal fixation.^3,9,10

We conducted a study to determine the management patterns for isolated greater tuberosity fractures. We hypothesized that greater tuberosity fractures displaced <5 mm may be managed nonoperatively and that greater tuberosity fractures displaced >5 mm require surgical fixation.

Methods

Search Strategy

We performed this systematic review according to the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) checklist¹¹ and registered it (CRD42014010691) with the PROSPERO international prospective register of systematic reviews. Literature searches using the PubMed/Medline database and the Cochrane Central Register of Clinical Trials were completed in August 2014. There were no date or year restrictions. Key words were used to capture all English- language studies with level I to IV evidence (Oxford Centre for Evidence-Based Medicine) and reported clinical or radiographic outcomes. Initial exclusion criteria were cadaveric, biomechanical, histologic, and kinematic results. An electronic search algorithm with key words and a series of NOT phrases was designed to match our exclusion criteria: 

((((((((((((((((((((((((((((((((((((((((((((((((((greater[Title/Abstract]) AND tuberosity [Title/Abstract] OR tubercle [Title/Abstract]) AND fracture[Title/Abstract]) AND proximal[Title/Abstract] AND (English[lang]))) NOT intramedullary[Title] AND (English[lang]))) NOT nonunion[Title] AND (English[lang]))) NOT malunion[Title] AND (English[lang]))) NOT biomechanical[Title/Abstract] AND (English[lang]))) NOT cadaveric[Title/Abstract] AND (English[lang]))) NOT cadaver[Title/Abstract] AND (English[lang]))) NOT ((basic[Title/Abstract]) AND science[Title/Abstract] AND (English[lang])) AND (English[lang]))) NOT revision[Title] AND (English[lang]))) NOT pediatric[Title] AND (English[lang]))) NOT physeal[Title] AND (English[lang]))) NOT children[Title] AND (English[lang]))) NOT instability[Title] AND (English[lang]))) NOT imaging[Title])) NOT salter[Title])) NOT physis[Title])) NOT shaft[Title])) NOT distal[Title])) NOT clavicle[Title])) NOT scapula[Title])) NOT ((diaphysis[Title]) AND diaphyseal[Title]))) NOT infection[Title])) NOT laboratory[Title/Abstract])) NOT metastatic[Title/Abstract])) NOT (((((((malignancy[Title/Abstract]) OR malignant[Title/Abstract]) OR tumor[Title/Abstract]) OR oncologic[Title/Abstract]) OR cyst[Title/Abstract]) OR aneurysmal[Title/Abstract]) OR unicameral[Title/Abstract]).

Study Selection

We extracted data from the 13 studies that met the eligibility criteria. Details of study design, sample size, and patient demographics, including age, sex, and hand dominance, were recorded, as were mechanism of injury and concomitant anterior shoulder instability. To capture the most patients, we noted radiographic fracture displacement categorically rather than continuously; patients were divided into 2 displacement groups (<5 mm, >5 mm). Most studies did not define degree of comminution or specific direction of displacement per fracture, so these variables were not included in the data analysis. Nonoperative management and operative management were studied. We abstracted surgical factors, such as approach, method, fixation type (screws or sutures), and technique (suture anchors or transosseous tunnels). Clinical outcomes included physical examination findings, functional assessment results (patient satisfaction; Constant and University of California Los Angeles [UCLA] shoulder scores), and the number of revisions. Radiologic outcomes, retrieved from radiographs or computed tomography scans, focused on loss of reduction (as determined by the respective authors), malunion, nonunion, and heterotopic ossification. Each study’s methodologic quality and bias were evaluated with the 15-item Modified Coleman Methodology Score (MCMS), which was described by Cowan and colleagues.²³ The MCMS has been used to assess randomized and nonrandomized patient trials.^24,25 Its scaled potential score ranges from 0 to 100 (85-100, excellent; 70-84, good; 55-69, fair; <55, poor).

Statistical Analysis

We report our data as weighted means (SDs). A mean was calculated for each study that reported a respective data point, and each mean was then weighed according to its study sample size. This calculation was performed by multiplying a study’s individual mean by the number of patients enrolled in that study and dividing the sum of these weighted data points by the number of eligible patients in all relevant studies. The result was that the nonweighted means from studies with smaller sample sizes did not carry as much weight as the nonweighted means from larger studies. We compared 3 paired groups: treatment type (nonoperative vs operative), fracture displacement amount (<5 mm vs >5 mm), and surgery type (open vs arthroscopic). Regarding all patient, surgery, and outcomes data, unpaired Student t tests were used for continuous variables and 2-tailed Fisher exact tests for categorical variables with α = 0.05 (SPSS Version 18; IBM).

Results

Postoperative physical examination findings were underreported so that surgical groups could be compared. Of all the surgical studies, 4 reported postoperative forward elevation (mean, 160°; SD, 9.8°) and external rotation (mean, 46.4°; SD 26.3°).^14,15,18,22 No malunions and only 1 nonunion were reported in all 13 studies. No deaths or other serious medical complications were reported. Patients with anterior instability more often underwent surgery than were treated nonoperatively (39.2% vs 12.0%; P < .01) and more often had fractures displaced >5 mm than <5 mm (44.3% vs 14.5%; P < .01).

Fisher exact tests were used to perform isolated comparisons of screws and sutures as well as suture anchors and transosseous tunnels. Patients with screw fixation were significantly (P = .051) less likely to require reoperation (0/56; 0%) than patients with suture fixation (8/100; 8.0%). Screw fixation also led to significantly less stiffness (0% vs 12.0%; P < .01) but trended toward a higher rate of superficial infection (3.6% vs 0%; P = .13). There was no statistical difference in nerve injury rates between screws and sutures (1.8% vs 3.0%; P = 1.0). There were no significant differences in reoperations, stiffness, superficial infections, or nerve injuries between suture anchor and transosseous tunnel constructs.

For all 13 studies, mean (SD) MCMS was 41.1 (8.6).

Discussion

Five percent of all fractures involve the proximal humerus, and 20% of proximal humerus fractures are isolated greater tuberosity fractures.^26,27 In his classic 1970 article, Neer⁶ formulated the 4-part proximal humerus fracture classification and defined greater tuberosity fracture “parts” using the same criteria as for other fracture “parts.” Neer⁶ recommended nonoperative management for isolated greater tuberosity fractures displaced <1 cm but did not present evidence corroborating his recommendation. More recent cutoffs for nonoperative management include 5 mm (general population) and 3 mm (athletes).^7,17

In the present systematic review of greater tuberosity fractures, 3 separate comparisons were made: treatment type (nonoperative vs operative), fracture displacement amount (<5 mm vs >5 mm), and surgery type (open vs arthroscopic).

Treatment Type. Only 4 studies reported data on nonoperative treatment outcomes.^5,12,16,17 Of these 4 studies, 2 found successful outcomes for fractures displaced <5 mm.^12,17 Platzer and colleagues¹⁷ found good or excellent results in 97% of 135 shoulders after 4 years. Good results were defined with shoulder scores of ≥80 (Constant), <8 (Vienna), and >28 (UCLA), and excellent results were defined with maximum scores on 2 of the 3 systems. Platzer and colleagues¹⁷ also found nonsignificantly worse shoulder scores with superior displacement of 3 mm to 5 mm and recommended surgery for overhead athletes in this group. Rath and colleagues¹² described a successful 3-phase rehabilitation protocol of sling immobilization for 3 weeks, pendulum exercises for 3 weeks, and active exercises thereafter. By an average of 31 months, patient satisfaction scores improved to 9.5 from 4.2 (10-point scale), though the authors cautioned that pain and decreased motion lasted 8 months on average. Conservative treatment was far less successful in the 2 studies of fractures displaced >5 mm.^5,16 Keene and colleagues¹⁶ reported unsatisfactory results in all 4 patients with fractures displaced >1.5 cm. In a study separate from their 2005 analysis,¹⁷ Platzer and colleagues⁵ in 2008 evaluated displaced fractures and found function and patient satisfaction were inferior after nonoperative treatment than after surgery. The studies by Keene and colleagues¹⁶ and Platzer and colleagues⁵ support the finding of an overall lower patient satisfaction rate in nonoperative patients.

Fracture Displacement Amount. Only 2 arthroscopic studies and no open studies addressed surgery for fractures displaced <5 mm. Fewer than 16% of these fractures were managed operatively, and <1% required reoperation. By contrast, almost all fractures displaced >5 mm were managed operatively, and 3.6% required reoperation. Radiographic loss of reduction was more common in fractures displaced <5 mm, primarily because they were managed without fixation. Radiographic loss of reduction was reported in only 9 operatively treated patients, none of whom was symptomatic enough to require another surgery.⁵ Reoperations were most commonly performed for stiffness, which itself was significantly more common in fractures displaced >5 mm. Bhatia and colleagues¹⁴ reported the highest reoperation rate (14.3%; 3/21), but they studied more complex, comminuted fractures of the greater tuberosity. Two of their 3 reoperations were biceps tenodeses for inflamed, stiff tenosynovitis, and the third patient had a foreign body giant cell reaction to suture material. Fewer than 1% of patients with operatively managed displaced fractures required revision ORIF, and <2% developed a superficial infection or postoperative nerve palsy.^19,22 For displaced greater tuberosity fractures, surgery is highly successful overall, complication rates are very low, and 90% of patients report being satisfied.

Surgery Type. Patients were divided into 2 groups. In the nonarthroscopic group, open and percutaneous approaches were used. All studies that described a percutaneous approach used screw fixation^5,21; in addition, 32 patients were treated with screws through an open approach.^2,5 The other open and arthroscopic studies used suture fixation. Interestingly, no studies reported on clinical outcomes of fragment excision. There were no statistically significant differences in rates of reoperation, stiffness, infection, or neurologic injury between the arthroscopic and nonarthroscopic groups. Patient satisfaction scores were slightly higher in the nonarthroscopic group (91.0% vs 87.8%), but the difference was not statistically significant.

With surgical techniques isolated, there were no significant differences between suture anchors and transosseous tunnel constructs, but screws performed significantly better than suture techniques. Compared with suture fixation, screw fixation led to significantly fewer cases of stiffness and reoperation, which suggests surgeons need to give screws more consideration in the operative management of these fractures. However, the number of patients treated with screws was smaller than the number treated with suture fixation; it is possible the differences between these cohorts would be eliminated if there were more patients in the screw cohort. In addition, screw fixation was universally performed with an open or percutaneous approach and trended toward a higher infection rate. As screw and suture techniques have low rates of complications and reoperations, we recommend leaving fixation choice to the surgeon.

Anterior shoulder instability has been associated with greater tuberosity fractures.^1,8,19 The supraspinatus, infraspinatus, and teres minor muscles all insert into the greater tuberosity and resist anterior translation of the proximal humerus. Loss of this dynamic muscle stabilization is amplified by tuberosity fracture displacement: Anterior shoulder instability was significantly more common in fractures displaced >5 mm (44.3%) vs <5 mm (14.5%). In turn, glenohumeral instability was more common in patients treated with surgery, specifically open surgery, because displaced fractures may not be as easily accessed with arthroscopic techniques. No studies reported concomitant labral repair or capsular plication techniques.

This systematic review was limited by the studies analyzed. All but 1 study⁵ had level IV evidence. Mean (SD) MCMS was 41.8 (8.6). Any MCMS score <54 indicates a poor methodology level, but this scoring system is designed for randomized controlled trials,²³ and there were none in this study. Physical examination findings, such as range of motion, were underreported. In addition, radiographic parameters were not consistently described but rather were determined by the respective authors’ subjective interpretations of malunion, nonunion, and loss of reduction. Publication bias is present in that we excluded non- English language studies and medical conference abstracts and may have omitted potentially eligible studies not discoverable with our search methodology. Performance bias is a factor in any systematic review with multiple surgeons and wide variation in surgical technique.

Conclusion

Greater tuberosity fractures displaced <5 mm may be safely managed nonoperatively, as there are no reports of nonoperatively managed fractures that subsequently required surgery. Nonoperative treatment was initially associated with low patient satisfaction, but only because displaced fractures were conservatively managed in early studies.^5,16 Fractures displaced >5 mm respond well to operative fixation with screws, suture anchors, or transosseous suture tunnels. Stiffness is the most common postoperative complication (<6%), followed by heterotopic ossification, transient neurapraxias, and superficial infection. There are no discernible differences in outcome between open and arthroscopic techniques, but screw fixation may lead to significantly fewer cases of stiffness and reoperation in comparison with suture constructs.

Take-Home Points

• Fractures of the greater tuberosity are often mismanaged.
• Comprehension of greater tuberosity fractures involves classification into nonoperative and operative treatment, displacement >5mm or <5 mm, and open vs arthroscopic surgery.
• Nearly a third of patients may suffer concomitant anterior glenohumeral instability.
• Stiffness is the most common postoperative complication.
• Surgery is associated with high patient satisfaction and low rates of complications and reoperations.

Although proximal humerus fractures are common in the elderly, isolated fractures of the greater tuberosity occur less often. Management depends on several factors, including fracture pattern and displacement.^1,2 Nondisplaced fractures are often successfully managed with sling immobilization and early range of motion.^3,4 Although surgical intervention improves outcomes in displaced greater tuberosity fractures, the ideal surgical treatment is less clear.⁵

Displaced greater tuberosity fractures may require surgery for prevention of subacromial impingement and range-of-motion deficits.² Superior fracture displacement results in decreased shoulder abduction, and posterior displacement can limit external rotation.⁶ Although the greater tuberosity can displace in any direction, posterosuperior displacement has the worst outcomes.¹ The exact surgery-warranting displacement amount ranges from 3 mm to 10 mm but is yet to be clearly elucidated.^5,6 Less displacement is tolerated by young overhead athletes, and more displacement by older less active patients.^5,7,8 Surgical options for isolated greater tuberosity fractures include fragment excision, open reduction and internal fixation (ORIF), closed reduction with percutaneous fixation, and arthroscopically assisted reduction with internal fixation.^3,9,10

We conducted a study to determine the management patterns for isolated greater tuberosity fractures. We hypothesized that greater tuberosity fractures displaced <5 mm may be managed nonoperatively and that greater tuberosity fractures displaced >5 mm require surgical fixation.

Methods

Search Strategy

We performed this systematic review according to the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) checklist¹¹ and registered it (CRD42014010691) with the PROSPERO international prospective register of systematic reviews. Literature searches using the PubMed/Medline database and the Cochrane Central Register of Clinical Trials were completed in August 2014. There were no date or year restrictions. Key words were used to capture all English- language studies with level I to IV evidence (Oxford Centre for Evidence-Based Medicine) and reported clinical or radiographic outcomes. Initial exclusion criteria were cadaveric, biomechanical, histologic, and kinematic results. An electronic search algorithm with key words and a series of NOT phrases was designed to match our exclusion criteria: 

((((((((((((((((((((((((((((((((((((((((((((((((((greater[Title/Abstract]) AND tuberosity [Title/Abstract] OR tubercle [Title/Abstract]) AND fracture[Title/Abstract]) AND proximal[Title/Abstract] AND (English[lang]))) NOT intramedullary[Title] AND (English[lang]))) NOT nonunion[Title] AND (English[lang]))) NOT malunion[Title] AND (English[lang]))) NOT biomechanical[Title/Abstract] AND (English[lang]))) NOT cadaveric[Title/Abstract] AND (English[lang]))) NOT cadaver[Title/Abstract] AND (English[lang]))) NOT ((basic[Title/Abstract]) AND science[Title/Abstract] AND (English[lang])) AND (English[lang]))) NOT revision[Title] AND (English[lang]))) NOT pediatric[Title] AND (English[lang]))) NOT physeal[Title] AND (English[lang]))) NOT children[Title] AND (English[lang]))) NOT instability[Title] AND (English[lang]))) NOT imaging[Title])) NOT salter[Title])) NOT physis[Title])) NOT shaft[Title])) NOT distal[Title])) NOT clavicle[Title])) NOT scapula[Title])) NOT ((diaphysis[Title]) AND diaphyseal[Title]))) NOT infection[Title])) NOT laboratory[Title/Abstract])) NOT metastatic[Title/Abstract])) NOT (((((((malignancy[Title/Abstract]) OR malignant[Title/Abstract]) OR tumor[Title/Abstract]) OR oncologic[Title/Abstract]) OR cyst[Title/Abstract]) OR aneurysmal[Title/Abstract]) OR unicameral[Title/Abstract]).

Study Selection

We extracted data from the 13 studies that met the eligibility criteria. Details of study design, sample size, and patient demographics, including age, sex, and hand dominance, were recorded, as were mechanism of injury and concomitant anterior shoulder instability. To capture the most patients, we noted radiographic fracture displacement categorically rather than continuously; patients were divided into 2 displacement groups (<5 mm, >5 mm). Most studies did not define degree of comminution or specific direction of displacement per fracture, so these variables were not included in the data analysis. Nonoperative management and operative management were studied. We abstracted surgical factors, such as approach, method, fixation type (screws or sutures), and technique (suture anchors or transosseous tunnels). Clinical outcomes included physical examination findings, functional assessment results (patient satisfaction; Constant and University of California Los Angeles [UCLA] shoulder scores), and the number of revisions. Radiologic outcomes, retrieved from radiographs or computed tomography scans, focused on loss of reduction (as determined by the respective authors), malunion, nonunion, and heterotopic ossification. Each study’s methodologic quality and bias were evaluated with the 15-item Modified Coleman Methodology Score (MCMS), which was described by Cowan and colleagues.²³ The MCMS has been used to assess randomized and nonrandomized patient trials.^24,25 Its scaled potential score ranges from 0 to 100 (85-100, excellent; 70-84, good; 55-69, fair; <55, poor).

Statistical Analysis

We report our data as weighted means (SDs). A mean was calculated for each study that reported a respective data point, and each mean was then weighed according to its study sample size. This calculation was performed by multiplying a study’s individual mean by the number of patients enrolled in that study and dividing the sum of these weighted data points by the number of eligible patients in all relevant studies. The result was that the nonweighted means from studies with smaller sample sizes did not carry as much weight as the nonweighted means from larger studies. We compared 3 paired groups: treatment type (nonoperative vs operative), fracture displacement amount (<5 mm vs >5 mm), and surgery type (open vs arthroscopic). Regarding all patient, surgery, and outcomes data, unpaired Student t tests were used for continuous variables and 2-tailed Fisher exact tests for categorical variables with α = 0.05 (SPSS Version 18; IBM).

Results

Postoperative physical examination findings were underreported so that surgical groups could be compared. Of all the surgical studies, 4 reported postoperative forward elevation (mean, 160°; SD, 9.8°) and external rotation (mean, 46.4°; SD 26.3°).^14,15,18,22 No malunions and only 1 nonunion were reported in all 13 studies. No deaths or other serious medical complications were reported. Patients with anterior instability more often underwent surgery than were treated nonoperatively (39.2% vs 12.0%; P < .01) and more often had fractures displaced >5 mm than <5 mm (44.3% vs 14.5%; P < .01).

Fisher exact tests were used to perform isolated comparisons of screws and sutures as well as suture anchors and transosseous tunnels. Patients with screw fixation were significantly (P = .051) less likely to require reoperation (0/56; 0%) than patients with suture fixation (8/100; 8.0%). Screw fixation also led to significantly less stiffness (0% vs 12.0%; P < .01) but trended toward a higher rate of superficial infection (3.6% vs 0%; P = .13). There was no statistical difference in nerve injury rates between screws and sutures (1.8% vs 3.0%; P = 1.0). There were no significant differences in reoperations, stiffness, superficial infections, or nerve injuries between suture anchor and transosseous tunnel constructs.

For all 13 studies, mean (SD) MCMS was 41.1 (8.6).

Discussion

Five percent of all fractures involve the proximal humerus, and 20% of proximal humerus fractures are isolated greater tuberosity fractures.^26,27 In his classic 1970 article, Neer⁶ formulated the 4-part proximal humerus fracture classification and defined greater tuberosity fracture “parts” using the same criteria as for other fracture “parts.” Neer⁶ recommended nonoperative management for isolated greater tuberosity fractures displaced <1 cm but did not present evidence corroborating his recommendation. More recent cutoffs for nonoperative management include 5 mm (general population) and 3 mm (athletes).^7,17

In the present systematic review of greater tuberosity fractures, 3 separate comparisons were made: treatment type (nonoperative vs operative), fracture displacement amount (<5 mm vs >5 mm), and surgery type (open vs arthroscopic).

Treatment Type. Only 4 studies reported data on nonoperative treatment outcomes.^5,12,16,17 Of these 4 studies, 2 found successful outcomes for fractures displaced <5 mm.^12,17 Platzer and colleagues¹⁷ found good or excellent results in 97% of 135 shoulders after 4 years. Good results were defined with shoulder scores of ≥80 (Constant), <8 (Vienna), and >28 (UCLA), and excellent results were defined with maximum scores on 2 of the 3 systems. Platzer and colleagues¹⁷ also found nonsignificantly worse shoulder scores with superior displacement of 3 mm to 5 mm and recommended surgery for overhead athletes in this group. Rath and colleagues¹² described a successful 3-phase rehabilitation protocol of sling immobilization for 3 weeks, pendulum exercises for 3 weeks, and active exercises thereafter. By an average of 31 months, patient satisfaction scores improved to 9.5 from 4.2 (10-point scale), though the authors cautioned that pain and decreased motion lasted 8 months on average. Conservative treatment was far less successful in the 2 studies of fractures displaced >5 mm.^5,16 Keene and colleagues¹⁶ reported unsatisfactory results in all 4 patients with fractures displaced >1.5 cm. In a study separate from their 2005 analysis,¹⁷ Platzer and colleagues⁵ in 2008 evaluated displaced fractures and found function and patient satisfaction were inferior after nonoperative treatment than after surgery. The studies by Keene and colleagues¹⁶ and Platzer and colleagues⁵ support the finding of an overall lower patient satisfaction rate in nonoperative patients.

Fracture Displacement Amount. Only 2 arthroscopic studies and no open studies addressed surgery for fractures displaced <5 mm. Fewer than 16% of these fractures were managed operatively, and <1% required reoperation. By contrast, almost all fractures displaced >5 mm were managed operatively, and 3.6% required reoperation. Radiographic loss of reduction was more common in fractures displaced <5 mm, primarily because they were managed without fixation. Radiographic loss of reduction was reported in only 9 operatively treated patients, none of whom was symptomatic enough to require another surgery.⁵ Reoperations were most commonly performed for stiffness, which itself was significantly more common in fractures displaced >5 mm. Bhatia and colleagues¹⁴ reported the highest reoperation rate (14.3%; 3/21), but they studied more complex, comminuted fractures of the greater tuberosity. Two of their 3 reoperations were biceps tenodeses for inflamed, stiff tenosynovitis, and the third patient had a foreign body giant cell reaction to suture material. Fewer than 1% of patients with operatively managed displaced fractures required revision ORIF, and <2% developed a superficial infection or postoperative nerve palsy.^19,22 For displaced greater tuberosity fractures, surgery is highly successful overall, complication rates are very low, and 90% of patients report being satisfied.

Surgery Type. Patients were divided into 2 groups. In the nonarthroscopic group, open and percutaneous approaches were used. All studies that described a percutaneous approach used screw fixation^5,21; in addition, 32 patients were treated with screws through an open approach.^2,5 The other open and arthroscopic studies used suture fixation. Interestingly, no studies reported on clinical outcomes of fragment excision. There were no statistically significant differences in rates of reoperation, stiffness, infection, or neurologic injury between the arthroscopic and nonarthroscopic groups. Patient satisfaction scores were slightly higher in the nonarthroscopic group (91.0% vs 87.8%), but the difference was not statistically significant.

With surgical techniques isolated, there were no significant differences between suture anchors and transosseous tunnel constructs, but screws performed significantly better than suture techniques. Compared with suture fixation, screw fixation led to significantly fewer cases of stiffness and reoperation, which suggests surgeons need to give screws more consideration in the operative management of these fractures. However, the number of patients treated with screws was smaller than the number treated with suture fixation; it is possible the differences between these cohorts would be eliminated if there were more patients in the screw cohort. In addition, screw fixation was universally performed with an open or percutaneous approach and trended toward a higher infection rate. As screw and suture techniques have low rates of complications and reoperations, we recommend leaving fixation choice to the surgeon.

Anterior shoulder instability has been associated with greater tuberosity fractures.^1,8,19 The supraspinatus, infraspinatus, and teres minor muscles all insert into the greater tuberosity and resist anterior translation of the proximal humerus. Loss of this dynamic muscle stabilization is amplified by tuberosity fracture displacement: Anterior shoulder instability was significantly more common in fractures displaced >5 mm (44.3%) vs <5 mm (14.5%). In turn, glenohumeral instability was more common in patients treated with surgery, specifically open surgery, because displaced fractures may not be as easily accessed with arthroscopic techniques. No studies reported concomitant labral repair or capsular plication techniques.

This systematic review was limited by the studies analyzed. All but 1 study⁵ had level IV evidence. Mean (SD) MCMS was 41.8 (8.6). Any MCMS score <54 indicates a poor methodology level, but this scoring system is designed for randomized controlled trials,²³ and there were none in this study. Physical examination findings, such as range of motion, were underreported. In addition, radiographic parameters were not consistently described but rather were determined by the respective authors’ subjective interpretations of malunion, nonunion, and loss of reduction. Publication bias is present in that we excluded non- English language studies and medical conference abstracts and may have omitted potentially eligible studies not discoverable with our search methodology. Performance bias is a factor in any systematic review with multiple surgeons and wide variation in surgical technique.

Conclusion

Greater tuberosity fractures displaced <5 mm may be safely managed nonoperatively, as there are no reports of nonoperatively managed fractures that subsequently required surgery. Nonoperative treatment was initially associated with low patient satisfaction, but only because displaced fractures were conservatively managed in early studies.^5,16 Fractures displaced >5 mm respond well to operative fixation with screws, suture anchors, or transosseous suture tunnels. Stiffness is the most common postoperative complication (<6%), followed by heterotopic ossification, transient neurapraxias, and superficial infection. There are no discernible differences in outcome between open and arthroscopic techniques, but screw fixation may lead to significantly fewer cases of stiffness and reoperation in comparison with suture constructs.

Take-Home Points

• Cellular healing response differs between bony and soft tissue biceps tenodesis.
• Bony tenodesis incites an inflammatory healing response.
• Bony tenodesis healing occurs at the tendon-bone interface.
• Intrasseous bony fixation leads to tendon degeneration within the bone.
• Tendon-to-tendon tenodesis may result in regenerative tendon healing.

The long head of the biceps tendon (LHBT) is a well-established pain generator of the anterior shoulder^1,2 and may be surgically addressed in refractory cases.³ According to a recent study of 44,932 cases, biceps tenodesis rates increased 80% over just 3 years (2008-2011).⁴ Nevertheless, optimal tenodesis location and technique remain controversial. Proximal and distal tenodesis, including numerous soft-tissue and bony techniques, have been described.^5-7 Several studies have focused on the biomechanical strength of various fixation modalities.^8-14 These data highlight the ongoing evolution of our understanding of biceps-labrum complex (BLC) disease.

Over the years, tenodesis location has proved to be an important factor in outcomes.^3,15-20 Several recent studies have elucidated the role of the extra-articular LHBT and the limited capabilities of diagnostic arthroscopy.^15-17,20,21 Taylor and colleagues¹⁷ defined the bicipital tunnel as the extra-articular segment of LHBT and its fibro-osseous enclosure. The tunnel extends from the articular margin through the subpectoral region and can be divided into 3 zones: Zone 1 goes from the articular margin to the inferior margin of the subscapularis, zone 2 goes from the inferior margin of the subscapularis to the proximal margin of the pectoralis major tendon, and zone 3 is the subpectoral region. Zone 2 is often referred to as “no man’s land” for its relative invisibility from arthroscopy above and open exposure below.^17,21 Notably, a recent study reported a 47% prevalence of hidden tunnel lesions in patients with chronic BLC disease symptoms.¹⁸ Other studies have shown that standard proximal tenodesis methods often fail to address LHBT pathology in this area, leading to residual symptoms.^9,22 It is evident that tenodesis location and technique play important roles in patient outcomes. Sanders and colleagues¹⁶ found that the revision rate was significantly higher among patients who underwent biceps tenodesis without release of the bicipital tunnel sheath than among patients who underwent tenodesis with the release. Dr. O’Brien developed an alternative option: soft-tissue tenodesis with transfer of the LHBT to the conjoint tendon within the subdeltoid space.^23,24 This technique addresses intra-articular and extra-articular tunnel disease while mitigating the complications associated with bony tenodesis. Early and midterm studies have shown this to be an effective intervention for chronically symptomatic BLC disease.^25,26

Despite the abundance of literature on tenodesis techniques, no one has histologically evaluated the location-dependent healing and inflammatory responses. We conducted a study to determine the impact of tenodesis location on healing and inflammation in a rat model. We hypothesized that, compared with tendon-to-bone techniques, soft-tissue tenodesis would minimize inflammatory response and optimize healing.

Methods 

The study was approved by the Institutional Animal Care and Use Committee at the Hospital for Special Surgery. 

Animals

Biceps tenodesis was performed at 1 of 3 locations in 36 thirteen-week-old Sprague-Dawley rats (Charles River Laboratories). All rats were prepared for surgery by an experienced veterinary technician. Sedation was induced with isoflurane gas through a nose cone. 

Surgical Procedure

Animals were randomly assigned to 3 different tenodesis groups: tendon-to-bone in the bicipital groove (metaphyseal, M); tendon-to-bone in the subpectoral region (diaphyseal, D); and soft tissue-to-soft tissue transfer to the conjoint tendon (T). A standard deltopectoral approach was used to expose the biceps tendon. The tendon was tagged with a 5-0 polypropylene suture and tenotomized at the level of the bicipital groove (zone 1). All wounds were irrigated and closed with 4-0 nylon suture.

For animals undergoing tendon-to-bone metaphyseal tenodesis, a 0.045-mm Kirschner wire was used to drill bicortically into the intertubercular sulcus. Wire positioning distal to the physeal plate was confirmed with fluoroscopy. A locking stitch of 5-0 polypropylene suture was run along the free edge of the tendon. The tendon was then passed through the bone tunnel in an anterior-to-posterior direction, and the limbs of the suture were tied around the lateral cortex. 

The process was repeated for animals undergoing diaphyseal tenodesis; only the tenodesis location was different. The inferior border of the pectoralis major was identified, and a bicortical tunnel was made in the center of the diaphyseal bone. The tendon was then prepared and tenodesed to bone using the method already described.

In soft-tissue tenodesis, the conjoint tendon was identified and carefully dissected from surrounding tissues. The LHBT was then tenodesed to the attached conjoint tendon with interrupted simple stitches of 5-0 polypropylene suture.

The animals were allowed to bear weight on the operative limb immediately after surgery and without immobilization.

Specimen Harvest and Preparation

Four animals from each group were sacrificed at 6, 12, and 24 weeks. Harvested specimens were fixed in 10% neutral-buffered formalin solution. Bony specimens consisted of the upper half of the humerus and the tenodesed biceps tendon, and soft-tissue specimens consisted of the tenodesed LHBT-conjoint tendon complex. Bony specimens were decalcified in 10% ethylenediaminetetraacetic acid. All specimens were paraffin-embedded and sectioned at 7 microns.

Analysis of Cellularity

Sections were stained with hematoxylin-eosin. Overall cellularity at the tenodesis interface was quantified by averaging the nuclei count within 3 separate standardized ×20 magnification high power fields. Only nucleated cells were included in the cell count. Immunohistochemical staining with tenomodulin (Santa Cruz Laboratories, sc-49324) was performed to characterize the cell population at the interface. Deparaffinized sections underwent antigen retrieval with pronase for 30 minutes at 37°C and were incubated overnight with the anti-tenomodulin goat monoclonal antibody diluted to 1:200 in 1% phosphate-buffered saline. The prepared slides were then counterstained with methyl green. Specimens treated with tenomodulin were evaluated for presence or absence of a positive reaction at the tenodesis interface. 

Analysis of Inflammation

Inflammation at the interface was evaluated with the CD68 macrophage marker (ABcam, ab31630). Deparaffinized sections underwent antigen retrieval with pronase for 30 minutes at 37°C and were incubated overnight with anti-CD68 mouse monoclonal antibodies diluted to 1:200 in 1% phosphate-buffered saline. The prepared slides were then counterstained with neutral red. Inflammation was quantified by averaging the number of reactive cells within 3 separate standardized ×20 magnification high power fields.

Statistical Analysis

Descriptive statistics were calculated for cell and macrophage counts for each group at every time point. Two-way analysis of variance was used to compare the cell and macrophage counts between groups at each time point as well as the count differences within each group between time points. P values were Bonferroni-corrected to account for the multiple comparisons between groups. P < .05 was used to signify statistical significance.

Results

All 36 animals survived to their designated harvest time without complications. Twelve specimens were successfully harvested at 6 weeks and another 12 at 24 weeks. At 12 weeks, tenodesis failure occurred in 1 animal in group D, leaving 11 specimens for analysis.

Cellularity

Within-group analysis revealed a trend of increasing cellularity at 12 weeks followed by a decrease at 24 weeks in all 3 groups (Table 2).

Inflammatory Response 

During specimen processing, 1 group D specimen was severely degraded after pronase treatment, leaving 3 specimens for evaluation. Descriptive statistics for each group are listed in Table 3A.

At 6 weeks, mean CD68 cell count was significantly higher in group M than in group D (P = .011) and group T (P < .001) (Table 3B). Likewise, CD68 count was significantly higher in group D than in group T (P < .001). There were no differences in CD68 counts between the 2 bony tenodesis groups at 12 weeks (P = .486) or 24 weeks (P = .315). Both bony tenodesis groups, however, had persistently higher CD68 counts at 12 weeks when compared with group T (group M, P = .002; group D, P < .001). In these specimens, an inflammatory milieu characterized by a large accumulation of lymphocytes and giant cells was noted at the bone-tendon interface.

Tissue-Specific Staining

At 6 weeks, antigen retrieval resulted in severe degradation of 2 group M specimens, 2 group D specimens, and 1 group T specimen. The most notable tenomodulin reaction occurred in group T at the 6- and 12-week harvests, with the 6-week group having the most robust reaction. There was scant reaction in this group at 24 weeks.

Discussion

In this study, the healing response differed between bony and soft-tissue tenodesis techniques in a rat model. Tendon-to-bone tenodesis, both diaphyseal and metaphyseal, appeared to incite an inflammatory degenerative response, whereas tendon-to-tendon healing occurred in a more quiescent and perhaps even regenerative manner.

The early inflammatory response that occurred in the bony tenodesis groups is not unlike what occurs in fracture healing.²⁷ The reaction was even more robust at 12 weeks, signifying an ongoing inflammatory process. In this context, tendon degeneration may plausibly explain the consistent absence of mature tendon within the tunnels at all 3 time points. Some tendon degeneration may be explained by the vascular damage that occurred during surgery, but this damage was a constant factor in all 3 study groups. Interestingly, group M showed the highest early CD68 counts, consistent with this being the more biologically active region of bone.²⁸

Group T had significantly lower cell and macrophage counts throughout the study period, possibly indicating improved healing—an observation supported by a study in which the impact of macrophage depletion on bone-tendon interface healing was evaluated.²⁹ The authors found that, in suppressing macrophage activity, the morphologic and biomechanical properties at the healing interface were significantly improved.²⁹ These findings are consistent with Dr. O’Brien’s anecdotal experience with patients who previously underwent the biceps transfer; on second-look arthroscopy, there was complete seamless integration of tendon and conjoint tendon (Figure 4). 

Studies have found that the inflammatory process is closely associated with pain, and pain syndromes such as fibromyalgia.^30,31 Persistent inflammation, as seen in our bony tenodesis group, could explain the recalcitrant anterior shoulder pain that often occurs in patients after bony tenodesis of the LHBT.^2,6,19,32 

Studies have also suggested that osteoclasts at the bone-tendon interface—osteoclasts share a cell lineage with macrophages—may contribute to bone loss and tunnel widening.^33,34 Osteoclasts are expected at the bone tunnel, as fracture healing occurs at the bone-tendon interface. These osteoclasts could have contributed to the strong CD68 reaction in our bony tenodesis groups. However, CD68 historically has been described as the classic macrophage marker.³⁵ We specifically selected CD68 for this reason: Macrophages are the primary inflammatory cells involved in early healing and are key to the inflammatory process.³⁶

Results of the tenomodulin analysis suggested 2 different healing processes are occurring in the bony and tendon groups. Tenomodulin is a known tenocyte marker for developing and mature tendon in both rats and humans.^37,38 In our study, only group T had a positive tenomodulin reaction. Notably, the reaction occurred only at 6 and 12 weeks. This finding may indicate that a regenerative healing pattern becomes quiescent by 24 weeks. Indeed, it has been suggested that tenomodulin is a key regulator of tenocyte proliferation and tendon maturation.³⁹

The complete absence of tenomodulin reaction in our bony tenodesis groups in the setting of significant inflammation further supports our theory of tendon degeneration within the tunnel. One potential explanation for this finding may be that as the tendon heals to the surface of the bone, the intra-osseous tendon is no longer load-bearing and is resorbed by the body through an inflammatory response. This finding differs from those in previous studies, which have described viable tendon within the bone tunnel at all time points up to 26 weeks.⁴⁰ More recently, it has been suggested that callus formation at the external cortical tendon-bone interface is critical for healing and mechanical strength.^41,42 In addition, recent studies have found a predominantly fibroblastic healing process at the midtunnel, potentially leading to the formation of loose fibrovascular tissue at the tendon-bone interface.⁴³ These data, in concert with ours, call into question the rationale for performing intra-osseous tenodesis through bone tunnels.

Our study results, if confirmed in humans, will have significant clinical implications. If a similar effect can be confirmed in the human shoulder, one could argue that soft-tissue tenodesis may result in decreased postoperative shoulder pain. In addition, if tendon degeneration does occur within the intramedullary tunnel, surface fixation may be the better, safer alternative. Although older studies reported suboptimal strength with this type of fixation,^8,44 more recent studies have found surface fixation strength equivalent to screw fixation strength.^45,46 Such a shift in the treatment paradigm would obviate the need for violation of the humeral cortex, eliminating potential stress risers associated with screw fixation,⁴⁷ and effectively eliminating the risk of iatrogenic fracture.^48,49 It would be interesting to investigate what occurs histologically at the bone-tendon interface in surface fixation (ie, suture anchors). Would the inflammatory response at the surface be similar to the inflammatory intramedullary healing, or would it be similar to the quieter tendon-tendon healing? Answers to such questions have the potential to streamline the treatment algorithm for patients who require tenodesis.

Study Limitations

Our study had several limitations. First, as this was a basic science study using a rat model, its conclusions can only be extrapolated to humans. Second, given the nonspecific nature of the cellular analysis, we cannot draw any definitive conclusions about the cell population at the bone-tendon interface. For example, although tenomodulin is expressed by tenocytes, it is not an established specific marker for tenocytes and may be expressed by other fibroblastic cells. Still, our results provide insight into the local microenvironment and identify important differences between the tenodesis methods. Similarly, the complete absence of tendon within the bone tunnels suggests that an analysis of osteoclastic activity at the tenodesis interface may have been a valuable addition to the study. This finding, however, was unexpected, and we did not have the foresight to include it in our methods. A third limitation is that our fixation method essentially uses the suspension tenodesis method. This fixation method differs from the common fixation techniques used in the clinical setting. Testing of other fixation constructs would require a larger animal model. Furthermore, in suspension- type constructs, micromotion within the bone tunnel may independently elicit an inflammatory response. Inert suture was used in our fixation in order to reduce the risk of an iatrogenic inflammatory response. Last, it would have been valuable to perform a biomechanical analysis of the strength of each tenodesis construct. This was explored with our institution’s biomechanics team, but specimen size precluded successful analysis.

Conclusion

Our results indicated that, compared with tendon-to-tendon fixation, tendon-to-bone tenodesis produces a significantly greater inflammatory response at the tenodesis interface. An inflammatory milieu in the absence of tendon within the bony tunnel suggests intraosseous tendon degeneration. Tendon-to-tendon tenodesis, on the other hand, seems to limit the inflammatory response. In addition, a robust tenomodulin reaction in the early phases of tendon-to-tendon healing suggests regenerative healing. Our results showed a fundamental difference in the healing response between the 2 tenodesis methods. Further study is needed to evaluate the validity and applicability of our findings to the human patient population. Most important, our results underscore the need for more study to elucidate optimal tenodesis location and encourage orthopedic surgeons to reexamine current clinical practice patterns.

Take-Home Points

• Cellular healing response differs between bony and soft tissue biceps tenodesis.
• Bony tenodesis incites an inflammatory healing response.
• Bony tenodesis healing occurs at the tendon-bone interface.
• Intrasseous bony fixation leads to tendon degeneration within the bone.
• Tendon-to-tendon tenodesis may result in regenerative tendon healing.

The long head of the biceps tendon (LHBT) is a well-established pain generator of the anterior shoulder^1,2 and may be surgically addressed in refractory cases.³ According to a recent study of 44,932 cases, biceps tenodesis rates increased 80% over just 3 years (2008-2011).⁴ Nevertheless, optimal tenodesis location and technique remain controversial. Proximal and distal tenodesis, including numerous soft-tissue and bony techniques, have been described.^5-7 Several studies have focused on the biomechanical strength of various fixation modalities.^8-14 These data highlight the ongoing evolution of our understanding of biceps-labrum complex (BLC) disease.

Over the years, tenodesis location has proved to be an important factor in outcomes.^3,15-20 Several recent studies have elucidated the role of the extra-articular LHBT and the limited capabilities of diagnostic arthroscopy.^15-17,20,21 Taylor and colleagues¹⁷ defined the bicipital tunnel as the extra-articular segment of LHBT and its fibro-osseous enclosure. The tunnel extends from the articular margin through the subpectoral region and can be divided into 3 zones: Zone 1 goes from the articular margin to the inferior margin of the subscapularis, zone 2 goes from the inferior margin of the subscapularis to the proximal margin of the pectoralis major tendon, and zone 3 is the subpectoral region. Zone 2 is often referred to as “no man’s land” for its relative invisibility from arthroscopy above and open exposure below.^17,21 Notably, a recent study reported a 47% prevalence of hidden tunnel lesions in patients with chronic BLC disease symptoms.¹⁸ Other studies have shown that standard proximal tenodesis methods often fail to address LHBT pathology in this area, leading to residual symptoms.^9,22 It is evident that tenodesis location and technique play important roles in patient outcomes. Sanders and colleagues¹⁶ found that the revision rate was significantly higher among patients who underwent biceps tenodesis without release of the bicipital tunnel sheath than among patients who underwent tenodesis with the release. Dr. O’Brien developed an alternative option: soft-tissue tenodesis with transfer of the LHBT to the conjoint tendon within the subdeltoid space.^23,24 This technique addresses intra-articular and extra-articular tunnel disease while mitigating the complications associated with bony tenodesis. Early and midterm studies have shown this to be an effective intervention for chronically symptomatic BLC disease.^25,26

Despite the abundance of literature on tenodesis techniques, no one has histologically evaluated the location-dependent healing and inflammatory responses. We conducted a study to determine the impact of tenodesis location on healing and inflammation in a rat model. We hypothesized that, compared with tendon-to-bone techniques, soft-tissue tenodesis would minimize inflammatory response and optimize healing.

Methods 

The study was approved by the Institutional Animal Care and Use Committee at the Hospital for Special Surgery. 

Animals

Biceps tenodesis was performed at 1 of 3 locations in 36 thirteen-week-old Sprague-Dawley rats (Charles River Laboratories). All rats were prepared for surgery by an experienced veterinary technician. Sedation was induced with isoflurane gas through a nose cone. 

Surgical Procedure

Animals were randomly assigned to 3 different tenodesis groups: tendon-to-bone in the bicipital groove (metaphyseal, M); tendon-to-bone in the subpectoral region (diaphyseal, D); and soft tissue-to-soft tissue transfer to the conjoint tendon (T). A standard deltopectoral approach was used to expose the biceps tendon. The tendon was tagged with a 5-0 polypropylene suture and tenotomized at the level of the bicipital groove (zone 1). All wounds were irrigated and closed with 4-0 nylon suture.

For animals undergoing tendon-to-bone metaphyseal tenodesis, a 0.045-mm Kirschner wire was used to drill bicortically into the intertubercular sulcus. Wire positioning distal to the physeal plate was confirmed with fluoroscopy. A locking stitch of 5-0 polypropylene suture was run along the free edge of the tendon. The tendon was then passed through the bone tunnel in an anterior-to-posterior direction, and the limbs of the suture were tied around the lateral cortex. 

The process was repeated for animals undergoing diaphyseal tenodesis; only the tenodesis location was different. The inferior border of the pectoralis major was identified, and a bicortical tunnel was made in the center of the diaphyseal bone. The tendon was then prepared and tenodesed to bone using the method already described.

In soft-tissue tenodesis, the conjoint tendon was identified and carefully dissected from surrounding tissues. The LHBT was then tenodesed to the attached conjoint tendon with interrupted simple stitches of 5-0 polypropylene suture.

The animals were allowed to bear weight on the operative limb immediately after surgery and without immobilization.

Specimen Harvest and Preparation

Four animals from each group were sacrificed at 6, 12, and 24 weeks. Harvested specimens were fixed in 10% neutral-buffered formalin solution. Bony specimens consisted of the upper half of the humerus and the tenodesed biceps tendon, and soft-tissue specimens consisted of the tenodesed LHBT-conjoint tendon complex. Bony specimens were decalcified in 10% ethylenediaminetetraacetic acid. All specimens were paraffin-embedded and sectioned at 7 microns.

Analysis of Cellularity

Sections were stained with hematoxylin-eosin. Overall cellularity at the tenodesis interface was quantified by averaging the nuclei count within 3 separate standardized ×20 magnification high power fields. Only nucleated cells were included in the cell count. Immunohistochemical staining with tenomodulin (Santa Cruz Laboratories, sc-49324) was performed to characterize the cell population at the interface. Deparaffinized sections underwent antigen retrieval with pronase for 30 minutes at 37°C and were incubated overnight with the anti-tenomodulin goat monoclonal antibody diluted to 1:200 in 1% phosphate-buffered saline. The prepared slides were then counterstained with methyl green. Specimens treated with tenomodulin were evaluated for presence or absence of a positive reaction at the tenodesis interface. 

Analysis of Inflammation

Inflammation at the interface was evaluated with the CD68 macrophage marker (ABcam, ab31630). Deparaffinized sections underwent antigen retrieval with pronase for 30 minutes at 37°C and were incubated overnight with anti-CD68 mouse monoclonal antibodies diluted to 1:200 in 1% phosphate-buffered saline. The prepared slides were then counterstained with neutral red. Inflammation was quantified by averaging the number of reactive cells within 3 separate standardized ×20 magnification high power fields.

Statistical Analysis

Descriptive statistics were calculated for cell and macrophage counts for each group at every time point. Two-way analysis of variance was used to compare the cell and macrophage counts between groups at each time point as well as the count differences within each group between time points. P values were Bonferroni-corrected to account for the multiple comparisons between groups. P < .05 was used to signify statistical significance.

Results

All 36 animals survived to their designated harvest time without complications. Twelve specimens were successfully harvested at 6 weeks and another 12 at 24 weeks. At 12 weeks, tenodesis failure occurred in 1 animal in group D, leaving 11 specimens for analysis.

Cellularity

Within-group analysis revealed a trend of increasing cellularity at 12 weeks followed by a decrease at 24 weeks in all 3 groups (Table 2).

Inflammatory Response 

During specimen processing, 1 group D specimen was severely degraded after pronase treatment, leaving 3 specimens for evaluation. Descriptive statistics for each group are listed in Table 3A.

At 6 weeks, mean CD68 cell count was significantly higher in group M than in group D (P = .011) and group T (P < .001) (Table 3B). Likewise, CD68 count was significantly higher in group D than in group T (P < .001). There were no differences in CD68 counts between the 2 bony tenodesis groups at 12 weeks (P = .486) or 24 weeks (P = .315). Both bony tenodesis groups, however, had persistently higher CD68 counts at 12 weeks when compared with group T (group M, P = .002; group D, P < .001). In these specimens, an inflammatory milieu characterized by a large accumulation of lymphocytes and giant cells was noted at the bone-tendon interface.

Tissue-Specific Staining

At 6 weeks, antigen retrieval resulted in severe degradation of 2 group M specimens, 2 group D specimens, and 1 group T specimen. The most notable tenomodulin reaction occurred in group T at the 6- and 12-week harvests, with the 6-week group having the most robust reaction. There was scant reaction in this group at 24 weeks.

Discussion

In this study, the healing response differed between bony and soft-tissue tenodesis techniques in a rat model. Tendon-to-bone tenodesis, both diaphyseal and metaphyseal, appeared to incite an inflammatory degenerative response, whereas tendon-to-tendon healing occurred in a more quiescent and perhaps even regenerative manner.

The early inflammatory response that occurred in the bony tenodesis groups is not unlike what occurs in fracture healing.²⁷ The reaction was even more robust at 12 weeks, signifying an ongoing inflammatory process. In this context, tendon degeneration may plausibly explain the consistent absence of mature tendon within the tunnels at all 3 time points. Some tendon degeneration may be explained by the vascular damage that occurred during surgery, but this damage was a constant factor in all 3 study groups. Interestingly, group M showed the highest early CD68 counts, consistent with this being the more biologically active region of bone.²⁸

Group T had significantly lower cell and macrophage counts throughout the study period, possibly indicating improved healing—an observation supported by a study in which the impact of macrophage depletion on bone-tendon interface healing was evaluated.²⁹ The authors found that, in suppressing macrophage activity, the morphologic and biomechanical properties at the healing interface were significantly improved.²⁹ These findings are consistent with Dr. O’Brien’s anecdotal experience with patients who previously underwent the biceps transfer; on second-look arthroscopy, there was complete seamless integration of tendon and conjoint tendon (Figure 4). 

Studies have found that the inflammatory process is closely associated with pain, and pain syndromes such as fibromyalgia.^30,31 Persistent inflammation, as seen in our bony tenodesis group, could explain the recalcitrant anterior shoulder pain that often occurs in patients after bony tenodesis of the LHBT.^2,6,19,32 

Studies have also suggested that osteoclasts at the bone-tendon interface—osteoclasts share a cell lineage with macrophages—may contribute to bone loss and tunnel widening.^33,34 Osteoclasts are expected at the bone tunnel, as fracture healing occurs at the bone-tendon interface. These osteoclasts could have contributed to the strong CD68 reaction in our bony tenodesis groups. However, CD68 historically has been described as the classic macrophage marker.³⁵ We specifically selected CD68 for this reason: Macrophages are the primary inflammatory cells involved in early healing and are key to the inflammatory process.³⁶

Results of the tenomodulin analysis suggested 2 different healing processes are occurring in the bony and tendon groups. Tenomodulin is a known tenocyte marker for developing and mature tendon in both rats and humans.^37,38 In our study, only group T had a positive tenomodulin reaction. Notably, the reaction occurred only at 6 and 12 weeks. This finding may indicate that a regenerative healing pattern becomes quiescent by 24 weeks. Indeed, it has been suggested that tenomodulin is a key regulator of tenocyte proliferation and tendon maturation.³⁹

The complete absence of tenomodulin reaction in our bony tenodesis groups in the setting of significant inflammation further supports our theory of tendon degeneration within the tunnel. One potential explanation for this finding may be that as the tendon heals to the surface of the bone, the intra-osseous tendon is no longer load-bearing and is resorbed by the body through an inflammatory response. This finding differs from those in previous studies, which have described viable tendon within the bone tunnel at all time points up to 26 weeks.⁴⁰ More recently, it has been suggested that callus formation at the external cortical tendon-bone interface is critical for healing and mechanical strength.^41,42 In addition, recent studies have found a predominantly fibroblastic healing process at the midtunnel, potentially leading to the formation of loose fibrovascular tissue at the tendon-bone interface.⁴³ These data, in concert with ours, call into question the rationale for performing intra-osseous tenodesis through bone tunnels.

Our study results, if confirmed in humans, will have significant clinical implications. If a similar effect can be confirmed in the human shoulder, one could argue that soft-tissue tenodesis may result in decreased postoperative shoulder pain. In addition, if tendon degeneration does occur within the intramedullary tunnel, surface fixation may be the better, safer alternative. Although older studies reported suboptimal strength with this type of fixation,^8,44 more recent studies have found surface fixation strength equivalent to screw fixation strength.^45,46 Such a shift in the treatment paradigm would obviate the need for violation of the humeral cortex, eliminating potential stress risers associated with screw fixation,⁴⁷ and effectively eliminating the risk of iatrogenic fracture.^48,49 It would be interesting to investigate what occurs histologically at the bone-tendon interface in surface fixation (ie, suture anchors). Would the inflammatory response at the surface be similar to the inflammatory intramedullary healing, or would it be similar to the quieter tendon-tendon healing? Answers to such questions have the potential to streamline the treatment algorithm for patients who require tenodesis.

Study Limitations

Our study had several limitations. First, as this was a basic science study using a rat model, its conclusions can only be extrapolated to humans. Second, given the nonspecific nature of the cellular analysis, we cannot draw any definitive conclusions about the cell population at the bone-tendon interface. For example, although tenomodulin is expressed by tenocytes, it is not an established specific marker for tenocytes and may be expressed by other fibroblastic cells. Still, our results provide insight into the local microenvironment and identify important differences between the tenodesis methods. Similarly, the complete absence of tendon within the bone tunnels suggests that an analysis of osteoclastic activity at the tenodesis interface may have been a valuable addition to the study. This finding, however, was unexpected, and we did not have the foresight to include it in our methods. A third limitation is that our fixation method essentially uses the suspension tenodesis method. This fixation method differs from the common fixation techniques used in the clinical setting. Testing of other fixation constructs would require a larger animal model. Furthermore, in suspension- type constructs, micromotion within the bone tunnel may independently elicit an inflammatory response. Inert suture was used in our fixation in order to reduce the risk of an iatrogenic inflammatory response. Last, it would have been valuable to perform a biomechanical analysis of the strength of each tenodesis construct. This was explored with our institution’s biomechanics team, but specimen size precluded successful analysis.

Conclusion

Our results indicated that, compared with tendon-to-tendon fixation, tendon-to-bone tenodesis produces a significantly greater inflammatory response at the tenodesis interface. An inflammatory milieu in the absence of tendon within the bony tunnel suggests intraosseous tendon degeneration. Tendon-to-tendon tenodesis, on the other hand, seems to limit the inflammatory response. In addition, a robust tenomodulin reaction in the early phases of tendon-to-tendon healing suggests regenerative healing. Our results showed a fundamental difference in the healing response between the 2 tenodesis methods. Further study is needed to evaluate the validity and applicability of our findings to the human patient population. Most important, our results underscore the need for more study to elucidate optimal tenodesis location and encourage orthopedic surgeons to reexamine current clinical practice patterns.

Take-Home Points

• Cellular healing response differs between bony and soft tissue biceps tenodesis.
• Bony tenodesis incites an inflammatory healing response.
• Bony tenodesis healing occurs at the tendon-bone interface.
• Intrasseous bony fixation leads to tendon degeneration within the bone.
• Tendon-to-tendon tenodesis may result in regenerative tendon healing.

The long head of the biceps tendon (LHBT) is a well-established pain generator of the anterior shoulder^1,2 and may be surgically addressed in refractory cases.³ According to a recent study of 44,932 cases, biceps tenodesis rates increased 80% over just 3 years (2008-2011).⁴ Nevertheless, optimal tenodesis location and technique remain controversial. Proximal and distal tenodesis, including numerous soft-tissue and bony techniques, have been described.^5-7 Several studies have focused on the biomechanical strength of various fixation modalities.^8-14 These data highlight the ongoing evolution of our understanding of biceps-labrum complex (BLC) disease.

Over the years, tenodesis location has proved to be an important factor in outcomes.^3,15-20 Several recent studies have elucidated the role of the extra-articular LHBT and the limited capabilities of diagnostic arthroscopy.^15-17,20,21 Taylor and colleagues¹⁷ defined the bicipital tunnel as the extra-articular segment of LHBT and its fibro-osseous enclosure. The tunnel extends from the articular margin through the subpectoral region and can be divided into 3 zones: Zone 1 goes from the articular margin to the inferior margin of the subscapularis, zone 2 goes from the inferior margin of the subscapularis to the proximal margin of the pectoralis major tendon, and zone 3 is the subpectoral region. Zone 2 is often referred to as “no man’s land” for its relative invisibility from arthroscopy above and open exposure below.^17,21 Notably, a recent study reported a 47% prevalence of hidden tunnel lesions in patients with chronic BLC disease symptoms.¹⁸ Other studies have shown that standard proximal tenodesis methods often fail to address LHBT pathology in this area, leading to residual symptoms.^9,22 It is evident that tenodesis location and technique play important roles in patient outcomes. Sanders and colleagues¹⁶ found that the revision rate was significantly higher among patients who underwent biceps tenodesis without release of the bicipital tunnel sheath than among patients who underwent tenodesis with the release. Dr. O’Brien developed an alternative option: soft-tissue tenodesis with transfer of the LHBT to the conjoint tendon within the subdeltoid space.^23,24 This technique addresses intra-articular and extra-articular tunnel disease while mitigating the complications associated with bony tenodesis. Early and midterm studies have shown this to be an effective intervention for chronically symptomatic BLC disease.^25,26

Despite the abundance of literature on tenodesis techniques, no one has histologically evaluated the location-dependent healing and inflammatory responses. We conducted a study to determine the impact of tenodesis location on healing and inflammation in a rat model. We hypothesized that, compared with tendon-to-bone techniques, soft-tissue tenodesis would minimize inflammatory response and optimize healing.

Methods 

The study was approved by the Institutional Animal Care and Use Committee at the Hospital for Special Surgery. 

Animals

Biceps tenodesis was performed at 1 of 3 locations in 36 thirteen-week-old Sprague-Dawley rats (Charles River Laboratories). All rats were prepared for surgery by an experienced veterinary technician. Sedation was induced with isoflurane gas through a nose cone. 

Surgical Procedure

Animals were randomly assigned to 3 different tenodesis groups: tendon-to-bone in the bicipital groove (metaphyseal, M); tendon-to-bone in the subpectoral region (diaphyseal, D); and soft tissue-to-soft tissue transfer to the conjoint tendon (T). A standard deltopectoral approach was used to expose the biceps tendon. The tendon was tagged with a 5-0 polypropylene suture and tenotomized at the level of the bicipital groove (zone 1). All wounds were irrigated and closed with 4-0 nylon suture.

For animals undergoing tendon-to-bone metaphyseal tenodesis, a 0.045-mm Kirschner wire was used to drill bicortically into the intertubercular sulcus. Wire positioning distal to the physeal plate was confirmed with fluoroscopy. A locking stitch of 5-0 polypropylene suture was run along the free edge of the tendon. The tendon was then passed through the bone tunnel in an anterior-to-posterior direction, and the limbs of the suture were tied around the lateral cortex. 

The process was repeated for animals undergoing diaphyseal tenodesis; only the tenodesis location was different. The inferior border of the pectoralis major was identified, and a bicortical tunnel was made in the center of the diaphyseal bone. The tendon was then prepared and tenodesed to bone using the method already described.

In soft-tissue tenodesis, the conjoint tendon was identified and carefully dissected from surrounding tissues. The LHBT was then tenodesed to the attached conjoint tendon with interrupted simple stitches of 5-0 polypropylene suture.

The animals were allowed to bear weight on the operative limb immediately after surgery and without immobilization.

Specimen Harvest and Preparation

Four animals from each group were sacrificed at 6, 12, and 24 weeks. Harvested specimens were fixed in 10% neutral-buffered formalin solution. Bony specimens consisted of the upper half of the humerus and the tenodesed biceps tendon, and soft-tissue specimens consisted of the tenodesed LHBT-conjoint tendon complex. Bony specimens were decalcified in 10% ethylenediaminetetraacetic acid. All specimens were paraffin-embedded and sectioned at 7 microns.

Analysis of Cellularity

Sections were stained with hematoxylin-eosin. Overall cellularity at the tenodesis interface was quantified by averaging the nuclei count within 3 separate standardized ×20 magnification high power fields. Only nucleated cells were included in the cell count. Immunohistochemical staining with tenomodulin (Santa Cruz Laboratories, sc-49324) was performed to characterize the cell population at the interface. Deparaffinized sections underwent antigen retrieval with pronase for 30 minutes at 37°C and were incubated overnight with the anti-tenomodulin goat monoclonal antibody diluted to 1:200 in 1% phosphate-buffered saline. The prepared slides were then counterstained with methyl green. Specimens treated with tenomodulin were evaluated for presence or absence of a positive reaction at the tenodesis interface. 

Analysis of Inflammation

Inflammation at the interface was evaluated with the CD68 macrophage marker (ABcam, ab31630). Deparaffinized sections underwent antigen retrieval with pronase for 30 minutes at 37°C and were incubated overnight with anti-CD68 mouse monoclonal antibodies diluted to 1:200 in 1% phosphate-buffered saline. The prepared slides were then counterstained with neutral red. Inflammation was quantified by averaging the number of reactive cells within 3 separate standardized ×20 magnification high power fields.

Statistical Analysis

Descriptive statistics were calculated for cell and macrophage counts for each group at every time point. Two-way analysis of variance was used to compare the cell and macrophage counts between groups at each time point as well as the count differences within each group between time points. P values were Bonferroni-corrected to account for the multiple comparisons between groups. P < .05 was used to signify statistical significance.

Results

All 36 animals survived to their designated harvest time without complications. Twelve specimens were successfully harvested at 6 weeks and another 12 at 24 weeks. At 12 weeks, tenodesis failure occurred in 1 animal in group D, leaving 11 specimens for analysis.

Cellularity

Within-group analysis revealed a trend of increasing cellularity at 12 weeks followed by a decrease at 24 weeks in all 3 groups (Table 2).

Inflammatory Response 

During specimen processing, 1 group D specimen was severely degraded after pronase treatment, leaving 3 specimens for evaluation. Descriptive statistics for each group are listed in Table 3A.

At 6 weeks, mean CD68 cell count was significantly higher in group M than in group D (P = .011) and group T (P < .001) (Table 3B). Likewise, CD68 count was significantly higher in group D than in group T (P < .001). There were no differences in CD68 counts between the 2 bony tenodesis groups at 12 weeks (P = .486) or 24 weeks (P = .315). Both bony tenodesis groups, however, had persistently higher CD68 counts at 12 weeks when compared with group T (group M, P = .002; group D, P < .001). In these specimens, an inflammatory milieu characterized by a large accumulation of lymphocytes and giant cells was noted at the bone-tendon interface.

Tissue-Specific Staining

At 6 weeks, antigen retrieval resulted in severe degradation of 2 group M specimens, 2 group D specimens, and 1 group T specimen. The most notable tenomodulin reaction occurred in group T at the 6- and 12-week harvests, with the 6-week group having the most robust reaction. There was scant reaction in this group at 24 weeks.

Discussion

In this study, the healing response differed between bony and soft-tissue tenodesis techniques in a rat model. Tendon-to-bone tenodesis, both diaphyseal and metaphyseal, appeared to incite an inflammatory degenerative response, whereas tendon-to-tendon healing occurred in a more quiescent and perhaps even regenerative manner.

The early inflammatory response that occurred in the bony tenodesis groups is not unlike what occurs in fracture healing.²⁷ The reaction was even more robust at 12 weeks, signifying an ongoing inflammatory process. In this context, tendon degeneration may plausibly explain the consistent absence of mature tendon within the tunnels at all 3 time points. Some tendon degeneration may be explained by the vascular damage that occurred during surgery, but this damage was a constant factor in all 3 study groups. Interestingly, group M showed the highest early CD68 counts, consistent with this being the more biologically active region of bone.²⁸

Group T had significantly lower cell and macrophage counts throughout the study period, possibly indicating improved healing—an observation supported by a study in which the impact of macrophage depletion on bone-tendon interface healing was evaluated.²⁹ The authors found that, in suppressing macrophage activity, the morphologic and biomechanical properties at the healing interface were significantly improved.²⁹ These findings are consistent with Dr. O’Brien’s anecdotal experience with patients who previously underwent the biceps transfer; on second-look arthroscopy, there was complete seamless integration of tendon and conjoint tendon (Figure 4). 

Studies have found that the inflammatory process is closely associated with pain, and pain syndromes such as fibromyalgia.^30,31 Persistent inflammation, as seen in our bony tenodesis group, could explain the recalcitrant anterior shoulder pain that often occurs in patients after bony tenodesis of the LHBT.^2,6,19,32 

Studies have also suggested that osteoclasts at the bone-tendon interface—osteoclasts share a cell lineage with macrophages—may contribute to bone loss and tunnel widening.^33,34 Osteoclasts are expected at the bone tunnel, as fracture healing occurs at the bone-tendon interface. These osteoclasts could have contributed to the strong CD68 reaction in our bony tenodesis groups. However, CD68 historically has been described as the classic macrophage marker.³⁵ We specifically selected CD68 for this reason: Macrophages are the primary inflammatory cells involved in early healing and are key to the inflammatory process.³⁶

Results of the tenomodulin analysis suggested 2 different healing processes are occurring in the bony and tendon groups. Tenomodulin is a known tenocyte marker for developing and mature tendon in both rats and humans.^37,38 In our study, only group T had a positive tenomodulin reaction. Notably, the reaction occurred only at 6 and 12 weeks. This finding may indicate that a regenerative healing pattern becomes quiescent by 24 weeks. Indeed, it has been suggested that tenomodulin is a key regulator of tenocyte proliferation and tendon maturation.³⁹

The complete absence of tenomodulin reaction in our bony tenodesis groups in the setting of significant inflammation further supports our theory of tendon degeneration within the tunnel. One potential explanation for this finding may be that as the tendon heals to the surface of the bone, the intra-osseous tendon is no longer load-bearing and is resorbed by the body through an inflammatory response. This finding differs from those in previous studies, which have described viable tendon within the bone tunnel at all time points up to 26 weeks.⁴⁰ More recently, it has been suggested that callus formation at the external cortical tendon-bone interface is critical for healing and mechanical strength.^41,42 In addition, recent studies have found a predominantly fibroblastic healing process at the midtunnel, potentially leading to the formation of loose fibrovascular tissue at the tendon-bone interface.⁴³ These data, in concert with ours, call into question the rationale for performing intra-osseous tenodesis through bone tunnels.

Our study results, if confirmed in humans, will have significant clinical implications. If a similar effect can be confirmed in the human shoulder, one could argue that soft-tissue tenodesis may result in decreased postoperative shoulder pain. In addition, if tendon degeneration does occur within the intramedullary tunnel, surface fixation may be the better, safer alternative. Although older studies reported suboptimal strength with this type of fixation,^8,44 more recent studies have found surface fixation strength equivalent to screw fixation strength.^45,46 Such a shift in the treatment paradigm would obviate the need for violation of the humeral cortex, eliminating potential stress risers associated with screw fixation,⁴⁷ and effectively eliminating the risk of iatrogenic fracture.^48,49 It would be interesting to investigate what occurs histologically at the bone-tendon interface in surface fixation (ie, suture anchors). Would the inflammatory response at the surface be similar to the inflammatory intramedullary healing, or would it be similar to the quieter tendon-tendon healing? Answers to such questions have the potential to streamline the treatment algorithm for patients who require tenodesis.

Study Limitations

Our study had several limitations. First, as this was a basic science study using a rat model, its conclusions can only be extrapolated to humans. Second, given the nonspecific nature of the cellular analysis, we cannot draw any definitive conclusions about the cell population at the bone-tendon interface. For example, although tenomodulin is expressed by tenocytes, it is not an established specific marker for tenocytes and may be expressed by other fibroblastic cells. Still, our results provide insight into the local microenvironment and identify important differences between the tenodesis methods. Similarly, the complete absence of tendon within the bone tunnels suggests that an analysis of osteoclastic activity at the tenodesis interface may have been a valuable addition to the study. This finding, however, was unexpected, and we did not have the foresight to include it in our methods. A third limitation is that our fixation method essentially uses the suspension tenodesis method. This fixation method differs from the common fixation techniques used in the clinical setting. Testing of other fixation constructs would require a larger animal model. Furthermore, in suspension- type constructs, micromotion within the bone tunnel may independently elicit an inflammatory response. Inert suture was used in our fixation in order to reduce the risk of an iatrogenic inflammatory response. Last, it would have been valuable to perform a biomechanical analysis of the strength of each tenodesis construct. This was explored with our institution’s biomechanics team, but specimen size precluded successful analysis.

Conclusion

Our results indicated that, compared with tendon-to-tendon fixation, tendon-to-bone tenodesis produces a significantly greater inflammatory response at the tenodesis interface. An inflammatory milieu in the absence of tendon within the bony tunnel suggests intraosseous tendon degeneration. Tendon-to-tendon tenodesis, on the other hand, seems to limit the inflammatory response. In addition, a robust tenomodulin reaction in the early phases of tendon-to-tendon healing suggests regenerative healing. Our results showed a fundamental difference in the healing response between the 2 tenodesis methods. Further study is needed to evaluate the validity and applicability of our findings to the human patient population. Most important, our results underscore the need for more study to elucidate optimal tenodesis location and encourage orthopedic surgeons to reexamine current clinical practice patterns.

SAN DIEGO – Between 1980 and 2016, women with RA had a higher rate of small-joint orthopedic surgery procedures than did men, but the rate of small-joint procedures is declining for both sexes. However, no differences in rates of large-joint procedures between sexes were observed during the same time period.

Those are key findings from a retrospective study which set out to determine if there are sex differences in the incidence and trends of large- versus small-joint surgery rates in rheumatoid arthritis over time. “Why is orthopedic surgery important to rheumatology? The main reason is because it’s a surrogate for failed medical management,” lead study author Michael D. Richter, MD, said at the annual meeting of the American College of Rheumatology.

[email protected]

SAN DIEGO – Between 1980 and 2016, women with RA had a higher rate of small-joint orthopedic surgery procedures than did men, but the rate of small-joint procedures is declining for both sexes. However, no differences in rates of large-joint procedures between sexes were observed during the same time period.

Those are key findings from a retrospective study which set out to determine if there are sex differences in the incidence and trends of large- versus small-joint surgery rates in rheumatoid arthritis over time. “Why is orthopedic surgery important to rheumatology? The main reason is because it’s a surrogate for failed medical management,” lead study author Michael D. Richter, MD, said at the annual meeting of the American College of Rheumatology.

[email protected]

SAN DIEGO – Between 1980 and 2016, women with RA had a higher rate of small-joint orthopedic surgery procedures than did men, but the rate of small-joint procedures is declining for both sexes. However, no differences in rates of large-joint procedures between sexes were observed during the same time period.

Those are key findings from a retrospective study which set out to determine if there are sex differences in the incidence and trends of large- versus small-joint surgery rates in rheumatoid arthritis over time. “Why is orthopedic surgery important to rheumatology? The main reason is because it’s a surrogate for failed medical management,” lead study author Michael D. Richter, MD, said at the annual meeting of the American College of Rheumatology.

[email protected]

Take-Home Points

• Shared decision-making tools, such as predictive models, can help empower the patient to make decisions for or against surgery equipped with more information about the expected outcome.
• There is a role for preoperative collection of PROMs in the clinical decision-making process.
• Mental health state, as reported by the VR-12 MCS, is a significant predictor of postoperative pain and function as reported by the VAS pain and ASES function scores.
• A significant portion of the predictive ability of this model comes from the fact that at 1-year postoperatively, patients receiving a rTSA will on average have a 3.8 point lower on ASES function score than those receiving a TSA (P < .001, ω²=.083).
• Future studies to discern the role of different modalities to improve a patient’s emotional health preoperatively will be beneficial as the healthcare industry trends toward value based medicine collecting PROMs as part of reimbursement schemes.

Over the past few decades, decisions regarding patients’ care have gradually transitioned from a paternalistic model to a more cooperative exchange between patient and physician. Shared decision-making provides patients a measure of autonomy in making choices for their health and their future. Patient participation may mitigate uncertainty and discomfort during selection of a course of treatment, which may lead to increased satisfaction levels after surgery.¹ Moreover, shared decision-making may help patients better manage postoperative expectations through evidenced-based discussions of preoperative health levels and their corresponding outcomes. Patient-reported outcome measures (PROMs) use clinically sensitive and specific metrics to evaluate a patient’s self-reported pain, functional ability, and mental state.² These metrics are useful in setting patient expectations for potential outcomes of treatment options. Use of evidence-based clinical decision-making tools, such as PROM-based predictive models, can facilitate a collaborative decision-making environment for patient and physician. Given the present cost-containment era, and the need for preoperative metrics that can assist in predictive analysis of postoperative improvement, models are clearly valuable.

In attempts to help patients set well-informed and reasonable expectations, physicians have turned to PROMs to facilitate preoperative evidence-based discussions. Although PROMs have been in use for almost 30 years, only recently have they been used to create tools that can aid quantitatively in the surgical decision-making process.^2-6 Combining physical examination findings, imaging studies, comorbidities, and quantitative tools, such as this model, may enhance patients’ understanding of their preoperative condition and expected prognosis and thereby guide their surgical decisions.

We conducted a study to determine whether certain preoperative PROMs can predict 1-year postoperative visual analog scale (VAS) pain scores and American Shoulder and Elbow Surgeons (ASES) Function scores in total shoulder arthroplasty (TSA) and reverse TSA (rTSA). We hypothesized that preoperative mental health status as captured by Veterans RAND 12-Item Health Survey (VR-12) mental health component summary (MCS) score and preoperative VAS pain score would predict both VAS pain score and ASES Function score 1 year after surgery. Specifically, we hypothesized that a higher preoperative VR-12 MCS score would predict less pain and better function 1 year after surgery and that a higher preoperative VAS pain score would predict more pain and worse function 1 year after surgery.

Methods

This study was approved by the Institutional Review Board of Partners Healthcare. The study used the Surgical Outcome System (Arthrex), a comprehensive prospective database that stores preoperative and 1-year postoperative patient demographics and TSA-PROM data. Surveys are emailed to all enrolled patients before surgery and 1 year after surgery. As indicated by the Institutional Review Boards of all participating institutions, patients in the Surgical Outcome System have to sign a consent form to permit use of their responses in research.

The database includes patient data from 42 orthopedic surgeons across the United States. All primary TSAs and primary rTSAs in the database were included in this study, regardless of arthroplasty indication. Revisions were excluded. Also excluded were cases in which the 1-year postoperative questionnaire was not completed. Of the 1681 patients eligible for 1-year follow-up, 1225 (73%) completed the 1-year postoperative questionnaire. PROMs used in the study were VAS pain score, ASES Function score, VR-12 MCS score, and Single Assessment Numerical Evaluation (SANE). Unfortunately, not all surgeons use every measure in the 1-year postoperative questionnaire set. Thus, in our complete models, total number of observations was 1004 for modeling 1-year postoperative VAS pain scores and 986 for modeling 1-year postoperative ASES Function scores. 

Metrics

On VAS, pain is rated from 0 (no pain) to 10 (pain as bad as it can be). Tashjian and colleagues⁷ estimated that the minimal clinically important difference (MCID) for postoperative VAS pain scores was 1.4 in a cohort of 326 patients who had TSA, rTSA, or shoulder hemiarthroplasty. ASES Function score is scaled from 0 to 30, with 30 representing best function.⁸ Wong and colleagues⁹ identified an MCID of 6.5 for ASES Function scores in a cohort of 107 patients who had TSA or rTSA. SANE ratings range from 0% to 100%, with 100% indicating the patient’s shoulder was totally “normal.”10 VR-12 MCS scores appear on a logarithmic scale, with higher numbers representing better mental health. The population mean estimate for VR-12 MCS scores is 50.1 (SD, 11.49; overall possible range, –2.47 to 76.1).11 Our patient population’s scores ranged from 12.5 to 73.8.

Statistical Analysis

Simple bivariate and multivariate linear regressions were performed to evaluate the predictive value of each of the outlined PROMs. Our complete model controls for patient sex, age, and type of arthroplasty. Categorical variables were dummy-coded. Both 1-year postoperative VAS pain score and 1-year postoperative ASES Function score were investigated as dependent variables. Regression coefficients and P and ω² values are reported. Omega square represents how much of the variance in an outcome variable a model explains, like R², and ω² values can also be calculated for individual factors to see how much variance a given factor accounts for. For a simple relative risk calculation, we divided our cohort into 3 equal-sized groups based on preoperative VR-12 MCS scores and compared the risk that patients with scores in the top third (better mental health) would end up below certain ASES Total scores with the risk of patients with scores in the bottom third (worse mental health). All statistical analyses were performed with Stata (StataCorp).

Results

Table 1 lists summary statistics for the population used in these models.

Predicting VAS Pain Score (Table 2)

Preoperative VAS pain score and VR-12 MCS score both predicted 1-year postoperative VAS pain score (P < .001). Preoperative ASES Function score did not predict pain 1 year after surgery. By contrast, higher preoperative VAS pain scores were associated with higher VAS pain scores 1 year after surgery. Higher preoperative VR-12 MCS scores were significantly associated with lower VAS pain scores 1 year after surgery, indicating that better preoperative mental health is significantly associated with better self-reported outcomes in terms of pain 1 year after surgery. These associations remained statistically significant when controlling for age at time of surgery, sex, and type of arthroplasty.

Preoperative VR-12 MCS score was more predictive of 1-year postoperative VAS pain score than preoperative VAS pain score was. In other words, preoperative VR-12 MCS score accounted for more variability in outcome for 1-year postoperative VAS pain score (2.4%; ω² = .023) than preoperative VAS pain score did (1.6%; ω² = .015). 

Predicting ASES Function Score (Table 3)

By contrast, preoperative VAS pain score did not predict 1-year postoperative ASES Function score. Preoperative ASES Function and VR-12 MCS scores both predicted 1-year postoperative ASES Function score (P < .001). Higher preoperative ASES Function scores were associated with higher 1-year postoperative ASES Function scores. In other words, reporting better shoulder function before surgery was associated with reporting better shoulder function after surgery.

An example gives a sense of the effect size associated with the coefficient for preoperative ASES Function score. Our model predicts that, compared with a patient who reports 5 points lower on preoperative ASES Function (which ranges from 0-30), a patient who reports 5 points higher will report on average about 1 point higher on 1-year postoperative ASES Function. As in the model for postoperative pain, these associations with preoperative function and mental health scores held when controlling for age, sex, and type of arthroplasty. 

As in the postoperative pain model, preoperative VR-12 MCS score was more predictive of 1-year postoperative ASES Function score than preoperative ASES Function score was. Preoperative VR-12 MCS score accounted for more of the variation that our model predicts (ω² = .029) than preoperative ASES Function score did (ω² = .020). We compared the risk that patients with high preoperative VR-12 MCS scores (top third of cohort) would end up with ASES Total scores below 70, below 80, or below 90 with the risk of patients with low preoperative VR-12 MCS scores (bottom third). Results appear in Table 4.

A significant part of the predictive ability of our model for postoperative ASES Function scores stems from the fact that a patient who undergoes rTSA (vs TSA) is predicted to have an ASES Function score 3.8 points lower 1 year after surgery (P < .001, ω² = .083). With type of arthroplasty controlled for, female sex is associated with an ASES Function score 1.6 points lower 1 year after surgery (P < .001, ω² = .016).

Preoperative SANE score did not predict 1-year postoperative VAS pain score or ASES Function score. In addition, when our complete model was run with 1-year postoperative SANE score as the dependent variable, preoperative SANE score did not predict 1-year postoperative SANE score. Our data provide no supporting evidence for the use of SANE scores for predictive modeling for shoulder arthroplasty.

Discussion

We prospectively gathered data to determine which factors would predict patient subjective outcomes of primary TSA and primary rTSA. We hypothesized that preoperative VR-12 MCS scores and preoperative VAS pain scores would predict postoperative pain and function as measured with those PROMs. Second, we hypothesized that better preoperative mental health (as measured with VR-12 MCS scores) would predict lower postoperative pain (VAS pain scores) and better postoperative function (ASES Function scores). Third, we hypothesized that higher preoperative pain (VAS pain scores) would correlate with higher postoperative pain (VAS pain scores) and worse postoperative function (ASES Function scores).

Our main goal is to provide patients and surgeons with a predictive model that generates insights into what patients can expect after surgery. This model is not intended to be a screening tool for operative indications, but a clinical tool for helping set expectations.

Our results showed that patients with more pain before surgery were more likely to have more pain 1 year after surgery—confirming the hypothesized relationship between pain before and after surgery. Contrary to the hypothesis, however, degree of pain before surgery was not associated with function 1 year after surgery. Our mental health hypothesis was confirmed: Patients with better preoperative mental health scores had on average less pain and better function 1 year after surgery. Not surprisingly, our model demonstrated that patients with better self-reported function before surgery had better self-reported function after surgery. Patient-reported function before surgery did not significantly affect how much pain the patient had 1 year after surgery. Although we did not hypothesize about the role of function in predicting 1-year outcomes, function is a significant factor to be considered when setting patient expectations regarding shoulder arthroplasty outcomes (Table 5).

Although the effect sizes of each analyzed factor are small, together our models for 1-year postoperative pain and function provide significant insight into patients’ likely outcomes 1 year after TSA and rTSA.

Many studies have found that mental health correlated with pain and function during recovery from orthopedic trauma.^12-18 For example, Wylie and colleagues¹⁹ found that preoperative mental health, as measured with the 36-Item Short Form Health Survey (SF-36) MCS score, predicted patient-reported pain and function in the setting of rotator cuff injury, regardless of treatment type (operative, nonoperative). Others have found that mental health may play a role in how patients report their pain and function on various PROMs.^20,21 Modalities for improving patients’ emotional health baseline may even become a preoperative requirement as the healthcare industry moves toward value-based medicine and collection of patient-related outcomes as part of reimbursement schemes. 

By contrast, some studies have found that preoperative mental health did not predict postoperative outcomes. For example, Kennedy and colleagues²² found that preoperative mental health (as measured with SF-36 MCS scores) did not predict functional outcome in patients with ankle arthritis treated with ankle arthroplasty or arthrodesis. Likewise, Styron and colleagues²³ found no correlation between preoperative mental health (SF-12 MCS scores) and postoperative mental health and function in TSA. Their findings contradict those of the present study and many other studies.^12-18 The contradiction in findings demonstrates the need for well-designed, sufficiently powered studies of the link between preoperative mental health and postoperative outcome. Our study, with its large sample and heterogeneous population, is a start.

Two other groups (Simmen and colleagues,¹⁸ Matsen and colleagues²⁴) have attempted to develop a model predicting outcomes of shoulder arthroplasty. Simmen and colleagues¹⁸ estimated the probability of “treatment success” 1 year after TSA. Their model had 4 factors predictive of patient outcomes. Previous shoulder surgery and age over 75 years were significantly associated with lower probability of success, whereas higher preoperative SF-36 MCS scores and higher preoperative DASH (Disabilities of the Arm, Shoulder, and Hand) Function scores were associated with higher probability of success. The authors deemed TSA successful if the patient achieved a Constant score of ≥80 out of 100. Their model predicts probability of TSA “success,” whereas our models predict particular outcome scores. Both their results and ours support the hypothesis that preoperative mental health and function scores can predict how well a patient fares after surgery. Simmen and colleagues18 based their model on a cohort of only 140 patients and reported a 33.6% success rate (47/140 surgeries).

Matsen and colleagues²⁴ used a 1-practice cohort of 337 patients who underwent different types of arthroplasties, including TSA, rTSA, hemiarthroplasty, and ream-and-run arthroplasty. Although their focus was not preoperative PROMs predicting postoperative PROMs, they used the Simple Shoulder Test (SST) baseline score as a predictive variable. They found that 6 baseline characteristics—American Society of Anesthesiologists class I, shoulder problem unrelated to work, no prior shoulder surgery, glenoid type other than A1, humeral head not superiorly displaced on anteroposterior radiograph, and lower baseline SST score—were statistically associated with better outcomes, and they developed a model driven by these characteristics. They urged other investigators to perform the same kind of analysis with larger patient populations from multiple practices. One of the strengths of our study is its large patient population. We collected data on 1004 patients for modeling 1-year postoperative VAS pain scores and 986 patients for modeling 1-year postoperative ASES Function scores.

Our study had several limitations. First, its data came from a 42-surgeon database, and there may be variations in how these surgeons enroll patients in the registry. If some surgeons did not enroll all their surgical patients, our sample could have been subject to selection bias. Second, in developing our model, we used only patient characteristics that were available in the database. On the other hand, the heterogeneity of the surgeon sample lended external validity to the model. A third limitation was that the model always predicts better pain and function outcomes after TSA than after rTSA. In other words, it does not consider whether TSA is appropriate for a particular patient. Instead, it predicts 1-year shoulder arthroplasty outcomes. 

Our goal here is not to provide outcomes information or a surgical screening tool, but to report on our use of a simple data-driven tool for setting expectations. When appropriate data become available, tools like this should be expanded to predict longer-term shoulder arthroplasty outcomes. We need more studies that combine preoperative PROMs, more baseline clinical and patient characteristics (following the Matsen and colleagues²⁴ model), and large sample sizes.

Conclusion

The educational models presented here can help patients and surgeons learn what to expect after surgery. These models reveal the value in collecting preoperative subjective PROMs and show how a quantitative tool can help facilitate shared decision-making and set patient expectations. Separately, the effect size of each factor is small, but together a patient’s preoperative VAS pain score, ASES Function score, VR-12 MCS score, age, sex, and type of arthroplasty can provide information predictive of the patient’s self-reported pain and function 1 year after surgery.

Take-Home Points

• Shared decision-making tools, such as predictive models, can help empower the patient to make decisions for or against surgery equipped with more information about the expected outcome.
• There is a role for preoperative collection of PROMs in the clinical decision-making process.
• Mental health state, as reported by the VR-12 MCS, is a significant predictor of postoperative pain and function as reported by the VAS pain and ASES function scores.
• A significant portion of the predictive ability of this model comes from the fact that at 1-year postoperatively, patients receiving a rTSA will on average have a 3.8 point lower on ASES function score than those receiving a TSA (P < .001, ω²=.083).
• Future studies to discern the role of different modalities to improve a patient’s emotional health preoperatively will be beneficial as the healthcare industry trends toward value based medicine collecting PROMs as part of reimbursement schemes.

Over the past few decades, decisions regarding patients’ care have gradually transitioned from a paternalistic model to a more cooperative exchange between patient and physician. Shared decision-making provides patients a measure of autonomy in making choices for their health and their future. Patient participation may mitigate uncertainty and discomfort during selection of a course of treatment, which may lead to increased satisfaction levels after surgery.¹ Moreover, shared decision-making may help patients better manage postoperative expectations through evidenced-based discussions of preoperative health levels and their corresponding outcomes. Patient-reported outcome measures (PROMs) use clinically sensitive and specific metrics to evaluate a patient’s self-reported pain, functional ability, and mental state.² These metrics are useful in setting patient expectations for potential outcomes of treatment options. Use of evidence-based clinical decision-making tools, such as PROM-based predictive models, can facilitate a collaborative decision-making environment for patient and physician. Given the present cost-containment era, and the need for preoperative metrics that can assist in predictive analysis of postoperative improvement, models are clearly valuable.

In attempts to help patients set well-informed and reasonable expectations, physicians have turned to PROMs to facilitate preoperative evidence-based discussions. Although PROMs have been in use for almost 30 years, only recently have they been used to create tools that can aid quantitatively in the surgical decision-making process.^2-6 Combining physical examination findings, imaging studies, comorbidities, and quantitative tools, such as this model, may enhance patients’ understanding of their preoperative condition and expected prognosis and thereby guide their surgical decisions.

We conducted a study to determine whether certain preoperative PROMs can predict 1-year postoperative visual analog scale (VAS) pain scores and American Shoulder and Elbow Surgeons (ASES) Function scores in total shoulder arthroplasty (TSA) and reverse TSA (rTSA). We hypothesized that preoperative mental health status as captured by Veterans RAND 12-Item Health Survey (VR-12) mental health component summary (MCS) score and preoperative VAS pain score would predict both VAS pain score and ASES Function score 1 year after surgery. Specifically, we hypothesized that a higher preoperative VR-12 MCS score would predict less pain and better function 1 year after surgery and that a higher preoperative VAS pain score would predict more pain and worse function 1 year after surgery.

Methods

This study was approved by the Institutional Review Board of Partners Healthcare. The study used the Surgical Outcome System (Arthrex), a comprehensive prospective database that stores preoperative and 1-year postoperative patient demographics and TSA-PROM data. Surveys are emailed to all enrolled patients before surgery and 1 year after surgery. As indicated by the Institutional Review Boards of all participating institutions, patients in the Surgical Outcome System have to sign a consent form to permit use of their responses in research.

The database includes patient data from 42 orthopedic surgeons across the United States. All primary TSAs and primary rTSAs in the database were included in this study, regardless of arthroplasty indication. Revisions were excluded. Also excluded were cases in which the 1-year postoperative questionnaire was not completed. Of the 1681 patients eligible for 1-year follow-up, 1225 (73%) completed the 1-year postoperative questionnaire. PROMs used in the study were VAS pain score, ASES Function score, VR-12 MCS score, and Single Assessment Numerical Evaluation (SANE). Unfortunately, not all surgeons use every measure in the 1-year postoperative questionnaire set. Thus, in our complete models, total number of observations was 1004 for modeling 1-year postoperative VAS pain scores and 986 for modeling 1-year postoperative ASES Function scores. 

Metrics

On VAS, pain is rated from 0 (no pain) to 10 (pain as bad as it can be). Tashjian and colleagues⁷ estimated that the minimal clinically important difference (MCID) for postoperative VAS pain scores was 1.4 in a cohort of 326 patients who had TSA, rTSA, or shoulder hemiarthroplasty. ASES Function score is scaled from 0 to 30, with 30 representing best function.⁸ Wong and colleagues⁹ identified an MCID of 6.5 for ASES Function scores in a cohort of 107 patients who had TSA or rTSA. SANE ratings range from 0% to 100%, with 100% indicating the patient’s shoulder was totally “normal.”10 VR-12 MCS scores appear on a logarithmic scale, with higher numbers representing better mental health. The population mean estimate for VR-12 MCS scores is 50.1 (SD, 11.49; overall possible range, –2.47 to 76.1).11 Our patient population’s scores ranged from 12.5 to 73.8.

Statistical Analysis

Simple bivariate and multivariate linear regressions were performed to evaluate the predictive value of each of the outlined PROMs. Our complete model controls for patient sex, age, and type of arthroplasty. Categorical variables were dummy-coded. Both 1-year postoperative VAS pain score and 1-year postoperative ASES Function score were investigated as dependent variables. Regression coefficients and P and ω² values are reported. Omega square represents how much of the variance in an outcome variable a model explains, like R², and ω² values can also be calculated for individual factors to see how much variance a given factor accounts for. For a simple relative risk calculation, we divided our cohort into 3 equal-sized groups based on preoperative VR-12 MCS scores and compared the risk that patients with scores in the top third (better mental health) would end up below certain ASES Total scores with the risk of patients with scores in the bottom third (worse mental health). All statistical analyses were performed with Stata (StataCorp).

Results

Table 1 lists summary statistics for the population used in these models.

Predicting VAS Pain Score (Table 2)

Preoperative VAS pain score and VR-12 MCS score both predicted 1-year postoperative VAS pain score (P < .001). Preoperative ASES Function score did not predict pain 1 year after surgery. By contrast, higher preoperative VAS pain scores were associated with higher VAS pain scores 1 year after surgery. Higher preoperative VR-12 MCS scores were significantly associated with lower VAS pain scores 1 year after surgery, indicating that better preoperative mental health is significantly associated with better self-reported outcomes in terms of pain 1 year after surgery. These associations remained statistically significant when controlling for age at time of surgery, sex, and type of arthroplasty.

Preoperative VR-12 MCS score was more predictive of 1-year postoperative VAS pain score than preoperative VAS pain score was. In other words, preoperative VR-12 MCS score accounted for more variability in outcome for 1-year postoperative VAS pain score (2.4%; ω² = .023) than preoperative VAS pain score did (1.6%; ω² = .015). 

Predicting ASES Function Score (Table 3)

By contrast, preoperative VAS pain score did not predict 1-year postoperative ASES Function score. Preoperative ASES Function and VR-12 MCS scores both predicted 1-year postoperative ASES Function score (P < .001). Higher preoperative ASES Function scores were associated with higher 1-year postoperative ASES Function scores. In other words, reporting better shoulder function before surgery was associated with reporting better shoulder function after surgery.

An example gives a sense of the effect size associated with the coefficient for preoperative ASES Function score. Our model predicts that, compared with a patient who reports 5 points lower on preoperative ASES Function (which ranges from 0-30), a patient who reports 5 points higher will report on average about 1 point higher on 1-year postoperative ASES Function. As in the model for postoperative pain, these associations with preoperative function and mental health scores held when controlling for age, sex, and type of arthroplasty. 

As in the postoperative pain model, preoperative VR-12 MCS score was more predictive of 1-year postoperative ASES Function score than preoperative ASES Function score was. Preoperative VR-12 MCS score accounted for more of the variation that our model predicts (ω² = .029) than preoperative ASES Function score did (ω² = .020). We compared the risk that patients with high preoperative VR-12 MCS scores (top third of cohort) would end up with ASES Total scores below 70, below 80, or below 90 with the risk of patients with low preoperative VR-12 MCS scores (bottom third). Results appear in Table 4.

A significant part of the predictive ability of our model for postoperative ASES Function scores stems from the fact that a patient who undergoes rTSA (vs TSA) is predicted to have an ASES Function score 3.8 points lower 1 year after surgery (P < .001, ω² = .083). With type of arthroplasty controlled for, female sex is associated with an ASES Function score 1.6 points lower 1 year after surgery (P < .001, ω² = .016).

Preoperative SANE score did not predict 1-year postoperative VAS pain score or ASES Function score. In addition, when our complete model was run with 1-year postoperative SANE score as the dependent variable, preoperative SANE score did not predict 1-year postoperative SANE score. Our data provide no supporting evidence for the use of SANE scores for predictive modeling for shoulder arthroplasty.

Discussion

We prospectively gathered data to determine which factors would predict patient subjective outcomes of primary TSA and primary rTSA. We hypothesized that preoperative VR-12 MCS scores and preoperative VAS pain scores would predict postoperative pain and function as measured with those PROMs. Second, we hypothesized that better preoperative mental health (as measured with VR-12 MCS scores) would predict lower postoperative pain (VAS pain scores) and better postoperative function (ASES Function scores). Third, we hypothesized that higher preoperative pain (VAS pain scores) would correlate with higher postoperative pain (VAS pain scores) and worse postoperative function (ASES Function scores).

Our main goal is to provide patients and surgeons with a predictive model that generates insights into what patients can expect after surgery. This model is not intended to be a screening tool for operative indications, but a clinical tool for helping set expectations.

Our results showed that patients with more pain before surgery were more likely to have more pain 1 year after surgery—confirming the hypothesized relationship between pain before and after surgery. Contrary to the hypothesis, however, degree of pain before surgery was not associated with function 1 year after surgery. Our mental health hypothesis was confirmed: Patients with better preoperative mental health scores had on average less pain and better function 1 year after surgery. Not surprisingly, our model demonstrated that patients with better self-reported function before surgery had better self-reported function after surgery. Patient-reported function before surgery did not significantly affect how much pain the patient had 1 year after surgery. Although we did not hypothesize about the role of function in predicting 1-year outcomes, function is a significant factor to be considered when setting patient expectations regarding shoulder arthroplasty outcomes (Table 5).

Although the effect sizes of each analyzed factor are small, together our models for 1-year postoperative pain and function provide significant insight into patients’ likely outcomes 1 year after TSA and rTSA.

Many studies have found that mental health correlated with pain and function during recovery from orthopedic trauma.^12-18 For example, Wylie and colleagues¹⁹ found that preoperative mental health, as measured with the 36-Item Short Form Health Survey (SF-36) MCS score, predicted patient-reported pain and function in the setting of rotator cuff injury, regardless of treatment type (operative, nonoperative). Others have found that mental health may play a role in how patients report their pain and function on various PROMs.^20,21 Modalities for improving patients’ emotional health baseline may even become a preoperative requirement as the healthcare industry moves toward value-based medicine and collection of patient-related outcomes as part of reimbursement schemes. 

By contrast, some studies have found that preoperative mental health did not predict postoperative outcomes. For example, Kennedy and colleagues²² found that preoperative mental health (as measured with SF-36 MCS scores) did not predict functional outcome in patients with ankle arthritis treated with ankle arthroplasty or arthrodesis. Likewise, Styron and colleagues²³ found no correlation between preoperative mental health (SF-12 MCS scores) and postoperative mental health and function in TSA. Their findings contradict those of the present study and many other studies.^12-18 The contradiction in findings demonstrates the need for well-designed, sufficiently powered studies of the link between preoperative mental health and postoperative outcome. Our study, with its large sample and heterogeneous population, is a start.

Two other groups (Simmen and colleagues,¹⁸ Matsen and colleagues²⁴) have attempted to develop a model predicting outcomes of shoulder arthroplasty. Simmen and colleagues¹⁸ estimated the probability of “treatment success” 1 year after TSA. Their model had 4 factors predictive of patient outcomes. Previous shoulder surgery and age over 75 years were significantly associated with lower probability of success, whereas higher preoperative SF-36 MCS scores and higher preoperative DASH (Disabilities of the Arm, Shoulder, and Hand) Function scores were associated with higher probability of success. The authors deemed TSA successful if the patient achieved a Constant score of ≥80 out of 100. Their model predicts probability of TSA “success,” whereas our models predict particular outcome scores. Both their results and ours support the hypothesis that preoperative mental health and function scores can predict how well a patient fares after surgery. Simmen and colleagues18 based their model on a cohort of only 140 patients and reported a 33.6% success rate (47/140 surgeries).

Matsen and colleagues²⁴ used a 1-practice cohort of 337 patients who underwent different types of arthroplasties, including TSA, rTSA, hemiarthroplasty, and ream-and-run arthroplasty. Although their focus was not preoperative PROMs predicting postoperative PROMs, they used the Simple Shoulder Test (SST) baseline score as a predictive variable. They found that 6 baseline characteristics—American Society of Anesthesiologists class I, shoulder problem unrelated to work, no prior shoulder surgery, glenoid type other than A1, humeral head not superiorly displaced on anteroposterior radiograph, and lower baseline SST score—were statistically associated with better outcomes, and they developed a model driven by these characteristics. They urged other investigators to perform the same kind of analysis with larger patient populations from multiple practices. One of the strengths of our study is its large patient population. We collected data on 1004 patients for modeling 1-year postoperative VAS pain scores and 986 patients for modeling 1-year postoperative ASES Function scores.

Our study had several limitations. First, its data came from a 42-surgeon database, and there may be variations in how these surgeons enroll patients in the registry. If some surgeons did not enroll all their surgical patients, our sample could have been subject to selection bias. Second, in developing our model, we used only patient characteristics that were available in the database. On the other hand, the heterogeneity of the surgeon sample lended external validity to the model. A third limitation was that the model always predicts better pain and function outcomes after TSA than after rTSA. In other words, it does not consider whether TSA is appropriate for a particular patient. Instead, it predicts 1-year shoulder arthroplasty outcomes. 

Our goal here is not to provide outcomes information or a surgical screening tool, but to report on our use of a simple data-driven tool for setting expectations. When appropriate data become available, tools like this should be expanded to predict longer-term shoulder arthroplasty outcomes. We need more studies that combine preoperative PROMs, more baseline clinical and patient characteristics (following the Matsen and colleagues²⁴ model), and large sample sizes.

Conclusion

The educational models presented here can help patients and surgeons learn what to expect after surgery. These models reveal the value in collecting preoperative subjective PROMs and show how a quantitative tool can help facilitate shared decision-making and set patient expectations. Separately, the effect size of each factor is small, but together a patient’s preoperative VAS pain score, ASES Function score, VR-12 MCS score, age, sex, and type of arthroplasty can provide information predictive of the patient’s self-reported pain and function 1 year after surgery.

Take-Home Points

• Shared decision-making tools, such as predictive models, can help empower the patient to make decisions for or against surgery equipped with more information about the expected outcome.
• There is a role for preoperative collection of PROMs in the clinical decision-making process.
• Mental health state, as reported by the VR-12 MCS, is a significant predictor of postoperative pain and function as reported by the VAS pain and ASES function scores.
• A significant portion of the predictive ability of this model comes from the fact that at 1-year postoperatively, patients receiving a rTSA will on average have a 3.8 point lower on ASES function score than those receiving a TSA (P < .001, ω²=.083).
• Future studies to discern the role of different modalities to improve a patient’s emotional health preoperatively will be beneficial as the healthcare industry trends toward value based medicine collecting PROMs as part of reimbursement schemes.

Over the past few decades, decisions regarding patients’ care have gradually transitioned from a paternalistic model to a more cooperative exchange between patient and physician. Shared decision-making provides patients a measure of autonomy in making choices for their health and their future. Patient participation may mitigate uncertainty and discomfort during selection of a course of treatment, which may lead to increased satisfaction levels after surgery.¹ Moreover, shared decision-making may help patients better manage postoperative expectations through evidenced-based discussions of preoperative health levels and their corresponding outcomes. Patient-reported outcome measures (PROMs) use clinically sensitive and specific metrics to evaluate a patient’s self-reported pain, functional ability, and mental state.² These metrics are useful in setting patient expectations for potential outcomes of treatment options. Use of evidence-based clinical decision-making tools, such as PROM-based predictive models, can facilitate a collaborative decision-making environment for patient and physician. Given the present cost-containment era, and the need for preoperative metrics that can assist in predictive analysis of postoperative improvement, models are clearly valuable.

In attempts to help patients set well-informed and reasonable expectations, physicians have turned to PROMs to facilitate preoperative evidence-based discussions. Although PROMs have been in use for almost 30 years, only recently have they been used to create tools that can aid quantitatively in the surgical decision-making process.^2-6 Combining physical examination findings, imaging studies, comorbidities, and quantitative tools, such as this model, may enhance patients’ understanding of their preoperative condition and expected prognosis and thereby guide their surgical decisions.

We conducted a study to determine whether certain preoperative PROMs can predict 1-year postoperative visual analog scale (VAS) pain scores and American Shoulder and Elbow Surgeons (ASES) Function scores in total shoulder arthroplasty (TSA) and reverse TSA (rTSA). We hypothesized that preoperative mental health status as captured by Veterans RAND 12-Item Health Survey (VR-12) mental health component summary (MCS) score and preoperative VAS pain score would predict both VAS pain score and ASES Function score 1 year after surgery. Specifically, we hypothesized that a higher preoperative VR-12 MCS score would predict less pain and better function 1 year after surgery and that a higher preoperative VAS pain score would predict more pain and worse function 1 year after surgery.

Methods

This study was approved by the Institutional Review Board of Partners Healthcare. The study used the Surgical Outcome System (Arthrex), a comprehensive prospective database that stores preoperative and 1-year postoperative patient demographics and TSA-PROM data. Surveys are emailed to all enrolled patients before surgery and 1 year after surgery. As indicated by the Institutional Review Boards of all participating institutions, patients in the Surgical Outcome System have to sign a consent form to permit use of their responses in research.

The database includes patient data from 42 orthopedic surgeons across the United States. All primary TSAs and primary rTSAs in the database were included in this study, regardless of arthroplasty indication. Revisions were excluded. Also excluded were cases in which the 1-year postoperative questionnaire was not completed. Of the 1681 patients eligible for 1-year follow-up, 1225 (73%) completed the 1-year postoperative questionnaire. PROMs used in the study were VAS pain score, ASES Function score, VR-12 MCS score, and Single Assessment Numerical Evaluation (SANE). Unfortunately, not all surgeons use every measure in the 1-year postoperative questionnaire set. Thus, in our complete models, total number of observations was 1004 for modeling 1-year postoperative VAS pain scores and 986 for modeling 1-year postoperative ASES Function scores. 

Metrics

On VAS, pain is rated from 0 (no pain) to 10 (pain as bad as it can be). Tashjian and colleagues⁷ estimated that the minimal clinically important difference (MCID) for postoperative VAS pain scores was 1.4 in a cohort of 326 patients who had TSA, rTSA, or shoulder hemiarthroplasty. ASES Function score is scaled from 0 to 30, with 30 representing best function.⁸ Wong and colleagues⁹ identified an MCID of 6.5 for ASES Function scores in a cohort of 107 patients who had TSA or rTSA. SANE ratings range from 0% to 100%, with 100% indicating the patient’s shoulder was totally “normal.”10 VR-12 MCS scores appear on a logarithmic scale, with higher numbers representing better mental health. The population mean estimate for VR-12 MCS scores is 50.1 (SD, 11.49; overall possible range, –2.47 to 76.1).11 Our patient population’s scores ranged from 12.5 to 73.8.

Statistical Analysis

Simple bivariate and multivariate linear regressions were performed to evaluate the predictive value of each of the outlined PROMs. Our complete model controls for patient sex, age, and type of arthroplasty. Categorical variables were dummy-coded. Both 1-year postoperative VAS pain score and 1-year postoperative ASES Function score were investigated as dependent variables. Regression coefficients and P and ω² values are reported. Omega square represents how much of the variance in an outcome variable a model explains, like R², and ω² values can also be calculated for individual factors to see how much variance a given factor accounts for. For a simple relative risk calculation, we divided our cohort into 3 equal-sized groups based on preoperative VR-12 MCS scores and compared the risk that patients with scores in the top third (better mental health) would end up below certain ASES Total scores with the risk of patients with scores in the bottom third (worse mental health). All statistical analyses were performed with Stata (StataCorp).

Results

Table 1 lists summary statistics for the population used in these models.

Predicting VAS Pain Score (Table 2)

Preoperative VAS pain score and VR-12 MCS score both predicted 1-year postoperative VAS pain score (P < .001). Preoperative ASES Function score did not predict pain 1 year after surgery. By contrast, higher preoperative VAS pain scores were associated with higher VAS pain scores 1 year after surgery. Higher preoperative VR-12 MCS scores were significantly associated with lower VAS pain scores 1 year after surgery, indicating that better preoperative mental health is significantly associated with better self-reported outcomes in terms of pain 1 year after surgery. These associations remained statistically significant when controlling for age at time of surgery, sex, and type of arthroplasty.

Preoperative VR-12 MCS score was more predictive of 1-year postoperative VAS pain score than preoperative VAS pain score was. In other words, preoperative VR-12 MCS score accounted for more variability in outcome for 1-year postoperative VAS pain score (2.4%; ω² = .023) than preoperative VAS pain score did (1.6%; ω² = .015). 

Predicting ASES Function Score (Table 3)

By contrast, preoperative VAS pain score did not predict 1-year postoperative ASES Function score. Preoperative ASES Function and VR-12 MCS scores both predicted 1-year postoperative ASES Function score (P < .001). Higher preoperative ASES Function scores were associated with higher 1-year postoperative ASES Function scores. In other words, reporting better shoulder function before surgery was associated with reporting better shoulder function after surgery.

An example gives a sense of the effect size associated with the coefficient for preoperative ASES Function score. Our model predicts that, compared with a patient who reports 5 points lower on preoperative ASES Function (which ranges from 0-30), a patient who reports 5 points higher will report on average about 1 point higher on 1-year postoperative ASES Function. As in the model for postoperative pain, these associations with preoperative function and mental health scores held when controlling for age, sex, and type of arthroplasty. 

As in the postoperative pain model, preoperative VR-12 MCS score was more predictive of 1-year postoperative ASES Function score than preoperative ASES Function score was. Preoperative VR-12 MCS score accounted for more of the variation that our model predicts (ω² = .029) than preoperative ASES Function score did (ω² = .020). We compared the risk that patients with high preoperative VR-12 MCS scores (top third of cohort) would end up with ASES Total scores below 70, below 80, or below 90 with the risk of patients with low preoperative VR-12 MCS scores (bottom third). Results appear in Table 4.

A significant part of the predictive ability of our model for postoperative ASES Function scores stems from the fact that a patient who undergoes rTSA (vs TSA) is predicted to have an ASES Function score 3.8 points lower 1 year after surgery (P < .001, ω² = .083). With type of arthroplasty controlled for, female sex is associated with an ASES Function score 1.6 points lower 1 year after surgery (P < .001, ω² = .016).

Preoperative SANE score did not predict 1-year postoperative VAS pain score or ASES Function score. In addition, when our complete model was run with 1-year postoperative SANE score as the dependent variable, preoperative SANE score did not predict 1-year postoperative SANE score. Our data provide no supporting evidence for the use of SANE scores for predictive modeling for shoulder arthroplasty.

Discussion

We prospectively gathered data to determine which factors would predict patient subjective outcomes of primary TSA and primary rTSA. We hypothesized that preoperative VR-12 MCS scores and preoperative VAS pain scores would predict postoperative pain and function as measured with those PROMs. Second, we hypothesized that better preoperative mental health (as measured with VR-12 MCS scores) would predict lower postoperative pain (VAS pain scores) and better postoperative function (ASES Function scores). Third, we hypothesized that higher preoperative pain (VAS pain scores) would correlate with higher postoperative pain (VAS pain scores) and worse postoperative function (ASES Function scores).

Our main goal is to provide patients and surgeons with a predictive model that generates insights into what patients can expect after surgery. This model is not intended to be a screening tool for operative indications, but a clinical tool for helping set expectations.

Our results showed that patients with more pain before surgery were more likely to have more pain 1 year after surgery—confirming the hypothesized relationship between pain before and after surgery. Contrary to the hypothesis, however, degree of pain before surgery was not associated with function 1 year after surgery. Our mental health hypothesis was confirmed: Patients with better preoperative mental health scores had on average less pain and better function 1 year after surgery. Not surprisingly, our model demonstrated that patients with better self-reported function before surgery had better self-reported function after surgery. Patient-reported function before surgery did not significantly affect how much pain the patient had 1 year after surgery. Although we did not hypothesize about the role of function in predicting 1-year outcomes, function is a significant factor to be considered when setting patient expectations regarding shoulder arthroplasty outcomes (Table 5).

Although the effect sizes of each analyzed factor are small, together our models for 1-year postoperative pain and function provide significant insight into patients’ likely outcomes 1 year after TSA and rTSA.

Many studies have found that mental health correlated with pain and function during recovery from orthopedic trauma.^12-18 For example, Wylie and colleagues¹⁹ found that preoperative mental health, as measured with the 36-Item Short Form Health Survey (SF-36) MCS score, predicted patient-reported pain and function in the setting of rotator cuff injury, regardless of treatment type (operative, nonoperative). Others have found that mental health may play a role in how patients report their pain and function on various PROMs.^20,21 Modalities for improving patients’ emotional health baseline may even become a preoperative requirement as the healthcare industry moves toward value-based medicine and collection of patient-related outcomes as part of reimbursement schemes. 

By contrast, some studies have found that preoperative mental health did not predict postoperative outcomes. For example, Kennedy and colleagues²² found that preoperative mental health (as measured with SF-36 MCS scores) did not predict functional outcome in patients with ankle arthritis treated with ankle arthroplasty or arthrodesis. Likewise, Styron and colleagues²³ found no correlation between preoperative mental health (SF-12 MCS scores) and postoperative mental health and function in TSA. Their findings contradict those of the present study and many other studies.^12-18 The contradiction in findings demonstrates the need for well-designed, sufficiently powered studies of the link between preoperative mental health and postoperative outcome. Our study, with its large sample and heterogeneous population, is a start.

Two other groups (Simmen and colleagues,¹⁸ Matsen and colleagues²⁴) have attempted to develop a model predicting outcomes of shoulder arthroplasty. Simmen and colleagues¹⁸ estimated the probability of “treatment success” 1 year after TSA. Their model had 4 factors predictive of patient outcomes. Previous shoulder surgery and age over 75 years were significantly associated with lower probability of success, whereas higher preoperative SF-36 MCS scores and higher preoperative DASH (Disabilities of the Arm, Shoulder, and Hand) Function scores were associated with higher probability of success. The authors deemed TSA successful if the patient achieved a Constant score of ≥80 out of 100. Their model predicts probability of TSA “success,” whereas our models predict particular outcome scores. Both their results and ours support the hypothesis that preoperative mental health and function scores can predict how well a patient fares after surgery. Simmen and colleagues18 based their model on a cohort of only 140 patients and reported a 33.6% success rate (47/140 surgeries).

Matsen and colleagues²⁴ used a 1-practice cohort of 337 patients who underwent different types of arthroplasties, including TSA, rTSA, hemiarthroplasty, and ream-and-run arthroplasty. Although their focus was not preoperative PROMs predicting postoperative PROMs, they used the Simple Shoulder Test (SST) baseline score as a predictive variable. They found that 6 baseline characteristics—American Society of Anesthesiologists class I, shoulder problem unrelated to work, no prior shoulder surgery, glenoid type other than A1, humeral head not superiorly displaced on anteroposterior radiograph, and lower baseline SST score—were statistically associated with better outcomes, and they developed a model driven by these characteristics. They urged other investigators to perform the same kind of analysis with larger patient populations from multiple practices. One of the strengths of our study is its large patient population. We collected data on 1004 patients for modeling 1-year postoperative VAS pain scores and 986 patients for modeling 1-year postoperative ASES Function scores.

Our study had several limitations. First, its data came from a 42-surgeon database, and there may be variations in how these surgeons enroll patients in the registry. If some surgeons did not enroll all their surgical patients, our sample could have been subject to selection bias. Second, in developing our model, we used only patient characteristics that were available in the database. On the other hand, the heterogeneity of the surgeon sample lended external validity to the model. A third limitation was that the model always predicts better pain and function outcomes after TSA than after rTSA. In other words, it does not consider whether TSA is appropriate for a particular patient. Instead, it predicts 1-year shoulder arthroplasty outcomes. 

Our goal here is not to provide outcomes information or a surgical screening tool, but to report on our use of a simple data-driven tool for setting expectations. When appropriate data become available, tools like this should be expanded to predict longer-term shoulder arthroplasty outcomes. We need more studies that combine preoperative PROMs, more baseline clinical and patient characteristics (following the Matsen and colleagues²⁴ model), and large sample sizes.

Conclusion

The educational models presented here can help patients and surgeons learn what to expect after surgery. These models reveal the value in collecting preoperative subjective PROMs and show how a quantitative tool can help facilitate shared decision-making and set patient expectations. Separately, the effect size of each factor is small, but together a patient’s preoperative VAS pain score, ASES Function score, VR-12 MCS score, age, sex, and type of arthroplasty can provide information predictive of the patient’s self-reported pain and function 1 year after surgery.

Take-Home Points

• The authors have developed a total shoulder glenoid prosthesis that conforms with the humeral head in its center and is nonconforming on its peripheral edge.
• All clinical survey and range of motion parameters demonstrated statistically significant improvements at final follow-up.
• Only 3 shoulders (1.7%) required revision surgery.
• Eighty-six (63%) of 136 shoulders demonstrated no radiographic evidence of glenoid loosening.
• This is the first and largest study that evaluates the clinical and radiographic outcomes of this hybrid shoulder prosthesis.

Fixation of the glenoid component is the limiting factor in modern total shoulder arthroplasty (TSA). Glenoid loosening, the most common long-term complication, necessitates revision in up to 12% of patients.^1-4 By contrast, humeral component loosening is relatively uncommon, affecting as few as 0.34% of patients.⁵ Multiple long-term studies have found consistently high rates (45%-93%) of radiolucencies around the glenoid component.^3,6,7 Although their clinical significance has been debated, radiolucencies around the glenoid component raise concern about progressive loss of fixation.

Since TSA was introduced in the 1970s, complications with the glenoid component have been addressed with 2 different designs: conforming (congruent) and nonconforming. In a congruent articulation, the radii of curvature of the glenoid and humeral head components are identical, whereas they differ in a nonconforming model. Joint conformity is inversely related to glenohumeral translation.⁸ Neer’s original TSA was made congruent in order to limit translation and maximize the contact area. However, this design results in edge loading and a so-called rocking-horse phenomenon, which may lead to glenoid loosening.^9-13 Surgeons therefore have increasingly turned to nonconforming implants. In the nonconforming design, the radius of curvature of the humeral head is smaller than that of the glenoid. Although this design may reduce edge loading,¹⁴ it allows more translation and reduces the relative contact area of the glenohumeral joint. As a result, more contact stress is transmitted to the glenoid component, leading to polyethylene deformation and wear.^15,16

Dual radii of curvature are designed to augment joint stability without increasing component wear. Biomechanical data have indicated that edge loading is not increased by having a central conforming region added to a nonconforming model.¹⁷ The clinical value of this prosthesis, however, has not been determined. Therefore, we conducted a study to describe the intermediate-term clinical and radiographic outcomes of TSAs that use a novel hybrid glenoid component.

Materials and Methods

This study was approved (protocol AAAD3473) by the Institutional Review Board of Columbia University and was conducted in compliance with Health Insurance Portability and Accountability Act (HIPAA) regulations.

Patient Selection

At Columbia University Medical Center, Dr. Bigliani performed 196 TSAs with a hybrid glenoid component (Bigliani-Flatow; Zimmer Biomet) in 169 patients between September 1998 and November 2007. All patients had received a diagnosis of primary glenohumeral arthritis as defined by Neer.¹⁸ Patients with previous surgery such as rotator cuff repair or subacromial decompression were included in our review, and patients with a nonprimary form of arthritis, such as rheumatoid, posttraumatic, or post-capsulorrhaphy arthritis, were excluded.

Operative Technique

For all surgeries, Dr. Bigliani performed a subscapularis tenotomy with regional anesthesia and a standard deltopectoral approach. A partial anterior capsulectomy was performed to increase the glenoid’s visibility. The inferior labrum was removed with a needle-tip bovie while the axillary nerve was being protected with a metal finger or narrow Darrach retractor. After reaming and trialing, the final glenoid component was cemented into place. Cement was placed only in the peg or keel holes and pressurized twice before final implantation. Of the 196 glenoid components, 168 (86%) were pegged and 28 (14%) keeled; in addition,190 of these components were all-polyethylene, whereas 6 had trabecular-metal backing. All glenoid components incorporated the hybrid design of dual radii of curvature. After the glenoid was cemented, the final humeral component was placed in 30° of retroversion. Whenever posterior wear was found, retroversion was reduced by 5° to 10°. The humeral prosthesis was cemented in cases (104/196, 53%) of poor bone quality or a large canal.

After surgery, the patient’s sling was fitted with an abduction pillow and a swathe, to be worn the first 24 hours, and the arm was passively ranged. Patients typically were discharged on postoperative day 2. Then, for 2 weeks, they followed an assisted passive range of motion (ROM) protocol, with limited external rotation, for promotion of subscapularis healing.

Clinical Outcomes

Dr. Bigliani assessed preoperative ROM in all planes. During initial evaluation, patients completed a questionnaire that consisted of the 36-Item Short Form Health Survey^19,20 (SF-36) and the American Shoulder and Elbow Surgeons²¹ (ASES) and Simple Shoulder Test²² (SST) surveys. Postoperative clinical data were collected from office follow-up visits, survey questionnaires, or both. Postoperative office data included ROM, subscapularis integrity testing (belly-press or lift-off), and any complications. Patients with <1 year of office follow-up were excluded. In addition, the same survey questionnaire that was used before surgery was mailed to all patients after surgery; then, for anyone who did not respond by mail, we attempted contact by telephone. Neer criteria were based on patients’ subjective assessment of each arm on a 3-point Likert scale (1 = very satisfied, 2 = satisfied, 3 = dissatisfied). Patients were also asked about any specific complications or revision operations since their index procedure.

Physical examination and office follow-up data were obtained for 129 patients (148/196 shoulders, 76% follow-up) at a mean of 3.7 years (range 1.0-10.2 years) after surgery. Surveys were completed by 117 patients (139/196 shoulders, 71% follow-up) at a mean of 5.1 years (range, 1.6-11.2 years) after surgery. Only 15 patients had neither 1 year of office follow-up nor a completed questionnaire. The remaining 154 patients (178/196 shoulders, 91% follow-up) had clinical follow-up with office, mail, or telephone questionnaire at a mean of 4.8 years (range, 1.0-11.2 years) after surgery. This cohort of patients was used to determine rates of surgical revisions, subscapularis tears, dislocations, and other complications.

Radiographic Outcomes

Patients were included in the radiographic analysis if they had a shoulder radiograph at least 1 year after surgery. One hundred nineteen patients (136/196 shoulders, 69% follow-up) had radiographic follow-up at a mean of 3.7 years (range, 1.0-9.4 years) after surgery.

Statistical Analysis

Statistical analysis was performed with Stata Version 10.0. Paired t tests were used to compare preoperative and postoperative numerical data, including ROM and survey scores. We calculated 95% confidence intervals (CIs) and set statistical significance at P < .05. For qualitative measures, the Fisher exact test was used. Survivorship analysis was performed according to the Kaplan-Meier method, with right-censored data for no event or missing data.²⁵

Results

Clinical Analysis of Demographics

In demographics, the clinical and radiographic patient subgroups were similar to each other and to the overall study population (Table 2). Of 196 patients overall, 16 (8%) had a concomitant rotator cuff repair, and 27 (14%) underwent staged bilateral shoulder arthroplasties.

Clinical Analysis of ROM and Survey Scores

Operative shoulder ROM in forward elevation, external rotation at side, external rotation in abduction, and internal rotation all showed statistically significant (P < .001) improvement from before surgery to after surgery. Over 3.7 years, mean (SD) forward elevation improved from 107.3° (34.8°) to 159.0° (29.4°), external rotation at side improved from 20.4° (16.7°) to 49.4° (11.3°), and external rotation in abduction improved from 53.7° (24.3°) to 84.7° (9.1°). Internal rotation improved from a mean (SD) vertebral level of S1 (6.0 levels) to T9 (3.7 levels).

All validated survey scores also showed statistically significant (P < .001) improvement from before surgery to after surgery. Over 5.1 years, mean (SD) SF-36 scores improved from 64.9 (13.4) to 73.6 (17.1), ASES scores improved from 41.1 (22.5) to 82.7 (17.7), SST scores improved from 3.9 (2.8) to 9.7 (2.2), and visual analog scale pain scores improved from 5.6 (3.2) to 1.4 (2.1). Of 139 patients with follow-up, 130 (93.5%) were either satisfied or very satisfied with their TSA, and only 119 (86%) were either satisfied or very satisfied with the nonoperative shoulder.

Clinical Analysis of Postoperative Complications

Of the 178 shoulders evaluated for complications, 3 (1.7%) underwent revision surgery. Mean time to revision was 2.3 years (range, 1.5-3.9 years). Two revisions involved the glenoid component, and the third involved the humerus. In one of the glenoid cases, a 77-year-old woman fell and sustained a fracture at the base of the trabecular metal glenoid pegs; her component was revised to an all-polyethylene component, and she had no further complications. In the other glenoid case, a 73-year-old man’s all-polyethylene component loosened after 2 years and was revised to a trabecular metal implant, which loosened as well and was later converted to a hemiarthroplasty. In the humeral case, a 33-year-old man had his 4-year-old index TSA revised to a cemented stem and had no further complications.

Table 4 compares the clinical and radiographic outcomes of patients who required subscapularis repair, capsular shift, or implant revision with the outcomes of all other study patients, and Figure 3 shows Kaplan-Meier survivorship.

Postoperative Radiographic Analysis

Glenoid Component. At a mean of 3.7 years (minimum, 1 year) after surgery, 86 (63%) of 136 radiographically evaluated shoulders showed no glenoid lucencies; the other 50 (37%) showed ≥1 lucency. Of the 136 shoulders, 33 (24%) had a Lazarus score of 1, 15 (11%) had a score of 2, and only 2 (2%) had a score of 3. None of the shoulders had a score of 4 or 5.

Humeral Component. Of the 136 shoulders, 91 (67%) showed no lucencies in any of the 8 humeral stem zones; the other 45 (33%) showed 1 to 3 lucencies. Thirty (22%) of the 136 shoulders had 1 stem lucency zone, 8 (6%) had 2, and 3 (2%) had 3. None of the shoulders had >3 periprosthetic zones with lucent lines.

Discussion

In this article, we describe a hybrid glenoid TSA component with dual radii of curvature. Its central portion is congruent with the humeral head, and its peripheral portion is noncongruent and larger. The most significant finding of our study is the low rate (1.1%) of glenoid component revision 4.8 years after surgery. This rate is the lowest that has been reported in a study of ≥100 patients. Overall implant survival appeared as an almost flat Kaplan-Meir curve. We attribute this low revision rate to improved biomechanics with the hybrid glenoid design. 

Symptomatic glenoid component loosening is the most common TSA complication.^1,26-28 In a review of 73 Neer TSAs, Cofield7 found glenoid radiolucencies in 71% of patients 3.8 years after surgery. Radiographic evidence of loosening, defined as component migration, or tilt, or a circumferential lucency 1.5 mm thick, was present in another 11% of patients, and 4.1% developed symptomatic loosening that required glenoid revision. In a study with 12.2-year follow-up, Torchia and colleagues³ found rates of 84% for glenoid radiolucencies, 44% for radiographic loosening, and 5.6% for symptomatic loosening that required revision. In a systematic review of studies with follow-up of ≥10 years, Bohsali and colleagues²⁷ found similar lucency and radiographic loosening rates and a 7% glenoid revision rate. These data suggest glenoid radiolucencies may progress to component loosening.

Degree of joint congruence is a key factor in glenoid loosening. Neer’s congruent design increases the contact area with concentric loading and reduces glenohumeral translation, which leads to reduced polyethylene wear and improved joint stability. In extreme arm positions, however, humeral head subluxation results in edge loading and a glenoid rocking-horse effect.^{9-13,17,29-31} Conversely, nonconforming implants allow increased glenohumeral translation without edge loading,¹⁴ though they also reduce the relative glenohumeral contact area and thus transmit more contact stress to the glenoid.^16,17 A hybrid glenoid component with central conforming and peripheral nonconforming zones may reduce the rocking-horse effect while maximizing ROM and joint stability. Wang and colleagues32 studied the biomechanical properties of this glenoid design and found that the addition of a central conforming region did not increase edge loading.

Additional results from our study support the efficacy of a hybrid glenoid component. Patients’ clinical outcomes improved significantly. At 5.1 years after surgery, 93.5% of patients were satisfied or very satisfied with their procedure and reported less satisfaction (86%) with the nonoperative shoulder. Also significant was the reduced number of radiolucencies. At 3.7 years after surgery, the overall percentage of shoulders with ≥1 glenoid radiolucency was 37%, considerably lower than the 82% reported by Cofield7 and the rates in more recent studies.^3,16,33-36 Of the 178 shoulders in our study, 10 (5.6%) had subscapularis tears, and 6 (3.4%) of 178 had these tears surgically repaired. This 3.4% compares favorably with the 5.9% (of 119 patients) found by Miller and colleagues37 28 months after surgery. Of our 178 shoulders, 27 (15.2%) had clinically significant postoperative complications; 18 (10.1%) of the 178 had these complications surgically treated, and 9 (5.1%) had them managed nonoperatively. Bohsali and colleagues²⁷ systematically reviewed 33 TSA studies and found a slightly higher complication rate (16.3%) 5.3 years after surgery. Furthermore, in our study, the 11 patients who underwent revision, capsular shift, or subscapularis repair had final outcomes comparable to those of the rest of our study population.

Our study had several potential weaknesses. First, its minimum clinical and radiographic follow-up was 1 year, whereas most long-term TSA series set a minimum of 2 years. We used 1 year because this was the first clinical study of the hybrid glenoid component design, and we wanted to maximize its sample size by reporting on intermediate-length outcomes. Even so, 93% (166/178) of our clinical patients and 83% (113/136) of our radiographic patients have had ≥2 years of follow-up, and we continue to follow all study patients for long-term outcomes. Another weakness of the study was its lack of a uniform group of patients with all the office, survey, complications, and radiographic data. Our retrospective study design made it difficult to obtain such a group without significantly reducing the sample size, so we divided patients into 4 data groups. A third potential weakness was the study’s variable method for collecting complications data. Rates of complications in the 178 shoulders were calculated from either office evaluation or patient self-report by mail or telephone. This data collection method is subject to recall bias, but mail and telephone contact was needed so the study would capture the large number of patients who had traveled to our institution for their surgery or had since moved away. Fourth, belly-press and lift-off tests were used in part to assess subscapularis function, but recent literature suggests post-TSA subscapularis assessment can be unreliable.³⁸ These tests may be positive in up to two-thirds of patients after 2 years.³⁹ Fifth, the generalizability of our findings to diagnoses such as rheumatoid and posttraumatic arthritis is limited. We had to restrict the study to patients with primary glenohumeral arthritis in order to minimize confounders.

This study’s main strength is its description of the clinical and radiographic outcomes of using a single prosthetic system in operations performed by a single surgeon in a large number of patients. This was the first and largest study evaluating the clinical and radiographic outcomes of this hybrid glenoid implant. Excluding patients with nonprimary arthritis allowed us to minimize potential confounding factors that affect patient outcomes. In conclusion, our study results showed the favorable clinical and radiographic outcomes of TSAs that have a hybrid glenoid component with dual radii of curvature. At a mean of 3.7 years after surgery, 63% of patients had no glenoid lucencies, and, at a mean of 4.8 years, only 1.7% of patients required revision. We continue to follow these patients to obtain long-term results of this innovative prosthesis.

Take-Home Points

• The authors have developed a total shoulder glenoid prosthesis that conforms with the humeral head in its center and is nonconforming on its peripheral edge.
• All clinical survey and range of motion parameters demonstrated statistically significant improvements at final follow-up.
• Only 3 shoulders (1.7%) required revision surgery.
• Eighty-six (63%) of 136 shoulders demonstrated no radiographic evidence of glenoid loosening.
• This is the first and largest study that evaluates the clinical and radiographic outcomes of this hybrid shoulder prosthesis.

Fixation of the glenoid component is the limiting factor in modern total shoulder arthroplasty (TSA). Glenoid loosening, the most common long-term complication, necessitates revision in up to 12% of patients.^1-4 By contrast, humeral component loosening is relatively uncommon, affecting as few as 0.34% of patients.⁵ Multiple long-term studies have found consistently high rates (45%-93%) of radiolucencies around the glenoid component.^3,6,7 Although their clinical significance has been debated, radiolucencies around the glenoid component raise concern about progressive loss of fixation.

Since TSA was introduced in the 1970s, complications with the glenoid component have been addressed with 2 different designs: conforming (congruent) and nonconforming. In a congruent articulation, the radii of curvature of the glenoid and humeral head components are identical, whereas they differ in a nonconforming model. Joint conformity is inversely related to glenohumeral translation.⁸ Neer’s original TSA was made congruent in order to limit translation and maximize the contact area. However, this design results in edge loading and a so-called rocking-horse phenomenon, which may lead to glenoid loosening.^9-13 Surgeons therefore have increasingly turned to nonconforming implants. In the nonconforming design, the radius of curvature of the humeral head is smaller than that of the glenoid. Although this design may reduce edge loading,¹⁴ it allows more translation and reduces the relative contact area of the glenohumeral joint. As a result, more contact stress is transmitted to the glenoid component, leading to polyethylene deformation and wear.^15,16

Dual radii of curvature are designed to augment joint stability without increasing component wear. Biomechanical data have indicated that edge loading is not increased by having a central conforming region added to a nonconforming model.¹⁷ The clinical value of this prosthesis, however, has not been determined. Therefore, we conducted a study to describe the intermediate-term clinical and radiographic outcomes of TSAs that use a novel hybrid glenoid component.

Materials and Methods

This study was approved (protocol AAAD3473) by the Institutional Review Board of Columbia University and was conducted in compliance with Health Insurance Portability and Accountability Act (HIPAA) regulations.

Patient Selection

At Columbia University Medical Center, Dr. Bigliani performed 196 TSAs with a hybrid glenoid component (Bigliani-Flatow; Zimmer Biomet) in 169 patients between September 1998 and November 2007. All patients had received a diagnosis of primary glenohumeral arthritis as defined by Neer.¹⁸ Patients with previous surgery such as rotator cuff repair or subacromial decompression were included in our review, and patients with a nonprimary form of arthritis, such as rheumatoid, posttraumatic, or post-capsulorrhaphy arthritis, were excluded.

Operative Technique

For all surgeries, Dr. Bigliani performed a subscapularis tenotomy with regional anesthesia and a standard deltopectoral approach. A partial anterior capsulectomy was performed to increase the glenoid’s visibility. The inferior labrum was removed with a needle-tip bovie while the axillary nerve was being protected with a metal finger or narrow Darrach retractor. After reaming and trialing, the final glenoid component was cemented into place. Cement was placed only in the peg or keel holes and pressurized twice before final implantation. Of the 196 glenoid components, 168 (86%) were pegged and 28 (14%) keeled; in addition,190 of these components were all-polyethylene, whereas 6 had trabecular-metal backing. All glenoid components incorporated the hybrid design of dual radii of curvature. After the glenoid was cemented, the final humeral component was placed in 30° of retroversion. Whenever posterior wear was found, retroversion was reduced by 5° to 10°. The humeral prosthesis was cemented in cases (104/196, 53%) of poor bone quality or a large canal.

After surgery, the patient’s sling was fitted with an abduction pillow and a swathe, to be worn the first 24 hours, and the arm was passively ranged. Patients typically were discharged on postoperative day 2. Then, for 2 weeks, they followed an assisted passive range of motion (ROM) protocol, with limited external rotation, for promotion of subscapularis healing.

Clinical Outcomes

Dr. Bigliani assessed preoperative ROM in all planes. During initial evaluation, patients completed a questionnaire that consisted of the 36-Item Short Form Health Survey^19,20 (SF-36) and the American Shoulder and Elbow Surgeons²¹ (ASES) and Simple Shoulder Test²² (SST) surveys. Postoperative clinical data were collected from office follow-up visits, survey questionnaires, or both. Postoperative office data included ROM, subscapularis integrity testing (belly-press or lift-off), and any complications. Patients with <1 year of office follow-up were excluded. In addition, the same survey questionnaire that was used before surgery was mailed to all patients after surgery; then, for anyone who did not respond by mail, we attempted contact by telephone. Neer criteria were based on patients’ subjective assessment of each arm on a 3-point Likert scale (1 = very satisfied, 2 = satisfied, 3 = dissatisfied). Patients were also asked about any specific complications or revision operations since their index procedure.

Physical examination and office follow-up data were obtained for 129 patients (148/196 shoulders, 76% follow-up) at a mean of 3.7 years (range 1.0-10.2 years) after surgery. Surveys were completed by 117 patients (139/196 shoulders, 71% follow-up) at a mean of 5.1 years (range, 1.6-11.2 years) after surgery. Only 15 patients had neither 1 year of office follow-up nor a completed questionnaire. The remaining 154 patients (178/196 shoulders, 91% follow-up) had clinical follow-up with office, mail, or telephone questionnaire at a mean of 4.8 years (range, 1.0-11.2 years) after surgery. This cohort of patients was used to determine rates of surgical revisions, subscapularis tears, dislocations, and other complications.

Radiographic Outcomes

Patients were included in the radiographic analysis if they had a shoulder radiograph at least 1 year after surgery. One hundred nineteen patients (136/196 shoulders, 69% follow-up) had radiographic follow-up at a mean of 3.7 years (range, 1.0-9.4 years) after surgery.

Statistical Analysis

Statistical analysis was performed with Stata Version 10.0. Paired t tests were used to compare preoperative and postoperative numerical data, including ROM and survey scores. We calculated 95% confidence intervals (CIs) and set statistical significance at P < .05. For qualitative measures, the Fisher exact test was used. Survivorship analysis was performed according to the Kaplan-Meier method, with right-censored data for no event or missing data.²⁵

Results

Clinical Analysis of Demographics

In demographics, the clinical and radiographic patient subgroups were similar to each other and to the overall study population (Table 2). Of 196 patients overall, 16 (8%) had a concomitant rotator cuff repair, and 27 (14%) underwent staged bilateral shoulder arthroplasties.

Clinical Analysis of ROM and Survey Scores

Operative shoulder ROM in forward elevation, external rotation at side, external rotation in abduction, and internal rotation all showed statistically significant (P < .001) improvement from before surgery to after surgery. Over 3.7 years, mean (SD) forward elevation improved from 107.3° (34.8°) to 159.0° (29.4°), external rotation at side improved from 20.4° (16.7°) to 49.4° (11.3°), and external rotation in abduction improved from 53.7° (24.3°) to 84.7° (9.1°). Internal rotation improved from a mean (SD) vertebral level of S1 (6.0 levels) to T9 (3.7 levels).

All validated survey scores also showed statistically significant (P < .001) improvement from before surgery to after surgery. Over 5.1 years, mean (SD) SF-36 scores improved from 64.9 (13.4) to 73.6 (17.1), ASES scores improved from 41.1 (22.5) to 82.7 (17.7), SST scores improved from 3.9 (2.8) to 9.7 (2.2), and visual analog scale pain scores improved from 5.6 (3.2) to 1.4 (2.1). Of 139 patients with follow-up, 130 (93.5%) were either satisfied or very satisfied with their TSA, and only 119 (86%) were either satisfied or very satisfied with the nonoperative shoulder.

Clinical Analysis of Postoperative Complications

Of the 178 shoulders evaluated for complications, 3 (1.7%) underwent revision surgery. Mean time to revision was 2.3 years (range, 1.5-3.9 years). Two revisions involved the glenoid component, and the third involved the humerus. In one of the glenoid cases, a 77-year-old woman fell and sustained a fracture at the base of the trabecular metal glenoid pegs; her component was revised to an all-polyethylene component, and she had no further complications. In the other glenoid case, a 73-year-old man’s all-polyethylene component loosened after 2 years and was revised to a trabecular metal implant, which loosened as well and was later converted to a hemiarthroplasty. In the humeral case, a 33-year-old man had his 4-year-old index TSA revised to a cemented stem and had no further complications.

Table 4 compares the clinical and radiographic outcomes of patients who required subscapularis repair, capsular shift, or implant revision with the outcomes of all other study patients, and Figure 3 shows Kaplan-Meier survivorship.