The American Journal of Orthopedics

Three-dimensional (3-D) printing is a rapidly evolving technology with both medical and nonmedical applications.^1,2 Rapid prototyping involves creating a physical model of human tissue from a 3-D computer-generated rendering.³ The method relies on export of Digital Imaging and Communications in Medicine (DICOM)–based computed tomography (CT) or magnetic resonance imaging (MRI) data into standard triangular language (STL) format. Reducing CT or MRI slice thickness increases resolution of the final model.² Five types of rapid prototyping exist: STL, selective laser sintering, fused deposition modeling, multijet modeling, and 3-D printing.

Most implant manufacturers can produce a 3-D model based on surgeon-provided DICOM images. The ability to produce anatomical models in an office-based setting is a more recent development. Three-dimensional modeling may allow for more accurate and extensive preoperative planning than radiographic examination alone does, and may even allow surgeons to perform procedures as part of preoperative preparation. This can allow for early recognition of unanticipated intraoperative problems or of the need for special techniques and implants that would not have been otherwise available, all of which may ultimately reduce operative time.

The breadth of applications for office-based 3-D prototyping is not well described in the orthopedic surgery literature. In this article, we describe 7 cases of complex orthopedic disorders that were surgically treated after preoperative planning in which use of a 3-D printer allowed for “mock” surgery before the actual procedures. In 3 of the cases, the models were made by the implant manufacturers. Working with these models prompted us to buy a 3-D printer (Fortus 250; Stratasys, Eden Prairie, Minnesota) for in-office use. In the other 4 cases, we used this printer to create our own models. As indicated in the manufacturer’s literature, the printer uses fused deposition modeling, which builds a model layer by layer by heating thermoplastic material to a semi-liquid state and extruding it according to computer-controlled pathways.

We present preoperative images, preoperative 3-D modeling, and intraoperative and postoperative images along with brief case descriptions (Table). The patients provided written informed consent for print and electronic publication of these case reports.

Case Reports

Case 1

A 28-year-old woman with a history of spondyloepiphyseal dysplasia presented to our clinic with bilateral hip pain. About 8 years earlier, she had undergone bilateral proximal and distal femoral osteotomies. Her function had initially improved, but over the 2 to 3 years before presentation she began having more pain and stiffness with activity. At time of initial evaluation, she was able to walk only 1 to 2 blocks and had difficulty getting in and out of a car and up out of a seated position.

On physical examination, the patient was 3 feet 10 inches tall and weighed 77 pounds. She ambulated with decreased stance phase on both lower extremities and had developed a significant amount of increased forward pelvic inclination and increased lumbar lordosis. Both hips and thighs had multiple healed scars from prior surgeries and pin tracts. Range of motion (ROM) on both sides was restricted to 85° of flexion, 10° of internal rotation, 15° of external rotation, and 15° of abduction.

Plain radiographs showed advanced degenerative joint disease (DJD) of both hips with dysplastic acetabuli and evidence of healed osteotomies (Figure 1). Femoral deformities, noted bilaterally, consisted of marked valgus proximally and varus distally. Preoperative CT was used to create a 3-D model of the pelvis and femur. The model was created by the same implant manufacturer that produced the final components (Depuy, Warsaw, Indiana). Corrective femoral osteotomy was performed on the model to allow for design and use of a custom implant, while the modeled pelvis confirmed the ability to reproduce the normal hip center with a 44-mm conventional hemispherical socket.

After surgery, the patient was able to ambulate without a limp and return to work. Her hip ROM was pain-free passively and actively with flexion to 100°, internal rotation to 35°, external rotation to 20°, and abduction to 30°.

Case 2

A 48-year-old woman with a history of Crowe IV hip dysplasia presented to our clinic with a chronically dislocated right total hip arthroplasty (THA) (Figure 2). Her initial THA was revised 1 year later because of acetabular component failure. Two years later, she was diagnosed with a deep periprosthetic infection, which was ultimately treated with 2-stage reimplantation. She subsequently dislocated and underwent re-revision of the S-ROM body and stem (DePuy Synthes, Warsaw, Indiana). At a visit after that revision, she was noted to be chronically dislocated, and was sent to our clinic for further management.

Preoperative radiographs showed a right uncemented THA with the femoral head dislocated toward the false acetabulum, retained hardware, and an old ununited trochanteric fragment. Both the femoral and acetabular components appeared well-fixed, though the acetabular component was positioned inferior, toward the obturator foramen.

Preoperative CT with metal artifact subtraction was used to create a 3-D model of the residual bony pelvis. The model was made by an implant manufacturer (Zimmer, Warsaw, Indiana). The shape of the superior defect was amenable to reconstruction using a modified revision trabecular metal socket. The pelvic model was reamed to accept a conventional hemispherical socket. The defect was reamed to accept a modified revision trabecular metal socket. The real implant was fashioned before surgery and was sterilized to avoid the need for intraoperative modification. Use of the preoperative model significantly reduced the time that would have been needed to modify the implant during actual surgery.

The patient’s right THA was revised. At time of surgery, the modified revision trabecular metal acetabular component was noted to seat appropriately in the superior defect. The true acetabulum was reestablished, and a hemispherical socket was placed with multiple screws. The 2 components were then unitized using cement in the same manner as would be done with an off-the-shelf augment.

Case 3

A 57-year-old man presented with a 10-year history of right knee pain. About 30 years before presentation at our clinic, he was treated for an open right tibia fracture sustained in a motorcycle accident. He had been treated nonsurgically, with injections, but they failed to provide sustained relief.

Preoperative radiographs showed severe advanced DJD in conjunction with an extra-articular posttraumatic varus tibial shaft deformity (Figure 3). An implant manufacturer (Zimmer) used a CT scan to create a model of the deformity. The resultant center of rotation angle was calculated using preoperative images and conventional techniques for deformity correction, and a lateral closing-wedge osteotomy was performed on the CT-based model. The initial attempt at deformity correction was slightly excessive, and the amount of resected bone slightly thicker than the calculated wedge, resulting in a valgus deformity. This error was noted, and the decision was made to recut a new model with a slight amount of residual varus that could be corrected during the final knee arthroplasty procedure.

Corrective osteotomy was performed with a lateral plate. Six months later, the patient had no residual pain, and CT confirmed union at the osteotomy site and a slight amount of residual varus. The patient then underwent routine total knee arthroplasty (TKA) using an abbreviated keel to avoid the need for removal of the previously placed hardware. The varus deformity was completely corrected.

Case 4

A 73-year-old man had a history of shoulder pain dating back to his childhood. Despite treatment with nonsteroidal anti-inflammatory drugs, physical therapy, and injections, his debilitating pain persisted. Physical examination revealed limited ROM and an intact rotator cuff.

Plain radiographs showed severe DJD of the glenohumeral joint (Figure 4). Severe erosions of the glenoid were noted, prompting further workup with CT, which showed significant bone loss, particularly along the posterior margin of the glenoid. We used our 3-D printer to create a model of the scapula from CT images. The model was then reamed in the usual fashion to accept a 3-pegged glenoid component. On placement of a trial implant, a large deficiency was seen posteriorly. We thought the size and location of the defect made it amenable to grafting using the patient’s humeral head.

The patient elected to undergo right total shoulder arthroplasty. During the procedure, the glenoid defect was found to be identical to what was encountered with the model before surgery. A portion of the patient’s humeral head was then fashioned to fit the defect, and was secured with three 2.7-mm screws, after provisional fixation using 2.0-mm Kirschner wires. The screws were countersunk, and the graft was contoured by hand to match the previous reaming. A 3-pegged 52-mm glenoid component was then cemented into position with excellent stability.

Case 5

A 64-year-old man presented to our clinic with left hip pain 40 years after THA. The original procedure was performed for resolved proximal femoral osteomyelitis. Plain radiographs showed a loose cemented McKee-Farrar hip arthroplasty (Figure 5). Because of the elevated position of the acetabular component relative to the native hip center, CT was used to determine the amount of femoral bone loss.

We used our 3-D printer to create a model and tried to recreate the native hip center with conventional off-the-shelf implants. A 50-mm hemispherical socket trial was placed in the appropriate location, along with a trabecular metal augment trial to provide extended coverage over the superolateral portion of the socket. Noted between the socket and the augment was a large gap; a substantial amount of cement would have been needed to unitize the construct. We thought a custom acetabular component would avoid the need for cement. In addition, given the patient’s small stature, the conventional acetabular component would allow a head only 32 mm in diameter. With a custom implant, the head could be enlarged to 36 mm, providing improved ROM and stability.

The patient underwent revision left hip arthroplasty using a custom acetabular component. A 3-D model available at time of surgery was used to aid implant placement.

Case 6

A 23-year-old man with multiple hereditary exostoses presented to our clinic with a painful mass in the left calf. Plain radiographs showed extensive osteochondromatosis involving the left proximal tibiofibular joint (Figure 6). The exostosis extended posteromedially, displacing the arterial trifurcation. MRI showed a small cartilage cap without evidence of malignant transformation.

CT angiogram allowed the vasculature to be modeled along with the deformity. A 3-D model was fabricated. The model included the entire proximal tibiofibular joint, as well as the anterior tibial, peroneal, and posterior tibial arteries. Cautious intralesional resection was recommended because of the proximity to all 3 vessels.

The patient underwent tumor resection through a longitudinal posterior approach. The interval between the medial and lateral heads of the gastrocnemius muscles was developed to expose the underlying soleus muscle. The soleus was split longitudinally from its hiatus to the inferior portion of the exostosis. This allowed for identification of the trifurcation and the tibial nerve, which were protected. Osteotomes were used to resect the mass at its base, the edges were carefully trimmed, and bone wax was placed over the defect. Anterior and lateral to this mass was another large mass (under the soleus muscle), which was also transected using an osteotome. The gastrocnemius and soleus muscles were then reflected off the fibula in order to remove 2 other exostoses, beneath the neck and head of the fibula.

Case 7

A 71-year-old man with a history of idiopathic lymphedema and peripheral neuropathy presented to our clinic with a left cavovarus foot deformity and a history of recurrent neuropathic foot ulcers (Figure 7). Physical examination revealed a callus over the lateral aspect of the base of the fifth metatarsal. Preoperative radiograph showed evidence of prior triple arthrodesis with a cavovarus foot deformity. CT scan was used to create a 3-D model of the foot. The model was then used to identify an appropriate location for lateral midtarsal and calcaneal closing-wedge osteotomies.

The patient underwent midfoot and hindfoot surgical correction. At surgery, the lateral closing-wedge osteotomies were performed according to the preoperative model. Radiographs 1 year after surgery showed correction of the forefoot varus.

Discussion

Three-dimensional printing for medical applications of anatomical modeling is not a new concept.^1,3,4 Its use has been reported for a variety of applications in orthopedic surgery, including the printing of porous and metallic surfaces⁵ and bone-tissue engineering.^6-9 Rapid prototyping for medical application was first reported in 1990 when a CT-based model was used to create a cranial bone.¹⁰ Reports of using the technique are becoming more widespread, particularly in the dental and maxillofacial literature, which includes reports on a variety of applications, including patient-specific drill guides, splints, and implants.^11-14 The ability to perform mock surgery in advance of an actual procedure provides an invaluable opportunity to anticipate potential intraoperative problems, reduce operative time, and improve the accuracy of reconstruction.

Office-based rapid prototyping that uses an in-house 3-D printer is a novel application of this technology. It allows for creation of a patient-specific model for preoperative planning purposes. We are unaware of any other reports demonstrating the breadth and utility of office-based rapid prototyping in orthopedic surgery. For general reference, a printer similar to ours requires an initial investment of $52,000 to $56,000. This cost generally covers the printer, printer base cabinet, installation, training, and printer software (different from the 3-D modeling software), plus a 1-year warranty. A service agreement costs about $4000 annually. Printer and model supply expenses depend on the material used for the model (eg, ABS [acrylonitrile butadiene styrene]) and on the size and complexity of the 3-D models created. Average time to generate an appropriately formatted 3-D printing file is about 1 hour, though times can vary largely, according to amount of metal artifact subtraction necessary and the experience of the software user. For the rare, extremely complex deformities that require a significant amount of metal artifact subtraction, file preparation times can exceed 3 or 4 hours. We think these preparation times will decrease as communication between radiology file export format and modeling software ultimately allows for metal artifact subtraction images to function within the modeling software environment. Once an appropriately formatted file has been created, typical printing times vary according to the size of the to-be-modeled bone. For a hemipelvis, printing time is 30 to 40 hours; printing that is started on a Friday afternoon will be complete by Monday morning.

There are few reports of rapid prototyping in orthopedic surgery. In 2003, Minns and colleagues¹⁵ used a 3-D model in the planning of a tibial resection for TKA. They found the model to be accurate at time of surgery, resulting in appropriate tibial coverage by a conventional meniscal-bearing implant. Munjal and colleagues¹⁶ reported on 10 complex failed hip arthroplasty cases in which patients had revision surgery after preoperative planning using 3-D modeling techniques. The authors found that, in 8 of the 10 cases, conventional classification systems of bone loss were inaccurate in comparison with the prototype. Four cases required reconstruction with a custom triflange when conventional implants were not deemed reasonable based on the pelvic model. Tam and colleagues¹⁷ reported using a 3-D prototype as an aid in surgical planning for resection of a scapular osteochondroma in a 6-year-old patient. They found the rapid prototype to be useful at time of resection—similar to what we found with 1 patient (case 6). Adding contrast media to our patient’s scan allowed for 3-D visualization of the lesion and the encased vasculature. Fu and colleagues¹⁸ reported using a patient-specific drill template to insert anterior transpedicular screws. They constructed 24 prototypes of a formalin-preserved cervical vertebra to create a patient-specific biocompatible drill template for use in correcting multilevel cervical instability. They found the technique to be highly reproducible and accurate. Zein and colleagues¹⁹ used a rapid prototype of 3 consecutive human livers to preoperatively identify the vascular and biliary tract anatomy. They reported a high degree of accuracy—mean dimensional errors of less than 4 mm for the entire model and 1.3 mm for the vascular diameter.

The models created by implant manufacturers in this series were used to perform “mock” surgery before the actual procedures. Working with these models prompted us to buy our own 3-D printer. The learning curve can be steep, but commercially available 3-D printers allow for prompt in-office production of high-quality realistic prototypes at relatively low per-case cost (Figure 8). Three-dimensional modeling allows surgeons to assess the accuracy of their original surgical plans and, if necessary, correct them before surgery. Although computer-aided design models are useful, the ability to “perform surgery preoperatively” adds another element to surgeons’ understanding of the potential issues that may arise. Also, an in-office printer can help improve surgeons’ understanding and control over the process by which images are translated from radiographic file to 3-D model. Disadvantages of an in-office system include start-up and maintenance costs, office space requirements, and a significant learning curve for software and hardware applications. In addition, creation of 3-D models requires close interaction with radiologists who can provide appropriately formatted DICOM images, as metal artifact subtraction can be challenging. We think that, as image formatting and software capabilities are continually refined, this technology will become an invaluable part of multiple subspecialties across orthopedic surgery, with potentially infinite clinical, educational, and research applications.

Three-dimensional (3-D) printing is a rapidly evolving technology with both medical and nonmedical applications.^1,2 Rapid prototyping involves creating a physical model of human tissue from a 3-D computer-generated rendering.³ The method relies on export of Digital Imaging and Communications in Medicine (DICOM)–based computed tomography (CT) or magnetic resonance imaging (MRI) data into standard triangular language (STL) format. Reducing CT or MRI slice thickness increases resolution of the final model.² Five types of rapid prototyping exist: STL, selective laser sintering, fused deposition modeling, multijet modeling, and 3-D printing.

Most implant manufacturers can produce a 3-D model based on surgeon-provided DICOM images. The ability to produce anatomical models in an office-based setting is a more recent development. Three-dimensional modeling may allow for more accurate and extensive preoperative planning than radiographic examination alone does, and may even allow surgeons to perform procedures as part of preoperative preparation. This can allow for early recognition of unanticipated intraoperative problems or of the need for special techniques and implants that would not have been otherwise available, all of which may ultimately reduce operative time.

The breadth of applications for office-based 3-D prototyping is not well described in the orthopedic surgery literature. In this article, we describe 7 cases of complex orthopedic disorders that were surgically treated after preoperative planning in which use of a 3-D printer allowed for “mock” surgery before the actual procedures. In 3 of the cases, the models were made by the implant manufacturers. Working with these models prompted us to buy a 3-D printer (Fortus 250; Stratasys, Eden Prairie, Minnesota) for in-office use. In the other 4 cases, we used this printer to create our own models. As indicated in the manufacturer’s literature, the printer uses fused deposition modeling, which builds a model layer by layer by heating thermoplastic material to a semi-liquid state and extruding it according to computer-controlled pathways.

We present preoperative images, preoperative 3-D modeling, and intraoperative and postoperative images along with brief case descriptions (Table). The patients provided written informed consent for print and electronic publication of these case reports.

Case Reports

Case 1

A 28-year-old woman with a history of spondyloepiphyseal dysplasia presented to our clinic with bilateral hip pain. About 8 years earlier, she had undergone bilateral proximal and distal femoral osteotomies. Her function had initially improved, but over the 2 to 3 years before presentation she began having more pain and stiffness with activity. At time of initial evaluation, she was able to walk only 1 to 2 blocks and had difficulty getting in and out of a car and up out of a seated position.

On physical examination, the patient was 3 feet 10 inches tall and weighed 77 pounds. She ambulated with decreased stance phase on both lower extremities and had developed a significant amount of increased forward pelvic inclination and increased lumbar lordosis. Both hips and thighs had multiple healed scars from prior surgeries and pin tracts. Range of motion (ROM) on both sides was restricted to 85° of flexion, 10° of internal rotation, 15° of external rotation, and 15° of abduction.

Plain radiographs showed advanced degenerative joint disease (DJD) of both hips with dysplastic acetabuli and evidence of healed osteotomies (Figure 1). Femoral deformities, noted bilaterally, consisted of marked valgus proximally and varus distally. Preoperative CT was used to create a 3-D model of the pelvis and femur. The model was created by the same implant manufacturer that produced the final components (Depuy, Warsaw, Indiana). Corrective femoral osteotomy was performed on the model to allow for design and use of a custom implant, while the modeled pelvis confirmed the ability to reproduce the normal hip center with a 44-mm conventional hemispherical socket.

After surgery, the patient was able to ambulate without a limp and return to work. Her hip ROM was pain-free passively and actively with flexion to 100°, internal rotation to 35°, external rotation to 20°, and abduction to 30°.

Case 2

A 48-year-old woman with a history of Crowe IV hip dysplasia presented to our clinic with a chronically dislocated right total hip arthroplasty (THA) (Figure 2). Her initial THA was revised 1 year later because of acetabular component failure. Two years later, she was diagnosed with a deep periprosthetic infection, which was ultimately treated with 2-stage reimplantation. She subsequently dislocated and underwent re-revision of the S-ROM body and stem (DePuy Synthes, Warsaw, Indiana). At a visit after that revision, she was noted to be chronically dislocated, and was sent to our clinic for further management.

Preoperative radiographs showed a right uncemented THA with the femoral head dislocated toward the false acetabulum, retained hardware, and an old ununited trochanteric fragment. Both the femoral and acetabular components appeared well-fixed, though the acetabular component was positioned inferior, toward the obturator foramen.

Preoperative CT with metal artifact subtraction was used to create a 3-D model of the residual bony pelvis. The model was made by an implant manufacturer (Zimmer, Warsaw, Indiana). The shape of the superior defect was amenable to reconstruction using a modified revision trabecular metal socket. The pelvic model was reamed to accept a conventional hemispherical socket. The defect was reamed to accept a modified revision trabecular metal socket. The real implant was fashioned before surgery and was sterilized to avoid the need for intraoperative modification. Use of the preoperative model significantly reduced the time that would have been needed to modify the implant during actual surgery.

The patient’s right THA was revised. At time of surgery, the modified revision trabecular metal acetabular component was noted to seat appropriately in the superior defect. The true acetabulum was reestablished, and a hemispherical socket was placed with multiple screws. The 2 components were then unitized using cement in the same manner as would be done with an off-the-shelf augment.

Case 3

A 57-year-old man presented with a 10-year history of right knee pain. About 30 years before presentation at our clinic, he was treated for an open right tibia fracture sustained in a motorcycle accident. He had been treated nonsurgically, with injections, but they failed to provide sustained relief.

Preoperative radiographs showed severe advanced DJD in conjunction with an extra-articular posttraumatic varus tibial shaft deformity (Figure 3). An implant manufacturer (Zimmer) used a CT scan to create a model of the deformity. The resultant center of rotation angle was calculated using preoperative images and conventional techniques for deformity correction, and a lateral closing-wedge osteotomy was performed on the CT-based model. The initial attempt at deformity correction was slightly excessive, and the amount of resected bone slightly thicker than the calculated wedge, resulting in a valgus deformity. This error was noted, and the decision was made to recut a new model with a slight amount of residual varus that could be corrected during the final knee arthroplasty procedure.

Corrective osteotomy was performed with a lateral plate. Six months later, the patient had no residual pain, and CT confirmed union at the osteotomy site and a slight amount of residual varus. The patient then underwent routine total knee arthroplasty (TKA) using an abbreviated keel to avoid the need for removal of the previously placed hardware. The varus deformity was completely corrected.

Case 4

A 73-year-old man had a history of shoulder pain dating back to his childhood. Despite treatment with nonsteroidal anti-inflammatory drugs, physical therapy, and injections, his debilitating pain persisted. Physical examination revealed limited ROM and an intact rotator cuff.

Plain radiographs showed severe DJD of the glenohumeral joint (Figure 4). Severe erosions of the glenoid were noted, prompting further workup with CT, which showed significant bone loss, particularly along the posterior margin of the glenoid. We used our 3-D printer to create a model of the scapula from CT images. The model was then reamed in the usual fashion to accept a 3-pegged glenoid component. On placement of a trial implant, a large deficiency was seen posteriorly. We thought the size and location of the defect made it amenable to grafting using the patient’s humeral head.

The patient elected to undergo right total shoulder arthroplasty. During the procedure, the glenoid defect was found to be identical to what was encountered with the model before surgery. A portion of the patient’s humeral head was then fashioned to fit the defect, and was secured with three 2.7-mm screws, after provisional fixation using 2.0-mm Kirschner wires. The screws were countersunk, and the graft was contoured by hand to match the previous reaming. A 3-pegged 52-mm glenoid component was then cemented into position with excellent stability.

Case 5

A 64-year-old man presented to our clinic with left hip pain 40 years after THA. The original procedure was performed for resolved proximal femoral osteomyelitis. Plain radiographs showed a loose cemented McKee-Farrar hip arthroplasty (Figure 5). Because of the elevated position of the acetabular component relative to the native hip center, CT was used to determine the amount of femoral bone loss.

We used our 3-D printer to create a model and tried to recreate the native hip center with conventional off-the-shelf implants. A 50-mm hemispherical socket trial was placed in the appropriate location, along with a trabecular metal augment trial to provide extended coverage over the superolateral portion of the socket. Noted between the socket and the augment was a large gap; a substantial amount of cement would have been needed to unitize the construct. We thought a custom acetabular component would avoid the need for cement. In addition, given the patient’s small stature, the conventional acetabular component would allow a head only 32 mm in diameter. With a custom implant, the head could be enlarged to 36 mm, providing improved ROM and stability.

The patient underwent revision left hip arthroplasty using a custom acetabular component. A 3-D model available at time of surgery was used to aid implant placement.

Case 6

A 23-year-old man with multiple hereditary exostoses presented to our clinic with a painful mass in the left calf. Plain radiographs showed extensive osteochondromatosis involving the left proximal tibiofibular joint (Figure 6). The exostosis extended posteromedially, displacing the arterial trifurcation. MRI showed a small cartilage cap without evidence of malignant transformation.

CT angiogram allowed the vasculature to be modeled along with the deformity. A 3-D model was fabricated. The model included the entire proximal tibiofibular joint, as well as the anterior tibial, peroneal, and posterior tibial arteries. Cautious intralesional resection was recommended because of the proximity to all 3 vessels.

The patient underwent tumor resection through a longitudinal posterior approach. The interval between the medial and lateral heads of the gastrocnemius muscles was developed to expose the underlying soleus muscle. The soleus was split longitudinally from its hiatus to the inferior portion of the exostosis. This allowed for identification of the trifurcation and the tibial nerve, which were protected. Osteotomes were used to resect the mass at its base, the edges were carefully trimmed, and bone wax was placed over the defect. Anterior and lateral to this mass was another large mass (under the soleus muscle), which was also transected using an osteotome. The gastrocnemius and soleus muscles were then reflected off the fibula in order to remove 2 other exostoses, beneath the neck and head of the fibula.

Case 7

A 71-year-old man with a history of idiopathic lymphedema and peripheral neuropathy presented to our clinic with a left cavovarus foot deformity and a history of recurrent neuropathic foot ulcers (Figure 7). Physical examination revealed a callus over the lateral aspect of the base of the fifth metatarsal. Preoperative radiograph showed evidence of prior triple arthrodesis with a cavovarus foot deformity. CT scan was used to create a 3-D model of the foot. The model was then used to identify an appropriate location for lateral midtarsal and calcaneal closing-wedge osteotomies.

The patient underwent midfoot and hindfoot surgical correction. At surgery, the lateral closing-wedge osteotomies were performed according to the preoperative model. Radiographs 1 year after surgery showed correction of the forefoot varus.

Discussion

Three-dimensional printing for medical applications of anatomical modeling is not a new concept.^1,3,4 Its use has been reported for a variety of applications in orthopedic surgery, including the printing of porous and metallic surfaces⁵ and bone-tissue engineering.^6-9 Rapid prototyping for medical application was first reported in 1990 when a CT-based model was used to create a cranial bone.¹⁰ Reports of using the technique are becoming more widespread, particularly in the dental and maxillofacial literature, which includes reports on a variety of applications, including patient-specific drill guides, splints, and implants.^11-14 The ability to perform mock surgery in advance of an actual procedure provides an invaluable opportunity to anticipate potential intraoperative problems, reduce operative time, and improve the accuracy of reconstruction.

Office-based rapid prototyping that uses an in-house 3-D printer is a novel application of this technology. It allows for creation of a patient-specific model for preoperative planning purposes. We are unaware of any other reports demonstrating the breadth and utility of office-based rapid prototyping in orthopedic surgery. For general reference, a printer similar to ours requires an initial investment of $52,000 to $56,000. This cost generally covers the printer, printer base cabinet, installation, training, and printer software (different from the 3-D modeling software), plus a 1-year warranty. A service agreement costs about $4000 annually. Printer and model supply expenses depend on the material used for the model (eg, ABS [acrylonitrile butadiene styrene]) and on the size and complexity of the 3-D models created. Average time to generate an appropriately formatted 3-D printing file is about 1 hour, though times can vary largely, according to amount of metal artifact subtraction necessary and the experience of the software user. For the rare, extremely complex deformities that require a significant amount of metal artifact subtraction, file preparation times can exceed 3 or 4 hours. We think these preparation times will decrease as communication between radiology file export format and modeling software ultimately allows for metal artifact subtraction images to function within the modeling software environment. Once an appropriately formatted file has been created, typical printing times vary according to the size of the to-be-modeled bone. For a hemipelvis, printing time is 30 to 40 hours; printing that is started on a Friday afternoon will be complete by Monday morning.

There are few reports of rapid prototyping in orthopedic surgery. In 2003, Minns and colleagues¹⁵ used a 3-D model in the planning of a tibial resection for TKA. They found the model to be accurate at time of surgery, resulting in appropriate tibial coverage by a conventional meniscal-bearing implant. Munjal and colleagues¹⁶ reported on 10 complex failed hip arthroplasty cases in which patients had revision surgery after preoperative planning using 3-D modeling techniques. The authors found that, in 8 of the 10 cases, conventional classification systems of bone loss were inaccurate in comparison with the prototype. Four cases required reconstruction with a custom triflange when conventional implants were not deemed reasonable based on the pelvic model. Tam and colleagues¹⁷ reported using a 3-D prototype as an aid in surgical planning for resection of a scapular osteochondroma in a 6-year-old patient. They found the rapid prototype to be useful at time of resection—similar to what we found with 1 patient (case 6). Adding contrast media to our patient’s scan allowed for 3-D visualization of the lesion and the encased vasculature. Fu and colleagues¹⁸ reported using a patient-specific drill template to insert anterior transpedicular screws. They constructed 24 prototypes of a formalin-preserved cervical vertebra to create a patient-specific biocompatible drill template for use in correcting multilevel cervical instability. They found the technique to be highly reproducible and accurate. Zein and colleagues¹⁹ used a rapid prototype of 3 consecutive human livers to preoperatively identify the vascular and biliary tract anatomy. They reported a high degree of accuracy—mean dimensional errors of less than 4 mm for the entire model and 1.3 mm for the vascular diameter.

The models created by implant manufacturers in this series were used to perform “mock” surgery before the actual procedures. Working with these models prompted us to buy our own 3-D printer. The learning curve can be steep, but commercially available 3-D printers allow for prompt in-office production of high-quality realistic prototypes at relatively low per-case cost (Figure 8). Three-dimensional modeling allows surgeons to assess the accuracy of their original surgical plans and, if necessary, correct them before surgery. Although computer-aided design models are useful, the ability to “perform surgery preoperatively” adds another element to surgeons’ understanding of the potential issues that may arise. Also, an in-office printer can help improve surgeons’ understanding and control over the process by which images are translated from radiographic file to 3-D model. Disadvantages of an in-office system include start-up and maintenance costs, office space requirements, and a significant learning curve for software and hardware applications. In addition, creation of 3-D models requires close interaction with radiologists who can provide appropriately formatted DICOM images, as metal artifact subtraction can be challenging. We think that, as image formatting and software capabilities are continually refined, this technology will become an invaluable part of multiple subspecialties across orthopedic surgery, with potentially infinite clinical, educational, and research applications.

Three-dimensional (3-D) printing is a rapidly evolving technology with both medical and nonmedical applications.^1,2 Rapid prototyping involves creating a physical model of human tissue from a 3-D computer-generated rendering.³ The method relies on export of Digital Imaging and Communications in Medicine (DICOM)–based computed tomography (CT) or magnetic resonance imaging (MRI) data into standard triangular language (STL) format. Reducing CT or MRI slice thickness increases resolution of the final model.² Five types of rapid prototyping exist: STL, selective laser sintering, fused deposition modeling, multijet modeling, and 3-D printing.

Most implant manufacturers can produce a 3-D model based on surgeon-provided DICOM images. The ability to produce anatomical models in an office-based setting is a more recent development. Three-dimensional modeling may allow for more accurate and extensive preoperative planning than radiographic examination alone does, and may even allow surgeons to perform procedures as part of preoperative preparation. This can allow for early recognition of unanticipated intraoperative problems or of the need for special techniques and implants that would not have been otherwise available, all of which may ultimately reduce operative time.

The breadth of applications for office-based 3-D prototyping is not well described in the orthopedic surgery literature. In this article, we describe 7 cases of complex orthopedic disorders that were surgically treated after preoperative planning in which use of a 3-D printer allowed for “mock” surgery before the actual procedures. In 3 of the cases, the models were made by the implant manufacturers. Working with these models prompted us to buy a 3-D printer (Fortus 250; Stratasys, Eden Prairie, Minnesota) for in-office use. In the other 4 cases, we used this printer to create our own models. As indicated in the manufacturer’s literature, the printer uses fused deposition modeling, which builds a model layer by layer by heating thermoplastic material to a semi-liquid state and extruding it according to computer-controlled pathways.

We present preoperative images, preoperative 3-D modeling, and intraoperative and postoperative images along with brief case descriptions (Table). The patients provided written informed consent for print and electronic publication of these case reports.

Case Reports

Case 1

A 28-year-old woman with a history of spondyloepiphyseal dysplasia presented to our clinic with bilateral hip pain. About 8 years earlier, she had undergone bilateral proximal and distal femoral osteotomies. Her function had initially improved, but over the 2 to 3 years before presentation she began having more pain and stiffness with activity. At time of initial evaluation, she was able to walk only 1 to 2 blocks and had difficulty getting in and out of a car and up out of a seated position.

On physical examination, the patient was 3 feet 10 inches tall and weighed 77 pounds. She ambulated with decreased stance phase on both lower extremities and had developed a significant amount of increased forward pelvic inclination and increased lumbar lordosis. Both hips and thighs had multiple healed scars from prior surgeries and pin tracts. Range of motion (ROM) on both sides was restricted to 85° of flexion, 10° of internal rotation, 15° of external rotation, and 15° of abduction.

Plain radiographs showed advanced degenerative joint disease (DJD) of both hips with dysplastic acetabuli and evidence of healed osteotomies (Figure 1). Femoral deformities, noted bilaterally, consisted of marked valgus proximally and varus distally. Preoperative CT was used to create a 3-D model of the pelvis and femur. The model was created by the same implant manufacturer that produced the final components (Depuy, Warsaw, Indiana). Corrective femoral osteotomy was performed on the model to allow for design and use of a custom implant, while the modeled pelvis confirmed the ability to reproduce the normal hip center with a 44-mm conventional hemispherical socket.

After surgery, the patient was able to ambulate without a limp and return to work. Her hip ROM was pain-free passively and actively with flexion to 100°, internal rotation to 35°, external rotation to 20°, and abduction to 30°.

Case 2

A 48-year-old woman with a history of Crowe IV hip dysplasia presented to our clinic with a chronically dislocated right total hip arthroplasty (THA) (Figure 2). Her initial THA was revised 1 year later because of acetabular component failure. Two years later, she was diagnosed with a deep periprosthetic infection, which was ultimately treated with 2-stage reimplantation. She subsequently dislocated and underwent re-revision of the S-ROM body and stem (DePuy Synthes, Warsaw, Indiana). At a visit after that revision, she was noted to be chronically dislocated, and was sent to our clinic for further management.

Preoperative radiographs showed a right uncemented THA with the femoral head dislocated toward the false acetabulum, retained hardware, and an old ununited trochanteric fragment. Both the femoral and acetabular components appeared well-fixed, though the acetabular component was positioned inferior, toward the obturator foramen.

Preoperative CT with metal artifact subtraction was used to create a 3-D model of the residual bony pelvis. The model was made by an implant manufacturer (Zimmer, Warsaw, Indiana). The shape of the superior defect was amenable to reconstruction using a modified revision trabecular metal socket. The pelvic model was reamed to accept a conventional hemispherical socket. The defect was reamed to accept a modified revision trabecular metal socket. The real implant was fashioned before surgery and was sterilized to avoid the need for intraoperative modification. Use of the preoperative model significantly reduced the time that would have been needed to modify the implant during actual surgery.

The patient’s right THA was revised. At time of surgery, the modified revision trabecular metal acetabular component was noted to seat appropriately in the superior defect. The true acetabulum was reestablished, and a hemispherical socket was placed with multiple screws. The 2 components were then unitized using cement in the same manner as would be done with an off-the-shelf augment.

Case 3

A 57-year-old man presented with a 10-year history of right knee pain. About 30 years before presentation at our clinic, he was treated for an open right tibia fracture sustained in a motorcycle accident. He had been treated nonsurgically, with injections, but they failed to provide sustained relief.

Preoperative radiographs showed severe advanced DJD in conjunction with an extra-articular posttraumatic varus tibial shaft deformity (Figure 3). An implant manufacturer (Zimmer) used a CT scan to create a model of the deformity. The resultant center of rotation angle was calculated using preoperative images and conventional techniques for deformity correction, and a lateral closing-wedge osteotomy was performed on the CT-based model. The initial attempt at deformity correction was slightly excessive, and the amount of resected bone slightly thicker than the calculated wedge, resulting in a valgus deformity. This error was noted, and the decision was made to recut a new model with a slight amount of residual varus that could be corrected during the final knee arthroplasty procedure.

Corrective osteotomy was performed with a lateral plate. Six months later, the patient had no residual pain, and CT confirmed union at the osteotomy site and a slight amount of residual varus. The patient then underwent routine total knee arthroplasty (TKA) using an abbreviated keel to avoid the need for removal of the previously placed hardware. The varus deformity was completely corrected.

Case 4

A 73-year-old man had a history of shoulder pain dating back to his childhood. Despite treatment with nonsteroidal anti-inflammatory drugs, physical therapy, and injections, his debilitating pain persisted. Physical examination revealed limited ROM and an intact rotator cuff.

Plain radiographs showed severe DJD of the glenohumeral joint (Figure 4). Severe erosions of the glenoid were noted, prompting further workup with CT, which showed significant bone loss, particularly along the posterior margin of the glenoid. We used our 3-D printer to create a model of the scapula from CT images. The model was then reamed in the usual fashion to accept a 3-pegged glenoid component. On placement of a trial implant, a large deficiency was seen posteriorly. We thought the size and location of the defect made it amenable to grafting using the patient’s humeral head.

The patient elected to undergo right total shoulder arthroplasty. During the procedure, the glenoid defect was found to be identical to what was encountered with the model before surgery. A portion of the patient’s humeral head was then fashioned to fit the defect, and was secured with three 2.7-mm screws, after provisional fixation using 2.0-mm Kirschner wires. The screws were countersunk, and the graft was contoured by hand to match the previous reaming. A 3-pegged 52-mm glenoid component was then cemented into position with excellent stability.

Case 5

A 64-year-old man presented to our clinic with left hip pain 40 years after THA. The original procedure was performed for resolved proximal femoral osteomyelitis. Plain radiographs showed a loose cemented McKee-Farrar hip arthroplasty (Figure 5). Because of the elevated position of the acetabular component relative to the native hip center, CT was used to determine the amount of femoral bone loss.

We used our 3-D printer to create a model and tried to recreate the native hip center with conventional off-the-shelf implants. A 50-mm hemispherical socket trial was placed in the appropriate location, along with a trabecular metal augment trial to provide extended coverage over the superolateral portion of the socket. Noted between the socket and the augment was a large gap; a substantial amount of cement would have been needed to unitize the construct. We thought a custom acetabular component would avoid the need for cement. In addition, given the patient’s small stature, the conventional acetabular component would allow a head only 32 mm in diameter. With a custom implant, the head could be enlarged to 36 mm, providing improved ROM and stability.

The patient underwent revision left hip arthroplasty using a custom acetabular component. A 3-D model available at time of surgery was used to aid implant placement.

Case 6

A 23-year-old man with multiple hereditary exostoses presented to our clinic with a painful mass in the left calf. Plain radiographs showed extensive osteochondromatosis involving the left proximal tibiofibular joint (Figure 6). The exostosis extended posteromedially, displacing the arterial trifurcation. MRI showed a small cartilage cap without evidence of malignant transformation.

CT angiogram allowed the vasculature to be modeled along with the deformity. A 3-D model was fabricated. The model included the entire proximal tibiofibular joint, as well as the anterior tibial, peroneal, and posterior tibial arteries. Cautious intralesional resection was recommended because of the proximity to all 3 vessels.

The patient underwent tumor resection through a longitudinal posterior approach. The interval between the medial and lateral heads of the gastrocnemius muscles was developed to expose the underlying soleus muscle. The soleus was split longitudinally from its hiatus to the inferior portion of the exostosis. This allowed for identification of the trifurcation and the tibial nerve, which were protected. Osteotomes were used to resect the mass at its base, the edges were carefully trimmed, and bone wax was placed over the defect. Anterior and lateral to this mass was another large mass (under the soleus muscle), which was also transected using an osteotome. The gastrocnemius and soleus muscles were then reflected off the fibula in order to remove 2 other exostoses, beneath the neck and head of the fibula.

Case 7

A 71-year-old man with a history of idiopathic lymphedema and peripheral neuropathy presented to our clinic with a left cavovarus foot deformity and a history of recurrent neuropathic foot ulcers (Figure 7). Physical examination revealed a callus over the lateral aspect of the base of the fifth metatarsal. Preoperative radiograph showed evidence of prior triple arthrodesis with a cavovarus foot deformity. CT scan was used to create a 3-D model of the foot. The model was then used to identify an appropriate location for lateral midtarsal and calcaneal closing-wedge osteotomies.

The patient underwent midfoot and hindfoot surgical correction. At surgery, the lateral closing-wedge osteotomies were performed according to the preoperative model. Radiographs 1 year after surgery showed correction of the forefoot varus.

Discussion

Three-dimensional printing for medical applications of anatomical modeling is not a new concept.^1,3,4 Its use has been reported for a variety of applications in orthopedic surgery, including the printing of porous and metallic surfaces⁵ and bone-tissue engineering.^6-9 Rapid prototyping for medical application was first reported in 1990 when a CT-based model was used to create a cranial bone.¹⁰ Reports of using the technique are becoming more widespread, particularly in the dental and maxillofacial literature, which includes reports on a variety of applications, including patient-specific drill guides, splints, and implants.^11-14 The ability to perform mock surgery in advance of an actual procedure provides an invaluable opportunity to anticipate potential intraoperative problems, reduce operative time, and improve the accuracy of reconstruction.

Office-based rapid prototyping that uses an in-house 3-D printer is a novel application of this technology. It allows for creation of a patient-specific model for preoperative planning purposes. We are unaware of any other reports demonstrating the breadth and utility of office-based rapid prototyping in orthopedic surgery. For general reference, a printer similar to ours requires an initial investment of $52,000 to $56,000. This cost generally covers the printer, printer base cabinet, installation, training, and printer software (different from the 3-D modeling software), plus a 1-year warranty. A service agreement costs about $4000 annually. Printer and model supply expenses depend on the material used for the model (eg, ABS [acrylonitrile butadiene styrene]) and on the size and complexity of the 3-D models created. Average time to generate an appropriately formatted 3-D printing file is about 1 hour, though times can vary largely, according to amount of metal artifact subtraction necessary and the experience of the software user. For the rare, extremely complex deformities that require a significant amount of metal artifact subtraction, file preparation times can exceed 3 or 4 hours. We think these preparation times will decrease as communication between radiology file export format and modeling software ultimately allows for metal artifact subtraction images to function within the modeling software environment. Once an appropriately formatted file has been created, typical printing times vary according to the size of the to-be-modeled bone. For a hemipelvis, printing time is 30 to 40 hours; printing that is started on a Friday afternoon will be complete by Monday morning.

There are few reports of rapid prototyping in orthopedic surgery. In 2003, Minns and colleagues¹⁵ used a 3-D model in the planning of a tibial resection for TKA. They found the model to be accurate at time of surgery, resulting in appropriate tibial coverage by a conventional meniscal-bearing implant. Munjal and colleagues¹⁶ reported on 10 complex failed hip arthroplasty cases in which patients had revision surgery after preoperative planning using 3-D modeling techniques. The authors found that, in 8 of the 10 cases, conventional classification systems of bone loss were inaccurate in comparison with the prototype. Four cases required reconstruction with a custom triflange when conventional implants were not deemed reasonable based on the pelvic model. Tam and colleagues¹⁷ reported using a 3-D prototype as an aid in surgical planning for resection of a scapular osteochondroma in a 6-year-old patient. They found the rapid prototype to be useful at time of resection—similar to what we found with 1 patient (case 6). Adding contrast media to our patient’s scan allowed for 3-D visualization of the lesion and the encased vasculature. Fu and colleagues¹⁸ reported using a patient-specific drill template to insert anterior transpedicular screws. They constructed 24 prototypes of a formalin-preserved cervical vertebra to create a patient-specific biocompatible drill template for use in correcting multilevel cervical instability. They found the technique to be highly reproducible and accurate. Zein and colleagues¹⁹ used a rapid prototype of 3 consecutive human livers to preoperatively identify the vascular and biliary tract anatomy. They reported a high degree of accuracy—mean dimensional errors of less than 4 mm for the entire model and 1.3 mm for the vascular diameter.

The models created by implant manufacturers in this series were used to perform “mock” surgery before the actual procedures. Working with these models prompted us to buy our own 3-D printer. The learning curve can be steep, but commercially available 3-D printers allow for prompt in-office production of high-quality realistic prototypes at relatively low per-case cost (Figure 8). Three-dimensional modeling allows surgeons to assess the accuracy of their original surgical plans and, if necessary, correct them before surgery. Although computer-aided design models are useful, the ability to “perform surgery preoperatively” adds another element to surgeons’ understanding of the potential issues that may arise. Also, an in-office printer can help improve surgeons’ understanding and control over the process by which images are translated from radiographic file to 3-D model. Disadvantages of an in-office system include start-up and maintenance costs, office space requirements, and a significant learning curve for software and hardware applications. In addition, creation of 3-D models requires close interaction with radiologists who can provide appropriately formatted DICOM images, as metal artifact subtraction can be challenging. We think that, as image formatting and software capabilities are continually refined, this technology will become an invaluable part of multiple subspecialties across orthopedic surgery, with potentially infinite clinical, educational, and research applications.

Children often present to orthopedic surgeons with angular deformities about the knee. Temporary hemiepiphysiodesis, which is a frequently performed procedure to address such deformities, is safe and reversible. Specifically, tension band plating has become one of the most commonly performed techniques, especially given its low complication rates and minimally invasive nature.^1-4 Complications reported with this method include mechanical hardware failure,⁵ implant migration,⁴ and recurvatum.³

We present an unreported complication of a synovial fistula formation after the removal of a tension band plate in a child who had achieved appropriate correction of her genu valgum. The patient and her family provided written informed consent for print and electronic publication of this case report.

Case Report

An 11-year-old girl presented to the pediatric orthopedics clinic with concern for genu valgum of the right lower extremity. She underwent a right proximal tibia medial hemiepiphysiodesis via tension band plating technique. Her clinic visit 4 weeks after surgery showed well-healed incisions and no signs of infection. She achieved appropriate correction and underwent hardware removal approximately 6 months after her initial surgery. 

One month after hardware removal, the patient began to notice increased swelling and erythema around her incision site with associated pain. No fluid or drainage was seen at that time. She underwent irrigation and débridement shortly thereafter, and the wound was left open for wet-to-dry dressing changes (Figure 1). Intraoperative cultures were negative, but the patient received empiric antibiotic therapy. She continued to have difficulty with wound healing for the next month and was referred to plastic surgery. She underwent repeat irrigation and débridement, followed by coverage with a split-thickness skin graft by the plastic surgery service. Intraoperative cultures were again negative. During both irrigation and débridement procedures, care was taken to remain superficial and not violate the knee capsule.

At her 2-week postoperative check, the bolster covering the split thickness skin graft was removed, which revealed a 2×2-mm area of clear erosion near the central portion of her wound with synovial fluid drainage (Figure 2). Because of concern for a synovial fistula, magnetic resonance imaging (MRI) of the right knee was obtained, which confirmed the synovial fistula (Figures 3A, 3B). The coronal cut on MRI clearly showed the fistula with synovial fluid tracking into the epiphyseal screw tract through the breached capsule and to the level of the skin. She was immobilized in a long leg cast with the knee in extension for 6 weeks. Upon return, her fistula had closed, and she has not had any more wound issues. 

Discussion

To our knowledge, this is the first report of a synovial fistula after temporary hemiepiphysiodesis performed via tension band plating. Capsular knee anatomy may explain the etiology of the synovial fistula after hardware removal. The medial knee capsule composition and attachment sites have been extensively studied.⁶ In contrast to other joints, such as the shoulder, elbow, ankle, and hip, the metaphysis of the knee lies outside the capsule because the capsule inserts proximal at the level of the physis.⁷ During tension band plating, the epiphyseal screw breaches the capsule but serves as a plug while in place, which prevents the formation of a synovial fistula. When the screw is removed, the capsular rent spontaneously closes in almost all cases. However, the opportunity exists for a synovial fistula to form while the capsule heals, as evidenced by the current case. Such an issue does not apply to the metaphyseal screw because it is inserted outside the capsule.  

Although it is possible that the synovial fistula was inadvertently created during one of the irrigation and débridement procedures, this is very unlikely. The surgeons who performed these washout procedures are knowledgeable and familiar with knee anatomy. Both irrigation and débridement procedures were superficial, and care was taken not to violate the knee capsule.

A synovial fistula after knee surgery is rare. Larsen⁸ described the fistula as a phenomenon that develops when excessive synovial fluid forces its way through a synovial incision with knee flexion and muscle contraction. Such a complication is most routinely described after knee arthroscopy. Proffer and colleagues⁹ reported an incidence of 6.1 per 1000 after knee arthroscopies. The average number of days until fistula diagnosis was 6 days (range, 3-10 days). All fistulae were treated with immobilization and closed after an average of 9 days (range, 7-14 days). There were no associated infections, although prophylactic antibiotics were given. A national survey found that knee fistulae accounted for only 3.2% of all complications of knee arthroscopy.¹⁰ 

The treatment for a synovial fistula is largely nonoperative. Most will resolve with a brief period of immobilization, which allows the fistula to close.^9-10 Literature addressing fistulae that fail to heal with nonoperative treatment is limited. Excision and direct closure of the fistula, especially when chronic, often proves futile and leads to a high recurrence rate.¹¹ An alternative but more extensive treatment involves excision and coverage with a myofascial flap.¹²

Complications reported after tension band plating are uncommon. Two studies reported no complications regarding the use of the tension band plate.^1-2 Burghardt and colleagues,⁵ in reporting the results of a multicenter survey, found that 15% of surgeons who had used tension band plating had seen a total of 65 cases of mechanical failure. In all cases, the screws, not the plate, failed. Another study reported implant migration in 1 patient but attributed the complication to a technical error from placing the distal screw too close to the physis.⁴ A third study documented that 2 patients developed clinically significant recurvatum, most likely because of anterior placement of the plate.³ It is important to identify a synovial fistula postoperatively because it provides a direct route for pathogens from the external environment to enter the intra-articular space and the opportunity for a septic joint to develop. Infection should always be ruled out and, if present, appropriately treated. 

Conclusion

Physicians performing tension band plating in the knee should be aware of the possible complication of a synovial fistula, which has traditionally been reported only in relation to knee arthroscopy. Given the proposed etiology of the synovial fistula, we recommend a brief period of immobilization of 3 to 5 days after tension band plate removal, allowing the capsular rent to heal and minimizing the risk of a synovial fistula.

Children often present to orthopedic surgeons with angular deformities about the knee. Temporary hemiepiphysiodesis, which is a frequently performed procedure to address such deformities, is safe and reversible. Specifically, tension band plating has become one of the most commonly performed techniques, especially given its low complication rates and minimally invasive nature.^1-4 Complications reported with this method include mechanical hardware failure,⁵ implant migration,⁴ and recurvatum.³

We present an unreported complication of a synovial fistula formation after the removal of a tension band plate in a child who had achieved appropriate correction of her genu valgum. The patient and her family provided written informed consent for print and electronic publication of this case report.

Case Report

An 11-year-old girl presented to the pediatric orthopedics clinic with concern for genu valgum of the right lower extremity. She underwent a right proximal tibia medial hemiepiphysiodesis via tension band plating technique. Her clinic visit 4 weeks after surgery showed well-healed incisions and no signs of infection. She achieved appropriate correction and underwent hardware removal approximately 6 months after her initial surgery. 

One month after hardware removal, the patient began to notice increased swelling and erythema around her incision site with associated pain. No fluid or drainage was seen at that time. She underwent irrigation and débridement shortly thereafter, and the wound was left open for wet-to-dry dressing changes (Figure 1). Intraoperative cultures were negative, but the patient received empiric antibiotic therapy. She continued to have difficulty with wound healing for the next month and was referred to plastic surgery. She underwent repeat irrigation and débridement, followed by coverage with a split-thickness skin graft by the plastic surgery service. Intraoperative cultures were again negative. During both irrigation and débridement procedures, care was taken to remain superficial and not violate the knee capsule.

At her 2-week postoperative check, the bolster covering the split thickness skin graft was removed, which revealed a 2×2-mm area of clear erosion near the central portion of her wound with synovial fluid drainage (Figure 2). Because of concern for a synovial fistula, magnetic resonance imaging (MRI) of the right knee was obtained, which confirmed the synovial fistula (Figures 3A, 3B). The coronal cut on MRI clearly showed the fistula with synovial fluid tracking into the epiphyseal screw tract through the breached capsule and to the level of the skin. She was immobilized in a long leg cast with the knee in extension for 6 weeks. Upon return, her fistula had closed, and she has not had any more wound issues. 

Discussion

To our knowledge, this is the first report of a synovial fistula after temporary hemiepiphysiodesis performed via tension band plating. Capsular knee anatomy may explain the etiology of the synovial fistula after hardware removal. The medial knee capsule composition and attachment sites have been extensively studied.⁶ In contrast to other joints, such as the shoulder, elbow, ankle, and hip, the metaphysis of the knee lies outside the capsule because the capsule inserts proximal at the level of the physis.⁷ During tension band plating, the epiphyseal screw breaches the capsule but serves as a plug while in place, which prevents the formation of a synovial fistula. When the screw is removed, the capsular rent spontaneously closes in almost all cases. However, the opportunity exists for a synovial fistula to form while the capsule heals, as evidenced by the current case. Such an issue does not apply to the metaphyseal screw because it is inserted outside the capsule.  

Although it is possible that the synovial fistula was inadvertently created during one of the irrigation and débridement procedures, this is very unlikely. The surgeons who performed these washout procedures are knowledgeable and familiar with knee anatomy. Both irrigation and débridement procedures were superficial, and care was taken not to violate the knee capsule.

A synovial fistula after knee surgery is rare. Larsen⁸ described the fistula as a phenomenon that develops when excessive synovial fluid forces its way through a synovial incision with knee flexion and muscle contraction. Such a complication is most routinely described after knee arthroscopy. Proffer and colleagues⁹ reported an incidence of 6.1 per 1000 after knee arthroscopies. The average number of days until fistula diagnosis was 6 days (range, 3-10 days). All fistulae were treated with immobilization and closed after an average of 9 days (range, 7-14 days). There were no associated infections, although prophylactic antibiotics were given. A national survey found that knee fistulae accounted for only 3.2% of all complications of knee arthroscopy.¹⁰ 

The treatment for a synovial fistula is largely nonoperative. Most will resolve with a brief period of immobilization, which allows the fistula to close.^9-10 Literature addressing fistulae that fail to heal with nonoperative treatment is limited. Excision and direct closure of the fistula, especially when chronic, often proves futile and leads to a high recurrence rate.¹¹ An alternative but more extensive treatment involves excision and coverage with a myofascial flap.¹²

Complications reported after tension band plating are uncommon. Two studies reported no complications regarding the use of the tension band plate.^1-2 Burghardt and colleagues,⁵ in reporting the results of a multicenter survey, found that 15% of surgeons who had used tension band plating had seen a total of 65 cases of mechanical failure. In all cases, the screws, not the plate, failed. Another study reported implant migration in 1 patient but attributed the complication to a technical error from placing the distal screw too close to the physis.⁴ A third study documented that 2 patients developed clinically significant recurvatum, most likely because of anterior placement of the plate.³ It is important to identify a synovial fistula postoperatively because it provides a direct route for pathogens from the external environment to enter the intra-articular space and the opportunity for a septic joint to develop. Infection should always be ruled out and, if present, appropriately treated. 

Conclusion

Physicians performing tension band plating in the knee should be aware of the possible complication of a synovial fistula, which has traditionally been reported only in relation to knee arthroscopy. Given the proposed etiology of the synovial fistula, we recommend a brief period of immobilization of 3 to 5 days after tension band plate removal, allowing the capsular rent to heal and minimizing the risk of a synovial fistula.

Children often present to orthopedic surgeons with angular deformities about the knee. Temporary hemiepiphysiodesis, which is a frequently performed procedure to address such deformities, is safe and reversible. Specifically, tension band plating has become one of the most commonly performed techniques, especially given its low complication rates and minimally invasive nature.^1-4 Complications reported with this method include mechanical hardware failure,⁵ implant migration,⁴ and recurvatum.³

We present an unreported complication of a synovial fistula formation after the removal of a tension band plate in a child who had achieved appropriate correction of her genu valgum. The patient and her family provided written informed consent for print and electronic publication of this case report.

Case Report

An 11-year-old girl presented to the pediatric orthopedics clinic with concern for genu valgum of the right lower extremity. She underwent a right proximal tibia medial hemiepiphysiodesis via tension band plating technique. Her clinic visit 4 weeks after surgery showed well-healed incisions and no signs of infection. She achieved appropriate correction and underwent hardware removal approximately 6 months after her initial surgery. 

One month after hardware removal, the patient began to notice increased swelling and erythema around her incision site with associated pain. No fluid or drainage was seen at that time. She underwent irrigation and débridement shortly thereafter, and the wound was left open for wet-to-dry dressing changes (Figure 1). Intraoperative cultures were negative, but the patient received empiric antibiotic therapy. She continued to have difficulty with wound healing for the next month and was referred to plastic surgery. She underwent repeat irrigation and débridement, followed by coverage with a split-thickness skin graft by the plastic surgery service. Intraoperative cultures were again negative. During both irrigation and débridement procedures, care was taken to remain superficial and not violate the knee capsule.

At her 2-week postoperative check, the bolster covering the split thickness skin graft was removed, which revealed a 2×2-mm area of clear erosion near the central portion of her wound with synovial fluid drainage (Figure 2). Because of concern for a synovial fistula, magnetic resonance imaging (MRI) of the right knee was obtained, which confirmed the synovial fistula (Figures 3A, 3B). The coronal cut on MRI clearly showed the fistula with synovial fluid tracking into the epiphyseal screw tract through the breached capsule and to the level of the skin. She was immobilized in a long leg cast with the knee in extension for 6 weeks. Upon return, her fistula had closed, and she has not had any more wound issues. 

Discussion

To our knowledge, this is the first report of a synovial fistula after temporary hemiepiphysiodesis performed via tension band plating. Capsular knee anatomy may explain the etiology of the synovial fistula after hardware removal. The medial knee capsule composition and attachment sites have been extensively studied.⁶ In contrast to other joints, such as the shoulder, elbow, ankle, and hip, the metaphysis of the knee lies outside the capsule because the capsule inserts proximal at the level of the physis.⁷ During tension band plating, the epiphyseal screw breaches the capsule but serves as a plug while in place, which prevents the formation of a synovial fistula. When the screw is removed, the capsular rent spontaneously closes in almost all cases. However, the opportunity exists for a synovial fistula to form while the capsule heals, as evidenced by the current case. Such an issue does not apply to the metaphyseal screw because it is inserted outside the capsule.  

Although it is possible that the synovial fistula was inadvertently created during one of the irrigation and débridement procedures, this is very unlikely. The surgeons who performed these washout procedures are knowledgeable and familiar with knee anatomy. Both irrigation and débridement procedures were superficial, and care was taken not to violate the knee capsule.

A synovial fistula after knee surgery is rare. Larsen⁸ described the fistula as a phenomenon that develops when excessive synovial fluid forces its way through a synovial incision with knee flexion and muscle contraction. Such a complication is most routinely described after knee arthroscopy. Proffer and colleagues⁹ reported an incidence of 6.1 per 1000 after knee arthroscopies. The average number of days until fistula diagnosis was 6 days (range, 3-10 days). All fistulae were treated with immobilization and closed after an average of 9 days (range, 7-14 days). There were no associated infections, although prophylactic antibiotics were given. A national survey found that knee fistulae accounted for only 3.2% of all complications of knee arthroscopy.¹⁰ 

The treatment for a synovial fistula is largely nonoperative. Most will resolve with a brief period of immobilization, which allows the fistula to close.^9-10 Literature addressing fistulae that fail to heal with nonoperative treatment is limited. Excision and direct closure of the fistula, especially when chronic, often proves futile and leads to a high recurrence rate.¹¹ An alternative but more extensive treatment involves excision and coverage with a myofascial flap.¹²

Complications reported after tension band plating are uncommon. Two studies reported no complications regarding the use of the tension band plate.^1-2 Burghardt and colleagues,⁵ in reporting the results of a multicenter survey, found that 15% of surgeons who had used tension band plating had seen a total of 65 cases of mechanical failure. In all cases, the screws, not the plate, failed. Another study reported implant migration in 1 patient but attributed the complication to a technical error from placing the distal screw too close to the physis.⁴ A third study documented that 2 patients developed clinically significant recurvatum, most likely because of anterior placement of the plate.³ It is important to identify a synovial fistula postoperatively because it provides a direct route for pathogens from the external environment to enter the intra-articular space and the opportunity for a septic joint to develop. Infection should always be ruled out and, if present, appropriately treated. 

Conclusion

Physicians performing tension band plating in the knee should be aware of the possible complication of a synovial fistula, which has traditionally been reported only in relation to knee arthroscopy. Given the proposed etiology of the synovial fistula, we recommend a brief period of immobilization of 3 to 5 days after tension band plate removal, allowing the capsular rent to heal and minimizing the risk of a synovial fistula.

The goal of surgical treatment of adolescent idiopathic scoliosis (AIS) is to prevent disability associated with curve progression.¹ Early studies tended to focus on radiographic measures, such as curve correction and sagittal balance, rather than on improvements in quality of life (QOL).^2-5 Although studies have reported on QOL in patients treated surgically for scoliosis,^6-11 these studies were largely limited by small sample size and inclusion of patients with congenital and neuromuscular scoliosis,⁹ lack of a generic measure of QOL,^6,7 or lack of surgical treatment of patients in the cohort.¹⁰

We conducted a study to determine disease-specific and general health-related QOL (HR-QOL) in young adults who underwent surgical correction of their spinal deformity during adolescence and to evaluate associated complications and reoperations.

Materials and Methods

After obtaining institutional review board approval, we queried the surgical database of a large metropolitan tertiary referral center for consecutive patients who had undergone spine deformity correction between the ages of 10 and 17 years (January 1993–December 2003). Hospital and medical records were retrospectively reviewed to confirm the diagnosis of AIS. Patients with congenital, neuromuscular, juvenile, or infantile scoliosis were excluded. Patients with intraspinal pathology (eg, tethered cord, syringomyelia), developmental delay, chromosomal abnormality, or congenital heart disease were also excluded. Patients were contacted by mail or telephone, and the Scoliosis Research Society–22R (SRS-22R)^12-15 and the Short Form–12 (SF-12)¹⁶ were administered. Standard demographic and surgical data were also collected.

The SRS-22R is a scoliosis-specific HR-QOL questionnaire with 22 items, 5 domains (pain, activity, appearance, mental, satisfaction), and a total score.^12-15 Each domain score ranges from 1 to 5 (higher scores indicating better outcomes). The SRS-22R is the outcome instrument most widely used to measure HR-QOL changes in patients with scoliosis, and it is available in several languages.^17-26

The SF-12, a 12-item self-administered short-form health status survey developed in the Medical Outcomes Study, measures patient-based health status. Two composite scores can be calculated: physical composite summary (PCS) and mental composite summary (MCS).¹⁶ Using norm-based scoring, all domain scales have a mean (SD) of 50 (10) based on the general 1998 US population. Thus, scores under 50 fall below the general population mean.

In addition, patients were surveyed to determine the incidence of spine-related symptoms and complaints, including activity limitations, rib prominence, waistline asymmetry, back pain, limited range of motion (ROM), shortness of breath, wound/scar problems, lung disease/asthma, heart disease, high blood pressure, and arthritis. Data regarding postoperative treatment regimens of physical therapy, narcotic pain medication, spinal/epidural injections, and nonsteroidal anti-inflammatory drug (NSAID) use were collected. Patients were also queried regarding their current working status and smoking status.

Standard demographic and surgical data were collected from hospital and office charts and radiographs. Data collected included history of bracing, age at index surgery, number of levels fused, surgical approach (anterior, posterior, combined), postoperative complications (eg, ileus, wound infection, anemia, pneumonia), and immediate preoperative and final postoperative radiographic measures. Data on need for subsequent revision surgery and indications for revision surgery were also collected.

Preoperative and latest follow-up radiographs were measured to determine curve magnitude, sagittal and coronal balance, and percentage curve correction. Coronal balance was defined as the distance between a plumb line drawn vertically from the spinous process of C7 and the central sacral line on full-length posteroanterior radiographs. Sagittal balance was defined as the distance of a plumb line drawn vertically from the center of the body of C7 and the posterosuperior endplate of S1.²⁷

Regression analysis was performed to identify factors predictive of SRS-22R total scores. Factors included in the analysis were sex, age at surgery, Lenke type, surgery type (anterior, posterior, anteroposterior), number of levels fused, lowest instrumented vertebra, perioperative complications, percentage curve correction, postoperative coronal and sagittal balance, smoking status, and need for revision surgery. Although age and sex were considered variables outside the surgeon’s control, they were included in the model, as previous studies have shown that SRS scores varied by age and sex both in adolescents²⁸ and adults.²⁹ Significance was set at P < .01. All data analysis was performed with IBM SPSS Version 19.0 (Somers, New York).

Results

Of the 384 postoperative patients identified for study inclusion, 134 (35%) completed surveys. Sixteen patients with nonidiopathic scoliosis were excluded, leaving 118 available for analysis. Of the remaining patients, 248 (64%) could not be contacted because of a change in address or phone number. Two patients (1%) were unwilling to complete survey requests. There was no statistically significant difference in demographics between patients with and without follow-up data available. Demographics are summarized in Table 1. There were 109 females (92%). Mean (SD) age at surgery was 14.1 (1.9) years. Only 37 (31%) were braced before surgery. Table 2 summarizes the radiographic data. Mean (SD) major Cobb angle was 49.7° (7.8°). Eighty-five patients (72%) underwent posterior fusion with instrumentation using hooks only; another 16 (14%) had anterior-only surgery, and another 17 (14%) had combined anterior-posterior surgery. A mean of 7.8 levels were fused. Index surgery data and lowest instrumented vertebra distribution are summarized in Table 3. Mean (SD) percentage curve correction was 48.9% (8.4%).

Seven patients had a total of 8 perioperative complications: anemia requiring transfusion (2), ileus necessitating nasogastric tube insertion (2), superficial wound infection treated with oral antibiotics and local wound care (2), wound drainage and erythema (1), and pneumonia (1). Mean (SD) length of clinical and radiographic follow-up was 57.9 (36.3) months.

Table 4 summarizes the long-term complications. Of the 38 patients with long-term complications, 14 required reoperation. The indications were disc herniation (2 patients), painful instrumentation (7), crankshaft phenomenon (1), nonunion (1), and adjacent-level degeneration (3). Both disc herniations were at L5–S1, several segments below the distal extent of the fusion. Of the 7 patients who had painful instrumentation removed, 6 had the entire construct removed, and 1 had the proximal half of a rod taken out. The 3 patients with adjacent-level degeneration had stenosis at the distal end of the construct—at L5–S1 (2 patients) or L2–L3 (1 patient).

Mean (SD) time between surgery and completion of the surveys/questionnaires was 12.7 (3.2) years (range, 10-18 years). Mean age of respondents was 26.8 years. Twenty-five respondents (21%) were smokers. Mean (SD) outcome scores were 50.9 (9.4) for SF-12 PCS and 49.4 (10.2) for SF-12 MCS. Eighteen patients (15%) had SF-12 PCS scores 1 SD below normal, and 15 (13%) had SF-12 MCS scores 1 SD below normal. Mean (SD) SRS-22R Total score was 4.0 (0.7). Means, standard deviations, and distribution of SRS domain scores are summarized in Table 5. Of the variables, only current smoking (P < .001) was predictive of SRS-22R Total scores, accounting for 20% of their variability (Table 6).

One hundred patients (85%) had jobs, mostly desk jobs. The postoperative limitations most commonly reported are summarized in Table 7. These included at least intermittent back pain in 90 patients (76%), limited ROM in 52 (44%), and activity limitations in 54 (46%). Less common limitations were waistline imbalance in 41 (35%), rib prominence in 28 (24%), wound/scar problems in 18 (15%), and shortness of breath in 18 (15%). Other related medical problems were lung disease/asthma in 11 (9%), osteoarthritis/degenerative arthritis in 11 (9%), heart disease in 3 (3%), and high blood pressure in 2 (2%).

A minority of patients also participated in postoperative treatment regimens. The most common treatment was regular use of NSAIDs (25 patients, 21%). Other treatments were physical therapy (14, 12%), narcotic pain medication use (5, 4%), and epidural steroid injections (5, 4%). Table 8 summarizes the postoperative treatments used by patients with scoliosis.

Discussion

A major concern about prophylactic interventions for diseases is that the treatment will harm the patient. This is especially true for major spine surgery performed on adolescents with minimal symptoms. Although the incidence of perioperative complications in children undergoing corrective spinal surgery for AIS has been reported,^30-32 the effect of the surgery on the disease-specific HR-QOL outcomes of these individuals as young adults has not been previously studied. Over the past few decades, a paradigm shift in understanding health and disability has occurred, with increased emphasis being placed on HR-QOL outcomes measures and understanding disability as relating to a measureable impact of the functioning of an individual after a change in health or environment. This change was substantiated when the World Health Organization endorsed the International Classification of Functioning, Disability and Health.³³ In light of this shift, we present the disease-specific and general HR-QOL outcomes of young adults who had undergone surgical correction for spinal deformity during adolescence, as well as their associated complications and reoperations, in an attempt to identify targets for improvement.

Our patient-reported outcomes demonstrated a high incidence of occasional back pain, activity-related complaints, and limited ROM. Comparison of our cohort’s SRS-22R outcomes with previously published normative values for the unaffected adolescent population^28,34 suggests worse scores for the disease-specific SRS-22R domains of pain and appearance. In 2012, Daubs and colleagues³⁴ reported that normative scores on various SRS-22 domains were statistically lower with age (scores decreased from age 10 to age 19 years). Both Verma and colleagues²⁸ and Daubs and colleagues³⁴ reported lower scores for females than for males. Therefore, it is unclear whether the differences observed in our cohort may be accounted for by the larger proportion of females compared with the normative data.

General health scores on the SF-12 were similar to the population norm (mean [SD]) of 50 (10) referenced by Ware and colleagues.¹⁶ These findings suggest that, though pain and appearance may be statistically lower in our cohort—as measured with the SRS-22R—the cohort’s spine-related symptoms do not seem to lower its general health. Eighty-five percent of the patients were working at the time of the survey, further supporting a relatively normal level of overall function. In a retrospective review by Takayama and colleagues,⁹ similar results were found with regard to working after AIS fusion surgery. Of 32 patients treated surgically for scoliosis, at a mean of 21.1 years after the index fusion 27 (84.4%) were or had been engaged in various occupations without marked difficulty.

Our results in a cohort of patients with segmental instrumentation using hooks are similar to results in other studies of long-term HR-QOL measures in patients with AIS and Harrington rod instrumentation. Danielsson and Nachemson³⁵ evaluated patients with surgically treated AIS with at least 20-year follow-up and reported that, in their surgical cohort with a mean age of 39.7 years, mean SF-36 PCS score was 50.9, and mean SF-36 MCS score was 50.2. In a recent study of patients with AIS and Harrington rod instrumentation, those of a mean age of 32.3 years had a mean score of 50.9 for both SF-36 PCS and SF-36 MCS.³⁶

Regression analysis identified only smoking as a predictor of SRS-22R Total scores. This finding, that smokers have a lower health state, is expected even in the general population.³⁷ Interestingly, bracing before surgery, Lenke type, surgery type, number of levels fused, lowest instrumented vertebra, incidence of perioperative complications, percentage curve correction, postoperative sagittal and coronal balance, and need for revision surgery did not influence HR-QOL measures in this cohort.

Our cohort’s incidence of occasional back pain was 76% (90/118 patients). Other reports have had similar findings. In 2012, Bas and colleagues³⁸ studied self-reported pain in 126 consecutive patients with scoliosis and instrumented fusion. In their cohort, “most participants reported ‘no pain’ (38.5%) or ‘mild pain’ (30.8%) and 72.1% of participants reported a current work/school activity level of 100% normal.” Also in 2012, Rushton and Grevitt³⁹ reported on a review and statistical analysis of the literature on HR-QOL in adolescents with untreated AIS and in unaffected adolescents. Their goal was to identify whether there were any differences in HR-QOL and, if so, whether they were clinically relevant. The authors concluded that pain and self-image tended to be statistically lower among cohorts with AIS but that only self-image was consistently different clinically between untreated patients with AIS and their unaffected peers.

Cosmetic complaints, though less common than functional concerns, affected a substantial percentage of our cohort. Waistline imbalance complaints were more common than rib prominence or scar-related complaints. The validity of patient-reported waistline imbalance is not known but may contribute to the SRS-22R outcomes in this cohort, particularly with regard to appearance scores. Respiratory symptoms, particularly those related to shortness of breath, were reported by 15% of patients. Respiratory symptoms may be in part secondary to underlying lung disease; smoking was reported by 21% of patients and asthma by 9%.

Few additional postoperative treatments were reported by patients. The most common treatment was regular use of NSAIDs (21%), followed by postoperative physical therapy (12%). Opiate medication use and spinal injections were rare—consistent with results reported by Danielsson and Nachemson³⁵ in 2003.

Implant-related complaints, including painful instrumentation (13%) and implant prominence (9%), were some of the most common complaints in our study group. Although not all symptomatic instrumentation required surgical revision, 7 (50%) of the 14 additional spine surgeries were related to painful and/or prominent posterior instrumentation. Additional spine surgery was reported in 11.9% of our patients. Other indications for reoperation were disc herniation, crankshaft phenomenon, nonunion, and adjacent-level degeneration. Our rate of revision surgery is supported by the literature. In 2009, Luhmann and colleagues⁴⁰ reported that 41 (3.9%) of 1057 primary spine fusions for idiopathic scoliosis required reoperation; the indications included infection (16/1057, 1.5%), pseudarthrosis (12, 1.1%), and painful/prominent implant (7, 0.7%). Richards and colleagues⁴¹ similarly reported on 1046 patients who underwent fusion for AIS. Of these patients, 135 underwent 172 repeat surgical interventions (12.9% reoperation rate), with 29 (21.5%) of the 135 undergoing 2 or more separate procedures. The most common reasons for reoperation were infection, symptomatic implant, and pseudarthrosis. The authors concluded that repeat surgeries were relatively common after the initial surgical procedures. Having a clearer understanding of instrumentation-related complaints and reoperations may lead to improvement in this surgeon-controlled variable.

There are limitations to this study. The data regarding clinical courses were collected by retrospective chart review, which has known limitations. To offset this, we collected prospective outcome data with use of the SF-12, the SRS-22R, and a spine-related complaints questionnaire. No control group was available for comparison of outcomes in our cohort. We used the SF-12 and previously published normative values for the SRS-22R for comparison with population norms. Such comparisons have inherent limitations, as the groups vary by sex and mean age; our cohort was primarily female and more than a decade older than the controls.

Only 35% of the patients who met the inclusion criteria had complete data that could be included in our analysis. Although there was no statistically significant difference in demographics between patients with and without follow-up data available, this low response rate could have introduced selection bias. Ideally, patients should have been seen in clinic, standing radiographs should have been taken, and pulmonary function tests should have been performed. However, these patients were asymptomatic, and ethical and insurance issues prevented those actions. Thus, any radiographic changes occurring over the intervening years, from the last clinic visit to completion of the surveys, were not documented. This situation may or may not have limited our findings, as other authors have found low correlation between radiographic outcomes and clinical outcome measures.^13,14,19,36 During the period when these surgeries were performed, segmental spine instrumentation with hooks was the standard of care for deformity correction in AIS; therefore, all posterior instrumentations were done with hook-only segmental fixation. Current pedicle screw–based techniques that allow for additional correction of the deformity may provide different outcomes in the future.

We think that, despite the inherent limitations of this study, our data will be useful in the treatment of AIS. Our results suggest that postoperative spinal complaints are common and that, compared with an unaffected adolescent population, patients with AIS score significantly lower on pain and appearance domains of outcomes testing at a mean of 12.7 years after index fusion. Nevertheless, the outcomes do not seem to be of sufficient severity to affect general health and QOL as measured by outcomes testing.

Spinal deformity correction is performed to prevent impaired pulmonary function and spine-related disability later in life.^42,43 Thus, longer-term studies, involving patients in their fifth and sixth decades of life, are needed to determine whether patients with AIS will have QOL outcomes, pulmonary function, and spine-related problems similar to those in the general population. In this cohort of young adults, smoking status was the only predictor of HR-QOL measures, and spinal deformity correction did not lead to decreased HR-QOL.

The goal of surgical treatment of adolescent idiopathic scoliosis (AIS) is to prevent disability associated with curve progression.¹ Early studies tended to focus on radiographic measures, such as curve correction and sagittal balance, rather than on improvements in quality of life (QOL).^2-5 Although studies have reported on QOL in patients treated surgically for scoliosis,^6-11 these studies were largely limited by small sample size and inclusion of patients with congenital and neuromuscular scoliosis,⁹ lack of a generic measure of QOL,^6,7 or lack of surgical treatment of patients in the cohort.¹⁰

We conducted a study to determine disease-specific and general health-related QOL (HR-QOL) in young adults who underwent surgical correction of their spinal deformity during adolescence and to evaluate associated complications and reoperations.

Materials and Methods

After obtaining institutional review board approval, we queried the surgical database of a large metropolitan tertiary referral center for consecutive patients who had undergone spine deformity correction between the ages of 10 and 17 years (January 1993–December 2003). Hospital and medical records were retrospectively reviewed to confirm the diagnosis of AIS. Patients with congenital, neuromuscular, juvenile, or infantile scoliosis were excluded. Patients with intraspinal pathology (eg, tethered cord, syringomyelia), developmental delay, chromosomal abnormality, or congenital heart disease were also excluded. Patients were contacted by mail or telephone, and the Scoliosis Research Society–22R (SRS-22R)^12-15 and the Short Form–12 (SF-12)¹⁶ were administered. Standard demographic and surgical data were also collected.

The SRS-22R is a scoliosis-specific HR-QOL questionnaire with 22 items, 5 domains (pain, activity, appearance, mental, satisfaction), and a total score.^12-15 Each domain score ranges from 1 to 5 (higher scores indicating better outcomes). The SRS-22R is the outcome instrument most widely used to measure HR-QOL changes in patients with scoliosis, and it is available in several languages.^17-26

The SF-12, a 12-item self-administered short-form health status survey developed in the Medical Outcomes Study, measures patient-based health status. Two composite scores can be calculated: physical composite summary (PCS) and mental composite summary (MCS).¹⁶ Using norm-based scoring, all domain scales have a mean (SD) of 50 (10) based on the general 1998 US population. Thus, scores under 50 fall below the general population mean.

In addition, patients were surveyed to determine the incidence of spine-related symptoms and complaints, including activity limitations, rib prominence, waistline asymmetry, back pain, limited range of motion (ROM), shortness of breath, wound/scar problems, lung disease/asthma, heart disease, high blood pressure, and arthritis. Data regarding postoperative treatment regimens of physical therapy, narcotic pain medication, spinal/epidural injections, and nonsteroidal anti-inflammatory drug (NSAID) use were collected. Patients were also queried regarding their current working status and smoking status.

Standard demographic and surgical data were collected from hospital and office charts and radiographs. Data collected included history of bracing, age at index surgery, number of levels fused, surgical approach (anterior, posterior, combined), postoperative complications (eg, ileus, wound infection, anemia, pneumonia), and immediate preoperative and final postoperative radiographic measures. Data on need for subsequent revision surgery and indications for revision surgery were also collected.

Preoperative and latest follow-up radiographs were measured to determine curve magnitude, sagittal and coronal balance, and percentage curve correction. Coronal balance was defined as the distance between a plumb line drawn vertically from the spinous process of C7 and the central sacral line on full-length posteroanterior radiographs. Sagittal balance was defined as the distance of a plumb line drawn vertically from the center of the body of C7 and the posterosuperior endplate of S1.²⁷

Regression analysis was performed to identify factors predictive of SRS-22R total scores. Factors included in the analysis were sex, age at surgery, Lenke type, surgery type (anterior, posterior, anteroposterior), number of levels fused, lowest instrumented vertebra, perioperative complications, percentage curve correction, postoperative coronal and sagittal balance, smoking status, and need for revision surgery. Although age and sex were considered variables outside the surgeon’s control, they were included in the model, as previous studies have shown that SRS scores varied by age and sex both in adolescents²⁸ and adults.²⁹ Significance was set at P < .01. All data analysis was performed with IBM SPSS Version 19.0 (Somers, New York).

Results

Of the 384 postoperative patients identified for study inclusion, 134 (35%) completed surveys. Sixteen patients with nonidiopathic scoliosis were excluded, leaving 118 available for analysis. Of the remaining patients, 248 (64%) could not be contacted because of a change in address or phone number. Two patients (1%) were unwilling to complete survey requests. There was no statistically significant difference in demographics between patients with and without follow-up data available. Demographics are summarized in Table 1. There were 109 females (92%). Mean (SD) age at surgery was 14.1 (1.9) years. Only 37 (31%) were braced before surgery. Table 2 summarizes the radiographic data. Mean (SD) major Cobb angle was 49.7° (7.8°). Eighty-five patients (72%) underwent posterior fusion with instrumentation using hooks only; another 16 (14%) had anterior-only surgery, and another 17 (14%) had combined anterior-posterior surgery. A mean of 7.8 levels were fused. Index surgery data and lowest instrumented vertebra distribution are summarized in Table 3. Mean (SD) percentage curve correction was 48.9% (8.4%).

Seven patients had a total of 8 perioperative complications: anemia requiring transfusion (2), ileus necessitating nasogastric tube insertion (2), superficial wound infection treated with oral antibiotics and local wound care (2), wound drainage and erythema (1), and pneumonia (1). Mean (SD) length of clinical and radiographic follow-up was 57.9 (36.3) months.

Table 4 summarizes the long-term complications. Of the 38 patients with long-term complications, 14 required reoperation. The indications were disc herniation (2 patients), painful instrumentation (7), crankshaft phenomenon (1), nonunion (1), and adjacent-level degeneration (3). Both disc herniations were at L5–S1, several segments below the distal extent of the fusion. Of the 7 patients who had painful instrumentation removed, 6 had the entire construct removed, and 1 had the proximal half of a rod taken out. The 3 patients with adjacent-level degeneration had stenosis at the distal end of the construct—at L5–S1 (2 patients) or L2–L3 (1 patient).

Mean (SD) time between surgery and completion of the surveys/questionnaires was 12.7 (3.2) years (range, 10-18 years). Mean age of respondents was 26.8 years. Twenty-five respondents (21%) were smokers. Mean (SD) outcome scores were 50.9 (9.4) for SF-12 PCS and 49.4 (10.2) for SF-12 MCS. Eighteen patients (15%) had SF-12 PCS scores 1 SD below normal, and 15 (13%) had SF-12 MCS scores 1 SD below normal. Mean (SD) SRS-22R Total score was 4.0 (0.7). Means, standard deviations, and distribution of SRS domain scores are summarized in Table 5. Of the variables, only current smoking (P < .001) was predictive of SRS-22R Total scores, accounting for 20% of their variability (Table 6).

One hundred patients (85%) had jobs, mostly desk jobs. The postoperative limitations most commonly reported are summarized in Table 7. These included at least intermittent back pain in 90 patients (76%), limited ROM in 52 (44%), and activity limitations in 54 (46%). Less common limitations were waistline imbalance in 41 (35%), rib prominence in 28 (24%), wound/scar problems in 18 (15%), and shortness of breath in 18 (15%). Other related medical problems were lung disease/asthma in 11 (9%), osteoarthritis/degenerative arthritis in 11 (9%), heart disease in 3 (3%), and high blood pressure in 2 (2%).

A minority of patients also participated in postoperative treatment regimens. The most common treatment was regular use of NSAIDs (25 patients, 21%). Other treatments were physical therapy (14, 12%), narcotic pain medication use (5, 4%), and epidural steroid injections (5, 4%). Table 8 summarizes the postoperative treatments used by patients with scoliosis.

Discussion

A major concern about prophylactic interventions for diseases is that the treatment will harm the patient. This is especially true for major spine surgery performed on adolescents with minimal symptoms. Although the incidence of perioperative complications in children undergoing corrective spinal surgery for AIS has been reported,^30-32 the effect of the surgery on the disease-specific HR-QOL outcomes of these individuals as young adults has not been previously studied. Over the past few decades, a paradigm shift in understanding health and disability has occurred, with increased emphasis being placed on HR-QOL outcomes measures and understanding disability as relating to a measureable impact of the functioning of an individual after a change in health or environment. This change was substantiated when the World Health Organization endorsed the International Classification of Functioning, Disability and Health.³³ In light of this shift, we present the disease-specific and general HR-QOL outcomes of young adults who had undergone surgical correction for spinal deformity during adolescence, as well as their associated complications and reoperations, in an attempt to identify targets for improvement.

Our patient-reported outcomes demonstrated a high incidence of occasional back pain, activity-related complaints, and limited ROM. Comparison of our cohort’s SRS-22R outcomes with previously published normative values for the unaffected adolescent population^28,34 suggests worse scores for the disease-specific SRS-22R domains of pain and appearance. In 2012, Daubs and colleagues³⁴ reported that normative scores on various SRS-22 domains were statistically lower with age (scores decreased from age 10 to age 19 years). Both Verma and colleagues²⁸ and Daubs and colleagues³⁴ reported lower scores for females than for males. Therefore, it is unclear whether the differences observed in our cohort may be accounted for by the larger proportion of females compared with the normative data.

General health scores on the SF-12 were similar to the population norm (mean [SD]) of 50 (10) referenced by Ware and colleagues.¹⁶ These findings suggest that, though pain and appearance may be statistically lower in our cohort—as measured with the SRS-22R—the cohort’s spine-related symptoms do not seem to lower its general health. Eighty-five percent of the patients were working at the time of the survey, further supporting a relatively normal level of overall function. In a retrospective review by Takayama and colleagues,⁹ similar results were found with regard to working after AIS fusion surgery. Of 32 patients treated surgically for scoliosis, at a mean of 21.1 years after the index fusion 27 (84.4%) were or had been engaged in various occupations without marked difficulty.

Our results in a cohort of patients with segmental instrumentation using hooks are similar to results in other studies of long-term HR-QOL measures in patients with AIS and Harrington rod instrumentation. Danielsson and Nachemson³⁵ evaluated patients with surgically treated AIS with at least 20-year follow-up and reported that, in their surgical cohort with a mean age of 39.7 years, mean SF-36 PCS score was 50.9, and mean SF-36 MCS score was 50.2. In a recent study of patients with AIS and Harrington rod instrumentation, those of a mean age of 32.3 years had a mean score of 50.9 for both SF-36 PCS and SF-36 MCS.³⁶

Regression analysis identified only smoking as a predictor of SRS-22R Total scores. This finding, that smokers have a lower health state, is expected even in the general population.³⁷ Interestingly, bracing before surgery, Lenke type, surgery type, number of levels fused, lowest instrumented vertebra, incidence of perioperative complications, percentage curve correction, postoperative sagittal and coronal balance, and need for revision surgery did not influence HR-QOL measures in this cohort.

Our cohort’s incidence of occasional back pain was 76% (90/118 patients). Other reports have had similar findings. In 2012, Bas and colleagues³⁸ studied self-reported pain in 126 consecutive patients with scoliosis and instrumented fusion. In their cohort, “most participants reported ‘no pain’ (38.5%) or ‘mild pain’ (30.8%) and 72.1% of participants reported a current work/school activity level of 100% normal.” Also in 2012, Rushton and Grevitt³⁹ reported on a review and statistical analysis of the literature on HR-QOL in adolescents with untreated AIS and in unaffected adolescents. Their goal was to identify whether there were any differences in HR-QOL and, if so, whether they were clinically relevant. The authors concluded that pain and self-image tended to be statistically lower among cohorts with AIS but that only self-image was consistently different clinically between untreated patients with AIS and their unaffected peers.

Cosmetic complaints, though less common than functional concerns, affected a substantial percentage of our cohort. Waistline imbalance complaints were more common than rib prominence or scar-related complaints. The validity of patient-reported waistline imbalance is not known but may contribute to the SRS-22R outcomes in this cohort, particularly with regard to appearance scores. Respiratory symptoms, particularly those related to shortness of breath, were reported by 15% of patients. Respiratory symptoms may be in part secondary to underlying lung disease; smoking was reported by 21% of patients and asthma by 9%.

Few additional postoperative treatments were reported by patients. The most common treatment was regular use of NSAIDs (21%), followed by postoperative physical therapy (12%). Opiate medication use and spinal injections were rare—consistent with results reported by Danielsson and Nachemson³⁵ in 2003.

Implant-related complaints, including painful instrumentation (13%) and implant prominence (9%), were some of the most common complaints in our study group. Although not all symptomatic instrumentation required surgical revision, 7 (50%) of the 14 additional spine surgeries were related to painful and/or prominent posterior instrumentation. Additional spine surgery was reported in 11.9% of our patients. Other indications for reoperation were disc herniation, crankshaft phenomenon, nonunion, and adjacent-level degeneration. Our rate of revision surgery is supported by the literature. In 2009, Luhmann and colleagues⁴⁰ reported that 41 (3.9%) of 1057 primary spine fusions for idiopathic scoliosis required reoperation; the indications included infection (16/1057, 1.5%), pseudarthrosis (12, 1.1%), and painful/prominent implant (7, 0.7%). Richards and colleagues⁴¹ similarly reported on 1046 patients who underwent fusion for AIS. Of these patients, 135 underwent 172 repeat surgical interventions (12.9% reoperation rate), with 29 (21.5%) of the 135 undergoing 2 or more separate procedures. The most common reasons for reoperation were infection, symptomatic implant, and pseudarthrosis. The authors concluded that repeat surgeries were relatively common after the initial surgical procedures. Having a clearer understanding of instrumentation-related complaints and reoperations may lead to improvement in this surgeon-controlled variable.

There are limitations to this study. The data regarding clinical courses were collected by retrospective chart review, which has known limitations. To offset this, we collected prospective outcome data with use of the SF-12, the SRS-22R, and a spine-related complaints questionnaire. No control group was available for comparison of outcomes in our cohort. We used the SF-12 and previously published normative values for the SRS-22R for comparison with population norms. Such comparisons have inherent limitations, as the groups vary by sex and mean age; our cohort was primarily female and more than a decade older than the controls.

Only 35% of the patients who met the inclusion criteria had complete data that could be included in our analysis. Although there was no statistically significant difference in demographics between patients with and without follow-up data available, this low response rate could have introduced selection bias. Ideally, patients should have been seen in clinic, standing radiographs should have been taken, and pulmonary function tests should have been performed. However, these patients were asymptomatic, and ethical and insurance issues prevented those actions. Thus, any radiographic changes occurring over the intervening years, from the last clinic visit to completion of the surveys, were not documented. This situation may or may not have limited our findings, as other authors have found low correlation between radiographic outcomes and clinical outcome measures.^13,14,19,36 During the period when these surgeries were performed, segmental spine instrumentation with hooks was the standard of care for deformity correction in AIS; therefore, all posterior instrumentations were done with hook-only segmental fixation. Current pedicle screw–based techniques that allow for additional correction of the deformity may provide different outcomes in the future.

We think that, despite the inherent limitations of this study, our data will be useful in the treatment of AIS. Our results suggest that postoperative spinal complaints are common and that, compared with an unaffected adolescent population, patients with AIS score significantly lower on pain and appearance domains of outcomes testing at a mean of 12.7 years after index fusion. Nevertheless, the outcomes do not seem to be of sufficient severity to affect general health and QOL as measured by outcomes testing.

Spinal deformity correction is performed to prevent impaired pulmonary function and spine-related disability later in life.^42,43 Thus, longer-term studies, involving patients in their fifth and sixth decades of life, are needed to determine whether patients with AIS will have QOL outcomes, pulmonary function, and spine-related problems similar to those in the general population. In this cohort of young adults, smoking status was the only predictor of HR-QOL measures, and spinal deformity correction did not lead to decreased HR-QOL.

The goal of surgical treatment of adolescent idiopathic scoliosis (AIS) is to prevent disability associated with curve progression.¹ Early studies tended to focus on radiographic measures, such as curve correction and sagittal balance, rather than on improvements in quality of life (QOL).^2-5 Although studies have reported on QOL in patients treated surgically for scoliosis,^6-11 these studies were largely limited by small sample size and inclusion of patients with congenital and neuromuscular scoliosis,⁹ lack of a generic measure of QOL,^6,7 or lack of surgical treatment of patients in the cohort.¹⁰

We conducted a study to determine disease-specific and general health-related QOL (HR-QOL) in young adults who underwent surgical correction of their spinal deformity during adolescence and to evaluate associated complications and reoperations.

Materials and Methods

After obtaining institutional review board approval, we queried the surgical database of a large metropolitan tertiary referral center for consecutive patients who had undergone spine deformity correction between the ages of 10 and 17 years (January 1993–December 2003). Hospital and medical records were retrospectively reviewed to confirm the diagnosis of AIS. Patients with congenital, neuromuscular, juvenile, or infantile scoliosis were excluded. Patients with intraspinal pathology (eg, tethered cord, syringomyelia), developmental delay, chromosomal abnormality, or congenital heart disease were also excluded. Patients were contacted by mail or telephone, and the Scoliosis Research Society–22R (SRS-22R)^12-15 and the Short Form–12 (SF-12)¹⁶ were administered. Standard demographic and surgical data were also collected.

The SRS-22R is a scoliosis-specific HR-QOL questionnaire with 22 items, 5 domains (pain, activity, appearance, mental, satisfaction), and a total score.^12-15 Each domain score ranges from 1 to 5 (higher scores indicating better outcomes). The SRS-22R is the outcome instrument most widely used to measure HR-QOL changes in patients with scoliosis, and it is available in several languages.^17-26

The SF-12, a 12-item self-administered short-form health status survey developed in the Medical Outcomes Study, measures patient-based health status. Two composite scores can be calculated: physical composite summary (PCS) and mental composite summary (MCS).¹⁶ Using norm-based scoring, all domain scales have a mean (SD) of 50 (10) based on the general 1998 US population. Thus, scores under 50 fall below the general population mean.

In addition, patients were surveyed to determine the incidence of spine-related symptoms and complaints, including activity limitations, rib prominence, waistline asymmetry, back pain, limited range of motion (ROM), shortness of breath, wound/scar problems, lung disease/asthma, heart disease, high blood pressure, and arthritis. Data regarding postoperative treatment regimens of physical therapy, narcotic pain medication, spinal/epidural injections, and nonsteroidal anti-inflammatory drug (NSAID) use were collected. Patients were also queried regarding their current working status and smoking status.

Standard demographic and surgical data were collected from hospital and office charts and radiographs. Data collected included history of bracing, age at index surgery, number of levels fused, surgical approach (anterior, posterior, combined), postoperative complications (eg, ileus, wound infection, anemia, pneumonia), and immediate preoperative and final postoperative radiographic measures. Data on need for subsequent revision surgery and indications for revision surgery were also collected.

Preoperative and latest follow-up radiographs were measured to determine curve magnitude, sagittal and coronal balance, and percentage curve correction. Coronal balance was defined as the distance between a plumb line drawn vertically from the spinous process of C7 and the central sacral line on full-length posteroanterior radiographs. Sagittal balance was defined as the distance of a plumb line drawn vertically from the center of the body of C7 and the posterosuperior endplate of S1.²⁷

Regression analysis was performed to identify factors predictive of SRS-22R total scores. Factors included in the analysis were sex, age at surgery, Lenke type, surgery type (anterior, posterior, anteroposterior), number of levels fused, lowest instrumented vertebra, perioperative complications, percentage curve correction, postoperative coronal and sagittal balance, smoking status, and need for revision surgery. Although age and sex were considered variables outside the surgeon’s control, they were included in the model, as previous studies have shown that SRS scores varied by age and sex both in adolescents²⁸ and adults.²⁹ Significance was set at P < .01. All data analysis was performed with IBM SPSS Version 19.0 (Somers, New York).

Results

Of the 384 postoperative patients identified for study inclusion, 134 (35%) completed surveys. Sixteen patients with nonidiopathic scoliosis were excluded, leaving 118 available for analysis. Of the remaining patients, 248 (64%) could not be contacted because of a change in address or phone number. Two patients (1%) were unwilling to complete survey requests. There was no statistically significant difference in demographics between patients with and without follow-up data available. Demographics are summarized in Table 1. There were 109 females (92%). Mean (SD) age at surgery was 14.1 (1.9) years. Only 37 (31%) were braced before surgery. Table 2 summarizes the radiographic data. Mean (SD) major Cobb angle was 49.7° (7.8°). Eighty-five patients (72%) underwent posterior fusion with instrumentation using hooks only; another 16 (14%) had anterior-only surgery, and another 17 (14%) had combined anterior-posterior surgery. A mean of 7.8 levels were fused. Index surgery data and lowest instrumented vertebra distribution are summarized in Table 3. Mean (SD) percentage curve correction was 48.9% (8.4%).

Seven patients had a total of 8 perioperative complications: anemia requiring transfusion (2), ileus necessitating nasogastric tube insertion (2), superficial wound infection treated with oral antibiotics and local wound care (2), wound drainage and erythema (1), and pneumonia (1). Mean (SD) length of clinical and radiographic follow-up was 57.9 (36.3) months.

Table 4 summarizes the long-term complications. Of the 38 patients with long-term complications, 14 required reoperation. The indications were disc herniation (2 patients), painful instrumentation (7), crankshaft phenomenon (1), nonunion (1), and adjacent-level degeneration (3). Both disc herniations were at L5–S1, several segments below the distal extent of the fusion. Of the 7 patients who had painful instrumentation removed, 6 had the entire construct removed, and 1 had the proximal half of a rod taken out. The 3 patients with adjacent-level degeneration had stenosis at the distal end of the construct—at L5–S1 (2 patients) or L2–L3 (1 patient).

Mean (SD) time between surgery and completion of the surveys/questionnaires was 12.7 (3.2) years (range, 10-18 years). Mean age of respondents was 26.8 years. Twenty-five respondents (21%) were smokers. Mean (SD) outcome scores were 50.9 (9.4) for SF-12 PCS and 49.4 (10.2) for SF-12 MCS. Eighteen patients (15%) had SF-12 PCS scores 1 SD below normal, and 15 (13%) had SF-12 MCS scores 1 SD below normal. Mean (SD) SRS-22R Total score was 4.0 (0.7). Means, standard deviations, and distribution of SRS domain scores are summarized in Table 5. Of the variables, only current smoking (P < .001) was predictive of SRS-22R Total scores, accounting for 20% of their variability (Table 6).

One hundred patients (85%) had jobs, mostly desk jobs. The postoperative limitations most commonly reported are summarized in Table 7. These included at least intermittent back pain in 90 patients (76%), limited ROM in 52 (44%), and activity limitations in 54 (46%). Less common limitations were waistline imbalance in 41 (35%), rib prominence in 28 (24%), wound/scar problems in 18 (15%), and shortness of breath in 18 (15%). Other related medical problems were lung disease/asthma in 11 (9%), osteoarthritis/degenerative arthritis in 11 (9%), heart disease in 3 (3%), and high blood pressure in 2 (2%).

A minority of patients also participated in postoperative treatment regimens. The most common treatment was regular use of NSAIDs (25 patients, 21%). Other treatments were physical therapy (14, 12%), narcotic pain medication use (5, 4%), and epidural steroid injections (5, 4%). Table 8 summarizes the postoperative treatments used by patients with scoliosis.

Discussion

A major concern about prophylactic interventions for diseases is that the treatment will harm the patient. This is especially true for major spine surgery performed on adolescents with minimal symptoms. Although the incidence of perioperative complications in children undergoing corrective spinal surgery for AIS has been reported,^30-32 the effect of the surgery on the disease-specific HR-QOL outcomes of these individuals as young adults has not been previously studied. Over the past few decades, a paradigm shift in understanding health and disability has occurred, with increased emphasis being placed on HR-QOL outcomes measures and understanding disability as relating to a measureable impact of the functioning of an individual after a change in health or environment. This change was substantiated when the World Health Organization endorsed the International Classification of Functioning, Disability and Health.³³ In light of this shift, we present the disease-specific and general HR-QOL outcomes of young adults who had undergone surgical correction for spinal deformity during adolescence, as well as their associated complications and reoperations, in an attempt to identify targets for improvement.

Our patient-reported outcomes demonstrated a high incidence of occasional back pain, activity-related complaints, and limited ROM. Comparison of our cohort’s SRS-22R outcomes with previously published normative values for the unaffected adolescent population^28,34 suggests worse scores for the disease-specific SRS-22R domains of pain and appearance. In 2012, Daubs and colleagues³⁴ reported that normative scores on various SRS-22 domains were statistically lower with age (scores decreased from age 10 to age 19 years). Both Verma and colleagues²⁸ and Daubs and colleagues³⁴ reported lower scores for females than for males. Therefore, it is unclear whether the differences observed in our cohort may be accounted for by the larger proportion of females compared with the normative data.

General health scores on the SF-12 were similar to the population norm (mean [SD]) of 50 (10) referenced by Ware and colleagues.¹⁶ These findings suggest that, though pain and appearance may be statistically lower in our cohort—as measured with the SRS-22R—the cohort’s spine-related symptoms do not seem to lower its general health. Eighty-five percent of the patients were working at the time of the survey, further supporting a relatively normal level of overall function. In a retrospective review by Takayama and colleagues,⁹ similar results were found with regard to working after AIS fusion surgery. Of 32 patients treated surgically for scoliosis, at a mean of 21.1 years after the index fusion 27 (84.4%) were or had been engaged in various occupations without marked difficulty.

Our results in a cohort of patients with segmental instrumentation using hooks are similar to results in other studies of long-term HR-QOL measures in patients with AIS and Harrington rod instrumentation. Danielsson and Nachemson³⁵ evaluated patients with surgically treated AIS with at least 20-year follow-up and reported that, in their surgical cohort with a mean age of 39.7 years, mean SF-36 PCS score was 50.9, and mean SF-36 MCS score was 50.2. In a recent study of patients with AIS and Harrington rod instrumentation, those of a mean age of 32.3 years had a mean score of 50.9 for both SF-36 PCS and SF-36 MCS.³⁶

Regression analysis identified only smoking as a predictor of SRS-22R Total scores. This finding, that smokers have a lower health state, is expected even in the general population.³⁷ Interestingly, bracing before surgery, Lenke type, surgery type, number of levels fused, lowest instrumented vertebra, incidence of perioperative complications, percentage curve correction, postoperative sagittal and coronal balance, and need for revision surgery did not influence HR-QOL measures in this cohort.

Our cohort’s incidence of occasional back pain was 76% (90/118 patients). Other reports have had similar findings. In 2012, Bas and colleagues³⁸ studied self-reported pain in 126 consecutive patients with scoliosis and instrumented fusion. In their cohort, “most participants reported ‘no pain’ (38.5%) or ‘mild pain’ (30.8%) and 72.1% of participants reported a current work/school activity level of 100% normal.” Also in 2012, Rushton and Grevitt³⁹ reported on a review and statistical analysis of the literature on HR-QOL in adolescents with untreated AIS and in unaffected adolescents. Their goal was to identify whether there were any differences in HR-QOL and, if so, whether they were clinically relevant. The authors concluded that pain and self-image tended to be statistically lower among cohorts with AIS but that only self-image was consistently different clinically between untreated patients with AIS and their unaffected peers.

Cosmetic complaints, though less common than functional concerns, affected a substantial percentage of our cohort. Waistline imbalance complaints were more common than rib prominence or scar-related complaints. The validity of patient-reported waistline imbalance is not known but may contribute to the SRS-22R outcomes in this cohort, particularly with regard to appearance scores. Respiratory symptoms, particularly those related to shortness of breath, were reported by 15% of patients. Respiratory symptoms may be in part secondary to underlying lung disease; smoking was reported by 21% of patients and asthma by 9%.

Few additional postoperative treatments were reported by patients. The most common treatment was regular use of NSAIDs (21%), followed by postoperative physical therapy (12%). Opiate medication use and spinal injections were rare—consistent with results reported by Danielsson and Nachemson³⁵ in 2003.

Implant-related complaints, including painful instrumentation (13%) and implant prominence (9%), were some of the most common complaints in our study group. Although not all symptomatic instrumentation required surgical revision, 7 (50%) of the 14 additional spine surgeries were related to painful and/or prominent posterior instrumentation. Additional spine surgery was reported in 11.9% of our patients. Other indications for reoperation were disc herniation, crankshaft phenomenon, nonunion, and adjacent-level degeneration. Our rate of revision surgery is supported by the literature. In 2009, Luhmann and colleagues⁴⁰ reported that 41 (3.9%) of 1057 primary spine fusions for idiopathic scoliosis required reoperation; the indications included infection (16/1057, 1.5%), pseudarthrosis (12, 1.1%), and painful/prominent implant (7, 0.7%). Richards and colleagues⁴¹ similarly reported on 1046 patients who underwent fusion for AIS. Of these patients, 135 underwent 172 repeat surgical interventions (12.9% reoperation rate), with 29 (21.5%) of the 135 undergoing 2 or more separate procedures. The most common reasons for reoperation were infection, symptomatic implant, and pseudarthrosis. The authors concluded that repeat surgeries were relatively common after the initial surgical procedures. Having a clearer understanding of instrumentation-related complaints and reoperations may lead to improvement in this surgeon-controlled variable.

There are limitations to this study. The data regarding clinical courses were collected by retrospective chart review, which has known limitations. To offset this, we collected prospective outcome data with use of the SF-12, the SRS-22R, and a spine-related complaints questionnaire. No control group was available for comparison of outcomes in our cohort. We used the SF-12 and previously published normative values for the SRS-22R for comparison with population norms. Such comparisons have inherent limitations, as the groups vary by sex and mean age; our cohort was primarily female and more than a decade older than the controls.

Only 35% of the patients who met the inclusion criteria had complete data that could be included in our analysis. Although there was no statistically significant difference in demographics between patients with and without follow-up data available, this low response rate could have introduced selection bias. Ideally, patients should have been seen in clinic, standing radiographs should have been taken, and pulmonary function tests should have been performed. However, these patients were asymptomatic, and ethical and insurance issues prevented those actions. Thus, any radiographic changes occurring over the intervening years, from the last clinic visit to completion of the surveys, were not documented. This situation may or may not have limited our findings, as other authors have found low correlation between radiographic outcomes and clinical outcome measures.^13,14,19,36 During the period when these surgeries were performed, segmental spine instrumentation with hooks was the standard of care for deformity correction in AIS; therefore, all posterior instrumentations were done with hook-only segmental fixation. Current pedicle screw–based techniques that allow for additional correction of the deformity may provide different outcomes in the future.

We think that, despite the inherent limitations of this study, our data will be useful in the treatment of AIS. Our results suggest that postoperative spinal complaints are common and that, compared with an unaffected adolescent population, patients with AIS score significantly lower on pain and appearance domains of outcomes testing at a mean of 12.7 years after index fusion. Nevertheless, the outcomes do not seem to be of sufficient severity to affect general health and QOL as measured by outcomes testing.

Spinal deformity correction is performed to prevent impaired pulmonary function and spine-related disability later in life.^42,43 Thus, longer-term studies, involving patients in their fifth and sixth decades of life, are needed to determine whether patients with AIS will have QOL outcomes, pulmonary function, and spine-related problems similar to those in the general population. In this cohort of young adults, smoking status was the only predictor of HR-QOL measures, and spinal deformity correction did not lead to decreased HR-QOL.

Carcinoma of the lung is the most common lethal form of cancer in both men and women worldwide.¹ It accounts for more deaths than the next 3 most common cancers combined. In 2012, 160,000 Americans are estimated to have died from lung cancer.¹ Lung cancer is known to have a high metastatic potential for the brain, bones, adrenal glands, lungs, and liver.² Orthopedic manifestations frequently include bony metastasis, most commonly the vertebrae (42%), ribs (20%), and pelvis (18%).³ Acral metastatic disease is defined as metastasis distal to the elbow or the knee. Bony acral metastases from lung carcinoma to the upper and lower extremities are extremely uncommon, accounting for only 1% each of total bone metastases from carcinoma of the lung.³ Metastases to the bones of the hand are even rarer. Only 0.1% of metastatic disease from any type of carcinoma or sarcoma manifests as metastasis in the hand.⁴ There are only a few reports in the literature of soft-tissue or muscular metastasis to the hand from a carcinoma. Of these cases, the majority are caused by metastatic lung carcinoma.^5-9 There are no reports in the literature of metastatic disease of squamous cell origin affecting the soft tissues of the hand.

We present a case of a man with known metastatic squamous cell carcinoma of the lung who presented with acral soft-tissue metastatic disease. This report highlights a rare clinical scenario that has not been reported in the literature. The report also emphasizes a rare but important consideration for clinicians who encounter acral soft-tissue lesions in patients with a history of a primary carcinoma. The patient provided written informed consent for print and electronic publication of this case report.

Case Report

A 56-year-old man presented with right-sided pleuritic flank pain, along with a 30-lb weight loss over a 6-month period. A computed tomographic scan revealed a 5.58×3.7-cm cavitary lesion in the right lower lobe with abutment of the posterior chest wall (Figure 1). He underwent biopsy and staging, and was found to be T3N1, with biopsy-proven well-differentiated bronchogenic squamous cell carcinoma. The patient then underwent right lower and middle lobectomy with concomitant en-bloc resection of the posterior portion of ribs 7 to 11, along with mediastinal lymph-node dissection with negative margins. After surgery, he was treated with 4 cycles of adjuvant chemotherapy with cisplatin and docetaxel.

Six months after surgery, the patient began to complain of right-hand pain isolated to the thenar eminence. He also described swelling and significant pain with active or passive movement of the thumb and with relatively mild-to-moderate palpation of the area. The patient reported that the functioning of his thumb deteriorated rapidly over the course of about 1 month. On physical examination, he was neurovascularly intact with no apparent deficit in sensation of his right hand. There was no erythema or overlying skin changes. His right thenar eminence was mildly enlarged as compared with the left, and a firm, focal mass was readily palpated. Range of motion at the metacarpophalangeal joint of the thumb and index finger was limited because of pain. Thumb opposition was markedly limited. After a detailed history and physical examination, we were concerned about possible deep space infection, old hematoma, or possible metastatic disease. Magnetic resonance imaging (MRI) was ordered to evaluate the palpable mass.

Radiographically, localized soft-tissue swelling was present on the palmar surface of the hand obliquely overlying the index finger metacarpal (Figures 2, 3). On MRI, the lesion measured approximately 1.8×3.3 cm and was isointense to slightly hyperintense diffusely with central hyperintensity on T1 images (Figure 4). On T2 and short tau inversion recovery images, the lesion was more strikingly hyperintense and infiltrative in appearance (Figure 5). Postcontrast images showed avid enhancement peripherally, with central nonenhancement consistent with necrosis in the adductor pollicis.

We performed a biopsy of the lesion with the aid of immediate adequacy by fine needle aspiration cytology. We saw mitotically active malignant cells with large nuclei, high nuclear-to-cytoplasmic ratios, nucleoli, and dense cytoplasm, suggesting a metastatic squamous cell carcinoma. Because infection was part of the differential, it is pertinent to note that there was no significant inflammatory infiltrate. The core biopsy was consistent with metastatic lung cancer (Figure 6).

Discussion

This patient presented an interesting diagnostic challenge, particularly because of his previous malignancy. The differential diagnosis of acute onset thenar pain without history of trauma would include encompassing soft-tissue abscess, osteomyelitis, and infectious myositis. Soft-tissue hematoma is also in the differential for this patient, especially given the malignancy. Bony metastasis should be considered in this patient given the propensity of lung carcinoma to metastasize to bone. The location would certainly be atypical, with metastasis to the bones of the forearm or hand representing only 0.1% of all metastasis of any type of primary carcinoma or sarcoma.⁴ Primary bone or soft-tissue sarcoma should also be considered. Some authors have also suggested that necrosis, peritumoral edema-like signal, and lobulation are more common with skeletal muscle metastasis than with a primary sarcoma.¹⁰ In this case, the degree of surrounding postcontrast enhancement made simple muscle tear with hematoma unlikely, despite the  presence of increased T1 signal. The lack of evidence for localized infection and the presence of a firm focal mass on physical examination made tumor more likely than infection.        

Acrometastasis

Metastatic disease distal to the elbow and knee is very rare; specifically, metastatic disease of the hands or feet accounts for approximately 0.1% of all metastases.⁴ Carcinoma of the lung accounts for 44% to 47% of all acrometastasis.^11,12 When hand acrometastasis is considered, the right hand accounts for 55% of bony cases, likely because of hand dominance, although approximately 10% of patients had bilateral acral metastatic disease.¹² The underlying mechanism of acrometastasis remains unclear; however, some authors have postulated that it may result from an increase in vascularity or a trauma to the affected extremity.^12,13 Flynn and colleagues¹² reviewed the literature and reported a total of 257 cases of acral metastasis to the hand; they found that the median age at presentation was 58 years. Men were more than twice as likely to be affected when compared with women. Most commonly, the primary malignancies were in the lung (44%), kidney (12%), and breast (10%). The authors also reported less common cases of acral metastasis with primary malignancies located in the stomach, liver, rectum, prostate, and colon. Most commonly, these metastases were found in the distal phalynx, followed by the metacarpals, proximal phalynx, and middle phalynx.¹²

Soft-Tissue Metastasis

Skeletal muscle metastasis occurs in 0.8% to 17.5% of metastatic neoplasms.^14-17 Studies in lung cancer patients have also revealed a low prevalence of muscular metastasis (0% to 0.8%).¹⁶ The rarity of muscular metastatic disease has been attributed to local inhibition of tumor survival secondary to muscle contraction, increased diffusing capacity of enzymes and immune cells, and extreme variability in blood flow and pH, lactate, and oxygen concentration. Skeletal muscular metastases most commonly arise from the lung, kidneys, colon, or melanoma.¹⁶ In a recent large series of more than 1400 patients imaged for soft-tissue masses, 2.5% were metastatic.¹⁸ There are only 2 reports of soft-tissue metastatic disease involving the hand: one from a patient with a thyroid carcinoma and the other from a patient with a lung adenocarcinoma.¹⁸ Soft-tissue metastatic disease from squamous cell carcinoma distal to the wrist has never been reported in the literature.  

Acral Soft-Tissue Metastasis

A review from 2012 found 264 cases of skeletal muscle metastasis from 151 articles.⁶ Only 2 (0.75%) of these patients, as reported above, had a soft-tissue metastasis distal to the wrist.^6,17

Conclusion

We report the first known case of a soft-tissue metastasis distal to the wrist from a primary bronchogenic squamous cell carcinoma. This report highlights the extremely uncommon presentation of soft-tissue acral metastatic disease of a bronchogenic squamous cell carcinoma of the lung. Although exceedingly rare, oncologists and physicians who manage pathology of the hand should consider metastatic disease when evaluating a patient with complaints of hand pain and a soft-tissue mass, especially in a patient with a known primary malignancy.

Carcinoma of the lung is the most common lethal form of cancer in both men and women worldwide.¹ It accounts for more deaths than the next 3 most common cancers combined. In 2012, 160,000 Americans are estimated to have died from lung cancer.¹ Lung cancer is known to have a high metastatic potential for the brain, bones, adrenal glands, lungs, and liver.² Orthopedic manifestations frequently include bony metastasis, most commonly the vertebrae (42%), ribs (20%), and pelvis (18%).³ Acral metastatic disease is defined as metastasis distal to the elbow or the knee. Bony acral metastases from lung carcinoma to the upper and lower extremities are extremely uncommon, accounting for only 1% each of total bone metastases from carcinoma of the lung.³ Metastases to the bones of the hand are even rarer. Only 0.1% of metastatic disease from any type of carcinoma or sarcoma manifests as metastasis in the hand.⁴ There are only a few reports in the literature of soft-tissue or muscular metastasis to the hand from a carcinoma. Of these cases, the majority are caused by metastatic lung carcinoma.^5-9 There are no reports in the literature of metastatic disease of squamous cell origin affecting the soft tissues of the hand.

We present a case of a man with known metastatic squamous cell carcinoma of the lung who presented with acral soft-tissue metastatic disease. This report highlights a rare clinical scenario that has not been reported in the literature. The report also emphasizes a rare but important consideration for clinicians who encounter acral soft-tissue lesions in patients with a history of a primary carcinoma. The patient provided written informed consent for print and electronic publication of this case report.

Case Report

A 56-year-old man presented with right-sided pleuritic flank pain, along with a 30-lb weight loss over a 6-month period. A computed tomographic scan revealed a 5.58×3.7-cm cavitary lesion in the right lower lobe with abutment of the posterior chest wall (Figure 1). He underwent biopsy and staging, and was found to be T3N1, with biopsy-proven well-differentiated bronchogenic squamous cell carcinoma. The patient then underwent right lower and middle lobectomy with concomitant en-bloc resection of the posterior portion of ribs 7 to 11, along with mediastinal lymph-node dissection with negative margins. After surgery, he was treated with 4 cycles of adjuvant chemotherapy with cisplatin and docetaxel.

Six months after surgery, the patient began to complain of right-hand pain isolated to the thenar eminence. He also described swelling and significant pain with active or passive movement of the thumb and with relatively mild-to-moderate palpation of the area. The patient reported that the functioning of his thumb deteriorated rapidly over the course of about 1 month. On physical examination, he was neurovascularly intact with no apparent deficit in sensation of his right hand. There was no erythema or overlying skin changes. His right thenar eminence was mildly enlarged as compared with the left, and a firm, focal mass was readily palpated. Range of motion at the metacarpophalangeal joint of the thumb and index finger was limited because of pain. Thumb opposition was markedly limited. After a detailed history and physical examination, we were concerned about possible deep space infection, old hematoma, or possible metastatic disease. Magnetic resonance imaging (MRI) was ordered to evaluate the palpable mass.

Radiographically, localized soft-tissue swelling was present on the palmar surface of the hand obliquely overlying the index finger metacarpal (Figures 2, 3). On MRI, the lesion measured approximately 1.8×3.3 cm and was isointense to slightly hyperintense diffusely with central hyperintensity on T1 images (Figure 4). On T2 and short tau inversion recovery images, the lesion was more strikingly hyperintense and infiltrative in appearance (Figure 5). Postcontrast images showed avid enhancement peripherally, with central nonenhancement consistent with necrosis in the adductor pollicis.

We performed a biopsy of the lesion with the aid of immediate adequacy by fine needle aspiration cytology. We saw mitotically active malignant cells with large nuclei, high nuclear-to-cytoplasmic ratios, nucleoli, and dense cytoplasm, suggesting a metastatic squamous cell carcinoma. Because infection was part of the differential, it is pertinent to note that there was no significant inflammatory infiltrate. The core biopsy was consistent with metastatic lung cancer (Figure 6).

Discussion

This patient presented an interesting diagnostic challenge, particularly because of his previous malignancy. The differential diagnosis of acute onset thenar pain without history of trauma would include encompassing soft-tissue abscess, osteomyelitis, and infectious myositis. Soft-tissue hematoma is also in the differential for this patient, especially given the malignancy. Bony metastasis should be considered in this patient given the propensity of lung carcinoma to metastasize to bone. The location would certainly be atypical, with metastasis to the bones of the forearm or hand representing only 0.1% of all metastasis of any type of primary carcinoma or sarcoma.⁴ Primary bone or soft-tissue sarcoma should also be considered. Some authors have also suggested that necrosis, peritumoral edema-like signal, and lobulation are more common with skeletal muscle metastasis than with a primary sarcoma.¹⁰ In this case, the degree of surrounding postcontrast enhancement made simple muscle tear with hematoma unlikely, despite the  presence of increased T1 signal. The lack of evidence for localized infection and the presence of a firm focal mass on physical examination made tumor more likely than infection.        

Acrometastasis

Metastatic disease distal to the elbow and knee is very rare; specifically, metastatic disease of the hands or feet accounts for approximately 0.1% of all metastases.⁴ Carcinoma of the lung accounts for 44% to 47% of all acrometastasis.^11,12 When hand acrometastasis is considered, the right hand accounts for 55% of bony cases, likely because of hand dominance, although approximately 10% of patients had bilateral acral metastatic disease.¹² The underlying mechanism of acrometastasis remains unclear; however, some authors have postulated that it may result from an increase in vascularity or a trauma to the affected extremity.^12,13 Flynn and colleagues¹² reviewed the literature and reported a total of 257 cases of acral metastasis to the hand; they found that the median age at presentation was 58 years. Men were more than twice as likely to be affected when compared with women. Most commonly, the primary malignancies were in the lung (44%), kidney (12%), and breast (10%). The authors also reported less common cases of acral metastasis with primary malignancies located in the stomach, liver, rectum, prostate, and colon. Most commonly, these metastases were found in the distal phalynx, followed by the metacarpals, proximal phalynx, and middle phalynx.¹²

Soft-Tissue Metastasis

Skeletal muscle metastasis occurs in 0.8% to 17.5% of metastatic neoplasms.^14-17 Studies in lung cancer patients have also revealed a low prevalence of muscular metastasis (0% to 0.8%).¹⁶ The rarity of muscular metastatic disease has been attributed to local inhibition of tumor survival secondary to muscle contraction, increased diffusing capacity of enzymes and immune cells, and extreme variability in blood flow and pH, lactate, and oxygen concentration. Skeletal muscular metastases most commonly arise from the lung, kidneys, colon, or melanoma.¹⁶ In a recent large series of more than 1400 patients imaged for soft-tissue masses, 2.5% were metastatic.¹⁸ There are only 2 reports of soft-tissue metastatic disease involving the hand: one from a patient with a thyroid carcinoma and the other from a patient with a lung adenocarcinoma.¹⁸ Soft-tissue metastatic disease from squamous cell carcinoma distal to the wrist has never been reported in the literature.  

Acral Soft-Tissue Metastasis

A review from 2012 found 264 cases of skeletal muscle metastasis from 151 articles.⁶ Only 2 (0.75%) of these patients, as reported above, had a soft-tissue metastasis distal to the wrist.^6,17

Conclusion

We report the first known case of a soft-tissue metastasis distal to the wrist from a primary bronchogenic squamous cell carcinoma. This report highlights the extremely uncommon presentation of soft-tissue acral metastatic disease of a bronchogenic squamous cell carcinoma of the lung. Although exceedingly rare, oncologists and physicians who manage pathology of the hand should consider metastatic disease when evaluating a patient with complaints of hand pain and a soft-tissue mass, especially in a patient with a known primary malignancy.

Carcinoma of the lung is the most common lethal form of cancer in both men and women worldwide.¹ It accounts for more deaths than the next 3 most common cancers combined. In 2012, 160,000 Americans are estimated to have died from lung cancer.¹ Lung cancer is known to have a high metastatic potential for the brain, bones, adrenal glands, lungs, and liver.² Orthopedic manifestations frequently include bony metastasis, most commonly the vertebrae (42%), ribs (20%), and pelvis (18%).³ Acral metastatic disease is defined as metastasis distal to the elbow or the knee. Bony acral metastases from lung carcinoma to the upper and lower extremities are extremely uncommon, accounting for only 1% each of total bone metastases from carcinoma of the lung.³ Metastases to the bones of the hand are even rarer. Only 0.1% of metastatic disease from any type of carcinoma or sarcoma manifests as metastasis in the hand.⁴ There are only a few reports in the literature of soft-tissue or muscular metastasis to the hand from a carcinoma. Of these cases, the majority are caused by metastatic lung carcinoma.^5-9 There are no reports in the literature of metastatic disease of squamous cell origin affecting the soft tissues of the hand.

We present a case of a man with known metastatic squamous cell carcinoma of the lung who presented with acral soft-tissue metastatic disease. This report highlights a rare clinical scenario that has not been reported in the literature. The report also emphasizes a rare but important consideration for clinicians who encounter acral soft-tissue lesions in patients with a history of a primary carcinoma. The patient provided written informed consent for print and electronic publication of this case report.

Case Report

A 56-year-old man presented with right-sided pleuritic flank pain, along with a 30-lb weight loss over a 6-month period. A computed tomographic scan revealed a 5.58×3.7-cm cavitary lesion in the right lower lobe with abutment of the posterior chest wall (Figure 1). He underwent biopsy and staging, and was found to be T3N1, with biopsy-proven well-differentiated bronchogenic squamous cell carcinoma. The patient then underwent right lower and middle lobectomy with concomitant en-bloc resection of the posterior portion of ribs 7 to 11, along with mediastinal lymph-node dissection with negative margins. After surgery, he was treated with 4 cycles of adjuvant chemotherapy with cisplatin and docetaxel.

Six months after surgery, the patient began to complain of right-hand pain isolated to the thenar eminence. He also described swelling and significant pain with active or passive movement of the thumb and with relatively mild-to-moderate palpation of the area. The patient reported that the functioning of his thumb deteriorated rapidly over the course of about 1 month. On physical examination, he was neurovascularly intact with no apparent deficit in sensation of his right hand. There was no erythema or overlying skin changes. His right thenar eminence was mildly enlarged as compared with the left, and a firm, focal mass was readily palpated. Range of motion at the metacarpophalangeal joint of the thumb and index finger was limited because of pain. Thumb opposition was markedly limited. After a detailed history and physical examination, we were concerned about possible deep space infection, old hematoma, or possible metastatic disease. Magnetic resonance imaging (MRI) was ordered to evaluate the palpable mass.

Radiographically, localized soft-tissue swelling was present on the palmar surface of the hand obliquely overlying the index finger metacarpal (Figures 2, 3). On MRI, the lesion measured approximately 1.8×3.3 cm and was isointense to slightly hyperintense diffusely with central hyperintensity on T1 images (Figure 4). On T2 and short tau inversion recovery images, the lesion was more strikingly hyperintense and infiltrative in appearance (Figure 5). Postcontrast images showed avid enhancement peripherally, with central nonenhancement consistent with necrosis in the adductor pollicis.

We performed a biopsy of the lesion with the aid of immediate adequacy by fine needle aspiration cytology. We saw mitotically active malignant cells with large nuclei, high nuclear-to-cytoplasmic ratios, nucleoli, and dense cytoplasm, suggesting a metastatic squamous cell carcinoma. Because infection was part of the differential, it is pertinent to note that there was no significant inflammatory infiltrate. The core biopsy was consistent with metastatic lung cancer (Figure 6).

Discussion

This patient presented an interesting diagnostic challenge, particularly because of his previous malignancy. The differential diagnosis of acute onset thenar pain without history of trauma would include encompassing soft-tissue abscess, osteomyelitis, and infectious myositis. Soft-tissue hematoma is also in the differential for this patient, especially given the malignancy. Bony metastasis should be considered in this patient given the propensity of lung carcinoma to metastasize to bone. The location would certainly be atypical, with metastasis to the bones of the forearm or hand representing only 0.1% of all metastasis of any type of primary carcinoma or sarcoma.⁴ Primary bone or soft-tissue sarcoma should also be considered. Some authors have also suggested that necrosis, peritumoral edema-like signal, and lobulation are more common with skeletal muscle metastasis than with a primary sarcoma.¹⁰ In this case, the degree of surrounding postcontrast enhancement made simple muscle tear with hematoma unlikely, despite the  presence of increased T1 signal. The lack of evidence for localized infection and the presence of a firm focal mass on physical examination made tumor more likely than infection.        

Acrometastasis

Metastatic disease distal to the elbow and knee is very rare; specifically, metastatic disease of the hands or feet accounts for approximately 0.1% of all metastases.⁴ Carcinoma of the lung accounts for 44% to 47% of all acrometastasis.^11,12 When hand acrometastasis is considered, the right hand accounts for 55% of bony cases, likely because of hand dominance, although approximately 10% of patients had bilateral acral metastatic disease.¹² The underlying mechanism of acrometastasis remains unclear; however, some authors have postulated that it may result from an increase in vascularity or a trauma to the affected extremity.^12,13 Flynn and colleagues¹² reviewed the literature and reported a total of 257 cases of acral metastasis to the hand; they found that the median age at presentation was 58 years. Men were more than twice as likely to be affected when compared with women. Most commonly, the primary malignancies were in the lung (44%), kidney (12%), and breast (10%). The authors also reported less common cases of acral metastasis with primary malignancies located in the stomach, liver, rectum, prostate, and colon. Most commonly, these metastases were found in the distal phalynx, followed by the metacarpals, proximal phalynx, and middle phalynx.¹²

Soft-Tissue Metastasis

Skeletal muscle metastasis occurs in 0.8% to 17.5% of metastatic neoplasms.^14-17 Studies in lung cancer patients have also revealed a low prevalence of muscular metastasis (0% to 0.8%).¹⁶ The rarity of muscular metastatic disease has been attributed to local inhibition of tumor survival secondary to muscle contraction, increased diffusing capacity of enzymes and immune cells, and extreme variability in blood flow and pH, lactate, and oxygen concentration. Skeletal muscular metastases most commonly arise from the lung, kidneys, colon, or melanoma.¹⁶ In a recent large series of more than 1400 patients imaged for soft-tissue masses, 2.5% were metastatic.¹⁸ There are only 2 reports of soft-tissue metastatic disease involving the hand: one from a patient with a thyroid carcinoma and the other from a patient with a lung adenocarcinoma.¹⁸ Soft-tissue metastatic disease from squamous cell carcinoma distal to the wrist has never been reported in the literature.  

Acral Soft-Tissue Metastasis

A review from 2012 found 264 cases of skeletal muscle metastasis from 151 articles.⁶ Only 2 (0.75%) of these patients, as reported above, had a soft-tissue metastasis distal to the wrist.^6,17

Conclusion

We report the first known case of a soft-tissue metastasis distal to the wrist from a primary bronchogenic squamous cell carcinoma. This report highlights the extremely uncommon presentation of soft-tissue acral metastatic disease of a bronchogenic squamous cell carcinoma of the lung. Although exceedingly rare, oncologists and physicians who manage pathology of the hand should consider metastatic disease when evaluating a patient with complaints of hand pain and a soft-tissue mass, especially in a patient with a known primary malignancy.

Hip arthroscopy has experienced a dramatic increase in popularity, largely resulting from improvements in techniques and technology.^1,2 As with any procedure, there are complications associated with arthroscopy of the hip. These include neurapraxia, iatrogenic cartilage and labral injuries, postoperative bleeding, perineal skin necrosis, infection, intra-articular instrument breakage, intra-abdominal fluid extravasation, avascular necrosis, and femoral neck fracture.^1-4 Many of these have been attributed to the expected learning curve seen with any new procedure, and are less likely to occur as surgeons become more familiar with the procedure.¹ One rare but serious complication is anterior dislocation of the hip.^5-7

We present a patient who experienced an anterior hip dislocation and instability after hip arthroscopy, and was successfully treated with an anterior capsuloligamentous reconstruction. The patient provided written informed consent for print and electronic publication of this case report.

Case Report

An otherwise healthy 37-year-old woman presented to our clinic with a 6-month history of right groin pain and an occasional popping sensation during activity, which was unresponsive to hip-specific physical therapy. On physical examination, she was 5 ft 10 in tall, weighed 150 lbs, and appeared in excellent physical condition. She had no signs of systemic ligamentous laxity. She had an otherwise normal musculoskeletal, neurologic, and vascular examination in her bilateral lower extremities. She had a mild antalgic gait on the right leg.

The affected right hip could be flexed painfully to 120º, extended to 0º, adducted 20º, and abducted 45º. At 90º of flexion, her right hip could be externally rotated 30º and internally rotated 20º. Internal rotation during hip flexion beyond 90º caused sharp pain in the groin. Her normal left hip could be flexed to 120º, extended to 0º, adducted 30º, and abducted 60º. At 90º of flexion, her left hip could be externally rotated 50º and internally rotated 30º. She had negative Ober tests bilaterally but had tenderness along the right iliotibial band. She had negative Patrick and Gaenslen tests bilaterally. She had no tenderness in the area of either greater trochanter. 

Imaging evaluation included plain radiographs and a magnetic resonance arthrogram (MRA) of the right hip. The plain radiographs showed signs of femoroacetabular impingement, but no joint space narrowing, no dysplasia, and no retroversion of the acetabulum (Figures 1A, 1B). The MRA showed a degenerative peripheral tear of the anterosuperior labrum without significant cartilage wear (Figure 2).

Based upon her findings on physical examination and imaging, we recommended arthroscopic treatment of her right hip pathology. Thirteen months after initial presentation, we performed a right hip arthroscopy with the patient in the supine position. Through modified anterior and anterolateral portals, we used electrocautery to perform a capsulotomy from the 9 o’clock to 12 o’clock positions. A central compartment diagnostic arthroscopy showed mild degenerative fraying of the labrum from the 9 o’clock to 12 o’clock positions without signs of detachment. There was grade III chondral fraying near the articular margin in that same arc. The femoral articular cartilage appeared normal, as did the ligamentum teres. We used a shaver to gently débride the torn labrum down to stable tissue. The frayed cartilage on the acetabulum was also gently débrided.

Traction was released and the hip was flexed. Minimal capsular release and débridement were performed for adequate visualization of the peripheral compartment. A diagnostic examination revealed a significant cam-type impingement lesion from the 12 o’clock to 6 o’clock positions. We performed a femoral neck resection, with a proximal-distal dimension of 15 mm and a depth of 7 mm. A dynamic fluoroscopic examination of the hip joint showed no signs of impingement. In accordance with our standard protocol, the anterior capsulotomy was not repaired.

Postoperatively, the patient was instructed to perform toe-touch weight-bearing with crutches for 2 weeks and to advance to full weight-bearing over the next 2 weeks. She did not use a hip orthosis. She was also advised to avoid combined hip extension/external rotation maneuvers for the first 4 weeks. She took part in a formal hip-specific physical therapy program for a total of 12 weeks. She was seen in clinic at 2, 6, and 12 weeks postoperatively and appeared to have had a typical, uneventful course. We advised her to gradually return to normal activities as tolerated at the 12-week visit.

Four months after the procedure, the patient returned to our clinic for evaluation after a right hip dislocation. Two days prior, she was at a school function with her child and experienced sudden pain and inability to bear weight after she extended and externally rotated her right hip in a low-energy manner. She was taken to an emergency room and found to have an anterior dislocation of the right hip (Figure 3), which was concentrically reduced under anesthesia.

Upon questioning, she reported having had feelings of mild instability of the right hip during demanding activities (jogging, yoga) after sustaining a low-energy fall 1 month prior to her dislocation. On examination, she had significant apprehension about the right hip during gentle external rotation maneuvers. An MRA 2 weeks after the dislocation showed a large defect of the anterosuperior capsuloligamentous complex measuring 4 cm from medial to lateral and 2.5 cm superior to inferior (Figure 4). No loose bodies, chondral injuries, or recurrent tears of the labrum were seen. Typical postoperative changes were observed at the femoral head-neck junction.

Initially, we recommended nonoperative management with 6 weeks of toe-touch weight-bearing and strict avoidance of hip extension–external rotation maneuvers. No hip orthosis was used. After this period, the patient advanced to full weight-bearing and continued in hip-specific physical therapy. Despite continued therapy and avoidance of provocative maneuvers, the patient reported persistent feelings of right hip instability with significant apprehension during extension and external rotation of the right hip. A repeat MRA 4 months after the hip dislocation showed a persistent defect in the anterosuperior capsuloligamentous complex and no signs of avascular necrosis. After 6 months of conservative treatment, we recommended an open capsulorrhaphy of the right hip with autograft iliotibial band reconstruction of the iliofemoral ligament and capsule.

Six months after the dislocation, the patient underwent the recommended procedure. After induction of general anesthesia, she was placed in the supine position on a standard operating table. A Smith-Petersen approach was used to visualize the anterior hip structures. During deep dissection, we observed a large defect, measuring 2.5×4 cm (Figure 5A), in the anterior hip capsule, with only a thin pseudocapsule covering the femoral head. Extensive mobilization of the anterior capsule was unsuccessful.

The decision was made to harvest a graft from the patient’s ipsilateral iliotibial band. A skin incision was made over the iliotibial band in the distal midthigh region, and a 2.5×4-cm graft was harvested from the central portion of the iliotibial band. An arthrotomy was performed on the hip joint (Figure 5B). The labrum appeared healthy without recurrent tearing or fraying, and other than focal thinning on the superior acetabulum, the cartilage appeared healthy. A double-loaded anchor was placed in the supra-acetabular region, and the sutures were passed through the graft. Then, No. 2 nonabsorbable sutures were sequentially placed between the capsular remnant and the graft medially, inferiorly, and laterally. The graft was placed into position (Figure 5C) and the sutures were tied (Figure 5D).

Postoperatively, the patient was allowed toe-touch weight-bearing for 6 weeks, with strict avoidance of extension–external rotation maneuvers. She participated in a 12-week course of physical therapy with gradual advancement of activities. About a year after the capsulorrhaphy, she was able to resume all previous activities with only occasional low-level discomfort. She returned to the clinic 16 months after the capsulorrhaphy complaining of increased pain with long-distance running but denied feelings of instability. We performed an intra-articular hip injection under ultrasound guidance, which provided 100% relief of her symptoms. We obtained an MRA to evaluate for any recurrent capsular or labral injury (Figure 6). The previous anterosuperior capsular defect was not visible, and no signs of recurrent labral or cartilage injury were seen.

Discussion

With the increasing popularity of hip arthroscopy, more complications are being reported as well, including postoperative hip instability. Three separate cases of anterior hip instability have been published in the past several years.^5-7

Ranawat and colleagues⁵ were the first to report a case of postoperative anterior hip dislocation after arthroscopy. Their patient was a 52-year-old woman with right hip pain and generalized ligamentous laxity. Her preoperative radiographs showed no evidence of degenerative changes, dysplasia, or femoroacetabular impingement. An MRA showed a peripheral tear of the anterosuperior labrum. At arthroscopy, her right hip was easily distracted 2 to 3 cm with what they described as “minimal traction.” A small 1- to 2-cm capsulotomy was performed about the anterior portal. A detached labral tear was identified and repaired with an anchor, and no rim resection was performed. To improve visualization of the peripheral compartment, they extended the previous capsulotomy 1 to 2 cm and débrided the edges. A cam-type lesion was identified and resected. Lastly, they performed an anterior capsular plication, specifically including the iliofemoral ligament. Postoperatively, the patient wore a hip orthosis for 6 weeks to prevent extension and external rotation of the hip as well as a foot brace at night for 3 weeks. The patient was allowed to partially bear weight for the first 6 weeks with use of crutches. Approximately 2 months postoperatively, she slipped and fell down a short flight of stairs. She was diagnosed with an anterior hip dislocation. After successful closed reduction, she was treated conservatively with the same regimen used earlier. She remained symptomatic over the next several months with signs of instability and apprehension, and she eventually underwent a repeat hip arthroscopy. A 1- to 2-cm tear of the anterior capsule and iliofemoral ligament was treated with a revision arthroscopic capsular plication. A postoperative regimen similar to that used at the index procedure was instituted and, at most recent follow-up, she was found to have occasional pain without instability.

Matsuda⁶ reported a case of acute iatrogenic hip dislocation after arthroscopic surgery. His patient was a 39-year-old woman with a mildly retroverted acetabulum leading to impingement about the hip. She had no signs of generalized ligamentous laxity. A hip arthroscopy in the lateral position was performed, with no comment about the extent of the capsulotomy. During the procedure, about 5 mm of anterosuperior acetabulum were removed as part of arthroscopic rim trimming for treatment of the pincer lesion. A femoral osteochondroplasty was also performed (unspecified size) to restore more normal anterolateral offset. One confounding factor was that supranormal hip distraction was needed for 20 minutes to aid in removal of a metallic piece from a radiofrequency ablator, which inadvertently detached. The patient experienced an anterior hip dislocation in the recovery room and was found to be unstable during closed reduction under general anesthesia. A mini-open capsular repair was performed, which showed a 1×1.5-cm defect in the anterolateral capsule. After closure of the defect, the hip was found to be stable under fluoroscopic examination. Postoperatively, the patient was allowed to perform partial weight-bearing in a hip-knee-ankle-foot orthosis for 2 months and then a flexible hip brace for 1 month. At 15-month follow-up, her hip was stable and she was pain-free.

Benali and Katthagen⁷ highlighted the significant contribution of the labrum to hip stability in a dysplastic hip. Their patient was a 49-year-old woman with mild hip dysplasia and a degenerative bucket-handle tear of the ventrolateral labrum. The patient underwent a near-complete labral resection and rim trimming at an outside institution. The patient began full weight-bearing at 3 weeks postoperatively and noticed considerable groin and back pain (no hip orthosis use was mentioned). After failed treatment for suspected lumbar pathology, she was referred to the authors’ clinic for further evaluation. Plain radiographs showed subluxation of the left hip with degenerative changes. The patient had an uneventful left total hip arthroplasty (THA).

After reviewing the 3 reported cases of hip instability after arthroscopy, we suggest that surgeons fully recognize and appreciate the delicate balance of stability and motion provided by the static and dynamic stabilizers of the hip joint, and be cognizant of potential imbalance created by surgical intervention.^8,9 Postarthroscopic hip instability appears to be multifactorial in nature, because all of the reported cases detailed different factors, both patient- and surgeon-related, contributing to instability.

Ranawat and colleagues⁵ identified several factors that may have contributed to the anterior hip dislocation sustained by their patient, including the patient’s generalized ligamentous laxity, performance of a capsulectomy (with repair of iliofemoral ligament), and a traumatic fall. Benali and Katthagen⁷ (although they did not perform the index procedure) described the disastrous complication of overzealous labral resection and rim trimming in a patient with hip dysplasia. Matsuda⁶ performed a labral resection and rim trimming, an extended (unspecified size) capsulotomy, and also used supranormal traction for 20 minutes to remove an iatrogenic foreign body. Surgeons performing hip arthroscopies should be aware of all these factors, because many are directly controlled by the surgeon.

The only factor we feel may have contributed to hip instability in our patient was the performance of a capsulotomy without closure. Our patient was an otherwise healthy woman with no signs of ligamentous laxity, hip dysplasia, or retroversion of the acetabulum. We did not perform a labral resection or rim trimming. We use modified anterior and anterolateral portals, and electrocautery to connect the portals. This typically leads to a release of a thin strip (less than 5 mm wide) of 3 cm of capsule. Based upon findings at rare second-look arthroscopy for recurrent symptoms, Dr. Guanche has observed that the capsulotomy from the initial procedure heals with normal-appearing tissue. Also, during peripheral compartment arthroscopy, we do not routinely release the iliofemoral ligament, and the orbicular ligament is left intact. Instead, we prefer to flex the hip and débride only enough capsular tissue to allow for adequate visualization. 

Little has been published on capsulotomy closure after hip arthroscopy, and no consensus exists. Our standard practice is to not close the capsulotomy, which accords with the practice of other surgeons.⁹ There is concern, however, that extensive capsulotomy leading to injury or disruption of the iliofemoral ligament may cause anterior hip instability, driving other prominent hip arthroscopists to routinely close the capsulotomy.^9,10 Myers and colleagues¹⁰ published a recent biomechanical study on the role of the labrum and the capsular ligaments in hip stability. They concluded that the iliofemoral ligament plays a significant role in limiting external rotation and anterior translation of the femoral head, and recommended closure of the capsulotomy after arthroscopy. Of note, Dr. Guanche has performed more than 1500 hip arthroscopic procedures in the past 5 years, and we are aware of only 2 patients who have sustained anterior hip dislocations, in spite of our not closing the capsulotomy defect. This highlights an important clinical question in need of further investigation.

Our case also raises questions about the ideal postoperative regimen after standard hip arthroscopy. Although we do not routinely prescribe hip orthoses for our patients, others do.⁵ We are unaware of any proven benefit to the standard use of hip orthoses, and are concerned over the possible lack of patient compliance and of adequate restraint. We prefer to educate our patients on avoiding the “at-risk” position of hip extension and external rotation and to counsel them on gradual return to activities. Studies are needed to determine the role of these devices in hip arthroscopy, as well as the ideal postoperative activity regimen.

Our patient failed 6 months of conservative treatment after her dislocation and continued to have feelings of hip instability even during light activities. As a result of this failure and given an anatomical defect in the anterior capsuloligamentous complex, we decided our patient would be best treated with reconstruction of the defect. We did not think a revision capsular plication, as done by Ranawat and colleagues,⁵ was a reasonable option for our patient because of a large defect in the capsular tissue. Even in smaller defects, plication could potentially lead to overtightening of the capsule and subsequent overconstraint of the joint. Also, plication of defects may place excessive strain on the suture, which may fail if the repair is even mildly stressed.

Recurrent anterior hip dislocations, although rare in their own right, are much more common after THA than after hip arthroscopy.¹¹ Fujishiro and colleagues¹² described a similar technique to ours developed to treat a patient with recurrent anterior hip instability from anterior capsular insufficiency after multiple revision THA procedures. They used a Leeds-Keio artificial ligament to reconstruct the iliofemoral ligament, and this successfully treated their patient’s instability.

Conclusion

We believe this is the first report of recurrent instability after hip arthroscopy, necessitating reconstruction of the anterior capsuloligamentous complex. This case shows that reconstruction of the iliofemoral ligament with iliotibial band autograft is safe, restores hip stability without compromising function, and should be considered by any hip arthroscopist encountering a similar scenario. It also highlights the importance of the capsuloligamentous complex surrounding the hip joint for its stability and the need for further research to better delineate the indications for capsular repair/closure after capsulotomy.

Hip arthroscopy has experienced a dramatic increase in popularity, largely resulting from improvements in techniques and technology.^1,2 As with any procedure, there are complications associated with arthroscopy of the hip. These include neurapraxia, iatrogenic cartilage and labral injuries, postoperative bleeding, perineal skin necrosis, infection, intra-articular instrument breakage, intra-abdominal fluid extravasation, avascular necrosis, and femoral neck fracture.^1-4 Many of these have been attributed to the expected learning curve seen with any new procedure, and are less likely to occur as surgeons become more familiar with the procedure.¹ One rare but serious complication is anterior dislocation of the hip.^5-7

We present a patient who experienced an anterior hip dislocation and instability after hip arthroscopy, and was successfully treated with an anterior capsuloligamentous reconstruction. The patient provided written informed consent for print and electronic publication of this case report.

Case Report

An otherwise healthy 37-year-old woman presented to our clinic with a 6-month history of right groin pain and an occasional popping sensation during activity, which was unresponsive to hip-specific physical therapy. On physical examination, she was 5 ft 10 in tall, weighed 150 lbs, and appeared in excellent physical condition. She had no signs of systemic ligamentous laxity. She had an otherwise normal musculoskeletal, neurologic, and vascular examination in her bilateral lower extremities. She had a mild antalgic gait on the right leg.

The affected right hip could be flexed painfully to 120º, extended to 0º, adducted 20º, and abducted 45º. At 90º of flexion, her right hip could be externally rotated 30º and internally rotated 20º. Internal rotation during hip flexion beyond 90º caused sharp pain in the groin. Her normal left hip could be flexed to 120º, extended to 0º, adducted 30º, and abducted 60º. At 90º of flexion, her left hip could be externally rotated 50º and internally rotated 30º. She had negative Ober tests bilaterally but had tenderness along the right iliotibial band. She had negative Patrick and Gaenslen tests bilaterally. She had no tenderness in the area of either greater trochanter. 

Imaging evaluation included plain radiographs and a magnetic resonance arthrogram (MRA) of the right hip. The plain radiographs showed signs of femoroacetabular impingement, but no joint space narrowing, no dysplasia, and no retroversion of the acetabulum (Figures 1A, 1B). The MRA showed a degenerative peripheral tear of the anterosuperior labrum without significant cartilage wear (Figure 2).

Based upon her findings on physical examination and imaging, we recommended arthroscopic treatment of her right hip pathology. Thirteen months after initial presentation, we performed a right hip arthroscopy with the patient in the supine position. Through modified anterior and anterolateral portals, we used electrocautery to perform a capsulotomy from the 9 o’clock to 12 o’clock positions. A central compartment diagnostic arthroscopy showed mild degenerative fraying of the labrum from the 9 o’clock to 12 o’clock positions without signs of detachment. There was grade III chondral fraying near the articular margin in that same arc. The femoral articular cartilage appeared normal, as did the ligamentum teres. We used a shaver to gently débride the torn labrum down to stable tissue. The frayed cartilage on the acetabulum was also gently débrided.

Traction was released and the hip was flexed. Minimal capsular release and débridement were performed for adequate visualization of the peripheral compartment. A diagnostic examination revealed a significant cam-type impingement lesion from the 12 o’clock to 6 o’clock positions. We performed a femoral neck resection, with a proximal-distal dimension of 15 mm and a depth of 7 mm. A dynamic fluoroscopic examination of the hip joint showed no signs of impingement. In accordance with our standard protocol, the anterior capsulotomy was not repaired.

Postoperatively, the patient was instructed to perform toe-touch weight-bearing with crutches for 2 weeks and to advance to full weight-bearing over the next 2 weeks. She did not use a hip orthosis. She was also advised to avoid combined hip extension/external rotation maneuvers for the first 4 weeks. She took part in a formal hip-specific physical therapy program for a total of 12 weeks. She was seen in clinic at 2, 6, and 12 weeks postoperatively and appeared to have had a typical, uneventful course. We advised her to gradually return to normal activities as tolerated at the 12-week visit.

Four months after the procedure, the patient returned to our clinic for evaluation after a right hip dislocation. Two days prior, she was at a school function with her child and experienced sudden pain and inability to bear weight after she extended and externally rotated her right hip in a low-energy manner. She was taken to an emergency room and found to have an anterior dislocation of the right hip (Figure 3), which was concentrically reduced under anesthesia.

Upon questioning, she reported having had feelings of mild instability of the right hip during demanding activities (jogging, yoga) after sustaining a low-energy fall 1 month prior to her dislocation. On examination, she had significant apprehension about the right hip during gentle external rotation maneuvers. An MRA 2 weeks after the dislocation showed a large defect of the anterosuperior capsuloligamentous complex measuring 4 cm from medial to lateral and 2.5 cm superior to inferior (Figure 4). No loose bodies, chondral injuries, or recurrent tears of the labrum were seen. Typical postoperative changes were observed at the femoral head-neck junction.

Initially, we recommended nonoperative management with 6 weeks of toe-touch weight-bearing and strict avoidance of hip extension–external rotation maneuvers. No hip orthosis was used. After this period, the patient advanced to full weight-bearing and continued in hip-specific physical therapy. Despite continued therapy and avoidance of provocative maneuvers, the patient reported persistent feelings of right hip instability with significant apprehension during extension and external rotation of the right hip. A repeat MRA 4 months after the hip dislocation showed a persistent defect in the anterosuperior capsuloligamentous complex and no signs of avascular necrosis. After 6 months of conservative treatment, we recommended an open capsulorrhaphy of the right hip with autograft iliotibial band reconstruction of the iliofemoral ligament and capsule.

Six months after the dislocation, the patient underwent the recommended procedure. After induction of general anesthesia, she was placed in the supine position on a standard operating table. A Smith-Petersen approach was used to visualize the anterior hip structures. During deep dissection, we observed a large defect, measuring 2.5×4 cm (Figure 5A), in the anterior hip capsule, with only a thin pseudocapsule covering the femoral head. Extensive mobilization of the anterior capsule was unsuccessful.

The decision was made to harvest a graft from the patient’s ipsilateral iliotibial band. A skin incision was made over the iliotibial band in the distal midthigh region, and a 2.5×4-cm graft was harvested from the central portion of the iliotibial band. An arthrotomy was performed on the hip joint (Figure 5B). The labrum appeared healthy without recurrent tearing or fraying, and other than focal thinning on the superior acetabulum, the cartilage appeared healthy. A double-loaded anchor was placed in the supra-acetabular region, and the sutures were passed through the graft. Then, No. 2 nonabsorbable sutures were sequentially placed between the capsular remnant and the graft medially, inferiorly, and laterally. The graft was placed into position (Figure 5C) and the sutures were tied (Figure 5D).

Postoperatively, the patient was allowed toe-touch weight-bearing for 6 weeks, with strict avoidance of extension–external rotation maneuvers. She participated in a 12-week course of physical therapy with gradual advancement of activities. About a year after the capsulorrhaphy, she was able to resume all previous activities with only occasional low-level discomfort. She returned to the clinic 16 months after the capsulorrhaphy complaining of increased pain with long-distance running but denied feelings of instability. We performed an intra-articular hip injection under ultrasound guidance, which provided 100% relief of her symptoms. We obtained an MRA to evaluate for any recurrent capsular or labral injury (Figure 6). The previous anterosuperior capsular defect was not visible, and no signs of recurrent labral or cartilage injury were seen.

Discussion

With the increasing popularity of hip arthroscopy, more complications are being reported as well, including postoperative hip instability. Three separate cases of anterior hip instability have been published in the past several years.^5-7

Ranawat and colleagues⁵ were the first to report a case of postoperative anterior hip dislocation after arthroscopy. Their patient was a 52-year-old woman with right hip pain and generalized ligamentous laxity. Her preoperative radiographs showed no evidence of degenerative changes, dysplasia, or femoroacetabular impingement. An MRA showed a peripheral tear of the anterosuperior labrum. At arthroscopy, her right hip was easily distracted 2 to 3 cm with what they described as “minimal traction.” A small 1- to 2-cm capsulotomy was performed about the anterior portal. A detached labral tear was identified and repaired with an anchor, and no rim resection was performed. To improve visualization of the peripheral compartment, they extended the previous capsulotomy 1 to 2 cm and débrided the edges. A cam-type lesion was identified and resected. Lastly, they performed an anterior capsular plication, specifically including the iliofemoral ligament. Postoperatively, the patient wore a hip orthosis for 6 weeks to prevent extension and external rotation of the hip as well as a foot brace at night for 3 weeks. The patient was allowed to partially bear weight for the first 6 weeks with use of crutches. Approximately 2 months postoperatively, she slipped and fell down a short flight of stairs. She was diagnosed with an anterior hip dislocation. After successful closed reduction, she was treated conservatively with the same regimen used earlier. She remained symptomatic over the next several months with signs of instability and apprehension, and she eventually underwent a repeat hip arthroscopy. A 1- to 2-cm tear of the anterior capsule and iliofemoral ligament was treated with a revision arthroscopic capsular plication. A postoperative regimen similar to that used at the index procedure was instituted and, at most recent follow-up, she was found to have occasional pain without instability.

Matsuda⁶ reported a case of acute iatrogenic hip dislocation after arthroscopic surgery. His patient was a 39-year-old woman with a mildly retroverted acetabulum leading to impingement about the hip. She had no signs of generalized ligamentous laxity. A hip arthroscopy in the lateral position was performed, with no comment about the extent of the capsulotomy. During the procedure, about 5 mm of anterosuperior acetabulum were removed as part of arthroscopic rim trimming for treatment of the pincer lesion. A femoral osteochondroplasty was also performed (unspecified size) to restore more normal anterolateral offset. One confounding factor was that supranormal hip distraction was needed for 20 minutes to aid in removal of a metallic piece from a radiofrequency ablator, which inadvertently detached. The patient experienced an anterior hip dislocation in the recovery room and was found to be unstable during closed reduction under general anesthesia. A mini-open capsular repair was performed, which showed a 1×1.5-cm defect in the anterolateral capsule. After closure of the defect, the hip was found to be stable under fluoroscopic examination. Postoperatively, the patient was allowed to perform partial weight-bearing in a hip-knee-ankle-foot orthosis for 2 months and then a flexible hip brace for 1 month. At 15-month follow-up, her hip was stable and she was pain-free.

Benali and Katthagen⁷ highlighted the significant contribution of the labrum to hip stability in a dysplastic hip. Their patient was a 49-year-old woman with mild hip dysplasia and a degenerative bucket-handle tear of the ventrolateral labrum. The patient underwent a near-complete labral resection and rim trimming at an outside institution. The patient began full weight-bearing at 3 weeks postoperatively and noticed considerable groin and back pain (no hip orthosis use was mentioned). After failed treatment for suspected lumbar pathology, she was referred to the authors’ clinic for further evaluation. Plain radiographs showed subluxation of the left hip with degenerative changes. The patient had an uneventful left total hip arthroplasty (THA).

After reviewing the 3 reported cases of hip instability after arthroscopy, we suggest that surgeons fully recognize and appreciate the delicate balance of stability and motion provided by the static and dynamic stabilizers of the hip joint, and be cognizant of potential imbalance created by surgical intervention.^8,9 Postarthroscopic hip instability appears to be multifactorial in nature, because all of the reported cases detailed different factors, both patient- and surgeon-related, contributing to instability.

Ranawat and colleagues⁵ identified several factors that may have contributed to the anterior hip dislocation sustained by their patient, including the patient’s generalized ligamentous laxity, performance of a capsulectomy (with repair of iliofemoral ligament), and a traumatic fall. Benali and Katthagen⁷ (although they did not perform the index procedure) described the disastrous complication of overzealous labral resection and rim trimming in a patient with hip dysplasia. Matsuda⁶ performed a labral resection and rim trimming, an extended (unspecified size) capsulotomy, and also used supranormal traction for 20 minutes to remove an iatrogenic foreign body. Surgeons performing hip arthroscopies should be aware of all these factors, because many are directly controlled by the surgeon.

The only factor we feel may have contributed to hip instability in our patient was the performance of a capsulotomy without closure. Our patient was an otherwise healthy woman with no signs of ligamentous laxity, hip dysplasia, or retroversion of the acetabulum. We did not perform a labral resection or rim trimming. We use modified anterior and anterolateral portals, and electrocautery to connect the portals. This typically leads to a release of a thin strip (less than 5 mm wide) of 3 cm of capsule. Based upon findings at rare second-look arthroscopy for recurrent symptoms, Dr. Guanche has observed that the capsulotomy from the initial procedure heals with normal-appearing tissue. Also, during peripheral compartment arthroscopy, we do not routinely release the iliofemoral ligament, and the orbicular ligament is left intact. Instead, we prefer to flex the hip and débride only enough capsular tissue to allow for adequate visualization. 

Little has been published on capsulotomy closure after hip arthroscopy, and no consensus exists. Our standard practice is to not close the capsulotomy, which accords with the practice of other surgeons.⁹ There is concern, however, that extensive capsulotomy leading to injury or disruption of the iliofemoral ligament may cause anterior hip instability, driving other prominent hip arthroscopists to routinely close the capsulotomy.^9,10 Myers and colleagues¹⁰ published a recent biomechanical study on the role of the labrum and the capsular ligaments in hip stability. They concluded that the iliofemoral ligament plays a significant role in limiting external rotation and anterior translation of the femoral head, and recommended closure of the capsulotomy after arthroscopy. Of note, Dr. Guanche has performed more than 1500 hip arthroscopic procedures in the past 5 years, and we are aware of only 2 patients who have sustained anterior hip dislocations, in spite of our not closing the capsulotomy defect. This highlights an important clinical question in need of further investigation.

Our case also raises questions about the ideal postoperative regimen after standard hip arthroscopy. Although we do not routinely prescribe hip orthoses for our patients, others do.⁵ We are unaware of any proven benefit to the standard use of hip orthoses, and are concerned over the possible lack of patient compliance and of adequate restraint. We prefer to educate our patients on avoiding the “at-risk” position of hip extension and external rotation and to counsel them on gradual return to activities. Studies are needed to determine the role of these devices in hip arthroscopy, as well as the ideal postoperative activity regimen.

Our patient failed 6 months of conservative treatment after her dislocation and continued to have feelings of hip instability even during light activities. As a result of this failure and given an anatomical defect in the anterior capsuloligamentous complex, we decided our patient would be best treated with reconstruction of the defect. We did not think a revision capsular plication, as done by Ranawat and colleagues,⁵ was a reasonable option for our patient because of a large defect in the capsular tissue. Even in smaller defects, plication could potentially lead to overtightening of the capsule and subsequent overconstraint of the joint. Also, plication of defects may place excessive strain on the suture, which may fail if the repair is even mildly stressed.

Recurrent anterior hip dislocations, although rare in their own right, are much more common after THA than after hip arthroscopy.¹¹ Fujishiro and colleagues¹² described a similar technique to ours developed to treat a patient with recurrent anterior hip instability from anterior capsular insufficiency after multiple revision THA procedures. They used a Leeds-Keio artificial ligament to reconstruct the iliofemoral ligament, and this successfully treated their patient’s instability.

Conclusion

We believe this is the first report of recurrent instability after hip arthroscopy, necessitating reconstruction of the anterior capsuloligamentous complex. This case shows that reconstruction of the iliofemoral ligament with iliotibial band autograft is safe, restores hip stability without compromising function, and should be considered by any hip arthroscopist encountering a similar scenario. It also highlights the importance of the capsuloligamentous complex surrounding the hip joint for its stability and the need for further research to better delineate the indications for capsular repair/closure after capsulotomy.

Hip arthroscopy has experienced a dramatic increase in popularity, largely resulting from improvements in techniques and technology.^1,2 As with any procedure, there are complications associated with arthroscopy of the hip. These include neurapraxia, iatrogenic cartilage and labral injuries, postoperative bleeding, perineal skin necrosis, infection, intra-articular instrument breakage, intra-abdominal fluid extravasation, avascular necrosis, and femoral neck fracture.^1-4 Many of these have been attributed to the expected learning curve seen with any new procedure, and are less likely to occur as surgeons become more familiar with the procedure.¹ One rare but serious complication is anterior dislocation of the hip.^5-7

We present a patient who experienced an anterior hip dislocation and instability after hip arthroscopy, and was successfully treated with an anterior capsuloligamentous reconstruction. The patient provided written informed consent for print and electronic publication of this case report.

Case Report

An otherwise healthy 37-year-old woman presented to our clinic with a 6-month history of right groin pain and an occasional popping sensation during activity, which was unresponsive to hip-specific physical therapy. On physical examination, she was 5 ft 10 in tall, weighed 150 lbs, and appeared in excellent physical condition. She had no signs of systemic ligamentous laxity. She had an otherwise normal musculoskeletal, neurologic, and vascular examination in her bilateral lower extremities. She had a mild antalgic gait on the right leg.

The affected right hip could be flexed painfully to 120º, extended to 0º, adducted 20º, and abducted 45º. At 90º of flexion, her right hip could be externally rotated 30º and internally rotated 20º. Internal rotation during hip flexion beyond 90º caused sharp pain in the groin. Her normal left hip could be flexed to 120º, extended to 0º, adducted 30º, and abducted 60º. At 90º of flexion, her left hip could be externally rotated 50º and internally rotated 30º. She had negative Ober tests bilaterally but had tenderness along the right iliotibial band. She had negative Patrick and Gaenslen tests bilaterally. She had no tenderness in the area of either greater trochanter. 

Imaging evaluation included plain radiographs and a magnetic resonance arthrogram (MRA) of the right hip. The plain radiographs showed signs of femoroacetabular impingement, but no joint space narrowing, no dysplasia, and no retroversion of the acetabulum (Figures 1A, 1B). The MRA showed a degenerative peripheral tear of the anterosuperior labrum without significant cartilage wear (Figure 2).

Based upon her findings on physical examination and imaging, we recommended arthroscopic treatment of her right hip pathology. Thirteen months after initial presentation, we performed a right hip arthroscopy with the patient in the supine position. Through modified anterior and anterolateral portals, we used electrocautery to perform a capsulotomy from the 9 o’clock to 12 o’clock positions. A central compartment diagnostic arthroscopy showed mild degenerative fraying of the labrum from the 9 o’clock to 12 o’clock positions without signs of detachment. There was grade III chondral fraying near the articular margin in that same arc. The femoral articular cartilage appeared normal, as did the ligamentum teres. We used a shaver to gently débride the torn labrum down to stable tissue. The frayed cartilage on the acetabulum was also gently débrided.

Traction was released and the hip was flexed. Minimal capsular release and débridement were performed for adequate visualization of the peripheral compartment. A diagnostic examination revealed a significant cam-type impingement lesion from the 12 o’clock to 6 o’clock positions. We performed a femoral neck resection, with a proximal-distal dimension of 15 mm and a depth of 7 mm. A dynamic fluoroscopic examination of the hip joint showed no signs of impingement. In accordance with our standard protocol, the anterior capsulotomy was not repaired.

Postoperatively, the patient was instructed to perform toe-touch weight-bearing with crutches for 2 weeks and to advance to full weight-bearing over the next 2 weeks. She did not use a hip orthosis. She was also advised to avoid combined hip extension/external rotation maneuvers for the first 4 weeks. She took part in a formal hip-specific physical therapy program for a total of 12 weeks. She was seen in clinic at 2, 6, and 12 weeks postoperatively and appeared to have had a typical, uneventful course. We advised her to gradually return to normal activities as tolerated at the 12-week visit.

Four months after the procedure, the patient returned to our clinic for evaluation after a right hip dislocation. Two days prior, she was at a school function with her child and experienced sudden pain and inability to bear weight after she extended and externally rotated her right hip in a low-energy manner. She was taken to an emergency room and found to have an anterior dislocation of the right hip (Figure 3), which was concentrically reduced under anesthesia.

Upon questioning, she reported having had feelings of mild instability of the right hip during demanding activities (jogging, yoga) after sustaining a low-energy fall 1 month prior to her dislocation. On examination, she had significant apprehension about the right hip during gentle external rotation maneuvers. An MRA 2 weeks after the dislocation showed a large defect of the anterosuperior capsuloligamentous complex measuring 4 cm from medial to lateral and 2.5 cm superior to inferior (Figure 4). No loose bodies, chondral injuries, or recurrent tears of the labrum were seen. Typical postoperative changes were observed at the femoral head-neck junction.

Initially, we recommended nonoperative management with 6 weeks of toe-touch weight-bearing and strict avoidance of hip extension–external rotation maneuvers. No hip orthosis was used. After this period, the patient advanced to full weight-bearing and continued in hip-specific physical therapy. Despite continued therapy and avoidance of provocative maneuvers, the patient reported persistent feelings of right hip instability with significant apprehension during extension and external rotation of the right hip. A repeat MRA 4 months after the hip dislocation showed a persistent defect in the anterosuperior capsuloligamentous complex and no signs of avascular necrosis. After 6 months of conservative treatment, we recommended an open capsulorrhaphy of the right hip with autograft iliotibial band reconstruction of the iliofemoral ligament and capsule.

Six months after the dislocation, the patient underwent the recommended procedure. After induction of general anesthesia, she was placed in the supine position on a standard operating table. A Smith-Petersen approach was used to visualize the anterior hip structures. During deep dissection, we observed a large defect, measuring 2.5×4 cm (Figure 5A), in the anterior hip capsule, with only a thin pseudocapsule covering the femoral head. Extensive mobilization of the anterior capsule was unsuccessful.

The decision was made to harvest a graft from the patient’s ipsilateral iliotibial band. A skin incision was made over the iliotibial band in the distal midthigh region, and a 2.5×4-cm graft was harvested from the central portion of the iliotibial band. An arthrotomy was performed on the hip joint (Figure 5B). The labrum appeared healthy without recurrent tearing or fraying, and other than focal thinning on the superior acetabulum, the cartilage appeared healthy. A double-loaded anchor was placed in the supra-acetabular region, and the sutures were passed through the graft. Then, No. 2 nonabsorbable sutures were sequentially placed between the capsular remnant and the graft medially, inferiorly, and laterally. The graft was placed into position (Figure 5C) and the sutures were tied (Figure 5D).

Postoperatively, the patient was allowed toe-touch weight-bearing for 6 weeks, with strict avoidance of extension–external rotation maneuvers. She participated in a 12-week course of physical therapy with gradual advancement of activities. About a year after the capsulorrhaphy, she was able to resume all previous activities with only occasional low-level discomfort. She returned to the clinic 16 months after the capsulorrhaphy complaining of increased pain with long-distance running but denied feelings of instability. We performed an intra-articular hip injection under ultrasound guidance, which provided 100% relief of her symptoms. We obtained an MRA to evaluate for any recurrent capsular or labral injury (Figure 6). The previous anterosuperior capsular defect was not visible, and no signs of recurrent labral or cartilage injury were seen.

Discussion

With the increasing popularity of hip arthroscopy, more complications are being reported as well, including postoperative hip instability. Three separate cases of anterior hip instability have been published in the past several years.^5-7

Ranawat and colleagues⁵ were the first to report a case of postoperative anterior hip dislocation after arthroscopy. Their patient was a 52-year-old woman with right hip pain and generalized ligamentous laxity. Her preoperative radiographs showed no evidence of degenerative changes, dysplasia, or femoroacetabular impingement. An MRA showed a peripheral tear of the anterosuperior labrum. At arthroscopy, her right hip was easily distracted 2 to 3 cm with what they described as “minimal traction.” A small 1- to 2-cm capsulotomy was performed about the anterior portal. A detached labral tear was identified and repaired with an anchor, and no rim resection was performed. To improve visualization of the peripheral compartment, they extended the previous capsulotomy 1 to 2 cm and débrided the edges. A cam-type lesion was identified and resected. Lastly, they performed an anterior capsular plication, specifically including the iliofemoral ligament. Postoperatively, the patient wore a hip orthosis for 6 weeks to prevent extension and external rotation of the hip as well as a foot brace at night for 3 weeks. The patient was allowed to partially bear weight for the first 6 weeks with use of crutches. Approximately 2 months postoperatively, she slipped and fell down a short flight of stairs. She was diagnosed with an anterior hip dislocation. After successful closed reduction, she was treated conservatively with the same regimen used earlier. She remained symptomatic over the next several months with signs of instability and apprehension, and she eventually underwent a repeat hip arthroscopy. A 1- to 2-cm tear of the anterior capsule and iliofemoral ligament was treated with a revision arthroscopic capsular plication. A postoperative regimen similar to that used at the index procedure was instituted and, at most recent follow-up, she was found to have occasional pain without instability.

Matsuda⁶ reported a case of acute iatrogenic hip dislocation after arthroscopic surgery. His patient was a 39-year-old woman with a mildly retroverted acetabulum leading to impingement about the hip. She had no signs of generalized ligamentous laxity. A hip arthroscopy in the lateral position was performed, with no comment about the extent of the capsulotomy. During the procedure, about 5 mm of anterosuperior acetabulum were removed as part of arthroscopic rim trimming for treatment of the pincer lesion. A femoral osteochondroplasty was also performed (unspecified size) to restore more normal anterolateral offset. One confounding factor was that supranormal hip distraction was needed for 20 minutes to aid in removal of a metallic piece from a radiofrequency ablator, which inadvertently detached. The patient experienced an anterior hip dislocation in the recovery room and was found to be unstable during closed reduction under general anesthesia. A mini-open capsular repair was performed, which showed a 1×1.5-cm defect in the anterolateral capsule. After closure of the defect, the hip was found to be stable under fluoroscopic examination. Postoperatively, the patient was allowed to perform partial weight-bearing in a hip-knee-ankle-foot orthosis for 2 months and then a flexible hip brace for 1 month. At 15-month follow-up, her hip was stable and she was pain-free.

Benali and Katthagen⁷ highlighted the significant contribution of the labrum to hip stability in a dysplastic hip. Their patient was a 49-year-old woman with mild hip dysplasia and a degenerative bucket-handle tear of the ventrolateral labrum. The patient underwent a near-complete labral resection and rim trimming at an outside institution. The patient began full weight-bearing at 3 weeks postoperatively and noticed considerable groin and back pain (no hip orthosis use was mentioned). After failed treatment for suspected lumbar pathology, she was referred to the authors’ clinic for further evaluation. Plain radiographs showed subluxation of the left hip with degenerative changes. The patient had an uneventful left total hip arthroplasty (THA).

After reviewing the 3 reported cases of hip instability after arthroscopy, we suggest that surgeons fully recognize and appreciate the delicate balance of stability and motion provided by the static and dynamic stabilizers of the hip joint, and be cognizant of potential imbalance created by surgical intervention.^8,9 Postarthroscopic hip instability appears to be multifactorial in nature, because all of the reported cases detailed different factors, both patient- and surgeon-related, contributing to instability.

Ranawat and colleagues⁵ identified several factors that may have contributed to the anterior hip dislocation sustained by their patient, including the patient’s generalized ligamentous laxity, performance of a capsulectomy (with repair of iliofemoral ligament), and a traumatic fall. Benali and Katthagen⁷ (although they did not perform the index procedure) described the disastrous complication of overzealous labral resection and rim trimming in a patient with hip dysplasia. Matsuda⁶ performed a labral resection and rim trimming, an extended (unspecified size) capsulotomy, and also used supranormal traction for 20 minutes to remove an iatrogenic foreign body. Surgeons performing hip arthroscopies should be aware of all these factors, because many are directly controlled by the surgeon.

The only factor we feel may have contributed to hip instability in our patient was the performance of a capsulotomy without closure. Our patient was an otherwise healthy woman with no signs of ligamentous laxity, hip dysplasia, or retroversion of the acetabulum. We did not perform a labral resection or rim trimming. We use modified anterior and anterolateral portals, and electrocautery to connect the portals. This typically leads to a release of a thin strip (less than 5 mm wide) of 3 cm of capsule. Based upon findings at rare second-look arthroscopy for recurrent symptoms, Dr. Guanche has observed that the capsulotomy from the initial procedure heals with normal-appearing tissue. Also, during peripheral compartment arthroscopy, we do not routinely release the iliofemoral ligament, and the orbicular ligament is left intact. Instead, we prefer to flex the hip and débride only enough capsular tissue to allow for adequate visualization. 

Little has been published on capsulotomy closure after hip arthroscopy, and no consensus exists. Our standard practice is to not close the capsulotomy, which accords with the practice of other surgeons.⁹ There is concern, however, that extensive capsulotomy leading to injury or disruption of the iliofemoral ligament may cause anterior hip instability, driving other prominent hip arthroscopists to routinely close the capsulotomy.^9,10 Myers and colleagues¹⁰ published a recent biomechanical study on the role of the labrum and the capsular ligaments in hip stability. They concluded that the iliofemoral ligament plays a significant role in limiting external rotation and anterior translation of the femoral head, and recommended closure of the capsulotomy after arthroscopy. Of note, Dr. Guanche has performed more than 1500 hip arthroscopic procedures in the past 5 years, and we are aware of only 2 patients who have sustained anterior hip dislocations, in spite of our not closing the capsulotomy defect. This highlights an important clinical question in need of further investigation.

Our case also raises questions about the ideal postoperative regimen after standard hip arthroscopy. Although we do not routinely prescribe hip orthoses for our patients, others do.⁵ We are unaware of any proven benefit to the standard use of hip orthoses, and are concerned over the possible lack of patient compliance and of adequate restraint. We prefer to educate our patients on avoiding the “at-risk” position of hip extension and external rotation and to counsel them on gradual return to activities. Studies are needed to determine the role of these devices in hip arthroscopy, as well as the ideal postoperative activity regimen.

Our patient failed 6 months of conservative treatment after her dislocation and continued to have feelings of hip instability even during light activities. As a result of this failure and given an anatomical defect in the anterior capsuloligamentous complex, we decided our patient would be best treated with reconstruction of the defect. We did not think a revision capsular plication, as done by Ranawat and colleagues,⁵ was a reasonable option for our patient because of a large defect in the capsular tissue. Even in smaller defects, plication could potentially lead to overtightening of the capsule and subsequent overconstraint of the joint. Also, plication of defects may place excessive strain on the suture, which may fail if the repair is even mildly stressed.

Recurrent anterior hip dislocations, although rare in their own right, are much more common after THA than after hip arthroscopy.¹¹ Fujishiro and colleagues¹² described a similar technique to ours developed to treat a patient with recurrent anterior hip instability from anterior capsular insufficiency after multiple revision THA procedures. They used a Leeds-Keio artificial ligament to reconstruct the iliofemoral ligament, and this successfully treated their patient’s instability.

Conclusion

We believe this is the first report of recurrent instability after hip arthroscopy, necessitating reconstruction of the anterior capsuloligamentous complex. This case shows that reconstruction of the iliofemoral ligament with iliotibial band autograft is safe, restores hip stability without compromising function, and should be considered by any hip arthroscopist encountering a similar scenario. It also highlights the importance of the capsuloligamentous complex surrounding the hip joint for its stability and the need for further research to better delineate the indications for capsular repair/closure after capsulotomy.

The tibia is the most commonly fractured long bone in adults, and tibial malunions occur in up to 60% of these patients.^1,2 Persistent tibial malalignment, particularly varus alignment, negatively alters gait and joint kinematics, leading to altered weight-bearing forces across the knee and ankle joints. These altered forces may lead to osteoarthritis.^3-8

Several studies have identified a relationship between extent of tibial malalignment and changes in joint reaction forces.^3,5-7,9-13 Puno and colleagues¹⁴ developed a mathematical model to better define the changes in neighboring joints relative to the pattern of the tibia malalignment. Not surprisingly, their work showed that, with distal tibial malunions, altered stress concentrations were realized at the ankle joint, and more proximal tibial deformities led to larger alterations in the joint stresses at the knee. More recently, van der Schoot and colleagues⁸ found a high prevalence of ipsilateral ankle osteoarthritis with tibial malalignment of 5° or more, and Greenwood and colleagues¹⁵ showed a higher incidence of knee pain, lower limb osteoarthritis, and disability in patients with previous tibia fractures. Given these findings, it would seem that correction of tibial malalignment would lead to normative lower extremity joint kinematic values, joint reaction forces, and overall quality of life (QOL).

The ability to ambulate has been recognized as an important milestone in functional recovery after lower extremity injury.^2,16,17 Gait analysis, assessment of joint kinematics, and QOL and health status questionnaires can provide information to evaluate rehabilitation protocols, treatment algorithms, and surgical outcomes. Recently, these measures have been used to assess patients recovering from acetabular fractures, femoral shaft fractures, and calcaneal fractures.^4,11,17-24 However, no study has used these measures to assess the benefits of surgical correction of malaligned tibias.

We conducted a study to determine improvement in gait, joint kinematics, and patients’ perceptions of overall well-being after surgical correction of tibial malunions. The null hypothesis was that correction of tibial malunion would have no effect on gait, joint kinematics, or patients’ perceptions of function and QOL.

Materials and Methods

This prospective double-time-point study, which was approved by the Institutional Review Board of Washington University/Barnes-Jewish Hospital, evaluated 11 consecutive patients with a varus tibial malunion treated by a single surgeon between September 2003 and January 2006. All patients were treated using a technique that included oblique osteotomy and open reduction and internal fixation (ORIF) or osteotomy and intramedullary nailing. Study inclusion criteria were age 18 years or older; symptomatic varus malunion of the tibia of 10º or more; absence of a developmental or pathologic process leading to the fracture and subsequent deformity; no neurologic deficit of either lower extremity or contralateral lower extremity deformity; and ability to ambulate 9 meters with or without use of an assistive device.

The 11 patients (6 men, 5 women) who met these criteria enrolled in the study. Mean age was 53 years (range, 43-68 years). Eight malunions involved the left tibia. The mechanisms of injury were motor vehicle crash (6 patients), fall from a great height (3), being struck by a motor vehicle (1), and gunshot (1). Mean time from injury to corrective surgery was 16.9 years (range, 1-34 years). Before surgery, each patient had a thorough physical examination, with plain radiographs, including anteroposterior (AP), lateral, and oblique views, obtained to assess degree of limb malalignment. Patients completed the Short Form-36 (SF-36) and the Musculoskeletal Function Assessment (MFA) and underwent joint kinematics and gait analysis. Five malunions were located in the mid-diaphysis of the tibia, 3 in the proximal third, and 2 in the distal third of the tibial shaft. One patient had posttraumatic deformity involving the proximal and the mid-diaphysis (Table 1). After surgery, each patient was followed at regular intervals in the surgeon’s private office. Minimum follow-up was 7 months (mean, 11 months; range 7-17 months). At follow-up, radiographs were obtained, and each patient completed the SF-36 and the MFA and underwent joint kinematics and gait analysis.

We obtained preoperative AP and lateral radiographs of the malaligned and contralateral normal tibias for each patient. Angular deformity was determined in the sagittal and coronal planes to determine location and magnitude of the deformity. Specifically, on each AP and lateral radiograph, a line was drawn the length of the tibia proximal and distal to the area of the deformity. The angle generated by the intersection of these lines on the AP and lateral radiographs was then plotted on a grid to determine the precise plane and magnitude of the deformity (Table 2).^1,12 Clinically, relevant rotational deformity of the involved limb was assessed by physical examination, and the results were compared with those of the contralateral limb. Owing to the lack of considerable rotational deformity in any of these 11 patients, we did not obtain computed tomography scans for further assessment of rotation.

Perioperative intravenous antibiotics were administered: 2 g cefazolin 30 minutes before incision and 1 g every 8 hours for 24 hours after surgery. A pneumatic tourniquet was placed on the proximal thigh, and the entire leg was prepared and draped in a sterile fashion. The limb was elevated and exsanguinated with an Esmark bandage and the tourniquet raised to 250 mm Hg. With fluoroscopy, the site of the tibial deformity was identified. Generally, an incision was made centered over the apex of the deformity and one fingerbreadth lateral to the palpable tibial crest. In most cases, the anterolateral aspect of the tibia was exposed while minimizing soft-tissue and periosteal stripping. The plane of the maximum deformity was identified with both direct visualization and fluoroscopy. The osteotomy was performed with an oscillating saw, and in each case a fibular osteotomy was also performed. Malalignment was corrected using a combination of manual manipulation and femoral distractor.^25,26 Intraoperative biplanar radiographs were compared with our preoperative plan and with reversed images of the contralateral tibia to assess correction of the deformity. If lengthening was required, in addition to the tibial osteotomy, a corticotomy was created, and a circular external fixator applied and distraction osteogenesis performed.

We maintained the limbs in a short-leg splint for about 10 days after surgery and then initiated active-assisted range of motion of neighboring joints. Patients were maintained on toe-touch weight-bearing for the initial 6 weeks and were then advanced to partial weight-bearing (23 kg). Physical therapy for lower extremity strengthening and gait training was started 6 weeks after surgery. Three months after surgery, patients were advanced to weight-bearing as tolerated and were allowed to return to their activities of daily living without restrictions if radiographs and clinical examination were consistent with healing of the osteotomy.

Each patient was examined and radiographs obtained at regular intervals (2, 6, and 12 weeks and then about every 3 months) after surgery until healing. Bone union was determined by history and physical examination with pain-free weight-bearing without use of assistive devices and by return of functional use of the extremity. Radiographic union was considered to have occurred when bridging trabeculae were present across the osteotomy and there was no loosening or failure of the implants. Occasionally, if there were questions regarding healing, a musculoskeletal radiologist was consulted. Acceptable tibia alignment was defined as alignment of less than 5° varus or less than 10° valgus in the coronal plane and less than 15° procurvatum or recurvatum in the sagittal plane. Immediate postoperative radiographs and most recent radiographs were used to determine the final amount of angular correction.²⁷

Two patients subsequently required secondary operative procedures. One had varus collapse through the regenerate, and the other developed a nonunion of the osteotomy site and required exchange intramedullary nailing. In each case, the final assessment was done after the patient had healed after the second surgery and had fully recovered.

Perceived Functional Assessment

The MFA is a 100-item self-administered QOL questionnaire designed to assess self-perception of physical, psychological, and social well-being in patients with a musculoskeletal injury or condition. The MFA provides a summary score and separate score for each of 10 functional domains. The lower the score, the better the patient’s perception of function. Validated and published norms are available.^20,28-30

Perceived Health Status

The Short Form-36 is a 36-item multipurpose self-administered health survey questionnaire. The SF-36, which assesses overall health status, provides a Physical Component Score (PCS) and a Mental Component Score (MCS). The higher the score, the better the patient’s perception of function. Validated and published norms are available.³¹

Gait Analysis

Video data from a 6-camera high-resolution system (Motion Analysis, Santa Rosa, California) were used to assess gait. A set of 3 reflective surface markers was placed on each of 4 areas: trunk, thighs, legs, and feet.^18,19 The patient walked barefoot along a 9-meter walkway, and video data were collected during the middle 2 meters. For each patient, data from 4 to 7 trials were collected. Computerized software produced data describing the averaged joint angle as a function of the gait cycle for each of the 3 principal planes of the body. Specific points in the gait cycle were analyzed. Variables included maximum knee varus in stance phase; maximum knee valgus in swing; maximum knee flexion in stance and swing; minimum knee flexion in stance; maximum ankle inversion in terminal stance; maximum ankle eversion in stance; maximum ankle dorsiflexion in stance and swing; and maximum ankle plantarflexion at takeoff. In addition to the lower extremity joint kinematics, angular measurements, basic gait measurements of step length, stride length, cadence, and speed were also recorded.

Statistical Analysis

Paired t tests were used to determine if significant changes occurred as a consequence of the surgery for the outcome variables (P < .05). Normative gait data were used to assess the quality of any changes that occurred in the variables, but no statistical analysis was performed to determine significant differences.¹⁸

Results

All 11 patients had clinical and radiographic evidence of healing and deformity correction at most recent follow-up. Nine patients (82%) healed after the index procedure. Mean total angular correction in the coronal plane was 21° (range, 14° varus to 7° valgus), and mean total angular correction in the sagittal plane was 9° (range, 21° recurvatum to 15° procurvatum) (Table 2).

For the group, mean preoperative MFA score was 39 (SD, 18; range, 10-69), and mean postoperative MFA score was 28 (SD, 14; range, 8-53). Patients reported the most improvement in 2 domains: In Leisure, mean (SD) preoperative score was 8 (2), and mean postoperative score was 5 (2); in Emotional, mean preoperative score was 5 (2), and mean postoperative score was 4 (1). The other domains were not significantly different between the 2 assessments.

 On the SF-36, mean (SD) PCS significantly (P < .05) improved from 32 (8) to 43 (9). Mean (SD) MCS showed little change: preoperative, 46 (16); postoperative, 48 (13). The PCS subcategories that showed the most improvement were Physical Function, mean (SD) preoperative, 26 (20), to postoperative, 52 (26); Role of Physical Health, preoperative, 18 (24), to postoperative, 60 (41); and Bodily Pain, preoperative, 39 (27), to 58 (18).

The results from the preoperative and postoperative gait analysis showed no significant differences for the ankle, knee, and hip variables during swing phase (Table 3). In an analysis of the changes in joint kinematics during stance, maximum hip adduction (increased) and maximum knee varus (decreased) on the operative side were significantly improved toward normative values as a consequence of the surgery (Table 3). The other kinematic stance variables were not significantly different. No significant changes were observed in stance time, step length, stride length, cadence, or speed as a consequence of the surgery (Table 4).

Discussion

Correction of malaligned tibias leads to improved limb alignment and patients’ perceptions of functional abilities and health but had a limited effect on joint kinematics and gait. In a group of like patients, we used common techniques to realign malunited tibias and validated instruments to measure functional outcome, health status, joint kinematics, and gait. The goals of this study were to evaluate changes in perceived function and health status and changes in joint kinematics and gait as a result of correction of a posttraumatic limb deformity.

Other investigators have reported outcomes of treating symptomatic malunions,³² nonunions,²⁴ and leg-length discrepancies.³³ In these reports, correction of deformity improved patient satisfaction and function, though objective means of assessment were infrequently used. Good results were reported with use of a dome-shaped supramalleolar osteotomy for the correction of tibial malunion.³² In this study, supramalleolar osteotomy was performed on 8 patients for correction of a malunited tibia. Postoperative assessment included subjective assessment of pain, limp, appearance, instability, and activity. Of these 8 patients, 7 reported overall symptomatic improvement after healing, and the 1 who lost the deformity correction remained symptomatic. Significant improvement in overall health has been reported after successful treatment of tibia nonunions.²⁴ The investigators used the SF-36 to assess patients who underwent treatment for a tibial nonunion. Analysis of these patients’ results showed a significant improvement in physical and mental functioning after healing. In addition, improved gait symmetry was reported in patients successfully treated for leg-length discrepancies.³³ Unfortunately, how improvement in gait related to overall patient function was not assessed. In the present study, we used stringent objective and subjective validated instruments to assess changes in joint gait kinematics and functional outcome before and after treatment of a tibial malunion. In general, our results are consistent with published results and indicate that realignment of tibial malunions improves patients’ perceptions of function. Our results also indicate improvements toward normative values in maximal hip adduction and knee varus, thus confirming the efficacy of the surgery from a functional perspective. Unfortunately, we did not show significant improvements in the remaining joint kinematics measurements or temporal gait parameters.

It is not entirely clear whether tibial malalignment leads to degenerative changes of the ipsilateral knee and/or ankle and what role this might play in functioning. In a retrospective analysis of 92 patients, angular deformity within 15° of normal alignment did not lead to ankle arthrosis.⁹ Milner and colleagues⁴ found that, though varus malunion of the tibia may lead to arthrosis of the medial compartment of the knee, other factors were more important in causing arthrosis of the ankle.

Wu and colleagues³⁴ used tibial osteotomies in New Zealand white rabbits to investigate cartilage and bone changes of the knee after creation of varus or valgus tibial deformities. Thirty-four weeks after osteotomy, rabbits with up to 30° of deformity had severe cartilage changes with osteophytes, fibrillation, derangement of cell columns, and associated increased subchondral bone density of the knees. Cadaveric studies have also shown increased contact pressures within the knees and ankles with ever increasing amounts of tibial deformity.^6,10 In each cadaveric study, malalignment in the distal third of the tibia caused the largest changes in the ankle, and changes in the alignment in the proximal third caused the largest changes in the knee.

Consistent with these animal and cadaveric studies are several retrospective clinical studies that have correlated tibial malalignment (particularly varus) with development of knee and ankle arthrosis.^3,5,8 Kettelkamp and colleagues³ found a direct correlation between magnitude of deformity and length of time with development of knee arthrosis. These findings have led many to recommend that surgeons try to restore tibial alignment to as near normal as possible to reduce the likelihood of arthrosis after tibia fracture. We found significant improvement toward normative values for maximum hip adduction (increased) and tibial varus (decreased) after surgery. These improvements would shift the weight-bearing forces back to the central part of the knee and therefore more uniformly distribute weight-bearing forces.

Posttraumatic arthrosis that develops after fracture is thought to result from increased joint pressures and possibly factors related to the injury. Although surgical correction of tibial alignment is unlikely to reverse these cartilage changes, it may restore joint pressure symmetry and “offload” compromised compartments. Offloading of already degenerative compartments may explain our patients’ improved perceptions of function and overall health status.

There were several limitations to our study. First, plain radiographs of malaligned and uninjured tibia and fibula were used, and these do not allow complete assessment of the weight-bearing access of the limb. Our patients, however, had isolated tibia fractures, which involved a normal limb before injury, so any alterations in joint kinematics, gait, or function would likely be the result of the fracture. Another limitation of our study is its nonrandomized design. However, the patients reflect the typical heterogeneous trauma patient population, who typically develop tibial malunions and seek correction. Another limitation was the lack of a treatment protocol regarding exact surgical technique and implants used to stabilize the osteotomies. In general, the patients were treated similarly, and their preoperative and postoperative assessments were exactly the same, as was their state-of-the-art joint kinematics and gait analysis, combined with the use of previously validated outcome measures. In addition, the lack of improvement in gait could have resulted from postoperative physical therapy that focused on joint mobilization and muscle strengthening and not on correction of abnormal gait parameters noted on preoperative gait analysis. Despite the potential limitations of the study, surgical correction of these symptomatic tibial malunions resulted in significant improvement in functional outcome and improved joint kinematics on the operative side.

Conclusion

Significant effort should be made to restore and maintain near-anatomical tibial alignment until a tibia fracture is healed. In patients who develop a symptomatic tibial malunion, surgical correction should be undertaken with the intent to restore normal limb alignment and improve joint kinematics, function, and overall health status.

The tibia is the most commonly fractured long bone in adults, and tibial malunions occur in up to 60% of these patients.^1,2 Persistent tibial malalignment, particularly varus alignment, negatively alters gait and joint kinematics, leading to altered weight-bearing forces across the knee and ankle joints. These altered forces may lead to osteoarthritis.^3-8

Several studies have identified a relationship between extent of tibial malalignment and changes in joint reaction forces.^3,5-7,9-13 Puno and colleagues¹⁴ developed a mathematical model to better define the changes in neighboring joints relative to the pattern of the tibia malalignment. Not surprisingly, their work showed that, with distal tibial malunions, altered stress concentrations were realized at the ankle joint, and more proximal tibial deformities led to larger alterations in the joint stresses at the knee. More recently, van der Schoot and colleagues⁸ found a high prevalence of ipsilateral ankle osteoarthritis with tibial malalignment of 5° or more, and Greenwood and colleagues¹⁵ showed a higher incidence of knee pain, lower limb osteoarthritis, and disability in patients with previous tibia fractures. Given these findings, it would seem that correction of tibial malalignment would lead to normative lower extremity joint kinematic values, joint reaction forces, and overall quality of life (QOL).

The ability to ambulate has been recognized as an important milestone in functional recovery after lower extremity injury.^2,16,17 Gait analysis, assessment of joint kinematics, and QOL and health status questionnaires can provide information to evaluate rehabilitation protocols, treatment algorithms, and surgical outcomes. Recently, these measures have been used to assess patients recovering from acetabular fractures, femoral shaft fractures, and calcaneal fractures.^4,11,17-24 However, no study has used these measures to assess the benefits of surgical correction of malaligned tibias.

We conducted a study to determine improvement in gait, joint kinematics, and patients’ perceptions of overall well-being after surgical correction of tibial malunions. The null hypothesis was that correction of tibial malunion would have no effect on gait, joint kinematics, or patients’ perceptions of function and QOL.

Materials and Methods

This prospective double-time-point study, which was approved by the Institutional Review Board of Washington University/Barnes-Jewish Hospital, evaluated 11 consecutive patients with a varus tibial malunion treated by a single surgeon between September 2003 and January 2006. All patients were treated using a technique that included oblique osteotomy and open reduction and internal fixation (ORIF) or osteotomy and intramedullary nailing. Study inclusion criteria were age 18 years or older; symptomatic varus malunion of the tibia of 10º or more; absence of a developmental or pathologic process leading to the fracture and subsequent deformity; no neurologic deficit of either lower extremity or contralateral lower extremity deformity; and ability to ambulate 9 meters with or without use of an assistive device.

The 11 patients (6 men, 5 women) who met these criteria enrolled in the study. Mean age was 53 years (range, 43-68 years). Eight malunions involved the left tibia. The mechanisms of injury were motor vehicle crash (6 patients), fall from a great height (3), being struck by a motor vehicle (1), and gunshot (1). Mean time from injury to corrective surgery was 16.9 years (range, 1-34 years). Before surgery, each patient had a thorough physical examination, with plain radiographs, including anteroposterior (AP), lateral, and oblique views, obtained to assess degree of limb malalignment. Patients completed the Short Form-36 (SF-36) and the Musculoskeletal Function Assessment (MFA) and underwent joint kinematics and gait analysis. Five malunions were located in the mid-diaphysis of the tibia, 3 in the proximal third, and 2 in the distal third of the tibial shaft. One patient had posttraumatic deformity involving the proximal and the mid-diaphysis (Table 1). After surgery, each patient was followed at regular intervals in the surgeon’s private office. Minimum follow-up was 7 months (mean, 11 months; range 7-17 months). At follow-up, radiographs were obtained, and each patient completed the SF-36 and the MFA and underwent joint kinematics and gait analysis.

We obtained preoperative AP and lateral radiographs of the malaligned and contralateral normal tibias for each patient. Angular deformity was determined in the sagittal and coronal planes to determine location and magnitude of the deformity. Specifically, on each AP and lateral radiograph, a line was drawn the length of the tibia proximal and distal to the area of the deformity. The angle generated by the intersection of these lines on the AP and lateral radiographs was then plotted on a grid to determine the precise plane and magnitude of the deformity (Table 2).^1,12 Clinically, relevant rotational deformity of the involved limb was assessed by physical examination, and the results were compared with those of the contralateral limb. Owing to the lack of considerable rotational deformity in any of these 11 patients, we did not obtain computed tomography scans for further assessment of rotation.

Perioperative intravenous antibiotics were administered: 2 g cefazolin 30 minutes before incision and 1 g every 8 hours for 24 hours after surgery. A pneumatic tourniquet was placed on the proximal thigh, and the entire leg was prepared and draped in a sterile fashion. The limb was elevated and exsanguinated with an Esmark bandage and the tourniquet raised to 250 mm Hg. With fluoroscopy, the site of the tibial deformity was identified. Generally, an incision was made centered over the apex of the deformity and one fingerbreadth lateral to the palpable tibial crest. In most cases, the anterolateral aspect of the tibia was exposed while minimizing soft-tissue and periosteal stripping. The plane of the maximum deformity was identified with both direct visualization and fluoroscopy. The osteotomy was performed with an oscillating saw, and in each case a fibular osteotomy was also performed. Malalignment was corrected using a combination of manual manipulation and femoral distractor.^25,26 Intraoperative biplanar radiographs were compared with our preoperative plan and with reversed images of the contralateral tibia to assess correction of the deformity. If lengthening was required, in addition to the tibial osteotomy, a corticotomy was created, and a circular external fixator applied and distraction osteogenesis performed.

We maintained the limbs in a short-leg splint for about 10 days after surgery and then initiated active-assisted range of motion of neighboring joints. Patients were maintained on toe-touch weight-bearing for the initial 6 weeks and were then advanced to partial weight-bearing (23 kg). Physical therapy for lower extremity strengthening and gait training was started 6 weeks after surgery. Three months after surgery, patients were advanced to weight-bearing as tolerated and were allowed to return to their activities of daily living without restrictions if radiographs and clinical examination were consistent with healing of the osteotomy.

Each patient was examined and radiographs obtained at regular intervals (2, 6, and 12 weeks and then about every 3 months) after surgery until healing. Bone union was determined by history and physical examination with pain-free weight-bearing without use of assistive devices and by return of functional use of the extremity. Radiographic union was considered to have occurred when bridging trabeculae were present across the osteotomy and there was no loosening or failure of the implants. Occasionally, if there were questions regarding healing, a musculoskeletal radiologist was consulted. Acceptable tibia alignment was defined as alignment of less than 5° varus or less than 10° valgus in the coronal plane and less than 15° procurvatum or recurvatum in the sagittal plane. Immediate postoperative radiographs and most recent radiographs were used to determine the final amount of angular correction.²⁷

Two patients subsequently required secondary operative procedures. One had varus collapse through the regenerate, and the other developed a nonunion of the osteotomy site and required exchange intramedullary nailing. In each case, the final assessment was done after the patient had healed after the second surgery and had fully recovered.

Perceived Functional Assessment

The MFA is a 100-item self-administered QOL questionnaire designed to assess self-perception of physical, psychological, and social well-being in patients with a musculoskeletal injury or condition. The MFA provides a summary score and separate score for each of 10 functional domains. The lower the score, the better the patient’s perception of function. Validated and published norms are available.^20,28-30

Perceived Health Status

The Short Form-36 is a 36-item multipurpose self-administered health survey questionnaire. The SF-36, which assesses overall health status, provides a Physical Component Score (PCS) and a Mental Component Score (MCS). The higher the score, the better the patient’s perception of function. Validated and published norms are available.³¹

Gait Analysis

Video data from a 6-camera high-resolution system (Motion Analysis, Santa Rosa, California) were used to assess gait. A set of 3 reflective surface markers was placed on each of 4 areas: trunk, thighs, legs, and feet.^18,19 The patient walked barefoot along a 9-meter walkway, and video data were collected during the middle 2 meters. For each patient, data from 4 to 7 trials were collected. Computerized software produced data describing the averaged joint angle as a function of the gait cycle for each of the 3 principal planes of the body. Specific points in the gait cycle were analyzed. Variables included maximum knee varus in stance phase; maximum knee valgus in swing; maximum knee flexion in stance and swing; minimum knee flexion in stance; maximum ankle inversion in terminal stance; maximum ankle eversion in stance; maximum ankle dorsiflexion in stance and swing; and maximum ankle plantarflexion at takeoff. In addition to the lower extremity joint kinematics, angular measurements, basic gait measurements of step length, stride length, cadence, and speed were also recorded.

Statistical Analysis

Paired t tests were used to determine if significant changes occurred as a consequence of the surgery for the outcome variables (P < .05). Normative gait data were used to assess the quality of any changes that occurred in the variables, but no statistical analysis was performed to determine significant differences.¹⁸

Results

All 11 patients had clinical and radiographic evidence of healing and deformity correction at most recent follow-up. Nine patients (82%) healed after the index procedure. Mean total angular correction in the coronal plane was 21° (range, 14° varus to 7° valgus), and mean total angular correction in the sagittal plane was 9° (range, 21° recurvatum to 15° procurvatum) (Table 2).

For the group, mean preoperative MFA score was 39 (SD, 18; range, 10-69), and mean postoperative MFA score was 28 (SD, 14; range, 8-53). Patients reported the most improvement in 2 domains: In Leisure, mean (SD) preoperative score was 8 (2), and mean postoperative score was 5 (2); in Emotional, mean preoperative score was 5 (2), and mean postoperative score was 4 (1). The other domains were not significantly different between the 2 assessments.

 On the SF-36, mean (SD) PCS significantly (P < .05) improved from 32 (8) to 43 (9). Mean (SD) MCS showed little change: preoperative, 46 (16); postoperative, 48 (13). The PCS subcategories that showed the most improvement were Physical Function, mean (SD) preoperative, 26 (20), to postoperative, 52 (26); Role of Physical Health, preoperative, 18 (24), to postoperative, 60 (41); and Bodily Pain, preoperative, 39 (27), to 58 (18).

The results from the preoperative and postoperative gait analysis showed no significant differences for the ankle, knee, and hip variables during swing phase (Table 3). In an analysis of the changes in joint kinematics during stance, maximum hip adduction (increased) and maximum knee varus (decreased) on the operative side were significantly improved toward normative values as a consequence of the surgery (Table 3). The other kinematic stance variables were not significantly different. No significant changes were observed in stance time, step length, stride length, cadence, or speed as a consequence of the surgery (Table 4).

Discussion

Correction of malaligned tibias leads to improved limb alignment and patients’ perceptions of functional abilities and health but had a limited effect on joint kinematics and gait. In a group of like patients, we used common techniques to realign malunited tibias and validated instruments to measure functional outcome, health status, joint kinematics, and gait. The goals of this study were to evaluate changes in perceived function and health status and changes in joint kinematics and gait as a result of correction of a posttraumatic limb deformity.

Other investigators have reported outcomes of treating symptomatic malunions,³² nonunions,²⁴ and leg-length discrepancies.³³ In these reports, correction of deformity improved patient satisfaction and function, though objective means of assessment were infrequently used. Good results were reported with use of a dome-shaped supramalleolar osteotomy for the correction of tibial malunion.³² In this study, supramalleolar osteotomy was performed on 8 patients for correction of a malunited tibia. Postoperative assessment included subjective assessment of pain, limp, appearance, instability, and activity. Of these 8 patients, 7 reported overall symptomatic improvement after healing, and the 1 who lost the deformity correction remained symptomatic. Significant improvement in overall health has been reported after successful treatment of tibia nonunions.²⁴ The investigators used the SF-36 to assess patients who underwent treatment for a tibial nonunion. Analysis of these patients’ results showed a significant improvement in physical and mental functioning after healing. In addition, improved gait symmetry was reported in patients successfully treated for leg-length discrepancies.³³ Unfortunately, how improvement in gait related to overall patient function was not assessed. In the present study, we used stringent objective and subjective validated instruments to assess changes in joint gait kinematics and functional outcome before and after treatment of a tibial malunion. In general, our results are consistent with published results and indicate that realignment of tibial malunions improves patients’ perceptions of function. Our results also indicate improvements toward normative values in maximal hip adduction and knee varus, thus confirming the efficacy of the surgery from a functional perspective. Unfortunately, we did not show significant improvements in the remaining joint kinematics measurements or temporal gait parameters.

It is not entirely clear whether tibial malalignment leads to degenerative changes of the ipsilateral knee and/or ankle and what role this might play in functioning. In a retrospective analysis of 92 patients, angular deformity within 15° of normal alignment did not lead to ankle arthrosis.⁹ Milner and colleagues⁴ found that, though varus malunion of the tibia may lead to arthrosis of the medial compartment of the knee, other factors were more important in causing arthrosis of the ankle.

Wu and colleagues³⁴ used tibial osteotomies in New Zealand white rabbits to investigate cartilage and bone changes of the knee after creation of varus or valgus tibial deformities. Thirty-four weeks after osteotomy, rabbits with up to 30° of deformity had severe cartilage changes with osteophytes, fibrillation, derangement of cell columns, and associated increased subchondral bone density of the knees. Cadaveric studies have also shown increased contact pressures within the knees and ankles with ever increasing amounts of tibial deformity.^6,10 In each cadaveric study, malalignment in the distal third of the tibia caused the largest changes in the ankle, and changes in the alignment in the proximal third caused the largest changes in the knee.

Consistent with these animal and cadaveric studies are several retrospective clinical studies that have correlated tibial malalignment (particularly varus) with development of knee and ankle arthrosis.^3,5,8 Kettelkamp and colleagues³ found a direct correlation between magnitude of deformity and length of time with development of knee arthrosis. These findings have led many to recommend that surgeons try to restore tibial alignment to as near normal as possible to reduce the likelihood of arthrosis after tibia fracture. We found significant improvement toward normative values for maximum hip adduction (increased) and tibial varus (decreased) after surgery. These improvements would shift the weight-bearing forces back to the central part of the knee and therefore more uniformly distribute weight-bearing forces.

Posttraumatic arthrosis that develops after fracture is thought to result from increased joint pressures and possibly factors related to the injury. Although surgical correction of tibial alignment is unlikely to reverse these cartilage changes, it may restore joint pressure symmetry and “offload” compromised compartments. Offloading of already degenerative compartments may explain our patients’ improved perceptions of function and overall health status.

There were several limitations to our study. First, plain radiographs of malaligned and uninjured tibia and fibula were used, and these do not allow complete assessment of the weight-bearing access of the limb. Our patients, however, had isolated tibia fractures, which involved a normal limb before injury, so any alterations in joint kinematics, gait, or function would likely be the result of the fracture. Another limitation of our study is its nonrandomized design. However, the patients reflect the typical heterogeneous trauma patient population, who typically develop tibial malunions and seek correction. Another limitation was the lack of a treatment protocol regarding exact surgical technique and implants used to stabilize the osteotomies. In general, the patients were treated similarly, and their preoperative and postoperative assessments were exactly the same, as was their state-of-the-art joint kinematics and gait analysis, combined with the use of previously validated outcome measures. In addition, the lack of improvement in gait could have resulted from postoperative physical therapy that focused on joint mobilization and muscle strengthening and not on correction of abnormal gait parameters noted on preoperative gait analysis. Despite the potential limitations of the study, surgical correction of these symptomatic tibial malunions resulted in significant improvement in functional outcome and improved joint kinematics on the operative side.

Conclusion

Significant effort should be made to restore and maintain near-anatomical tibial alignment until a tibia fracture is healed. In patients who develop a symptomatic tibial malunion, surgical correction should be undertaken with the intent to restore normal limb alignment and improve joint kinematics, function, and overall health status.

The tibia is the most commonly fractured long bone in adults, and tibial malunions occur in up to 60% of these patients.^1,2 Persistent tibial malalignment, particularly varus alignment, negatively alters gait and joint kinematics, leading to altered weight-bearing forces across the knee and ankle joints. These altered forces may lead to osteoarthritis.^3-8

Several studies have identified a relationship between extent of tibial malalignment and changes in joint reaction forces.^3,5-7,9-13 Puno and colleagues¹⁴ developed a mathematical model to better define the changes in neighboring joints relative to the pattern of the tibia malalignment. Not surprisingly, their work showed that, with distal tibial malunions, altered stress concentrations were realized at the ankle joint, and more proximal tibial deformities led to larger alterations in the joint stresses at the knee. More recently, van der Schoot and colleagues⁸ found a high prevalence of ipsilateral ankle osteoarthritis with tibial malalignment of 5° or more, and Greenwood and colleagues¹⁵ showed a higher incidence of knee pain, lower limb osteoarthritis, and disability in patients with previous tibia fractures. Given these findings, it would seem that correction of tibial malalignment would lead to normative lower extremity joint kinematic values, joint reaction forces, and overall quality of life (QOL).

The ability to ambulate has been recognized as an important milestone in functional recovery after lower extremity injury.^2,16,17 Gait analysis, assessment of joint kinematics, and QOL and health status questionnaires can provide information to evaluate rehabilitation protocols, treatment algorithms, and surgical outcomes. Recently, these measures have been used to assess patients recovering from acetabular fractures, femoral shaft fractures, and calcaneal fractures.^4,11,17-24 However, no study has used these measures to assess the benefits of surgical correction of malaligned tibias.

We conducted a study to determine improvement in gait, joint kinematics, and patients’ perceptions of overall well-being after surgical correction of tibial malunions. The null hypothesis was that correction of tibial malunion would have no effect on gait, joint kinematics, or patients’ perceptions of function and QOL.

Materials and Methods

This prospective double-time-point study, which was approved by the Institutional Review Board of Washington University/Barnes-Jewish Hospital, evaluated 11 consecutive patients with a varus tibial malunion treated by a single surgeon between September 2003 and January 2006. All patients were treated using a technique that included oblique osteotomy and open reduction and internal fixation (ORIF) or osteotomy and intramedullary nailing. Study inclusion criteria were age 18 years or older; symptomatic varus malunion of the tibia of 10º or more; absence of a developmental or pathologic process leading to the fracture and subsequent deformity; no neurologic deficit of either lower extremity or contralateral lower extremity deformity; and ability to ambulate 9 meters with or without use of an assistive device.

The 11 patients (6 men, 5 women) who met these criteria enrolled in the study. Mean age was 53 years (range, 43-68 years). Eight malunions involved the left tibia. The mechanisms of injury were motor vehicle crash (6 patients), fall from a great height (3), being struck by a motor vehicle (1), and gunshot (1). Mean time from injury to corrective surgery was 16.9 years (range, 1-34 years). Before surgery, each patient had a thorough physical examination, with plain radiographs, including anteroposterior (AP), lateral, and oblique views, obtained to assess degree of limb malalignment. Patients completed the Short Form-36 (SF-36) and the Musculoskeletal Function Assessment (MFA) and underwent joint kinematics and gait analysis. Five malunions were located in the mid-diaphysis of the tibia, 3 in the proximal third, and 2 in the distal third of the tibial shaft. One patient had posttraumatic deformity involving the proximal and the mid-diaphysis (Table 1). After surgery, each patient was followed at regular intervals in the surgeon’s private office. Minimum follow-up was 7 months (mean, 11 months; range 7-17 months). At follow-up, radiographs were obtained, and each patient completed the SF-36 and the MFA and underwent joint kinematics and gait analysis.

We obtained preoperative AP and lateral radiographs of the malaligned and contralateral normal tibias for each patient. Angular deformity was determined in the sagittal and coronal planes to determine location and magnitude of the deformity. Specifically, on each AP and lateral radiograph, a line was drawn the length of the tibia proximal and distal to the area of the deformity. The angle generated by the intersection of these lines on the AP and lateral radiographs was then plotted on a grid to determine the precise plane and magnitude of the deformity (Table 2).^1,12 Clinically, relevant rotational deformity of the involved limb was assessed by physical examination, and the results were compared with those of the contralateral limb. Owing to the lack of considerable rotational deformity in any of these 11 patients, we did not obtain computed tomography scans for further assessment of rotation.

Perioperative intravenous antibiotics were administered: 2 g cefazolin 30 minutes before incision and 1 g every 8 hours for 24 hours after surgery. A pneumatic tourniquet was placed on the proximal thigh, and the entire leg was prepared and draped in a sterile fashion. The limb was elevated and exsanguinated with an Esmark bandage and the tourniquet raised to 250 mm Hg. With fluoroscopy, the site of the tibial deformity was identified. Generally, an incision was made centered over the apex of the deformity and one fingerbreadth lateral to the palpable tibial crest. In most cases, the anterolateral aspect of the tibia was exposed while minimizing soft-tissue and periosteal stripping. The plane of the maximum deformity was identified with both direct visualization and fluoroscopy. The osteotomy was performed with an oscillating saw, and in each case a fibular osteotomy was also performed. Malalignment was corrected using a combination of manual manipulation and femoral distractor.^25,26 Intraoperative biplanar radiographs were compared with our preoperative plan and with reversed images of the contralateral tibia to assess correction of the deformity. If lengthening was required, in addition to the tibial osteotomy, a corticotomy was created, and a circular external fixator applied and distraction osteogenesis performed.

We maintained the limbs in a short-leg splint for about 10 days after surgery and then initiated active-assisted range of motion of neighboring joints. Patients were maintained on toe-touch weight-bearing for the initial 6 weeks and were then advanced to partial weight-bearing (23 kg). Physical therapy for lower extremity strengthening and gait training was started 6 weeks after surgery. Three months after surgery, patients were advanced to weight-bearing as tolerated and were allowed to return to their activities of daily living without restrictions if radiographs and clinical examination were consistent with healing of the osteotomy.

Each patient was examined and radiographs obtained at regular intervals (2, 6, and 12 weeks and then about every 3 months) after surgery until healing. Bone union was determined by history and physical examination with pain-free weight-bearing without use of assistive devices and by return of functional use of the extremity. Radiographic union was considered to have occurred when bridging trabeculae were present across the osteotomy and there was no loosening or failure of the implants. Occasionally, if there were questions regarding healing, a musculoskeletal radiologist was consulted. Acceptable tibia alignment was defined as alignment of less than 5° varus or less than 10° valgus in the coronal plane and less than 15° procurvatum or recurvatum in the sagittal plane. Immediate postoperative radiographs and most recent radiographs were used to determine the final amount of angular correction.²⁷

Two patients subsequently required secondary operative procedures. One had varus collapse through the regenerate, and the other developed a nonunion of the osteotomy site and required exchange intramedullary nailing. In each case, the final assessment was done after the patient had healed after the second surgery and had fully recovered.

Perceived Functional Assessment

The MFA is a 100-item self-administered QOL questionnaire designed to assess self-perception of physical, psychological, and social well-being in patients with a musculoskeletal injury or condition. The MFA provides a summary score and separate score for each of 10 functional domains. The lower the score, the better the patient’s perception of function. Validated and published norms are available.^20,28-30

Perceived Health Status

The Short Form-36 is a 36-item multipurpose self-administered health survey questionnaire. The SF-36, which assesses overall health status, provides a Physical Component Score (PCS) and a Mental Component Score (MCS). The higher the score, the better the patient’s perception of function. Validated and published norms are available.³¹

Gait Analysis

Video data from a 6-camera high-resolution system (Motion Analysis, Santa Rosa, California) were used to assess gait. A set of 3 reflective surface markers was placed on each of 4 areas: trunk, thighs, legs, and feet.^18,19 The patient walked barefoot along a 9-meter walkway, and video data were collected during the middle 2 meters. For each patient, data from 4 to 7 trials were collected. Computerized software produced data describing the averaged joint angle as a function of the gait cycle for each of the 3 principal planes of the body. Specific points in the gait cycle were analyzed. Variables included maximum knee varus in stance phase; maximum knee valgus in swing; maximum knee flexion in stance and swing; minimum knee flexion in stance; maximum ankle inversion in terminal stance; maximum ankle eversion in stance; maximum ankle dorsiflexion in stance and swing; and maximum ankle plantarflexion at takeoff. In addition to the lower extremity joint kinematics, angular measurements, basic gait measurements of step length, stride length, cadence, and speed were also recorded.

Statistical Analysis

Paired t tests were used to determine if significant changes occurred as a consequence of the surgery for the outcome variables (P < .05). Normative gait data were used to assess the quality of any changes that occurred in the variables, but no statistical analysis was performed to determine significant differences.¹⁸

Results

All 11 patients had clinical and radiographic evidence of healing and deformity correction at most recent follow-up. Nine patients (82%) healed after the index procedure. Mean total angular correction in the coronal plane was 21° (range, 14° varus to 7° valgus), and mean total angular correction in the sagittal plane was 9° (range, 21° recurvatum to 15° procurvatum) (Table 2).

For the group, mean preoperative MFA score was 39 (SD, 18; range, 10-69), and mean postoperative MFA score was 28 (SD, 14; range, 8-53). Patients reported the most improvement in 2 domains: In Leisure, mean (SD) preoperative score was 8 (2), and mean postoperative score was 5 (2); in Emotional, mean preoperative score was 5 (2), and mean postoperative score was 4 (1). The other domains were not significantly different between the 2 assessments.

 On the SF-36, mean (SD) PCS significantly (P < .05) improved from 32 (8) to 43 (9). Mean (SD) MCS showed little change: preoperative, 46 (16); postoperative, 48 (13). The PCS subcategories that showed the most improvement were Physical Function, mean (SD) preoperative, 26 (20), to postoperative, 52 (26); Role of Physical Health, preoperative, 18 (24), to postoperative, 60 (41); and Bodily Pain, preoperative, 39 (27), to 58 (18).

The results from the preoperative and postoperative gait analysis showed no significant differences for the ankle, knee, and hip variables during swing phase (Table 3). In an analysis of the changes in joint kinematics during stance, maximum hip adduction (increased) and maximum knee varus (decreased) on the operative side were significantly improved toward normative values as a consequence of the surgery (Table 3). The other kinematic stance variables were not significantly different. No significant changes were observed in stance time, step length, stride length, cadence, or speed as a consequence of the surgery (Table 4).

Discussion

Correction of malaligned tibias leads to improved limb alignment and patients’ perceptions of functional abilities and health but had a limited effect on joint kinematics and gait. In a group of like patients, we used common techniques to realign malunited tibias and validated instruments to measure functional outcome, health status, joint kinematics, and gait. The goals of this study were to evaluate changes in perceived function and health status and changes in joint kinematics and gait as a result of correction of a posttraumatic limb deformity.

Other investigators have reported outcomes of treating symptomatic malunions,³² nonunions,²⁴ and leg-length discrepancies.³³ In these reports, correction of deformity improved patient satisfaction and function, though objective means of assessment were infrequently used. Good results were reported with use of a dome-shaped supramalleolar osteotomy for the correction of tibial malunion.³² In this study, supramalleolar osteotomy was performed on 8 patients for correction of a malunited tibia. Postoperative assessment included subjective assessment of pain, limp, appearance, instability, and activity. Of these 8 patients, 7 reported overall symptomatic improvement after healing, and the 1 who lost the deformity correction remained symptomatic. Significant improvement in overall health has been reported after successful treatment of tibia nonunions.²⁴ The investigators used the SF-36 to assess patients who underwent treatment for a tibial nonunion. Analysis of these patients’ results showed a significant improvement in physical and mental functioning after healing. In addition, improved gait symmetry was reported in patients successfully treated for leg-length discrepancies.³³ Unfortunately, how improvement in gait related to overall patient function was not assessed. In the present study, we used stringent objective and subjective validated instruments to assess changes in joint gait kinematics and functional outcome before and after treatment of a tibial malunion. In general, our results are consistent with published results and indicate that realignment of tibial malunions improves patients’ perceptions of function. Our results also indicate improvements toward normative values in maximal hip adduction and knee varus, thus confirming the efficacy of the surgery from a functional perspective. Unfortunately, we did not show significant improvements in the remaining joint kinematics measurements or temporal gait parameters.

It is not entirely clear whether tibial malalignment leads to degenerative changes of the ipsilateral knee and/or ankle and what role this might play in functioning. In a retrospective analysis of 92 patients, angular deformity within 15° of normal alignment did not lead to ankle arthrosis.⁹ Milner and colleagues⁴ found that, though varus malunion of the tibia may lead to arthrosis of the medial compartment of the knee, other factors were more important in causing arthrosis of the ankle.

Wu and colleagues³⁴ used tibial osteotomies in New Zealand white rabbits to investigate cartilage and bone changes of the knee after creation of varus or valgus tibial deformities. Thirty-four weeks after osteotomy, rabbits with up to 30° of deformity had severe cartilage changes with osteophytes, fibrillation, derangement of cell columns, and associated increased subchondral bone density of the knees. Cadaveric studies have also shown increased contact pressures within the knees and ankles with ever increasing amounts of tibial deformity.^6,10 In each cadaveric study, malalignment in the distal third of the tibia caused the largest changes in the ankle, and changes in the alignment in the proximal third caused the largest changes in the knee.

Consistent with these animal and cadaveric studies are several retrospective clinical studies that have correlated tibial malalignment (particularly varus) with development of knee and ankle arthrosis.^3,5,8 Kettelkamp and colleagues³ found a direct correlation between magnitude of deformity and length of time with development of knee arthrosis. These findings have led many to recommend that surgeons try to restore tibial alignment to as near normal as possible to reduce the likelihood of arthrosis after tibia fracture. We found significant improvement toward normative values for maximum hip adduction (increased) and tibial varus (decreased) after surgery. These improvements would shift the weight-bearing forces back to the central part of the knee and therefore more uniformly distribute weight-bearing forces.

Posttraumatic arthrosis that develops after fracture is thought to result from increased joint pressures and possibly factors related to the injury. Although surgical correction of tibial alignment is unlikely to reverse these cartilage changes, it may restore joint pressure symmetry and “offload” compromised compartments. Offloading of already degenerative compartments may explain our patients’ improved perceptions of function and overall health status.

There were several limitations to our study. First, plain radiographs of malaligned and uninjured tibia and fibula were used, and these do not allow complete assessment of the weight-bearing access of the limb. Our patients, however, had isolated tibia fractures, which involved a normal limb before injury, so any alterations in joint kinematics, gait, or function would likely be the result of the fracture. Another limitation of our study is its nonrandomized design. However, the patients reflect the typical heterogeneous trauma patient population, who typically develop tibial malunions and seek correction. Another limitation was the lack of a treatment protocol regarding exact surgical technique and implants used to stabilize the osteotomies. In general, the patients were treated similarly, and their preoperative and postoperative assessments were exactly the same, as was their state-of-the-art joint kinematics and gait analysis, combined with the use of previously validated outcome measures. In addition, the lack of improvement in gait could have resulted from postoperative physical therapy that focused on joint mobilization and muscle strengthening and not on correction of abnormal gait parameters noted on preoperative gait analysis. Despite the potential limitations of the study, surgical correction of these symptomatic tibial malunions resulted in significant improvement in functional outcome and improved joint kinematics on the operative side.

Conclusion

Significant effort should be made to restore and maintain near-anatomical tibial alignment until a tibia fracture is healed. In patients who develop a symptomatic tibial malunion, surgical correction should be undertaken with the intent to restore normal limb alignment and improve joint kinematics, function, and overall health status.