The American Journal of Orthopedics

Reverse total shoulder arthroplasty (RTSA) performed in carefully selected patients often leads to satisfactory outcomes.^1,2 In recent years, its indications and the number performed per year have expanded. Subsequently, there has been a concomitant rise in reported complications,^2,3 with a rate ranging from 19% to 68%.^2,3 Some common complications include scapular notching,^2-4 fracture,^2,3,5-7 dislocation,^2,3,7 and infection.^2,3,7

In this series, we describe 2 cases of coracoid fracture after RTSA. The patients provided written informed consent for print and electronic publication of these case reports.

Case Series

Case 1

An independently functioning 81-year-old right hand–dominant woman (BMI, 22.1 [height, 160 cm; weight, 56.7 kg]) presented with increasing left shoulder pain and dysfunction after a motor vehicle accident 2 months earlier. She had reported vague chronic left shoulder pain in the past, but after the accident her pain was significantly worse. A subacromial corticosteroid injection by her primary care physician provided temporary symptomatic relief, but her symptoms recurred.

On presentation, there was obvious anterior superior escape of the humeral head, which was accentuated by shoulder shrug. Her deltoid motor function was found to be intact, and her active shoulder range of motion was severely limited (pseudoparesis). There was notable crepitation as well as significant weakness and pain with abduction and external rotation strength testing.

Radiographic imaging showed anterior superior escape of the humeral head with some early degenerative changes (Seebauer type IIB⁸ [Figure 1A]). Magnetic resonance imaging confirmed a full-thickness retracted massive rotator cuff tear with complete involvement of the supraspinatus, infraspinatus, and most of the subscapularis muscles. Significant glenohumeral degenerative changes consistent with cuff tear arthropathy were also seen without any evidence of fracture.

After thorough discussion of options, risks, and benefits, the decision was made to proceed with RTSA. The patient underwent the procedure without complications. A DePuy Delta Xtend prosthesis was used with a cemented humeral stem, polyethylene, and glenosphere, sizes of 12, +3, and 38, respectively. The glenosphere component, positioned inferiorly to avoid scapular notching, was secured with 3 screws, and the stem was placed in neutral version. The patient’s shoulder was reduced, ranged, and noted to be stable, allowing for supple passive range of motion without evidence of excessive tightness. She was placed in a sling with the shoulder positioned in neutral alignment. Her postoperative radiograph (Figure 1B) showed satisfactory implantation of the reverse total shoulder prosthesis. Her postoperative course was uneventful, and rehabilitation consisted of 6 weeks of sling protection, with advancing passive and active range of motion. Strengthening exercises were initiated 6 weeks after surgery.

At the patient’s 6-week postoperative visit, she demonstrated pain-free passive elevation to 80° and active forward elevation to 70°. At her 3-month postoperative visit, she reported a 1-week onset of anterior shoulder pain accompanied by a strange noise at the anterior aspect of the operative shoulder. She denied any recent trauma. She continued to have minimal shoulder pain with passive forward flexion of 80°; however, her active forward elevation was very limited because of pain in the anterior aspect of her shoulder. Active external rotation was noted to be 20° and internal rotation was to her buttock. She had pain to palpation of the coracoid process. Radiographs were unchanged from immediate postoperative radiographs. Computed tomography (CT), which was ordered to ensure that the implant was stable with no loosening, showed satisfactory alignment of the prosthesis and no loosening. However, CT was notable for a nondisplaced fracture through the base of the coracoid (Figures 2A-2D). The patient stopped formal physical therapy, and sling immobilization was initiated. After 3 weeks, the sling was discontinued and physical therapy was begun again. She responded satisfactorily to this treatment approach, and, at her 6-month postoperative follow-up, she was without pain, instability, or crepitation. Her range of motion had improved with pain-free active forward flexion, external rotation, and abduction of 100°, 15°, and 90°, respectively. At 28-month postoperative follow-up, her visual analog scale, American Shoulder and Elbow Surgeons score, and Simple Shoulder Test score were 3, 73, and 67, respectively. 

Case 2

A 68-year-old, right-handed woman (BMI, 22.5 [height, 160 cm; weight, 57.6 kg]) presented with right shoulder pain and dysfunction of 3 years’ duration. She had undergone an open rotator cuff repair at an outside facility 4 years ago that was unsuccessful. At the time of her presentation to our institution, she had already undergone a failed course of physical therapy. A trial of corticosteroid subacromial injections did not adequately manage her symptoms.

On presentation, her active forward flexion, abduction, and external rotation were 40°, 30°, and 10°, respectively. She had full passive range of motion and pain with active and passive shoulder motion. Radiographic imaging showed superior migration of the humeral head with evidence of glenohumeral arthropathy suggestive of rotator cuff arthropathy (Seebauer type IIA⁸). After thorough discussion of options, risks, and benefits, the decision was made to proceed with RTSA. She underwent the procedure without complications. A DePuy Delta Xtend prosthesis was used with a cemented humeral stem, polyethylene, and glenosphere, sizes of 8, +3, and 38, respectively. The glenosphere component, positioned inferiorly to avoid scapular notching, was secured with 4 screws, and the stem was placed in neutral version. Her shoulder was reduced, ranged, and noted to be stable, allowing for supple passive range of motion without evidence of excessive tightness. She was placed in a sling with the shoulder positioned in neutral alignment. Her postoperative radiographs revealed satisfactory implantation of the reverse total shoulder prosthesis. Her postoperative course was uneventful. She was taken out of her shoulder immobilizer 4 weeks after surgery and began home-based physical therapy.

At 1 year after surgery, the patient had minimal shoulder pain with active forward flexion, external rotation, and abduction of 135°, 20°, and 85°, respectively. She presented to our clinic 15 months after RTSA with acute onset of pain about her anterior shoulder. She denied any recent trauma or infectious exposures. On examination, her motion was unchanged from prior examinations. However, she was tender on palpation of the coracoid. Radiographs at that time were unchanged (Figures 3A, 3B). Laboratory tests (erythrocyte sedimentation rate, C-reactive protein, and complete blood count with differential) that were subsequently ordered to rule out an occult infection were within normal limits. Computed tomography, which was ordered for further assessment and to ensure that the implant was stable with no loosening, showed satisfactory alignment of the prosthesis without loosening. However, a lucency was noted in the midportion of the coracoid that was suggestive of a fracture (Figures 4A, 4B). A conservative plan of treatment was advised with sling immobilization for 3 weeks and follow-up visits. The patient responded satisfactorily to this treatment approach, and, at her latest follow-up, 8 months after presenting with a coracoid fracture, she was pain-free. At the 5-year postoperative follow-up, her visual analog scale, American Shoulder and Elbow Surgeons score, and Simple Shoulder Test score were 1-2, 78, and 75, respectively. 

Discussion

The reverse prosthesis, a semi-constrained ball-and-socket device, provides satisfactory functional outcomes when used in carefully selected patients with rotator cuff arthropathy and pseudoparalysis, failed shoulder arthroplasty, and fracture sequelae.^1,9-11 By the traditional Grammont principles of medializing the center of rotation and lowering the humerus, shear forces about the glenoid are reduced and the deltoid muscle is tensioned, allowing for adequate torque generation, required to facilitate shoulder motion.^12,13 While long-term outcomes  concerning durability and survivorship are pending, some studies have attempted to improve our understanding of implant and functional longevity. Guery and colleagues¹⁴ noted an implant survival of 91% at 120 months. However, increased pain and decreased function were seen at the 6-year mark.¹⁴ A more recent study by Cuff and colleagues¹⁵ revealed 94% implant survivorship and sustained improvement in range of motion and pain at 5 years. 

Despite considerable success, RTSA can be associated with a myriad of complications. The most common complications of RTSA include scapular notching (44%-96%), glenoid side failure (5%-40%), instability (2.4%-31%), and infection (1%-15.3%).^2,3 In the setting of inflammatory arthropathy, there is an increased risk for intraoperative and postoperative fractures.^16,17 To date, there are only 2 reported cases of coracoid process fractures after RTSA.^18,19 In the case by Nolan and colleagues,¹⁸ conservative management with a sling for 6 weeks led to successful resolution of symptoms. Although little information is provided on the management of these rare fractures, literature on the slightly more common scapular (0.9%-7.2%) and acromial (0.9%-4.9%) fractures suggest that periscapular fractures are on the rise, may increase the risk for revision surgery, and can lead to inferior outcomes when compared with patients without fractures.^5,20,21

Acromial fractures after RTSA have been reported to occur at a rate of 0.9% to 4.9%.^5,21 This is a concern because of RTSA reliance on a functional deltoid.^5,6 The cause of these fractures remains to be fully elucidated. Wahlquist and colleagues⁶ in 2011 reported the cases of 5 patients that sustained acromial base fractures after RTSA. All 5 patients were noted to have unsatisfactory functional results despite achieving union (3 were treated with open reduction and internal fixation, and 2 were treated nonoperatively). Acromial fractures tend to present with pain within 6 months of surgery, which may indicate excessive constraint about the scapula, eventually leading to fracture. Furthermore, disruption of this bony structure can lead to devastating results because the acromial base serves as a fulcrum for the deltoid.

Despite a well-placed reverse prosthesis, there is increased reliance on surrounding glenohumeral musculature, resulting from poor rotator cuff function and biomechanical differences compared with a native shoulder. Both our patients were found to have relatively small body habitus. It is possible that, by nature of their smaller statures, they were more susceptible to consequences of excessive joint and soft-tissue tension after RTSA. One explanation for acromial fractures after RTSA is that, by excessively lengthening and/or lateralizing the deltoid, the tension on the acromion in these elderly patients may be sufficient to cause a fracture. A similar mechanism may explain their coracoid fractures. As the arm is lengthened and the prosthesis is tightened, the conjoint tendon is significantly tensioned. We routinely check the tension of these muscles as an extra confirmation of joint stability. However, excessive tension for a significant duration may provide too much stress for bone turnover to match with the inherent repair process, potentially causing a fracture. Recent evidence has also found that bone mineral density of the coracoid diminishes with age, suggesting some predisposition to fracture with lower-energy mechanisms.²²

Another possible cause for coracoid fractures may be the orientation of the implants. While we did not have mechanistic evidence, it is possible that, with adduction and internal rotation, prosthetic impingement against the coracoid is feasible, particularly in patients of small stature. Although a glenoid implant placed high can increase the chance for coracoid–implant impingement, the fact that the patients improved without revision makes chronic mechanical impingement less likely. Drill holes, especially multiple ones, placed throughout the base of the coracoid may also predispose to coracoid fractures.

Patients with periscapular fractures (acromion, scapular spine, or coracoid) after RTSA often present with pain and occasional deficits in function. Both patients in this series noted pain out of proportion to examination. The onset of this pain differed, with 1 patient noting pain within the first 3 months and 1 noting discomfort later. Neither patient had any trauma. In the presence of significant symptoms, negative radiographs, and a poor response to conservative treatment, we recommend advanced imaging to rule out fracture. However, prior to obtaining advanced imaging, proper radiographic techniques should be utilized. Eyres and colleagues,²³ in a series of 12 fractures of the coracoid process, relied primarily on coracoid views directed 45° in a cephalic direction and thin-slice CT. An isotope bone scan identified 1 case not initially found on radiographs.²³

Conservative management with use of a sling until resolution of symptoms was successful in our series. If symptoms persist, a bone stimulator can be used prior to implementing a surgical solution; however, current evidence does not expound on timing and utility of such modalities. Perhaps as important as treatment is education of the patient and the rehabilitation team about the importance of identifying increasing pain as a potential sign of impending fracture in this population. Subsequent activity modification until the pain resolves can help avoid the setback in postoperative recovery that this complication may cause.

Conclusion

We present 2 patients with coracoid fractures encountered at 3 months and 15 months after RTSA. Nonoperative management proved adequate in treating both cases. We suggest a high level of suspicion for possible fracture in the patient who comes in with new-onset pain in a localized region with or without functional deficits.

Reverse total shoulder arthroplasty (RTSA) performed in carefully selected patients often leads to satisfactory outcomes.^1,2 In recent years, its indications and the number performed per year have expanded. Subsequently, there has been a concomitant rise in reported complications,^2,3 with a rate ranging from 19% to 68%.^2,3 Some common complications include scapular notching,^2-4 fracture,^2,3,5-7 dislocation,^2,3,7 and infection.^2,3,7

In this series, we describe 2 cases of coracoid fracture after RTSA. The patients provided written informed consent for print and electronic publication of these case reports.

Case Series

Case 1

An independently functioning 81-year-old right hand–dominant woman (BMI, 22.1 [height, 160 cm; weight, 56.7 kg]) presented with increasing left shoulder pain and dysfunction after a motor vehicle accident 2 months earlier. She had reported vague chronic left shoulder pain in the past, but after the accident her pain was significantly worse. A subacromial corticosteroid injection by her primary care physician provided temporary symptomatic relief, but her symptoms recurred.

On presentation, there was obvious anterior superior escape of the humeral head, which was accentuated by shoulder shrug. Her deltoid motor function was found to be intact, and her active shoulder range of motion was severely limited (pseudoparesis). There was notable crepitation as well as significant weakness and pain with abduction and external rotation strength testing.

Radiographic imaging showed anterior superior escape of the humeral head with some early degenerative changes (Seebauer type IIB⁸ [Figure 1A]). Magnetic resonance imaging confirmed a full-thickness retracted massive rotator cuff tear with complete involvement of the supraspinatus, infraspinatus, and most of the subscapularis muscles. Significant glenohumeral degenerative changes consistent with cuff tear arthropathy were also seen without any evidence of fracture.

After thorough discussion of options, risks, and benefits, the decision was made to proceed with RTSA. The patient underwent the procedure without complications. A DePuy Delta Xtend prosthesis was used with a cemented humeral stem, polyethylene, and glenosphere, sizes of 12, +3, and 38, respectively. The glenosphere component, positioned inferiorly to avoid scapular notching, was secured with 3 screws, and the stem was placed in neutral version. The patient’s shoulder was reduced, ranged, and noted to be stable, allowing for supple passive range of motion without evidence of excessive tightness. She was placed in a sling with the shoulder positioned in neutral alignment. Her postoperative radiograph (Figure 1B) showed satisfactory implantation of the reverse total shoulder prosthesis. Her postoperative course was uneventful, and rehabilitation consisted of 6 weeks of sling protection, with advancing passive and active range of motion. Strengthening exercises were initiated 6 weeks after surgery.

At the patient’s 6-week postoperative visit, she demonstrated pain-free passive elevation to 80° and active forward elevation to 70°. At her 3-month postoperative visit, she reported a 1-week onset of anterior shoulder pain accompanied by a strange noise at the anterior aspect of the operative shoulder. She denied any recent trauma. She continued to have minimal shoulder pain with passive forward flexion of 80°; however, her active forward elevation was very limited because of pain in the anterior aspect of her shoulder. Active external rotation was noted to be 20° and internal rotation was to her buttock. She had pain to palpation of the coracoid process. Radiographs were unchanged from immediate postoperative radiographs. Computed tomography (CT), which was ordered to ensure that the implant was stable with no loosening, showed satisfactory alignment of the prosthesis and no loosening. However, CT was notable for a nondisplaced fracture through the base of the coracoid (Figures 2A-2D). The patient stopped formal physical therapy, and sling immobilization was initiated. After 3 weeks, the sling was discontinued and physical therapy was begun again. She responded satisfactorily to this treatment approach, and, at her 6-month postoperative follow-up, she was without pain, instability, or crepitation. Her range of motion had improved with pain-free active forward flexion, external rotation, and abduction of 100°, 15°, and 90°, respectively. At 28-month postoperative follow-up, her visual analog scale, American Shoulder and Elbow Surgeons score, and Simple Shoulder Test score were 3, 73, and 67, respectively. 

Case 2

A 68-year-old, right-handed woman (BMI, 22.5 [height, 160 cm; weight, 57.6 kg]) presented with right shoulder pain and dysfunction of 3 years’ duration. She had undergone an open rotator cuff repair at an outside facility 4 years ago that was unsuccessful. At the time of her presentation to our institution, she had already undergone a failed course of physical therapy. A trial of corticosteroid subacromial injections did not adequately manage her symptoms.

On presentation, her active forward flexion, abduction, and external rotation were 40°, 30°, and 10°, respectively. She had full passive range of motion and pain with active and passive shoulder motion. Radiographic imaging showed superior migration of the humeral head with evidence of glenohumeral arthropathy suggestive of rotator cuff arthropathy (Seebauer type IIA⁸). After thorough discussion of options, risks, and benefits, the decision was made to proceed with RTSA. She underwent the procedure without complications. A DePuy Delta Xtend prosthesis was used with a cemented humeral stem, polyethylene, and glenosphere, sizes of 8, +3, and 38, respectively. The glenosphere component, positioned inferiorly to avoid scapular notching, was secured with 4 screws, and the stem was placed in neutral version. Her shoulder was reduced, ranged, and noted to be stable, allowing for supple passive range of motion without evidence of excessive tightness. She was placed in a sling with the shoulder positioned in neutral alignment. Her postoperative radiographs revealed satisfactory implantation of the reverse total shoulder prosthesis. Her postoperative course was uneventful. She was taken out of her shoulder immobilizer 4 weeks after surgery and began home-based physical therapy.

At 1 year after surgery, the patient had minimal shoulder pain with active forward flexion, external rotation, and abduction of 135°, 20°, and 85°, respectively. She presented to our clinic 15 months after RTSA with acute onset of pain about her anterior shoulder. She denied any recent trauma or infectious exposures. On examination, her motion was unchanged from prior examinations. However, she was tender on palpation of the coracoid. Radiographs at that time were unchanged (Figures 3A, 3B). Laboratory tests (erythrocyte sedimentation rate, C-reactive protein, and complete blood count with differential) that were subsequently ordered to rule out an occult infection were within normal limits. Computed tomography, which was ordered for further assessment and to ensure that the implant was stable with no loosening, showed satisfactory alignment of the prosthesis without loosening. However, a lucency was noted in the midportion of the coracoid that was suggestive of a fracture (Figures 4A, 4B). A conservative plan of treatment was advised with sling immobilization for 3 weeks and follow-up visits. The patient responded satisfactorily to this treatment approach, and, at her latest follow-up, 8 months after presenting with a coracoid fracture, she was pain-free. At the 5-year postoperative follow-up, her visual analog scale, American Shoulder and Elbow Surgeons score, and Simple Shoulder Test score were 1-2, 78, and 75, respectively. 

Discussion

The reverse prosthesis, a semi-constrained ball-and-socket device, provides satisfactory functional outcomes when used in carefully selected patients with rotator cuff arthropathy and pseudoparalysis, failed shoulder arthroplasty, and fracture sequelae.^1,9-11 By the traditional Grammont principles of medializing the center of rotation and lowering the humerus, shear forces about the glenoid are reduced and the deltoid muscle is tensioned, allowing for adequate torque generation, required to facilitate shoulder motion.^12,13 While long-term outcomes  concerning durability and survivorship are pending, some studies have attempted to improve our understanding of implant and functional longevity. Guery and colleagues¹⁴ noted an implant survival of 91% at 120 months. However, increased pain and decreased function were seen at the 6-year mark.¹⁴ A more recent study by Cuff and colleagues¹⁵ revealed 94% implant survivorship and sustained improvement in range of motion and pain at 5 years. 

Despite considerable success, RTSA can be associated with a myriad of complications. The most common complications of RTSA include scapular notching (44%-96%), glenoid side failure (5%-40%), instability (2.4%-31%), and infection (1%-15.3%).^2,3 In the setting of inflammatory arthropathy, there is an increased risk for intraoperative and postoperative fractures.^16,17 To date, there are only 2 reported cases of coracoid process fractures after RTSA.^18,19 In the case by Nolan and colleagues,¹⁸ conservative management with a sling for 6 weeks led to successful resolution of symptoms. Although little information is provided on the management of these rare fractures, literature on the slightly more common scapular (0.9%-7.2%) and acromial (0.9%-4.9%) fractures suggest that periscapular fractures are on the rise, may increase the risk for revision surgery, and can lead to inferior outcomes when compared with patients without fractures.^5,20,21

Acromial fractures after RTSA have been reported to occur at a rate of 0.9% to 4.9%.^5,21 This is a concern because of RTSA reliance on a functional deltoid.^5,6 The cause of these fractures remains to be fully elucidated. Wahlquist and colleagues⁶ in 2011 reported the cases of 5 patients that sustained acromial base fractures after RTSA. All 5 patients were noted to have unsatisfactory functional results despite achieving union (3 were treated with open reduction and internal fixation, and 2 were treated nonoperatively). Acromial fractures tend to present with pain within 6 months of surgery, which may indicate excessive constraint about the scapula, eventually leading to fracture. Furthermore, disruption of this bony structure can lead to devastating results because the acromial base serves as a fulcrum for the deltoid.

Despite a well-placed reverse prosthesis, there is increased reliance on surrounding glenohumeral musculature, resulting from poor rotator cuff function and biomechanical differences compared with a native shoulder. Both our patients were found to have relatively small body habitus. It is possible that, by nature of their smaller statures, they were more susceptible to consequences of excessive joint and soft-tissue tension after RTSA. One explanation for acromial fractures after RTSA is that, by excessively lengthening and/or lateralizing the deltoid, the tension on the acromion in these elderly patients may be sufficient to cause a fracture. A similar mechanism may explain their coracoid fractures. As the arm is lengthened and the prosthesis is tightened, the conjoint tendon is significantly tensioned. We routinely check the tension of these muscles as an extra confirmation of joint stability. However, excessive tension for a significant duration may provide too much stress for bone turnover to match with the inherent repair process, potentially causing a fracture. Recent evidence has also found that bone mineral density of the coracoid diminishes with age, suggesting some predisposition to fracture with lower-energy mechanisms.²²

Another possible cause for coracoid fractures may be the orientation of the implants. While we did not have mechanistic evidence, it is possible that, with adduction and internal rotation, prosthetic impingement against the coracoid is feasible, particularly in patients of small stature. Although a glenoid implant placed high can increase the chance for coracoid–implant impingement, the fact that the patients improved without revision makes chronic mechanical impingement less likely. Drill holes, especially multiple ones, placed throughout the base of the coracoid may also predispose to coracoid fractures.

Patients with periscapular fractures (acromion, scapular spine, or coracoid) after RTSA often present with pain and occasional deficits in function. Both patients in this series noted pain out of proportion to examination. The onset of this pain differed, with 1 patient noting pain within the first 3 months and 1 noting discomfort later. Neither patient had any trauma. In the presence of significant symptoms, negative radiographs, and a poor response to conservative treatment, we recommend advanced imaging to rule out fracture. However, prior to obtaining advanced imaging, proper radiographic techniques should be utilized. Eyres and colleagues,²³ in a series of 12 fractures of the coracoid process, relied primarily on coracoid views directed 45° in a cephalic direction and thin-slice CT. An isotope bone scan identified 1 case not initially found on radiographs.²³

Conservative management with use of a sling until resolution of symptoms was successful in our series. If symptoms persist, a bone stimulator can be used prior to implementing a surgical solution; however, current evidence does not expound on timing and utility of such modalities. Perhaps as important as treatment is education of the patient and the rehabilitation team about the importance of identifying increasing pain as a potential sign of impending fracture in this population. Subsequent activity modification until the pain resolves can help avoid the setback in postoperative recovery that this complication may cause.

Conclusion

We present 2 patients with coracoid fractures encountered at 3 months and 15 months after RTSA. Nonoperative management proved adequate in treating both cases. We suggest a high level of suspicion for possible fracture in the patient who comes in with new-onset pain in a localized region with or without functional deficits.

Reverse total shoulder arthroplasty (RTSA) performed in carefully selected patients often leads to satisfactory outcomes.^1,2 In recent years, its indications and the number performed per year have expanded. Subsequently, there has been a concomitant rise in reported complications,^2,3 with a rate ranging from 19% to 68%.^2,3 Some common complications include scapular notching,^2-4 fracture,^2,3,5-7 dislocation,^2,3,7 and infection.^2,3,7

In this series, we describe 2 cases of coracoid fracture after RTSA. The patients provided written informed consent for print and electronic publication of these case reports.

Case Series

Case 1

An independently functioning 81-year-old right hand–dominant woman (BMI, 22.1 [height, 160 cm; weight, 56.7 kg]) presented with increasing left shoulder pain and dysfunction after a motor vehicle accident 2 months earlier. She had reported vague chronic left shoulder pain in the past, but after the accident her pain was significantly worse. A subacromial corticosteroid injection by her primary care physician provided temporary symptomatic relief, but her symptoms recurred.

On presentation, there was obvious anterior superior escape of the humeral head, which was accentuated by shoulder shrug. Her deltoid motor function was found to be intact, and her active shoulder range of motion was severely limited (pseudoparesis). There was notable crepitation as well as significant weakness and pain with abduction and external rotation strength testing.

Radiographic imaging showed anterior superior escape of the humeral head with some early degenerative changes (Seebauer type IIB⁸ [Figure 1A]). Magnetic resonance imaging confirmed a full-thickness retracted massive rotator cuff tear with complete involvement of the supraspinatus, infraspinatus, and most of the subscapularis muscles. Significant glenohumeral degenerative changes consistent with cuff tear arthropathy were also seen without any evidence of fracture.

After thorough discussion of options, risks, and benefits, the decision was made to proceed with RTSA. The patient underwent the procedure without complications. A DePuy Delta Xtend prosthesis was used with a cemented humeral stem, polyethylene, and glenosphere, sizes of 12, +3, and 38, respectively. The glenosphere component, positioned inferiorly to avoid scapular notching, was secured with 3 screws, and the stem was placed in neutral version. The patient’s shoulder was reduced, ranged, and noted to be stable, allowing for supple passive range of motion without evidence of excessive tightness. She was placed in a sling with the shoulder positioned in neutral alignment. Her postoperative radiograph (Figure 1B) showed satisfactory implantation of the reverse total shoulder prosthesis. Her postoperative course was uneventful, and rehabilitation consisted of 6 weeks of sling protection, with advancing passive and active range of motion. Strengthening exercises were initiated 6 weeks after surgery.

At the patient’s 6-week postoperative visit, she demonstrated pain-free passive elevation to 80° and active forward elevation to 70°. At her 3-month postoperative visit, she reported a 1-week onset of anterior shoulder pain accompanied by a strange noise at the anterior aspect of the operative shoulder. She denied any recent trauma. She continued to have minimal shoulder pain with passive forward flexion of 80°; however, her active forward elevation was very limited because of pain in the anterior aspect of her shoulder. Active external rotation was noted to be 20° and internal rotation was to her buttock. She had pain to palpation of the coracoid process. Radiographs were unchanged from immediate postoperative radiographs. Computed tomography (CT), which was ordered to ensure that the implant was stable with no loosening, showed satisfactory alignment of the prosthesis and no loosening. However, CT was notable for a nondisplaced fracture through the base of the coracoid (Figures 2A-2D). The patient stopped formal physical therapy, and sling immobilization was initiated. After 3 weeks, the sling was discontinued and physical therapy was begun again. She responded satisfactorily to this treatment approach, and, at her 6-month postoperative follow-up, she was without pain, instability, or crepitation. Her range of motion had improved with pain-free active forward flexion, external rotation, and abduction of 100°, 15°, and 90°, respectively. At 28-month postoperative follow-up, her visual analog scale, American Shoulder and Elbow Surgeons score, and Simple Shoulder Test score were 3, 73, and 67, respectively. 

Case 2

A 68-year-old, right-handed woman (BMI, 22.5 [height, 160 cm; weight, 57.6 kg]) presented with right shoulder pain and dysfunction of 3 years’ duration. She had undergone an open rotator cuff repair at an outside facility 4 years ago that was unsuccessful. At the time of her presentation to our institution, she had already undergone a failed course of physical therapy. A trial of corticosteroid subacromial injections did not adequately manage her symptoms.

On presentation, her active forward flexion, abduction, and external rotation were 40°, 30°, and 10°, respectively. She had full passive range of motion and pain with active and passive shoulder motion. Radiographic imaging showed superior migration of the humeral head with evidence of glenohumeral arthropathy suggestive of rotator cuff arthropathy (Seebauer type IIA⁸). After thorough discussion of options, risks, and benefits, the decision was made to proceed with RTSA. She underwent the procedure without complications. A DePuy Delta Xtend prosthesis was used with a cemented humeral stem, polyethylene, and glenosphere, sizes of 8, +3, and 38, respectively. The glenosphere component, positioned inferiorly to avoid scapular notching, was secured with 4 screws, and the stem was placed in neutral version. Her shoulder was reduced, ranged, and noted to be stable, allowing for supple passive range of motion without evidence of excessive tightness. She was placed in a sling with the shoulder positioned in neutral alignment. Her postoperative radiographs revealed satisfactory implantation of the reverse total shoulder prosthesis. Her postoperative course was uneventful. She was taken out of her shoulder immobilizer 4 weeks after surgery and began home-based physical therapy.

At 1 year after surgery, the patient had minimal shoulder pain with active forward flexion, external rotation, and abduction of 135°, 20°, and 85°, respectively. She presented to our clinic 15 months after RTSA with acute onset of pain about her anterior shoulder. She denied any recent trauma or infectious exposures. On examination, her motion was unchanged from prior examinations. However, she was tender on palpation of the coracoid. Radiographs at that time were unchanged (Figures 3A, 3B). Laboratory tests (erythrocyte sedimentation rate, C-reactive protein, and complete blood count with differential) that were subsequently ordered to rule out an occult infection were within normal limits. Computed tomography, which was ordered for further assessment and to ensure that the implant was stable with no loosening, showed satisfactory alignment of the prosthesis without loosening. However, a lucency was noted in the midportion of the coracoid that was suggestive of a fracture (Figures 4A, 4B). A conservative plan of treatment was advised with sling immobilization for 3 weeks and follow-up visits. The patient responded satisfactorily to this treatment approach, and, at her latest follow-up, 8 months after presenting with a coracoid fracture, she was pain-free. At the 5-year postoperative follow-up, her visual analog scale, American Shoulder and Elbow Surgeons score, and Simple Shoulder Test score were 1-2, 78, and 75, respectively. 

Discussion

The reverse prosthesis, a semi-constrained ball-and-socket device, provides satisfactory functional outcomes when used in carefully selected patients with rotator cuff arthropathy and pseudoparalysis, failed shoulder arthroplasty, and fracture sequelae.^1,9-11 By the traditional Grammont principles of medializing the center of rotation and lowering the humerus, shear forces about the glenoid are reduced and the deltoid muscle is tensioned, allowing for adequate torque generation, required to facilitate shoulder motion.^12,13 While long-term outcomes  concerning durability and survivorship are pending, some studies have attempted to improve our understanding of implant and functional longevity. Guery and colleagues¹⁴ noted an implant survival of 91% at 120 months. However, increased pain and decreased function were seen at the 6-year mark.¹⁴ A more recent study by Cuff and colleagues¹⁵ revealed 94% implant survivorship and sustained improvement in range of motion and pain at 5 years. 

Despite considerable success, RTSA can be associated with a myriad of complications. The most common complications of RTSA include scapular notching (44%-96%), glenoid side failure (5%-40%), instability (2.4%-31%), and infection (1%-15.3%).^2,3 In the setting of inflammatory arthropathy, there is an increased risk for intraoperative and postoperative fractures.^16,17 To date, there are only 2 reported cases of coracoid process fractures after RTSA.^18,19 In the case by Nolan and colleagues,¹⁸ conservative management with a sling for 6 weeks led to successful resolution of symptoms. Although little information is provided on the management of these rare fractures, literature on the slightly more common scapular (0.9%-7.2%) and acromial (0.9%-4.9%) fractures suggest that periscapular fractures are on the rise, may increase the risk for revision surgery, and can lead to inferior outcomes when compared with patients without fractures.^5,20,21

Acromial fractures after RTSA have been reported to occur at a rate of 0.9% to 4.9%.^5,21 This is a concern because of RTSA reliance on a functional deltoid.^5,6 The cause of these fractures remains to be fully elucidated. Wahlquist and colleagues⁶ in 2011 reported the cases of 5 patients that sustained acromial base fractures after RTSA. All 5 patients were noted to have unsatisfactory functional results despite achieving union (3 were treated with open reduction and internal fixation, and 2 were treated nonoperatively). Acromial fractures tend to present with pain within 6 months of surgery, which may indicate excessive constraint about the scapula, eventually leading to fracture. Furthermore, disruption of this bony structure can lead to devastating results because the acromial base serves as a fulcrum for the deltoid.

Despite a well-placed reverse prosthesis, there is increased reliance on surrounding glenohumeral musculature, resulting from poor rotator cuff function and biomechanical differences compared with a native shoulder. Both our patients were found to have relatively small body habitus. It is possible that, by nature of their smaller statures, they were more susceptible to consequences of excessive joint and soft-tissue tension after RTSA. One explanation for acromial fractures after RTSA is that, by excessively lengthening and/or lateralizing the deltoid, the tension on the acromion in these elderly patients may be sufficient to cause a fracture. A similar mechanism may explain their coracoid fractures. As the arm is lengthened and the prosthesis is tightened, the conjoint tendon is significantly tensioned. We routinely check the tension of these muscles as an extra confirmation of joint stability. However, excessive tension for a significant duration may provide too much stress for bone turnover to match with the inherent repair process, potentially causing a fracture. Recent evidence has also found that bone mineral density of the coracoid diminishes with age, suggesting some predisposition to fracture with lower-energy mechanisms.²²

Another possible cause for coracoid fractures may be the orientation of the implants. While we did not have mechanistic evidence, it is possible that, with adduction and internal rotation, prosthetic impingement against the coracoid is feasible, particularly in patients of small stature. Although a glenoid implant placed high can increase the chance for coracoid–implant impingement, the fact that the patients improved without revision makes chronic mechanical impingement less likely. Drill holes, especially multiple ones, placed throughout the base of the coracoid may also predispose to coracoid fractures.

Patients with periscapular fractures (acromion, scapular spine, or coracoid) after RTSA often present with pain and occasional deficits in function. Both patients in this series noted pain out of proportion to examination. The onset of this pain differed, with 1 patient noting pain within the first 3 months and 1 noting discomfort later. Neither patient had any trauma. In the presence of significant symptoms, negative radiographs, and a poor response to conservative treatment, we recommend advanced imaging to rule out fracture. However, prior to obtaining advanced imaging, proper radiographic techniques should be utilized. Eyres and colleagues,²³ in a series of 12 fractures of the coracoid process, relied primarily on coracoid views directed 45° in a cephalic direction and thin-slice CT. An isotope bone scan identified 1 case not initially found on radiographs.²³

Conservative management with use of a sling until resolution of symptoms was successful in our series. If symptoms persist, a bone stimulator can be used prior to implementing a surgical solution; however, current evidence does not expound on timing and utility of such modalities. Perhaps as important as treatment is education of the patient and the rehabilitation team about the importance of identifying increasing pain as a potential sign of impending fracture in this population. Subsequent activity modification until the pain resolves can help avoid the setback in postoperative recovery that this complication may cause.

Conclusion

We present 2 patients with coracoid fractures encountered at 3 months and 15 months after RTSA. Nonoperative management proved adequate in treating both cases. We suggest a high level of suspicion for possible fracture in the patient who comes in with new-onset pain in a localized region with or without functional deficits.

Neuralgia and neuroma secondary to iatrogenic saphenous nerve injury have been described in the setting of orthopedic surgical interventions using a medial parapatellar approach, and in vascular surgery procedures for harvest of the saphenous vein.^1-3 However, postoperative neuropathic pain caused by saphenous neuroma in the setting of orthopedic trauma has not been described. 

We present a case of symptomatic posttraumatic saphenous neuroma after a displaced and laterally angulated open distal one-third tibial fracture. This unreported cause of postinjury neuralgia is an important complication to address as other similar and more common conditions, such as peripheral neuropathy and complex regional pain syndrome (CRPS), can present in a similar manner. Reaching the correct diagnosis can be challenging for clinicians unfamiliar with this condition or its clinical presentation. The patient provided written informed consent for print and electronic publication of this case report.

Case Report

A 43-year-old woman presented to our practice 2 years after an open distal one-third metadiaphyseal fracture of the tibia with associated segmental fibular fracture (Gustilo-Anderson type II)⁴ after an automobile/bicycle accident. At the time of injury, she was noted to have a complex medial wound in the region of an open fracture at the junction of the middle and distal thirds of her tibial shaft. She underwent definitive treatment at an outside facility with initial irrigation and débridement and primary wound closure, followed by staged intramedullary nail fixation. Both soft-tissue and bony injuries healed within the expected time frame, and the patient was discharged from orthopedic care. 

Approximately 1 year after her initial injury, the patient began to complain of progressive and persistent anteromedial knee pain as well as gradual-onset, medial-sided leg pain. The leg pain began at the level of her previous fracture site, at the distal one-third metadiaphyseal tibial junction, and radiated from the site of her previous medial open wound distally to the medial aspect of her foot. The pain was burning and tingling in nature, with associated hyperesthesia of the affected area. A diagnosis of CRPS was made, and the patient was prescribed a course of desensitization therapy, oral neuromodulating agents, and physical therapy. After 3 months’ therapy, she remained symptomatic and underwent removal of her proximal tibial interlocking screw fixation (Figure 1). When these measures failed to provide symptomatic relief, and having seen several therapists and physicians, including physiatrists, pain management specialists, and orthopedic surgeons, she presented to our clinic for consultation.

Diagnostic Assessment

On presentation, the patient’s surgical incisions were well healed. At the junction of the middle and distal thirds of the tibia, a 4-cm oblique scar was noted over the anteromedial border of the tibia, the site of her previous open fracture. She demonstrated decreased sensation along the length of this oblique scar, as well as in the distribution of the saphenous nerve distally. Further examination of the previously injured region revealed a positive Tinel sign over the course of the saphenous nerve, with radiating pain down the medial aspect of her leg, recreating her symptoms. She otherwise had full range of motion at the knee with mild tenderness to palpation at the medial joint line and patellar tendon. Her lower extremity motor examination, reflexes, and the remainder of her sensory examination were benign.

These findings were consistent with isolated saphenous neuralgia, and selective injection of the saphenous distribution over the injury site was performed. This injection provided immediate symptomatic relief, with the patient reporting preinjection and postinjection pain scores of 7/10 and 2/10, respectively. Because of the clinical improvement demonstrated with selective injection, surgical intervention with exploration and neurolysis of the saphenous nerve was recommended. 

Therapeutic Intervention

The patient underwent surgical exploration of her saphenous nerve at the level of her original open fracture. This was done concurrently with a left-knee diagnostic arthroscopy and removal of her intramedullary tibial implant both to exclude intra-articular pathology (given her medial joint-line tenderness and the limitation of magnetic resonance imaging to diagnose meniscus tear in the presence of her tibial hardware) and to remove any potential hardware irritation in the setting of her anterior knee pain.^5,6 

Preoperatively, the path of the saphenous nerve was marked using the saphenous vein as a guide. An incision overlying the presumed saphenous nerve course was made at the site of her previous open wound and clinical Tinel sign. The saphenous nerve was carefully dissected with loupe magnification, and the distal divisions of the anterior and posterior branches were identified. The anterior branch was found to be in continuity but encased in fibrotic neuroma. Selective neurolysis of this anterior branch was performed. The posterior branch was found to have been traumatically severed, with both the proximal and distal ends encased in neuromatous scar (Figure 2). Neurectomy of the posterior branch was performed and the severed proximal end of the nerve was buried into the adjacent medial gastrocnemius muscle beneath the fascia of the superficial posterior compartment.^7-9

Postoperative Course and Outcome

Upon transport to the postsurgical care unit and emergence from sedation, the patient experienced immediate resolution of her neuralgic symptoms. Pathology of the operative specimen showed a benign, disorganized arrangement of axons, Schwann cells, and perineural fibroblasts amidst a fibrous stroma, consistent with traumatic neuroma. At 1-month and 6-month follow-up visits, the patient remained symptom-free, aside from some continued anterior left knee pain near the site of intramedullary nail entry. Her positive Tinel sign had completely resolved, as did her neuralgic symptoms down the medial aspect of her leg. This proved consistent with a diagnosis of neuroma as the cause of the majority of her symptoms. Subjectively, she reported excellent overall pain relief and satisfaction with her treatment and postoperative course. 

Discussion

Postoperative pain after intramedullary fixation of tibial shaft fractures is common and can be caused by several clinical entities.^5,10 Anterior knee pain is a well-known complication present in up to 73% of patients treated with tibial nailing.¹⁰ Osteoarthritis of the knee or ankle as well as nonarthritic ipsilateral ankle pain are also common complaints, often resulting from tibial malunion or malrotation, leading to altered joint kinematics.¹¹ Additionally, superficial peroneal nerve and tibial neurovascular bundle injuries have been reported as potential complications of distal interlocking screw placement, and should be considered in such patients.¹² 

Another consideration for the development of postoperative pain is CRPS, which is thought to be caused by postinjury sympathetic activation that produces pain out of proportion to clinical examination findings.¹³ Although no postoperative incidence of CRPS in the setting of tibial nailing has been reported, it is a known contributor to poor functional outcomes after fractures or crush injuries to the lower extremity.⁹ When attempting to diagnose and treat chronic postoperative pain after tibial nailing, the clinician must keep these common etiologies in mind as well as an understanding of the adjacent anatomy. 

The saphenous nerve originates from the third and fourth lumbar nerve roots, coursing beneath the inguinal ligament as part of the femoral nerve. As the terminal branch of the femoral nerve, the saphenous nerve runs in the Hunter canal beneath the fascia of the sartorius muscle. It is bordered laterally by the vastus medialis muscle, and posteriorly and laterally by the adductor longus and magnus muscles. The saphenous nerve then crosses the femoral artery superficially from medial to lateral as it courses distally in the canal. As it emerges from the adductor hiatus, the saphenous nerve runs superficial to the gracilis muscle around the posterior border of the sartorius muscle with the descending genicular artery, and becomes a subcutaneous structure at the level of the knee joint. The infrapatellar branch of the saphenous nerve provides sensation to the medial knee, and continues in a subcutaneous course just medial to the posterior aspect of the tibial shaft with the great saphenous vein. The nerve distally supplies sensory input from the medial foot and ankle.^1,3,14

There are several causes of saphenous neuralgia related to surgical and nonsurgical trauma.^2,3,15,16 The most common cause of nerve injury is iatrogenic traction or transection causing neuralgic sequelae from subsequent neuroma formation. The anatomy of the saphenous nerve puts it at particular risk when performing saphenectomy for vascular procedures, and its infrapatellar branch is at particular risk when performing a medial parapatellar approach for total knee arthroplasty.^2,3 In the case of the surgically naïve patient, saphenous nerve entrapment syndromes have also been described, and occur most frequently at the level of the adductor hiatus or as the saphenous nerve courses between the sartorius and gracilis muscles proximal to the knee joint.¹⁶ 

As is illustrated in the present case, orthopedic trauma may be an additional cause of saphenous neuroma formation, leading to symptomatic neuralgia. This case suggests that symptomatic neuroma should be included in the differential diagnosis of posttraumatic pain in the orthopedic trauma patient. It is important to note that, although this case occurred after a severe injury, the intimate association of the saphenous nerve with the tibia places it in a vulnerable position, and traumatic transection is possible after closed injuries to the tibial metadiaphyseal junction or tibial shaft. 

Neuroma formation occurs in response to damage to the endoneurium and axon. For an axon to repair properly, the damaged proximal segment must join with, and reenter, the distal stump. As axons attempt to regenerate, occasionally the proximal stump can escape into the surrounding tissue and form a painful neuroma consisting of a disorganized mass of Schwann cells, fibroblasts, blood vessels, and axons with various degrees of myelination. The subsequent neuralgia associated with neuroma formation is caused by chemical or mechanical stimulation of the damaged axons or by spontaneously evoked potentials in the damaged axons. These signals can manifest as a variety of symptoms, including paresthesia and allodynia.^17,18

Making the diagnosis of neuroma-related neuralgia can be challenging and nebulous. A characteristic history and positive Tinel sign over the affected area are helpful clinical indicators. However, the clinical finding most predictive of favorable surgical outcome is symptomatic relief after local injection of 1% lidocaine to the affected area. This is an important diagnostic test, especially when attempting to differentiate painful neuroma from other causes of posttraumatic lower extremity pain (eg, CRPS). Such an injection should be performed in the diagnosis and treatment of symptomatic neuroma, and some authors would suggest that insufficient relief of symptoms with diagnostic nerve block is a contraindication to surgical treatment.¹⁹

Several treatments for painful neuromas have been described, with variable results.^19,20 The most widely accepted treatment of a complete nerve transection with associated neuroma is neurectomy with reimplantation of the proximal end into adjacent bone, muscle, or vein.^14,15 Balcin and colleagues²¹ suggest that vein transposition produces the most favorable outcomes. Simple neurolysis of in-continuity neuromas has also been described with favorable results.

Conclusion

Neuralgia-producing neuromas of the saphenous nerve are relatively uncommon but can lead to persistent pain and frustrating symptoms for the patient. As noted, the diagnosis may elude clinicians, especially in patients with less obvious clinical presentations. We suggest the following algorithm to help distinguish between painful neuroma and other causes of posttraumatic leg pain: (1) physical examination (including testing for instability, joint line tenderness, patellofemoral pain, Tinel sign, and Semmes-Weinstein testing) should be performed, and plain radiographs taken of the involved bones and joints; (2) if all of the above reveal no abnormality, and there is a positive Tinel sign directly over the course of a nerve, an injection of lidocaine over the region of the potential neuroma can be diagnostic; (3) should several abnormalities be present, further investigation using magnetic resonance imaging, bone scan, and/or electromyography may provide additional information that leads to a diagnosis. 

Neuralgia and neuroma secondary to iatrogenic saphenous nerve injury have been described in the setting of orthopedic surgical interventions using a medial parapatellar approach, and in vascular surgery procedures for harvest of the saphenous vein.^1-3 However, postoperative neuropathic pain caused by saphenous neuroma in the setting of orthopedic trauma has not been described. 

We present a case of symptomatic posttraumatic saphenous neuroma after a displaced and laterally angulated open distal one-third tibial fracture. This unreported cause of postinjury neuralgia is an important complication to address as other similar and more common conditions, such as peripheral neuropathy and complex regional pain syndrome (CRPS), can present in a similar manner. Reaching the correct diagnosis can be challenging for clinicians unfamiliar with this condition or its clinical presentation. The patient provided written informed consent for print and electronic publication of this case report.

Case Report

A 43-year-old woman presented to our practice 2 years after an open distal one-third metadiaphyseal fracture of the tibia with associated segmental fibular fracture (Gustilo-Anderson type II)⁴ after an automobile/bicycle accident. At the time of injury, she was noted to have a complex medial wound in the region of an open fracture at the junction of the middle and distal thirds of her tibial shaft. She underwent definitive treatment at an outside facility with initial irrigation and débridement and primary wound closure, followed by staged intramedullary nail fixation. Both soft-tissue and bony injuries healed within the expected time frame, and the patient was discharged from orthopedic care. 

Approximately 1 year after her initial injury, the patient began to complain of progressive and persistent anteromedial knee pain as well as gradual-onset, medial-sided leg pain. The leg pain began at the level of her previous fracture site, at the distal one-third metadiaphyseal tibial junction, and radiated from the site of her previous medial open wound distally to the medial aspect of her foot. The pain was burning and tingling in nature, with associated hyperesthesia of the affected area. A diagnosis of CRPS was made, and the patient was prescribed a course of desensitization therapy, oral neuromodulating agents, and physical therapy. After 3 months’ therapy, she remained symptomatic and underwent removal of her proximal tibial interlocking screw fixation (Figure 1). When these measures failed to provide symptomatic relief, and having seen several therapists and physicians, including physiatrists, pain management specialists, and orthopedic surgeons, she presented to our clinic for consultation.

Diagnostic Assessment

On presentation, the patient’s surgical incisions were well healed. At the junction of the middle and distal thirds of the tibia, a 4-cm oblique scar was noted over the anteromedial border of the tibia, the site of her previous open fracture. She demonstrated decreased sensation along the length of this oblique scar, as well as in the distribution of the saphenous nerve distally. Further examination of the previously injured region revealed a positive Tinel sign over the course of the saphenous nerve, with radiating pain down the medial aspect of her leg, recreating her symptoms. She otherwise had full range of motion at the knee with mild tenderness to palpation at the medial joint line and patellar tendon. Her lower extremity motor examination, reflexes, and the remainder of her sensory examination were benign.

These findings were consistent with isolated saphenous neuralgia, and selective injection of the saphenous distribution over the injury site was performed. This injection provided immediate symptomatic relief, with the patient reporting preinjection and postinjection pain scores of 7/10 and 2/10, respectively. Because of the clinical improvement demonstrated with selective injection, surgical intervention with exploration and neurolysis of the saphenous nerve was recommended. 

Therapeutic Intervention

The patient underwent surgical exploration of her saphenous nerve at the level of her original open fracture. This was done concurrently with a left-knee diagnostic arthroscopy and removal of her intramedullary tibial implant both to exclude intra-articular pathology (given her medial joint-line tenderness and the limitation of magnetic resonance imaging to diagnose meniscus tear in the presence of her tibial hardware) and to remove any potential hardware irritation in the setting of her anterior knee pain.^5,6 

Preoperatively, the path of the saphenous nerve was marked using the saphenous vein as a guide. An incision overlying the presumed saphenous nerve course was made at the site of her previous open wound and clinical Tinel sign. The saphenous nerve was carefully dissected with loupe magnification, and the distal divisions of the anterior and posterior branches were identified. The anterior branch was found to be in continuity but encased in fibrotic neuroma. Selective neurolysis of this anterior branch was performed. The posterior branch was found to have been traumatically severed, with both the proximal and distal ends encased in neuromatous scar (Figure 2). Neurectomy of the posterior branch was performed and the severed proximal end of the nerve was buried into the adjacent medial gastrocnemius muscle beneath the fascia of the superficial posterior compartment.^7-9

Postoperative Course and Outcome

Upon transport to the postsurgical care unit and emergence from sedation, the patient experienced immediate resolution of her neuralgic symptoms. Pathology of the operative specimen showed a benign, disorganized arrangement of axons, Schwann cells, and perineural fibroblasts amidst a fibrous stroma, consistent with traumatic neuroma. At 1-month and 6-month follow-up visits, the patient remained symptom-free, aside from some continued anterior left knee pain near the site of intramedullary nail entry. Her positive Tinel sign had completely resolved, as did her neuralgic symptoms down the medial aspect of her leg. This proved consistent with a diagnosis of neuroma as the cause of the majority of her symptoms. Subjectively, she reported excellent overall pain relief and satisfaction with her treatment and postoperative course. 

Discussion

Postoperative pain after intramedullary fixation of tibial shaft fractures is common and can be caused by several clinical entities.^5,10 Anterior knee pain is a well-known complication present in up to 73% of patients treated with tibial nailing.¹⁰ Osteoarthritis of the knee or ankle as well as nonarthritic ipsilateral ankle pain are also common complaints, often resulting from tibial malunion or malrotation, leading to altered joint kinematics.¹¹ Additionally, superficial peroneal nerve and tibial neurovascular bundle injuries have been reported as potential complications of distal interlocking screw placement, and should be considered in such patients.¹² 

Another consideration for the development of postoperative pain is CRPS, which is thought to be caused by postinjury sympathetic activation that produces pain out of proportion to clinical examination findings.¹³ Although no postoperative incidence of CRPS in the setting of tibial nailing has been reported, it is a known contributor to poor functional outcomes after fractures or crush injuries to the lower extremity.⁹ When attempting to diagnose and treat chronic postoperative pain after tibial nailing, the clinician must keep these common etiologies in mind as well as an understanding of the adjacent anatomy. 

The saphenous nerve originates from the third and fourth lumbar nerve roots, coursing beneath the inguinal ligament as part of the femoral nerve. As the terminal branch of the femoral nerve, the saphenous nerve runs in the Hunter canal beneath the fascia of the sartorius muscle. It is bordered laterally by the vastus medialis muscle, and posteriorly and laterally by the adductor longus and magnus muscles. The saphenous nerve then crosses the femoral artery superficially from medial to lateral as it courses distally in the canal. As it emerges from the adductor hiatus, the saphenous nerve runs superficial to the gracilis muscle around the posterior border of the sartorius muscle with the descending genicular artery, and becomes a subcutaneous structure at the level of the knee joint. The infrapatellar branch of the saphenous nerve provides sensation to the medial knee, and continues in a subcutaneous course just medial to the posterior aspect of the tibial shaft with the great saphenous vein. The nerve distally supplies sensory input from the medial foot and ankle.^1,3,14

There are several causes of saphenous neuralgia related to surgical and nonsurgical trauma.^2,3,15,16 The most common cause of nerve injury is iatrogenic traction or transection causing neuralgic sequelae from subsequent neuroma formation. The anatomy of the saphenous nerve puts it at particular risk when performing saphenectomy for vascular procedures, and its infrapatellar branch is at particular risk when performing a medial parapatellar approach for total knee arthroplasty.^2,3 In the case of the surgically naïve patient, saphenous nerve entrapment syndromes have also been described, and occur most frequently at the level of the adductor hiatus or as the saphenous nerve courses between the sartorius and gracilis muscles proximal to the knee joint.¹⁶ 

As is illustrated in the present case, orthopedic trauma may be an additional cause of saphenous neuroma formation, leading to symptomatic neuralgia. This case suggests that symptomatic neuroma should be included in the differential diagnosis of posttraumatic pain in the orthopedic trauma patient. It is important to note that, although this case occurred after a severe injury, the intimate association of the saphenous nerve with the tibia places it in a vulnerable position, and traumatic transection is possible after closed injuries to the tibial metadiaphyseal junction or tibial shaft. 

Neuroma formation occurs in response to damage to the endoneurium and axon. For an axon to repair properly, the damaged proximal segment must join with, and reenter, the distal stump. As axons attempt to regenerate, occasionally the proximal stump can escape into the surrounding tissue and form a painful neuroma consisting of a disorganized mass of Schwann cells, fibroblasts, blood vessels, and axons with various degrees of myelination. The subsequent neuralgia associated with neuroma formation is caused by chemical or mechanical stimulation of the damaged axons or by spontaneously evoked potentials in the damaged axons. These signals can manifest as a variety of symptoms, including paresthesia and allodynia.^17,18

Making the diagnosis of neuroma-related neuralgia can be challenging and nebulous. A characteristic history and positive Tinel sign over the affected area are helpful clinical indicators. However, the clinical finding most predictive of favorable surgical outcome is symptomatic relief after local injection of 1% lidocaine to the affected area. This is an important diagnostic test, especially when attempting to differentiate painful neuroma from other causes of posttraumatic lower extremity pain (eg, CRPS). Such an injection should be performed in the diagnosis and treatment of symptomatic neuroma, and some authors would suggest that insufficient relief of symptoms with diagnostic nerve block is a contraindication to surgical treatment.¹⁹

Several treatments for painful neuromas have been described, with variable results.^19,20 The most widely accepted treatment of a complete nerve transection with associated neuroma is neurectomy with reimplantation of the proximal end into adjacent bone, muscle, or vein.^14,15 Balcin and colleagues²¹ suggest that vein transposition produces the most favorable outcomes. Simple neurolysis of in-continuity neuromas has also been described with favorable results.

Conclusion

Neuralgia-producing neuromas of the saphenous nerve are relatively uncommon but can lead to persistent pain and frustrating symptoms for the patient. As noted, the diagnosis may elude clinicians, especially in patients with less obvious clinical presentations. We suggest the following algorithm to help distinguish between painful neuroma and other causes of posttraumatic leg pain: (1) physical examination (including testing for instability, joint line tenderness, patellofemoral pain, Tinel sign, and Semmes-Weinstein testing) should be performed, and plain radiographs taken of the involved bones and joints; (2) if all of the above reveal no abnormality, and there is a positive Tinel sign directly over the course of a nerve, an injection of lidocaine over the region of the potential neuroma can be diagnostic; (3) should several abnormalities be present, further investigation using magnetic resonance imaging, bone scan, and/or electromyography may provide additional information that leads to a diagnosis. 

Neuralgia and neuroma secondary to iatrogenic saphenous nerve injury have been described in the setting of orthopedic surgical interventions using a medial parapatellar approach, and in vascular surgery procedures for harvest of the saphenous vein.^1-3 However, postoperative neuropathic pain caused by saphenous neuroma in the setting of orthopedic trauma has not been described. 

We present a case of symptomatic posttraumatic saphenous neuroma after a displaced and laterally angulated open distal one-third tibial fracture. This unreported cause of postinjury neuralgia is an important complication to address as other similar and more common conditions, such as peripheral neuropathy and complex regional pain syndrome (CRPS), can present in a similar manner. Reaching the correct diagnosis can be challenging for clinicians unfamiliar with this condition or its clinical presentation. The patient provided written informed consent for print and electronic publication of this case report.

Case Report

A 43-year-old woman presented to our practice 2 years after an open distal one-third metadiaphyseal fracture of the tibia with associated segmental fibular fracture (Gustilo-Anderson type II)⁴ after an automobile/bicycle accident. At the time of injury, she was noted to have a complex medial wound in the region of an open fracture at the junction of the middle and distal thirds of her tibial shaft. She underwent definitive treatment at an outside facility with initial irrigation and débridement and primary wound closure, followed by staged intramedullary nail fixation. Both soft-tissue and bony injuries healed within the expected time frame, and the patient was discharged from orthopedic care. 

Approximately 1 year after her initial injury, the patient began to complain of progressive and persistent anteromedial knee pain as well as gradual-onset, medial-sided leg pain. The leg pain began at the level of her previous fracture site, at the distal one-third metadiaphyseal tibial junction, and radiated from the site of her previous medial open wound distally to the medial aspect of her foot. The pain was burning and tingling in nature, with associated hyperesthesia of the affected area. A diagnosis of CRPS was made, and the patient was prescribed a course of desensitization therapy, oral neuromodulating agents, and physical therapy. After 3 months’ therapy, she remained symptomatic and underwent removal of her proximal tibial interlocking screw fixation (Figure 1). When these measures failed to provide symptomatic relief, and having seen several therapists and physicians, including physiatrists, pain management specialists, and orthopedic surgeons, she presented to our clinic for consultation.

Diagnostic Assessment

On presentation, the patient’s surgical incisions were well healed. At the junction of the middle and distal thirds of the tibia, a 4-cm oblique scar was noted over the anteromedial border of the tibia, the site of her previous open fracture. She demonstrated decreased sensation along the length of this oblique scar, as well as in the distribution of the saphenous nerve distally. Further examination of the previously injured region revealed a positive Tinel sign over the course of the saphenous nerve, with radiating pain down the medial aspect of her leg, recreating her symptoms. She otherwise had full range of motion at the knee with mild tenderness to palpation at the medial joint line and patellar tendon. Her lower extremity motor examination, reflexes, and the remainder of her sensory examination were benign.

These findings were consistent with isolated saphenous neuralgia, and selective injection of the saphenous distribution over the injury site was performed. This injection provided immediate symptomatic relief, with the patient reporting preinjection and postinjection pain scores of 7/10 and 2/10, respectively. Because of the clinical improvement demonstrated with selective injection, surgical intervention with exploration and neurolysis of the saphenous nerve was recommended. 

Therapeutic Intervention

The patient underwent surgical exploration of her saphenous nerve at the level of her original open fracture. This was done concurrently with a left-knee diagnostic arthroscopy and removal of her intramedullary tibial implant both to exclude intra-articular pathology (given her medial joint-line tenderness and the limitation of magnetic resonance imaging to diagnose meniscus tear in the presence of her tibial hardware) and to remove any potential hardware irritation in the setting of her anterior knee pain.^5,6 

Preoperatively, the path of the saphenous nerve was marked using the saphenous vein as a guide. An incision overlying the presumed saphenous nerve course was made at the site of her previous open wound and clinical Tinel sign. The saphenous nerve was carefully dissected with loupe magnification, and the distal divisions of the anterior and posterior branches were identified. The anterior branch was found to be in continuity but encased in fibrotic neuroma. Selective neurolysis of this anterior branch was performed. The posterior branch was found to have been traumatically severed, with both the proximal and distal ends encased in neuromatous scar (Figure 2). Neurectomy of the posterior branch was performed and the severed proximal end of the nerve was buried into the adjacent medial gastrocnemius muscle beneath the fascia of the superficial posterior compartment.^7-9

Postoperative Course and Outcome

Upon transport to the postsurgical care unit and emergence from sedation, the patient experienced immediate resolution of her neuralgic symptoms. Pathology of the operative specimen showed a benign, disorganized arrangement of axons, Schwann cells, and perineural fibroblasts amidst a fibrous stroma, consistent with traumatic neuroma. At 1-month and 6-month follow-up visits, the patient remained symptom-free, aside from some continued anterior left knee pain near the site of intramedullary nail entry. Her positive Tinel sign had completely resolved, as did her neuralgic symptoms down the medial aspect of her leg. This proved consistent with a diagnosis of neuroma as the cause of the majority of her symptoms. Subjectively, she reported excellent overall pain relief and satisfaction with her treatment and postoperative course. 

Discussion

Postoperative pain after intramedullary fixation of tibial shaft fractures is common and can be caused by several clinical entities.^5,10 Anterior knee pain is a well-known complication present in up to 73% of patients treated with tibial nailing.¹⁰ Osteoarthritis of the knee or ankle as well as nonarthritic ipsilateral ankle pain are also common complaints, often resulting from tibial malunion or malrotation, leading to altered joint kinematics.¹¹ Additionally, superficial peroneal nerve and tibial neurovascular bundle injuries have been reported as potential complications of distal interlocking screw placement, and should be considered in such patients.¹² 

Another consideration for the development of postoperative pain is CRPS, which is thought to be caused by postinjury sympathetic activation that produces pain out of proportion to clinical examination findings.¹³ Although no postoperative incidence of CRPS in the setting of tibial nailing has been reported, it is a known contributor to poor functional outcomes after fractures or crush injuries to the lower extremity.⁹ When attempting to diagnose and treat chronic postoperative pain after tibial nailing, the clinician must keep these common etiologies in mind as well as an understanding of the adjacent anatomy. 

The saphenous nerve originates from the third and fourth lumbar nerve roots, coursing beneath the inguinal ligament as part of the femoral nerve. As the terminal branch of the femoral nerve, the saphenous nerve runs in the Hunter canal beneath the fascia of the sartorius muscle. It is bordered laterally by the vastus medialis muscle, and posteriorly and laterally by the adductor longus and magnus muscles. The saphenous nerve then crosses the femoral artery superficially from medial to lateral as it courses distally in the canal. As it emerges from the adductor hiatus, the saphenous nerve runs superficial to the gracilis muscle around the posterior border of the sartorius muscle with the descending genicular artery, and becomes a subcutaneous structure at the level of the knee joint. The infrapatellar branch of the saphenous nerve provides sensation to the medial knee, and continues in a subcutaneous course just medial to the posterior aspect of the tibial shaft with the great saphenous vein. The nerve distally supplies sensory input from the medial foot and ankle.^1,3,14

There are several causes of saphenous neuralgia related to surgical and nonsurgical trauma.^2,3,15,16 The most common cause of nerve injury is iatrogenic traction or transection causing neuralgic sequelae from subsequent neuroma formation. The anatomy of the saphenous nerve puts it at particular risk when performing saphenectomy for vascular procedures, and its infrapatellar branch is at particular risk when performing a medial parapatellar approach for total knee arthroplasty.^2,3 In the case of the surgically naïve patient, saphenous nerve entrapment syndromes have also been described, and occur most frequently at the level of the adductor hiatus or as the saphenous nerve courses between the sartorius and gracilis muscles proximal to the knee joint.¹⁶ 

As is illustrated in the present case, orthopedic trauma may be an additional cause of saphenous neuroma formation, leading to symptomatic neuralgia. This case suggests that symptomatic neuroma should be included in the differential diagnosis of posttraumatic pain in the orthopedic trauma patient. It is important to note that, although this case occurred after a severe injury, the intimate association of the saphenous nerve with the tibia places it in a vulnerable position, and traumatic transection is possible after closed injuries to the tibial metadiaphyseal junction or tibial shaft. 

Neuroma formation occurs in response to damage to the endoneurium and axon. For an axon to repair properly, the damaged proximal segment must join with, and reenter, the distal stump. As axons attempt to regenerate, occasionally the proximal stump can escape into the surrounding tissue and form a painful neuroma consisting of a disorganized mass of Schwann cells, fibroblasts, blood vessels, and axons with various degrees of myelination. The subsequent neuralgia associated with neuroma formation is caused by chemical or mechanical stimulation of the damaged axons or by spontaneously evoked potentials in the damaged axons. These signals can manifest as a variety of symptoms, including paresthesia and allodynia.^17,18

Making the diagnosis of neuroma-related neuralgia can be challenging and nebulous. A characteristic history and positive Tinel sign over the affected area are helpful clinical indicators. However, the clinical finding most predictive of favorable surgical outcome is symptomatic relief after local injection of 1% lidocaine to the affected area. This is an important diagnostic test, especially when attempting to differentiate painful neuroma from other causes of posttraumatic lower extremity pain (eg, CRPS). Such an injection should be performed in the diagnosis and treatment of symptomatic neuroma, and some authors would suggest that insufficient relief of symptoms with diagnostic nerve block is a contraindication to surgical treatment.¹⁹

Several treatments for painful neuromas have been described, with variable results.^19,20 The most widely accepted treatment of a complete nerve transection with associated neuroma is neurectomy with reimplantation of the proximal end into adjacent bone, muscle, or vein.^14,15 Balcin and colleagues²¹ suggest that vein transposition produces the most favorable outcomes. Simple neurolysis of in-continuity neuromas has also been described with favorable results.

Conclusion

Neuralgia-producing neuromas of the saphenous nerve are relatively uncommon but can lead to persistent pain and frustrating symptoms for the patient. As noted, the diagnosis may elude clinicians, especially in patients with less obvious clinical presentations. We suggest the following algorithm to help distinguish between painful neuroma and other causes of posttraumatic leg pain: (1) physical examination (including testing for instability, joint line tenderness, patellofemoral pain, Tinel sign, and Semmes-Weinstein testing) should be performed, and plain radiographs taken of the involved bones and joints; (2) if all of the above reveal no abnormality, and there is a positive Tinel sign directly over the course of a nerve, an injection of lidocaine over the region of the potential neuroma can be diagnostic; (3) should several abnormalities be present, further investigation using magnetic resonance imaging, bone scan, and/or electromyography may provide additional information that leads to a diagnosis. 

Over the past several decades, an increasing number of orthopedic surgery residents have pursued fellowship training.¹ This inclination parallels market trends toward subspecialization.^2-5 In 1984, 83% of orthopedics job announcements were for general orthopedists. Twenty-five years later, almost 70% of orthopedic opportunities were for fellowship-trained surgeons.⁶ Further, between 1990 and 2006, the proportion of practicing orthopedic generalists decreased from 44% to 29%.³ In 2007, the American Academy of Orthopaedic Surgery (AAOS) reported 90% of graduating residents were planning to pursue fellowship training.⁷ Reasons for the explosion in subspecialty training are plentiful and well documented.^2-5 Subspecialty positions now dominate the job market, further reinforcing incentives for residents to pursue fellowship training.

The past several decades have seen numerous changes in the orthopedic fellowship interview process. Early on, it was largely unregulated, dependent on personal and professional connections, and flush with the classic “exploding offer” (residents were given a fellowship offer that expired within hours or days). In the 1980s, as the number of fellowship applications surged, the Accreditation Council for Graduate Medical Education (ACGME) pushed for a more regulated process.⁸ To further standardize the system, the American Orthopaedic Association (AOA), the AAOS, and several other specialty organizations created the Orthopaedic Fellowship Match Program Initiative in 2008.⁹ Currently, all orthopedic specialties are represented in either the San Francisco Match Program or National Residency Match Program.

As the system currently stands, postgraduate year 4 (PGY-4) residents are required to interview across the country to secure postgraduate training. This process necessitates residents’ absence from their program, reducing educational opportunities and placing potential continuity-of-care constraints on the residency program. Despite the growing competitiveness for fellowship positions, the increasing number of fellowships available, the rising educational debt of residents, and the limitations of the 80-hour work week, the impact of the interview process on both residents and residency programs has received minimal attention.

We conducted a study to elucidate the impact of the fellowship interview process on residents and residency programs. We hypothesized the time and financial costs for fellowship interviews would be substantial.

Materials and Methods

We obtained institutional review board (IRB) approval for this study. Then, in April 2014, we sent 2 mixed-response questionnaires to orthopedic surgery residency directors and residents. There were 8 items on the director questionnaire and 11 on the resident questionnaire. The surveys were designed to determine the impact of the fellowship interview process on residents and residency programs with respect to finances, time, education, and continuity of care. Each survey had at least 1 free-response question, providing the opportunity to recommend changes to the interview process. The surveys were reviewed and approved by our IRB.

An email was sent to 155 orthopedic surgery program directors or their secretaries. The email asked that the director complete the director questionnaire and that the resident questionnaire be forwarded to senior-level residents, PGY-4s and PGY-5s, who had completed the fellowship interview process. Forty-five (29%) of the 155 directors responded, as did 129 (estimated 9.5%) of an estimated 1354 potential PGY-4s and PGY-5s.¹⁰

The Survey Monkey surveys could be completed over a 3-week period. All responses were anonymous. Using Survey Monkey, we aggregated individual responses into predefined clusters before performing statistical analysis. Descriptive statistics were generated with Microsoft Excel.

Results

Survey respondents represented all the orthopedic subspecialties (Table). Seventy-eight percent of residents applied to at least 13 programs (average, 19) (Figure 1). Ninety-two percent received at least 8 interview offers (average, 14). Eighty-three percent attended 8 or more interviews (average, 11). Seventy-one percent of all interviews were granted when requested, and 79% of all interviews were attended when offered.

Residents spent an average of $5875 (range, $500-$12,000+) on the fellowship interview process (Figure 2). The highest percentage of respondents, 39.5%, selected an average expense between $4000 and $6000. Forty-nine percent of residents borrowed money (from credit cards, additional loans, family members) to pay their expenses.

Average number of days away from residency programs was 11, with 86% of residents missing more than 8 days (Figure 1). About one-third of residents reported being away from their home program for almost 2 weeks during the interview season. Further, 74% of residents wanted changes made to the fellowship application process.

Thirty-seven (82%) of the 45 program directors were from academic programs, the other 8 from community-based programs. Average number of residents in programs per year was 4 (73% of the programs had 4-6 residents per year). Respondents rated the disruption caused by residents’ interview absences from 1 (least disruptive) to 10 (most disruptive) (Figure 3); the average rating was over 7 (high level of disruption). Although 9% of directors thought the process caused little or no disruption (rating, 1-3), 62% thought it extremely disruptive (rating, 8-10).

Thirty-one (69%) of the 45 directors agreed that the fellowship interview process should undergo fundamental change. Asked about possible solutions to current complaints, 60% of the directors agreed that interviews should be conducted in a central location. Of the directors who thought fundamental change was needed, 59% indicated AAOS and other specialty societies together should lead the change in the fellowship interview process.

Both residents and program directors were given the opportunity to write in suggestions regarding how to improve the fellowship interview process. Suggestions were made by 85 (66%) of the 129 residents and 24 (53%) of the 45 directors (Appendix).        

Discussion

Graduating residents are entering a health care environment in which they must be financially conscious because of increasing education debt and decreasing reimbursement prospects.³ Nevertheless, an overwhelming majority of residents delay entering practice to pursue fellowship training—an estimated opportunity cost of $350,000.³ Minimal attention has been given to the potential costs of the fellowship interview process.

Our study results highlight that time away from residency training, financial costs associated with the fellowship interview process, and disruption of the residency program are substantial. On average, residents applied to 19 programs, received 14 interview offers, attended 11 interviews, were away from residency training 11 days, and spent $5875 on travel. The great majority of both residents and program directors wanted changes in the current paradigm governing the orthopedic fellowship interview process.

It is reasonable to think that the number of days residents spend away on interviews would reduce the time available for education and patient care. Although unknown, it is plausible that residents of programs outside major metropolitan centers and residents who apply to more competitive fellowships may be forced to spend even more time away from training. Outside the focus of this study are the impact that residents’ absence might have on their education and the impact of this absence on the people who do the residents’ work while they are away.

Mean fellowship expense was similar to that reported by residents pursuing a pediatric general surgery fellowship ($6974) or a plastic surgery fellowship ($6100).^11,12 Unfortunately, we were unable to determine if average cost is influenced by choice of fellowship specialty or location of residency program. Regardless, fellowship cost may impose an additional financial burden on residents. According to the Association of American Medical Colleges (AAMC), the median salary for PGY-4 residents was $56,380 in 2013. Therefore, on average, the fellowship process consumes more than 10% of a resident’s pretax salary. For perspective, this equates to more than $40,000 for a practicing orthopedic surgeon with a median salary of $413,000.¹³ With an average medical student graduate debt of $175,000 and continuing decreases in reimbursement, further financial hardships to newly graduating residents cannot be understated.^5,11,12

Almost 70% of program directors thought the fellowship process significantly disrupted their program. Reasons given for this disruption mainly involved residents’ time away from the program and the resulting strains placed on maintaining adequate coverage for patient care. The overall disruption score of 7.4 out of 10 was consistent with the great majority thinking that the fellowship process negatively affects their residency program. Altering the fellowship interview process may provide unintended benefits to programs and program directors.

Both program directors and residents communicated that change is needed, but there was little consensus regarding how to effect change and who should lead. This lack of consensus highlights how important it is for the various orthopedic leadership committees to actively and collectively participate in discussions about redefining the system. It has been proposed that it would be ideal for the AOA to lead the change, as the AOA consists of a representative cohort of academic orthopedists and leaders across the spectrum of all fellowship specialties.¹⁴ Given the abundant concern of both residents and program directors, we find it prudent to issue a call to arms of sorts to the AAOS and the individual orthopedic subspecialty societies to work together on a common goal that would benefit residents, programs, and subspecialties within orthopedics.

In trying to understand the challenges that residents, program directors, and programs face, as well as the inherent complexity of the current system, we incorporated respondents’ write-in comments into suggested ways of improving the fellowship interview process. These comments had broad perspectives but overall were consistent with the survey results (Appendix).

Technology

Health care is continually finding new ways to take advantage of technological advances. This is occurring with the fellowship interview schema. Numerous disciplines are using videoconferencing platforms (eg, Skype) to conduct interviews. This practice is becoming more commonplace in the business sector. In a recent survey, more than 60% of human resource managers reported conducting video interviews.¹⁵ Two independent residency programs have used video interviews with mixed success.^16,17

Another technological change requested by residents is the creation and updating of fellowship web pages with standardized information. Such a service may prove useful to residents researching a program and may even lead to limiting the number of programs residents apply to, as they may be able to dial in on exactly what distinguishes one program from another before traveling for an interview. A recent study of orthopedic sports medicine fellowship programs found that most of these programs lacked pertinent information on their websites.¹⁸ Important information regarding case logs from current and former fellows; number of faculty, residents, and fellows; and schedules and facilities of interview sites are a few of the online data points that may help residents differentiate particular programs.^19,20 Questions like these are often asked at interviews and site visits. Having accurate information easily available online may reduce or eliminate the need to travel to a site for such information. Standardizing information would also increase transparency among available fellowships. Although not specifically mentioned, organizational software that improves the productivity of the process may help limit the large number of programs applied to, the interviews offered and attended, the days away, and the financial costs without reducing the match rate.

Timing and Location

The issue of timing—with respect to geographical or meteorological concerns—was another recurring theme among respondents. Numerous respondents indicated that certain programs located in geographic proximity tried to minimize travel by offering interviews around the same time. This coordination potentially minimizes travel expenses and time away from the residency program by allowing residents to interview at multiple locations during a single trip per region. The sports medicine fellowship process was identified as a good example of aligning interviews based on geography. Several respondents suggested an option that also reflects the practice of nonsurgical fellowships—delaying the interview season to bypass potential weather concerns. Winter 2013–2014 saw the most flight delays or cancellations in more than a decade; about 50% of all flights scheduled between December and February were delayed or canceled.²¹ Beyond the additional factor of more time away or missing an interview because of the weather are safety concerns related to the weather. One resident reported having a motor vehicle accident while traveling to an interview in poor weather conditions (Appendix).

National Meetings

Each orthopedic subspecialty has numerous national meetings. Many programs offer applicants the opportunity to interview at these meetings. One respondent mentioned that the annual meeting of the Orthopaedic Trauma Association offers trauma applicants the opportunity to interview with multiple programs. It might be beneficial to endorse this practice on a larger scale to help reduce travel and time away. We recognize that visiting individual programs is an important aspect of the match process, but doing so on a targeted level may make more sense, increasing financial efficiency and reducing time away from programs.

Proposed Solution

A combined proposed solution that can be implemented without a radical overhaul or significant investments might involve moving the interview season to early spring, switching to a 2-tiered system with a centralized first round of interview screening coinciding with subspecialty national meetings or the AAOS annual meeting, and standardizing online information for all orthopedic fellowship programs. A 2-tiered interview process would allow programs and candidates to obtain exposure to a significant number of programs in the first round without incurring significant costs and then would impose a cap on the number of programs to visit. This would level the playing field between candidates with more time and money and candidates who are more constrained in their training environment and finances. A stopgap or adjunct to residents or fellowship programs unable to attend a centralized meeting would be to combine technological tools, such as Internet-based videoconferencing (Skype), before site visits by residents. After this first round of introductions and interviews, residents could then decide on a limited number of programs to formally visit, attend, and ultimately rank. This proposed system would still be able to function within the confines of the match, and it would benefit from the protections offered to residents and programs. Although capping the number of interviews attended by residents clearly can lower costs across the board, we recognize the difficulty of enforcing such a requirement. These potential changes to the system are not exhaustive, and we hope this work will serve as a springboard to further discussion.

Our study had several inherent weaknesses. Our data came from survey responses, which reflect the perspectives only of the responding residents and program directors. Unfortunately, a small number of orthopedic residents responded to this survey, so there was a potential for bias. However, we think the central themes discovered in this survey are only echoes of the concerns of the larger population of residents and program directors. Our hope in designing such a study was to bring to light some of the discrepancies in the fellowship interview process, the goal being to stimulate interest among the orthopedic leadership representing future orthopedic surgeons. More study is needed to clarify if these issues are reflective of a larger segment of residents and program directors. In addition, action may be needed to fully elucidate the intricate interworking of the fellowship process in order to maximize the interest of the orthopedic surgeons who are seeking fellowship training. Another study limitation was the potential for recall bias in the more senior PGY-5 residents, who were further from the interview process than PGY-4 respondents were. Because of the need for anonymity with the surveys, we could not link some findings (eg, program impact, cost, time away) to individual programs or different specialty fellowships. Although it appears there is a desire for a more cost-effective system, given the financial pressures on medical students and residents, the desire to match increases costs because students are likely to attend more interviews than actually needed. Our proposed solution does not take into account residents’ behavior with respect to the current match system. For example, the prevailing thought is that interviewing at more programs increases the likelihood of matching into a desired subspecialty. Despite these study limitations, we think our results identified important points for discussion, investigation, and potential action by orthopedic leadership.

Conclusion

The challenge of critiquing and improving the orthopedic fellowship process requires the same courageous leadership that was recommended almost a decade ago.¹⁴ In this study, we tried to elucidate the impact of the PGY-4 fellowship interview process with respect to residents and residency programs. Our results highlight that time away from residency training, financial costs associated with the fellowship interview process, and disruption of the residency program are substantial and that both residents and program directors want changes made. Leadership needs to further investigate alternatives to the current process to lessen the impact on all parties in this important process.

Over the past several decades, an increasing number of orthopedic surgery residents have pursued fellowship training.¹ This inclination parallels market trends toward subspecialization.^2-5 In 1984, 83% of orthopedics job announcements were for general orthopedists. Twenty-five years later, almost 70% of orthopedic opportunities were for fellowship-trained surgeons.⁶ Further, between 1990 and 2006, the proportion of practicing orthopedic generalists decreased from 44% to 29%.³ In 2007, the American Academy of Orthopaedic Surgery (AAOS) reported 90% of graduating residents were planning to pursue fellowship training.⁷ Reasons for the explosion in subspecialty training are plentiful and well documented.^2-5 Subspecialty positions now dominate the job market, further reinforcing incentives for residents to pursue fellowship training.

The past several decades have seen numerous changes in the orthopedic fellowship interview process. Early on, it was largely unregulated, dependent on personal and professional connections, and flush with the classic “exploding offer” (residents were given a fellowship offer that expired within hours or days). In the 1980s, as the number of fellowship applications surged, the Accreditation Council for Graduate Medical Education (ACGME) pushed for a more regulated process.⁸ To further standardize the system, the American Orthopaedic Association (AOA), the AAOS, and several other specialty organizations created the Orthopaedic Fellowship Match Program Initiative in 2008.⁹ Currently, all orthopedic specialties are represented in either the San Francisco Match Program or National Residency Match Program.

As the system currently stands, postgraduate year 4 (PGY-4) residents are required to interview across the country to secure postgraduate training. This process necessitates residents’ absence from their program, reducing educational opportunities and placing potential continuity-of-care constraints on the residency program. Despite the growing competitiveness for fellowship positions, the increasing number of fellowships available, the rising educational debt of residents, and the limitations of the 80-hour work week, the impact of the interview process on both residents and residency programs has received minimal attention.

We conducted a study to elucidate the impact of the fellowship interview process on residents and residency programs. We hypothesized the time and financial costs for fellowship interviews would be substantial.

Materials and Methods

We obtained institutional review board (IRB) approval for this study. Then, in April 2014, we sent 2 mixed-response questionnaires to orthopedic surgery residency directors and residents. There were 8 items on the director questionnaire and 11 on the resident questionnaire. The surveys were designed to determine the impact of the fellowship interview process on residents and residency programs with respect to finances, time, education, and continuity of care. Each survey had at least 1 free-response question, providing the opportunity to recommend changes to the interview process. The surveys were reviewed and approved by our IRB.

An email was sent to 155 orthopedic surgery program directors or their secretaries. The email asked that the director complete the director questionnaire and that the resident questionnaire be forwarded to senior-level residents, PGY-4s and PGY-5s, who had completed the fellowship interview process. Forty-five (29%) of the 155 directors responded, as did 129 (estimated 9.5%) of an estimated 1354 potential PGY-4s and PGY-5s.¹⁰

The Survey Monkey surveys could be completed over a 3-week period. All responses were anonymous. Using Survey Monkey, we aggregated individual responses into predefined clusters before performing statistical analysis. Descriptive statistics were generated with Microsoft Excel.

Results

Survey respondents represented all the orthopedic subspecialties (Table). Seventy-eight percent of residents applied to at least 13 programs (average, 19) (Figure 1). Ninety-two percent received at least 8 interview offers (average, 14). Eighty-three percent attended 8 or more interviews (average, 11). Seventy-one percent of all interviews were granted when requested, and 79% of all interviews were attended when offered.

Residents spent an average of $5875 (range, $500-$12,000+) on the fellowship interview process (Figure 2). The highest percentage of respondents, 39.5%, selected an average expense between $4000 and $6000. Forty-nine percent of residents borrowed money (from credit cards, additional loans, family members) to pay their expenses.

Average number of days away from residency programs was 11, with 86% of residents missing more than 8 days (Figure 1). About one-third of residents reported being away from their home program for almost 2 weeks during the interview season. Further, 74% of residents wanted changes made to the fellowship application process.

Thirty-seven (82%) of the 45 program directors were from academic programs, the other 8 from community-based programs. Average number of residents in programs per year was 4 (73% of the programs had 4-6 residents per year). Respondents rated the disruption caused by residents’ interview absences from 1 (least disruptive) to 10 (most disruptive) (Figure 3); the average rating was over 7 (high level of disruption). Although 9% of directors thought the process caused little or no disruption (rating, 1-3), 62% thought it extremely disruptive (rating, 8-10).

Thirty-one (69%) of the 45 directors agreed that the fellowship interview process should undergo fundamental change. Asked about possible solutions to current complaints, 60% of the directors agreed that interviews should be conducted in a central location. Of the directors who thought fundamental change was needed, 59% indicated AAOS and other specialty societies together should lead the change in the fellowship interview process.

Both residents and program directors were given the opportunity to write in suggestions regarding how to improve the fellowship interview process. Suggestions were made by 85 (66%) of the 129 residents and 24 (53%) of the 45 directors (Appendix).        

Discussion

Graduating residents are entering a health care environment in which they must be financially conscious because of increasing education debt and decreasing reimbursement prospects.³ Nevertheless, an overwhelming majority of residents delay entering practice to pursue fellowship training—an estimated opportunity cost of $350,000.³ Minimal attention has been given to the potential costs of the fellowship interview process.

Our study results highlight that time away from residency training, financial costs associated with the fellowship interview process, and disruption of the residency program are substantial. On average, residents applied to 19 programs, received 14 interview offers, attended 11 interviews, were away from residency training 11 days, and spent $5875 on travel. The great majority of both residents and program directors wanted changes in the current paradigm governing the orthopedic fellowship interview process.

It is reasonable to think that the number of days residents spend away on interviews would reduce the time available for education and patient care. Although unknown, it is plausible that residents of programs outside major metropolitan centers and residents who apply to more competitive fellowships may be forced to spend even more time away from training. Outside the focus of this study are the impact that residents’ absence might have on their education and the impact of this absence on the people who do the residents’ work while they are away.

Mean fellowship expense was similar to that reported by residents pursuing a pediatric general surgery fellowship ($6974) or a plastic surgery fellowship ($6100).^11,12 Unfortunately, we were unable to determine if average cost is influenced by choice of fellowship specialty or location of residency program. Regardless, fellowship cost may impose an additional financial burden on residents. According to the Association of American Medical Colleges (AAMC), the median salary for PGY-4 residents was $56,380 in 2013. Therefore, on average, the fellowship process consumes more than 10% of a resident’s pretax salary. For perspective, this equates to more than $40,000 for a practicing orthopedic surgeon with a median salary of $413,000.¹³ With an average medical student graduate debt of $175,000 and continuing decreases in reimbursement, further financial hardships to newly graduating residents cannot be understated.^5,11,12

Almost 70% of program directors thought the fellowship process significantly disrupted their program. Reasons given for this disruption mainly involved residents’ time away from the program and the resulting strains placed on maintaining adequate coverage for patient care. The overall disruption score of 7.4 out of 10 was consistent with the great majority thinking that the fellowship process negatively affects their residency program. Altering the fellowship interview process may provide unintended benefits to programs and program directors.

Both program directors and residents communicated that change is needed, but there was little consensus regarding how to effect change and who should lead. This lack of consensus highlights how important it is for the various orthopedic leadership committees to actively and collectively participate in discussions about redefining the system. It has been proposed that it would be ideal for the AOA to lead the change, as the AOA consists of a representative cohort of academic orthopedists and leaders across the spectrum of all fellowship specialties.¹⁴ Given the abundant concern of both residents and program directors, we find it prudent to issue a call to arms of sorts to the AAOS and the individual orthopedic subspecialty societies to work together on a common goal that would benefit residents, programs, and subspecialties within orthopedics.

In trying to understand the challenges that residents, program directors, and programs face, as well as the inherent complexity of the current system, we incorporated respondents’ write-in comments into suggested ways of improving the fellowship interview process. These comments had broad perspectives but overall were consistent with the survey results (Appendix).

Technology

Health care is continually finding new ways to take advantage of technological advances. This is occurring with the fellowship interview schema. Numerous disciplines are using videoconferencing platforms (eg, Skype) to conduct interviews. This practice is becoming more commonplace in the business sector. In a recent survey, more than 60% of human resource managers reported conducting video interviews.¹⁵ Two independent residency programs have used video interviews with mixed success.^16,17

Another technological change requested by residents is the creation and updating of fellowship web pages with standardized information. Such a service may prove useful to residents researching a program and may even lead to limiting the number of programs residents apply to, as they may be able to dial in on exactly what distinguishes one program from another before traveling for an interview. A recent study of orthopedic sports medicine fellowship programs found that most of these programs lacked pertinent information on their websites.¹⁸ Important information regarding case logs from current and former fellows; number of faculty, residents, and fellows; and schedules and facilities of interview sites are a few of the online data points that may help residents differentiate particular programs.^19,20 Questions like these are often asked at interviews and site visits. Having accurate information easily available online may reduce or eliminate the need to travel to a site for such information. Standardizing information would also increase transparency among available fellowships. Although not specifically mentioned, organizational software that improves the productivity of the process may help limit the large number of programs applied to, the interviews offered and attended, the days away, and the financial costs without reducing the match rate.

Timing and Location

The issue of timing—with respect to geographical or meteorological concerns—was another recurring theme among respondents. Numerous respondents indicated that certain programs located in geographic proximity tried to minimize travel by offering interviews around the same time. This coordination potentially minimizes travel expenses and time away from the residency program by allowing residents to interview at multiple locations during a single trip per region. The sports medicine fellowship process was identified as a good example of aligning interviews based on geography. Several respondents suggested an option that also reflects the practice of nonsurgical fellowships—delaying the interview season to bypass potential weather concerns. Winter 2013–2014 saw the most flight delays or cancellations in more than a decade; about 50% of all flights scheduled between December and February were delayed or canceled.²¹ Beyond the additional factor of more time away or missing an interview because of the weather are safety concerns related to the weather. One resident reported having a motor vehicle accident while traveling to an interview in poor weather conditions (Appendix).

National Meetings

Each orthopedic subspecialty has numerous national meetings. Many programs offer applicants the opportunity to interview at these meetings. One respondent mentioned that the annual meeting of the Orthopaedic Trauma Association offers trauma applicants the opportunity to interview with multiple programs. It might be beneficial to endorse this practice on a larger scale to help reduce travel and time away. We recognize that visiting individual programs is an important aspect of the match process, but doing so on a targeted level may make more sense, increasing financial efficiency and reducing time away from programs.

Proposed Solution

A combined proposed solution that can be implemented without a radical overhaul or significant investments might involve moving the interview season to early spring, switching to a 2-tiered system with a centralized first round of interview screening coinciding with subspecialty national meetings or the AAOS annual meeting, and standardizing online information for all orthopedic fellowship programs. A 2-tiered interview process would allow programs and candidates to obtain exposure to a significant number of programs in the first round without incurring significant costs and then would impose a cap on the number of programs to visit. This would level the playing field between candidates with more time and money and candidates who are more constrained in their training environment and finances. A stopgap or adjunct to residents or fellowship programs unable to attend a centralized meeting would be to combine technological tools, such as Internet-based videoconferencing (Skype), before site visits by residents. After this first round of introductions and interviews, residents could then decide on a limited number of programs to formally visit, attend, and ultimately rank. This proposed system would still be able to function within the confines of the match, and it would benefit from the protections offered to residents and programs. Although capping the number of interviews attended by residents clearly can lower costs across the board, we recognize the difficulty of enforcing such a requirement. These potential changes to the system are not exhaustive, and we hope this work will serve as a springboard to further discussion.

Our study had several inherent weaknesses. Our data came from survey responses, which reflect the perspectives only of the responding residents and program directors. Unfortunately, a small number of orthopedic residents responded to this survey, so there was a potential for bias. However, we think the central themes discovered in this survey are only echoes of the concerns of the larger population of residents and program directors. Our hope in designing such a study was to bring to light some of the discrepancies in the fellowship interview process, the goal being to stimulate interest among the orthopedic leadership representing future orthopedic surgeons. More study is needed to clarify if these issues are reflective of a larger segment of residents and program directors. In addition, action may be needed to fully elucidate the intricate interworking of the fellowship process in order to maximize the interest of the orthopedic surgeons who are seeking fellowship training. Another study limitation was the potential for recall bias in the more senior PGY-5 residents, who were further from the interview process than PGY-4 respondents were. Because of the need for anonymity with the surveys, we could not link some findings (eg, program impact, cost, time away) to individual programs or different specialty fellowships. Although it appears there is a desire for a more cost-effective system, given the financial pressures on medical students and residents, the desire to match increases costs because students are likely to attend more interviews than actually needed. Our proposed solution does not take into account residents’ behavior with respect to the current match system. For example, the prevailing thought is that interviewing at more programs increases the likelihood of matching into a desired subspecialty. Despite these study limitations, we think our results identified important points for discussion, investigation, and potential action by orthopedic leadership.

Conclusion

The challenge of critiquing and improving the orthopedic fellowship process requires the same courageous leadership that was recommended almost a decade ago.¹⁴ In this study, we tried to elucidate the impact of the PGY-4 fellowship interview process with respect to residents and residency programs. Our results highlight that time away from residency training, financial costs associated with the fellowship interview process, and disruption of the residency program are substantial and that both residents and program directors want changes made. Leadership needs to further investigate alternatives to the current process to lessen the impact on all parties in this important process.

Over the past several decades, an increasing number of orthopedic surgery residents have pursued fellowship training.¹ This inclination parallels market trends toward subspecialization.^2-5 In 1984, 83% of orthopedics job announcements were for general orthopedists. Twenty-five years later, almost 70% of orthopedic opportunities were for fellowship-trained surgeons.⁶ Further, between 1990 and 2006, the proportion of practicing orthopedic generalists decreased from 44% to 29%.³ In 2007, the American Academy of Orthopaedic Surgery (AAOS) reported 90% of graduating residents were planning to pursue fellowship training.⁷ Reasons for the explosion in subspecialty training are plentiful and well documented.^2-5 Subspecialty positions now dominate the job market, further reinforcing incentives for residents to pursue fellowship training.

The past several decades have seen numerous changes in the orthopedic fellowship interview process. Early on, it was largely unregulated, dependent on personal and professional connections, and flush with the classic “exploding offer” (residents were given a fellowship offer that expired within hours or days). In the 1980s, as the number of fellowship applications surged, the Accreditation Council for Graduate Medical Education (ACGME) pushed for a more regulated process.⁸ To further standardize the system, the American Orthopaedic Association (AOA), the AAOS, and several other specialty organizations created the Orthopaedic Fellowship Match Program Initiative in 2008.⁹ Currently, all orthopedic specialties are represented in either the San Francisco Match Program or National Residency Match Program.

As the system currently stands, postgraduate year 4 (PGY-4) residents are required to interview across the country to secure postgraduate training. This process necessitates residents’ absence from their program, reducing educational opportunities and placing potential continuity-of-care constraints on the residency program. Despite the growing competitiveness for fellowship positions, the increasing number of fellowships available, the rising educational debt of residents, and the limitations of the 80-hour work week, the impact of the interview process on both residents and residency programs has received minimal attention.

We conducted a study to elucidate the impact of the fellowship interview process on residents and residency programs. We hypothesized the time and financial costs for fellowship interviews would be substantial.

Materials and Methods

We obtained institutional review board (IRB) approval for this study. Then, in April 2014, we sent 2 mixed-response questionnaires to orthopedic surgery residency directors and residents. There were 8 items on the director questionnaire and 11 on the resident questionnaire. The surveys were designed to determine the impact of the fellowship interview process on residents and residency programs with respect to finances, time, education, and continuity of care. Each survey had at least 1 free-response question, providing the opportunity to recommend changes to the interview process. The surveys were reviewed and approved by our IRB.

An email was sent to 155 orthopedic surgery program directors or their secretaries. The email asked that the director complete the director questionnaire and that the resident questionnaire be forwarded to senior-level residents, PGY-4s and PGY-5s, who had completed the fellowship interview process. Forty-five (29%) of the 155 directors responded, as did 129 (estimated 9.5%) of an estimated 1354 potential PGY-4s and PGY-5s.¹⁰

The Survey Monkey surveys could be completed over a 3-week period. All responses were anonymous. Using Survey Monkey, we aggregated individual responses into predefined clusters before performing statistical analysis. Descriptive statistics were generated with Microsoft Excel.

Results

Survey respondents represented all the orthopedic subspecialties (Table). Seventy-eight percent of residents applied to at least 13 programs (average, 19) (Figure 1). Ninety-two percent received at least 8 interview offers (average, 14). Eighty-three percent attended 8 or more interviews (average, 11). Seventy-one percent of all interviews were granted when requested, and 79% of all interviews were attended when offered.

Residents spent an average of $5875 (range, $500-$12,000+) on the fellowship interview process (Figure 2). The highest percentage of respondents, 39.5%, selected an average expense between $4000 and $6000. Forty-nine percent of residents borrowed money (from credit cards, additional loans, family members) to pay their expenses.

Average number of days away from residency programs was 11, with 86% of residents missing more than 8 days (Figure 1). About one-third of residents reported being away from their home program for almost 2 weeks during the interview season. Further, 74% of residents wanted changes made to the fellowship application process.

Thirty-seven (82%) of the 45 program directors were from academic programs, the other 8 from community-based programs. Average number of residents in programs per year was 4 (73% of the programs had 4-6 residents per year). Respondents rated the disruption caused by residents’ interview absences from 1 (least disruptive) to 10 (most disruptive) (Figure 3); the average rating was over 7 (high level of disruption). Although 9% of directors thought the process caused little or no disruption (rating, 1-3), 62% thought it extremely disruptive (rating, 8-10).

Thirty-one (69%) of the 45 directors agreed that the fellowship interview process should undergo fundamental change. Asked about possible solutions to current complaints, 60% of the directors agreed that interviews should be conducted in a central location. Of the directors who thought fundamental change was needed, 59% indicated AAOS and other specialty societies together should lead the change in the fellowship interview process.

Both residents and program directors were given the opportunity to write in suggestions regarding how to improve the fellowship interview process. Suggestions were made by 85 (66%) of the 129 residents and 24 (53%) of the 45 directors (Appendix).        

Discussion

Graduating residents are entering a health care environment in which they must be financially conscious because of increasing education debt and decreasing reimbursement prospects.³ Nevertheless, an overwhelming majority of residents delay entering practice to pursue fellowship training—an estimated opportunity cost of $350,000.³ Minimal attention has been given to the potential costs of the fellowship interview process.

Our study results highlight that time away from residency training, financial costs associated with the fellowship interview process, and disruption of the residency program are substantial. On average, residents applied to 19 programs, received 14 interview offers, attended 11 interviews, were away from residency training 11 days, and spent $5875 on travel. The great majority of both residents and program directors wanted changes in the current paradigm governing the orthopedic fellowship interview process.

It is reasonable to think that the number of days residents spend away on interviews would reduce the time available for education and patient care. Although unknown, it is plausible that residents of programs outside major metropolitan centers and residents who apply to more competitive fellowships may be forced to spend even more time away from training. Outside the focus of this study are the impact that residents’ absence might have on their education and the impact of this absence on the people who do the residents’ work while they are away.

Mean fellowship expense was similar to that reported by residents pursuing a pediatric general surgery fellowship ($6974) or a plastic surgery fellowship ($6100).^11,12 Unfortunately, we were unable to determine if average cost is influenced by choice of fellowship specialty or location of residency program. Regardless, fellowship cost may impose an additional financial burden on residents. According to the Association of American Medical Colleges (AAMC), the median salary for PGY-4 residents was $56,380 in 2013. Therefore, on average, the fellowship process consumes more than 10% of a resident’s pretax salary. For perspective, this equates to more than $40,000 for a practicing orthopedic surgeon with a median salary of $413,000.¹³ With an average medical student graduate debt of $175,000 and continuing decreases in reimbursement, further financial hardships to newly graduating residents cannot be understated.^5,11,12

Almost 70% of program directors thought the fellowship process significantly disrupted their program. Reasons given for this disruption mainly involved residents’ time away from the program and the resulting strains placed on maintaining adequate coverage for patient care. The overall disruption score of 7.4 out of 10 was consistent with the great majority thinking that the fellowship process negatively affects their residency program. Altering the fellowship interview process may provide unintended benefits to programs and program directors.

Both program directors and residents communicated that change is needed, but there was little consensus regarding how to effect change and who should lead. This lack of consensus highlights how important it is for the various orthopedic leadership committees to actively and collectively participate in discussions about redefining the system. It has been proposed that it would be ideal for the AOA to lead the change, as the AOA consists of a representative cohort of academic orthopedists and leaders across the spectrum of all fellowship specialties.¹⁴ Given the abundant concern of both residents and program directors, we find it prudent to issue a call to arms of sorts to the AAOS and the individual orthopedic subspecialty societies to work together on a common goal that would benefit residents, programs, and subspecialties within orthopedics.

In trying to understand the challenges that residents, program directors, and programs face, as well as the inherent complexity of the current system, we incorporated respondents’ write-in comments into suggested ways of improving the fellowship interview process. These comments had broad perspectives but overall were consistent with the survey results (Appendix).

Technology

Health care is continually finding new ways to take advantage of technological advances. This is occurring with the fellowship interview schema. Numerous disciplines are using videoconferencing platforms (eg, Skype) to conduct interviews. This practice is becoming more commonplace in the business sector. In a recent survey, more than 60% of human resource managers reported conducting video interviews.¹⁵ Two independent residency programs have used video interviews with mixed success.^16,17

Another technological change requested by residents is the creation and updating of fellowship web pages with standardized information. Such a service may prove useful to residents researching a program and may even lead to limiting the number of programs residents apply to, as they may be able to dial in on exactly what distinguishes one program from another before traveling for an interview. A recent study of orthopedic sports medicine fellowship programs found that most of these programs lacked pertinent information on their websites.¹⁸ Important information regarding case logs from current and former fellows; number of faculty, residents, and fellows; and schedules and facilities of interview sites are a few of the online data points that may help residents differentiate particular programs.^19,20 Questions like these are often asked at interviews and site visits. Having accurate information easily available online may reduce or eliminate the need to travel to a site for such information. Standardizing information would also increase transparency among available fellowships. Although not specifically mentioned, organizational software that improves the productivity of the process may help limit the large number of programs applied to, the interviews offered and attended, the days away, and the financial costs without reducing the match rate.

Timing and Location

The issue of timing—with respect to geographical or meteorological concerns—was another recurring theme among respondents. Numerous respondents indicated that certain programs located in geographic proximity tried to minimize travel by offering interviews around the same time. This coordination potentially minimizes travel expenses and time away from the residency program by allowing residents to interview at multiple locations during a single trip per region. The sports medicine fellowship process was identified as a good example of aligning interviews based on geography. Several respondents suggested an option that also reflects the practice of nonsurgical fellowships—delaying the interview season to bypass potential weather concerns. Winter 2013–2014 saw the most flight delays or cancellations in more than a decade; about 50% of all flights scheduled between December and February were delayed or canceled.²¹ Beyond the additional factor of more time away or missing an interview because of the weather are safety concerns related to the weather. One resident reported having a motor vehicle accident while traveling to an interview in poor weather conditions (Appendix).

National Meetings

Each orthopedic subspecialty has numerous national meetings. Many programs offer applicants the opportunity to interview at these meetings. One respondent mentioned that the annual meeting of the Orthopaedic Trauma Association offers trauma applicants the opportunity to interview with multiple programs. It might be beneficial to endorse this practice on a larger scale to help reduce travel and time away. We recognize that visiting individual programs is an important aspect of the match process, but doing so on a targeted level may make more sense, increasing financial efficiency and reducing time away from programs.

Proposed Solution

A combined proposed solution that can be implemented without a radical overhaul or significant investments might involve moving the interview season to early spring, switching to a 2-tiered system with a centralized first round of interview screening coinciding with subspecialty national meetings or the AAOS annual meeting, and standardizing online information for all orthopedic fellowship programs. A 2-tiered interview process would allow programs and candidates to obtain exposure to a significant number of programs in the first round without incurring significant costs and then would impose a cap on the number of programs to visit. This would level the playing field between candidates with more time and money and candidates who are more constrained in their training environment and finances. A stopgap or adjunct to residents or fellowship programs unable to attend a centralized meeting would be to combine technological tools, such as Internet-based videoconferencing (Skype), before site visits by residents. After this first round of introductions and interviews, residents could then decide on a limited number of programs to formally visit, attend, and ultimately rank. This proposed system would still be able to function within the confines of the match, and it would benefit from the protections offered to residents and programs. Although capping the number of interviews attended by residents clearly can lower costs across the board, we recognize the difficulty of enforcing such a requirement. These potential changes to the system are not exhaustive, and we hope this work will serve as a springboard to further discussion.

Our study had several inherent weaknesses. Our data came from survey responses, which reflect the perspectives only of the responding residents and program directors. Unfortunately, a small number of orthopedic residents responded to this survey, so there was a potential for bias. However, we think the central themes discovered in this survey are only echoes of the concerns of the larger population of residents and program directors. Our hope in designing such a study was to bring to light some of the discrepancies in the fellowship interview process, the goal being to stimulate interest among the orthopedic leadership representing future orthopedic surgeons. More study is needed to clarify if these issues are reflective of a larger segment of residents and program directors. In addition, action may be needed to fully elucidate the intricate interworking of the fellowship process in order to maximize the interest of the orthopedic surgeons who are seeking fellowship training. Another study limitation was the potential for recall bias in the more senior PGY-5 residents, who were further from the interview process than PGY-4 respondents were. Because of the need for anonymity with the surveys, we could not link some findings (eg, program impact, cost, time away) to individual programs or different specialty fellowships. Although it appears there is a desire for a more cost-effective system, given the financial pressures on medical students and residents, the desire to match increases costs because students are likely to attend more interviews than actually needed. Our proposed solution does not take into account residents’ behavior with respect to the current match system. For example, the prevailing thought is that interviewing at more programs increases the likelihood of matching into a desired subspecialty. Despite these study limitations, we think our results identified important points for discussion, investigation, and potential action by orthopedic leadership.

Conclusion

The challenge of critiquing and improving the orthopedic fellowship process requires the same courageous leadership that was recommended almost a decade ago.¹⁴ In this study, we tried to elucidate the impact of the PGY-4 fellowship interview process with respect to residents and residency programs. Our results highlight that time away from residency training, financial costs associated with the fellowship interview process, and disruption of the residency program are substantial and that both residents and program directors want changes made. Leadership needs to further investigate alternatives to the current process to lessen the impact on all parties in this important process.

Humeral shaft fractures account for about 1% of all fractures.¹ With the exception of the few absolute indications for surgical intervention, such as the presence of an open fracture, the current teaching on treatment of these fractures is that the majority can be successfully managed nonoperatively.^1-3 These conservative measures consist of bandages, abduction splints, U-casts, hanging arm casts, and, most commonly, functional bracing, which is considered the gold standard for treatment of humeral shaft fractures by many authors.^1-3 One of the most often cited disadvantages of nonoperative management over surgical treatment is the higher incidence of residual deformity, the most common of which is varus angulation.⁴

The incidence of malunion (>20° of angulation in any plane or shortening of ≥2.5 cm) after nonoperative treatment varies in the literature from 0% to 13%,^2,4-9 with a recent literature review documenting a mean incidence of 4.4% within the frontal plane and 2% within the sagittal plane across all studies.² As reported initially by Sarmiento and colleagues^3,9 and echoed by other authors,^2,5,8 angular deformity of less than 20° is thought to be both cosmetically and functionally acceptable. Whether angular deformities or malunion of more than 20° actually leads to functional limitations is unknown. Although some observational reports suggest that the degree of radiographic malalignment does not necessarily correlate with functional outcome,⁸ no studies have specifically evaluated patient outcomes of humeral shaft fracture malunions.

We conducted a study to determine the overall incidence and long-term clinical and functional outcomes of patients with malunion after nonoperative management of humeral shaft fractures. Long-term outcomes were assessed with current symptoms, physical examination findings, need for subsequent operative intervention, DASH (Disabilities of the Arm, Shoulder, and Hand) scores, and a self-reported questionnaire. We hypothesized that patients who develop a malunion after nonoperative treatment of a closed humeral shaft fracture will have satisfactory functional outcomes based on subjective reports, physical examination findings, and DASH scores.

Methods

After obtaining institutional review board approval for the study, we selected patients from a retrospective medical record review of all those 18 years or older with a humeral shaft fracture managed nonoperatively at our institution between January 1, 2001, and June 30, 2012, with a minimum 1-year follow-up. We identified 156 patients with nonoperatively managed midshaft humerus fractures. Study exclusion criteria included fracture associated with a tumor (3 patients), ipsilateral upper extremity injury (9), open/ballistic injury (18), nonunion (9), underlying cognitive disability or psychiatric illness (4), and insufficient follow-up to clinical or radiographic healing (22). Ninety-one patients were eligible for study inclusion. Radiographs at time of final clinical visit were reviewed to assess for evidence of malunion at the fracture site, as defined by previously reported criteria³ (>20° angulation in anterior/posterior or varus/valgus plane of motion or shortening of ≥2.5 cm). Fifteen patients met all the inclusion criteria for further evaluation.

Medical records were retrospectively reviewed for information on age at injury, sex, comorbidities (eg, diabetes, osteoporosis, smoking), body mass index, type and duration of immobilization, complications, return to work, cosmetic perception, time to final clinical follow-up, and symptoms at final clinical follow-up. Incidence of potential risk factors associated with malunion—obesity, noncompliance, and comorbidities such as smoking and diabetes—was compared between the 15 patients with malunion and the other study patients, who healed without malunion.

For long-term postoperative follow-up, patients were contacted to be seen in clinic to complete an updated physical examination, self-reported questionnaire, and the DASH form. Physical examination included measurements of range of motion (ROM) and strength involving the shoulder, elbow, and forearm, with ROM reported as the difference between the injured and contralateral upper extremities. Neurovascular status and focal tenderness to palpation were also assessed on examination. When in-person examination was not possible, the questionnaire and DASH form were completed over the telephone. The self-reported questionnaire asked for information on smoking status, pain, functional limitations, cosmetic perception, satisfaction, and whether or not the patient would still opt for nonoperative management if presented with the same injury again. Pain and satisfaction were measured on numerical scales: Pain scores ranged from 0 (no pain) to 10 (worst possible pain), and satisfaction scores ranged from 1 (not satisfied) to 5 (very satisfied). Data are presented as mean values.

Results

Of the 91 study-eligible patients, 15 (16%) met the radiographic criteria for the diagnosis of malunion. Retrospective data were available for all 15 patients from time of injury to final clinical follow-up (mean, 19 weeks; range, 7-53 weeks). Mean age at injury was 39 years (range, 20-79 years). Additional demographics are listed in Table 1. Incidence of potential risk factors, such as body mass index (26.5 vs 25.4), smoking (33% vs 33%), and diabetes (0% vs 8%), was not significantly different between the malunion and healed-without-malunion groups, respectively. Furthermore, all malunion patients were compliant with their treatment protocol.

Radiographs were assessed at time of final follow-up to confirm healing and to document malunion. Varus malunion was found in 13 patients (mean, 24°; range, 20.5°-35.5°), and shortening was documented in the other 2 patients (mean, 4 cm; range, 3-5 cm). Patients were immobilized a mean of 10 weeks (range, 6-13 weeks). Initial fracture management consisted of coaptation splinting for 1 to 2 weeks (12 patients), hanging arm cast for 1 week (1 patient), and posterior splint for 1 week (1 patient). Patients were then transitioned to Sarmiento fracture bracing for the duration of their treatment (range, 5-12 months). One patient, followed initially at an outside institution, was managed in a sling throughout the duration of treatment (12 weeks) (Table 1). All 15 patients were neurovascularly intact at time of final clinical examination, with return of full upper extremity ROM in all but 3 patients. Only 1 of these 3 patients reported residual pain and functional limitations 4 months after injury (Table 2). Twelve patients were evaluated for return to work, with all successfully returning to work without restrictions at time of final follow-up. The 1 minor complication noted during the treatment period involved medial-sided elbow skin breakdown from brace wear, which resolved with local wound care. No patient required or requested surgical intervention for their residual malunion.

Of the 15 patients, 8 (53%) were reached for in-person examination (6 patients) or telephone interview (2 patients) for follow-up assessment by means of DASH form and self-reported questionnaire a mean of 47 months (range, 12-99 months) after initial injury. The 6 patients who had a physical examination were neurovascularly intact, lacked focal tenderness to palpation, and demonstrated full (5/5) strength within the deltoid, biceps, triceps, pronator, and supinator musculature. Each patient had equal ROM compared with the contralateral uninjured extremity on shoulder forward flexion and abduction, elbow flexion and extension, and forearm pronation and supination. Three patients (50%) had mild residual loss of ROM, with 2 demonstrating decreased shoulder external rotation of 10° and 15°, respectively, and 1 demonstrating decreased shoulder internal rotation of 10°.

Mean DASH score was 10.4 (range, 0-49.2). Evaluation of the self-reported questionnaire revealed a mean pain score of 1.1 (range, 0-7), with only 2 patients reporting any ongoing pain. In addition, 2 patients reported functional limitations, both related to overhead activities. However, 6 (75%) of the 8 patients reported noticeable cosmetic deformity, most commonly varus angulation (4 patients), as well as palpable bony prominence (2) and muscle atrophy (1). The majority of patients were satisfied with the outcome of their treatment (mean, 4; range, 2-5), with 6 patients reporting being satisfied or very satisfied, and all 6 indicating they would undergo nonoperative management again if presented with the same injury. Two patients reported being dissatisfied with their outcome, 1 because of cosmetic appearance and 1 because of cosmetic appearance and functional limitations. Both patients indicated they would choose operative management if presented with the same injury. There was no apparent relationship between outcome and degree of residual deformity, as both patients with varus angulation of more than 30° reported no residual pain or functional limitation and were very satisfied with the outcome of their treatment (Table 2).

Of the 7 patients who could not be reached for final follow-up, 2 on initial contact expressed overall satisfaction with their outcome and denied functional limitations. However, both asked to complete the study at a later date. Subsequently, these 2 patients could not be reached to complete the formal follow-up.

Discussion

Humeral shaft fractures are usually managed nonoperatively. One of the most commonly cited disadvantages of nonoperative management is its higher incidence of residual angular deformity, up to 13% in previous studies.⁴ Our study found a slightly higher incidence, 16%, on review of 91 nonoperatively managed humeral shaft fractures treated over an 11.5 year period. Although previous studies have reported acceptable functional and cosmetic outcomes with residual angular deformity of less than 20°,^2,3,5,8,9 only observational reports have suggested acceptable function in patients with a documented malunion.⁸

To our knowledge, ours is the first study to correlate malunion with functional parameters and subjective patient-reported outcomes. We found that malunion was not associated with significant pain or functional limitation after nonoperative management of humeral shaft fractures. Furthermore, 75% of patients were satisfied or very satisfied with the outcome of their treatment and indicated they would undergo nonoperative management if presented with the same injury again. However, 75% of patients reported a noticeable cosmetic deformity, and one-third of these patients cited it as a major reason for dissatisfaction with their overall outcome. Regarding function, all patients returned to full strength and ROM of the affected extremity, aside from small losses of internal or external shoulder rotation on the magnitude of 10° to 15° in 50% of those patients tested. In addition, 75% of patients returned to regular activity without functional limitations; the other 25% reported trouble with overhead activities. There were no significant complications during the treatment or follow-up period, once the fracture had healed.

The major limitation of this study was its small patient population. (Obtaining a larger series of patients with malunion after nonoperative treatment of humeral shaft fractures likely would require a multicenter study.) Some of our study findings, such as lack of correlation between degree of malunion and subsequent functional or subjective outcomes, would require a larger sample size for verification and more definitive conclusions. Another limitation is that the study was not designed to evaluate the cause of malunion. Therefore, we cannot draw any definitive conclusions regarding what may have contributed to the development of malunion in our study population. However, all our malunion patients were compliant with their treatment protocol, and they showed no significant difference in incidence of potential risk factors (eg, obesity, comorbidities) compared with the patients who healed without malunion.

Conclusion

Malunion after nonoperative management of humeral shaft fractures does not appear to result in significant pain, dissatisfaction, or functional limitation as measured on physical examination and with validated objective outcome measures in the majority of patients. Furthermore, no patients in this study required surgical intervention for any residual limitations or complications after malunion. The majority of patients reported a noticeable cosmetic deformity, which left a small subset of patients dissatisfied. Overall, our study findings can be used to help counsel patients before and during nonoperative management—particularly patients who appear to be healing with some malunion. Our findings suggest that operative intervention to prevent malunion is not necessary, as it likely would not result in any overall improvement in patient function or satisfaction, but patients should be counseled regarding the high likelihood of cosmetic deformity, which may or may not be bothersome.

Humeral shaft fractures account for about 1% of all fractures.¹ With the exception of the few absolute indications for surgical intervention, such as the presence of an open fracture, the current teaching on treatment of these fractures is that the majority can be successfully managed nonoperatively.^1-3 These conservative measures consist of bandages, abduction splints, U-casts, hanging arm casts, and, most commonly, functional bracing, which is considered the gold standard for treatment of humeral shaft fractures by many authors.^1-3 One of the most often cited disadvantages of nonoperative management over surgical treatment is the higher incidence of residual deformity, the most common of which is varus angulation.⁴

The incidence of malunion (>20° of angulation in any plane or shortening of ≥2.5 cm) after nonoperative treatment varies in the literature from 0% to 13%,^2,4-9 with a recent literature review documenting a mean incidence of 4.4% within the frontal plane and 2% within the sagittal plane across all studies.² As reported initially by Sarmiento and colleagues^3,9 and echoed by other authors,^2,5,8 angular deformity of less than 20° is thought to be both cosmetically and functionally acceptable. Whether angular deformities or malunion of more than 20° actually leads to functional limitations is unknown. Although some observational reports suggest that the degree of radiographic malalignment does not necessarily correlate with functional outcome,⁸ no studies have specifically evaluated patient outcomes of humeral shaft fracture malunions.

We conducted a study to determine the overall incidence and long-term clinical and functional outcomes of patients with malunion after nonoperative management of humeral shaft fractures. Long-term outcomes were assessed with current symptoms, physical examination findings, need for subsequent operative intervention, DASH (Disabilities of the Arm, Shoulder, and Hand) scores, and a self-reported questionnaire. We hypothesized that patients who develop a malunion after nonoperative treatment of a closed humeral shaft fracture will have satisfactory functional outcomes based on subjective reports, physical examination findings, and DASH scores.

Methods

After obtaining institutional review board approval for the study, we selected patients from a retrospective medical record review of all those 18 years or older with a humeral shaft fracture managed nonoperatively at our institution between January 1, 2001, and June 30, 2012, with a minimum 1-year follow-up. We identified 156 patients with nonoperatively managed midshaft humerus fractures. Study exclusion criteria included fracture associated with a tumor (3 patients), ipsilateral upper extremity injury (9), open/ballistic injury (18), nonunion (9), underlying cognitive disability or psychiatric illness (4), and insufficient follow-up to clinical or radiographic healing (22). Ninety-one patients were eligible for study inclusion. Radiographs at time of final clinical visit were reviewed to assess for evidence of malunion at the fracture site, as defined by previously reported criteria³ (>20° angulation in anterior/posterior or varus/valgus plane of motion or shortening of ≥2.5 cm). Fifteen patients met all the inclusion criteria for further evaluation.

Medical records were retrospectively reviewed for information on age at injury, sex, comorbidities (eg, diabetes, osteoporosis, smoking), body mass index, type and duration of immobilization, complications, return to work, cosmetic perception, time to final clinical follow-up, and symptoms at final clinical follow-up. Incidence of potential risk factors associated with malunion—obesity, noncompliance, and comorbidities such as smoking and diabetes—was compared between the 15 patients with malunion and the other study patients, who healed without malunion.

For long-term postoperative follow-up, patients were contacted to be seen in clinic to complete an updated physical examination, self-reported questionnaire, and the DASH form. Physical examination included measurements of range of motion (ROM) and strength involving the shoulder, elbow, and forearm, with ROM reported as the difference between the injured and contralateral upper extremities. Neurovascular status and focal tenderness to palpation were also assessed on examination. When in-person examination was not possible, the questionnaire and DASH form were completed over the telephone. The self-reported questionnaire asked for information on smoking status, pain, functional limitations, cosmetic perception, satisfaction, and whether or not the patient would still opt for nonoperative management if presented with the same injury again. Pain and satisfaction were measured on numerical scales: Pain scores ranged from 0 (no pain) to 10 (worst possible pain), and satisfaction scores ranged from 1 (not satisfied) to 5 (very satisfied). Data are presented as mean values.

Results

Of the 91 study-eligible patients, 15 (16%) met the radiographic criteria for the diagnosis of malunion. Retrospective data were available for all 15 patients from time of injury to final clinical follow-up (mean, 19 weeks; range, 7-53 weeks). Mean age at injury was 39 years (range, 20-79 years). Additional demographics are listed in Table 1. Incidence of potential risk factors, such as body mass index (26.5 vs 25.4), smoking (33% vs 33%), and diabetes (0% vs 8%), was not significantly different between the malunion and healed-without-malunion groups, respectively. Furthermore, all malunion patients were compliant with their treatment protocol.

Radiographs were assessed at time of final follow-up to confirm healing and to document malunion. Varus malunion was found in 13 patients (mean, 24°; range, 20.5°-35.5°), and shortening was documented in the other 2 patients (mean, 4 cm; range, 3-5 cm). Patients were immobilized a mean of 10 weeks (range, 6-13 weeks). Initial fracture management consisted of coaptation splinting for 1 to 2 weeks (12 patients), hanging arm cast for 1 week (1 patient), and posterior splint for 1 week (1 patient). Patients were then transitioned to Sarmiento fracture bracing for the duration of their treatment (range, 5-12 months). One patient, followed initially at an outside institution, was managed in a sling throughout the duration of treatment (12 weeks) (Table 1). All 15 patients were neurovascularly intact at time of final clinical examination, with return of full upper extremity ROM in all but 3 patients. Only 1 of these 3 patients reported residual pain and functional limitations 4 months after injury (Table 2). Twelve patients were evaluated for return to work, with all successfully returning to work without restrictions at time of final follow-up. The 1 minor complication noted during the treatment period involved medial-sided elbow skin breakdown from brace wear, which resolved with local wound care. No patient required or requested surgical intervention for their residual malunion.

Of the 15 patients, 8 (53%) were reached for in-person examination (6 patients) or telephone interview (2 patients) for follow-up assessment by means of DASH form and self-reported questionnaire a mean of 47 months (range, 12-99 months) after initial injury. The 6 patients who had a physical examination were neurovascularly intact, lacked focal tenderness to palpation, and demonstrated full (5/5) strength within the deltoid, biceps, triceps, pronator, and supinator musculature. Each patient had equal ROM compared with the contralateral uninjured extremity on shoulder forward flexion and abduction, elbow flexion and extension, and forearm pronation and supination. Three patients (50%) had mild residual loss of ROM, with 2 demonstrating decreased shoulder external rotation of 10° and 15°, respectively, and 1 demonstrating decreased shoulder internal rotation of 10°.

Mean DASH score was 10.4 (range, 0-49.2). Evaluation of the self-reported questionnaire revealed a mean pain score of 1.1 (range, 0-7), with only 2 patients reporting any ongoing pain. In addition, 2 patients reported functional limitations, both related to overhead activities. However, 6 (75%) of the 8 patients reported noticeable cosmetic deformity, most commonly varus angulation (4 patients), as well as palpable bony prominence (2) and muscle atrophy (1). The majority of patients were satisfied with the outcome of their treatment (mean, 4; range, 2-5), with 6 patients reporting being satisfied or very satisfied, and all 6 indicating they would undergo nonoperative management again if presented with the same injury. Two patients reported being dissatisfied with their outcome, 1 because of cosmetic appearance and 1 because of cosmetic appearance and functional limitations. Both patients indicated they would choose operative management if presented with the same injury. There was no apparent relationship between outcome and degree of residual deformity, as both patients with varus angulation of more than 30° reported no residual pain or functional limitation and were very satisfied with the outcome of their treatment (Table 2).

Of the 7 patients who could not be reached for final follow-up, 2 on initial contact expressed overall satisfaction with their outcome and denied functional limitations. However, both asked to complete the study at a later date. Subsequently, these 2 patients could not be reached to complete the formal follow-up.

Discussion

Humeral shaft fractures are usually managed nonoperatively. One of the most commonly cited disadvantages of nonoperative management is its higher incidence of residual angular deformity, up to 13% in previous studies.⁴ Our study found a slightly higher incidence, 16%, on review of 91 nonoperatively managed humeral shaft fractures treated over an 11.5 year period. Although previous studies have reported acceptable functional and cosmetic outcomes with residual angular deformity of less than 20°,^2,3,5,8,9 only observational reports have suggested acceptable function in patients with a documented malunion.⁸

To our knowledge, ours is the first study to correlate malunion with functional parameters and subjective patient-reported outcomes. We found that malunion was not associated with significant pain or functional limitation after nonoperative management of humeral shaft fractures. Furthermore, 75% of patients were satisfied or very satisfied with the outcome of their treatment and indicated they would undergo nonoperative management if presented with the same injury again. However, 75% of patients reported a noticeable cosmetic deformity, and one-third of these patients cited it as a major reason for dissatisfaction with their overall outcome. Regarding function, all patients returned to full strength and ROM of the affected extremity, aside from small losses of internal or external shoulder rotation on the magnitude of 10° to 15° in 50% of those patients tested. In addition, 75% of patients returned to regular activity without functional limitations; the other 25% reported trouble with overhead activities. There were no significant complications during the treatment or follow-up period, once the fracture had healed.

The major limitation of this study was its small patient population. (Obtaining a larger series of patients with malunion after nonoperative treatment of humeral shaft fractures likely would require a multicenter study.) Some of our study findings, such as lack of correlation between degree of malunion and subsequent functional or subjective outcomes, would require a larger sample size for verification and more definitive conclusions. Another limitation is that the study was not designed to evaluate the cause of malunion. Therefore, we cannot draw any definitive conclusions regarding what may have contributed to the development of malunion in our study population. However, all our malunion patients were compliant with their treatment protocol, and they showed no significant difference in incidence of potential risk factors (eg, obesity, comorbidities) compared with the patients who healed without malunion.

Conclusion

Malunion after nonoperative management of humeral shaft fractures does not appear to result in significant pain, dissatisfaction, or functional limitation as measured on physical examination and with validated objective outcome measures in the majority of patients. Furthermore, no patients in this study required surgical intervention for any residual limitations or complications after malunion. The majority of patients reported a noticeable cosmetic deformity, which left a small subset of patients dissatisfied. Overall, our study findings can be used to help counsel patients before and during nonoperative management—particularly patients who appear to be healing with some malunion. Our findings suggest that operative intervention to prevent malunion is not necessary, as it likely would not result in any overall improvement in patient function or satisfaction, but patients should be counseled regarding the high likelihood of cosmetic deformity, which may or may not be bothersome.

Humeral shaft fractures account for about 1% of all fractures.¹ With the exception of the few absolute indications for surgical intervention, such as the presence of an open fracture, the current teaching on treatment of these fractures is that the majority can be successfully managed nonoperatively.^1-3 These conservative measures consist of bandages, abduction splints, U-casts, hanging arm casts, and, most commonly, functional bracing, which is considered the gold standard for treatment of humeral shaft fractures by many authors.^1-3 One of the most often cited disadvantages of nonoperative management over surgical treatment is the higher incidence of residual deformity, the most common of which is varus angulation.⁴

The incidence of malunion (>20° of angulation in any plane or shortening of ≥2.5 cm) after nonoperative treatment varies in the literature from 0% to 13%,^2,4-9 with a recent literature review documenting a mean incidence of 4.4% within the frontal plane and 2% within the sagittal plane across all studies.² As reported initially by Sarmiento and colleagues^3,9 and echoed by other authors,^2,5,8 angular deformity of less than 20° is thought to be both cosmetically and functionally acceptable. Whether angular deformities or malunion of more than 20° actually leads to functional limitations is unknown. Although some observational reports suggest that the degree of radiographic malalignment does not necessarily correlate with functional outcome,⁸ no studies have specifically evaluated patient outcomes of humeral shaft fracture malunions.

We conducted a study to determine the overall incidence and long-term clinical and functional outcomes of patients with malunion after nonoperative management of humeral shaft fractures. Long-term outcomes were assessed with current symptoms, physical examination findings, need for subsequent operative intervention, DASH (Disabilities of the Arm, Shoulder, and Hand) scores, and a self-reported questionnaire. We hypothesized that patients who develop a malunion after nonoperative treatment of a closed humeral shaft fracture will have satisfactory functional outcomes based on subjective reports, physical examination findings, and DASH scores.

Methods

After obtaining institutional review board approval for the study, we selected patients from a retrospective medical record review of all those 18 years or older with a humeral shaft fracture managed nonoperatively at our institution between January 1, 2001, and June 30, 2012, with a minimum 1-year follow-up. We identified 156 patients with nonoperatively managed midshaft humerus fractures. Study exclusion criteria included fracture associated with a tumor (3 patients), ipsilateral upper extremity injury (9), open/ballistic injury (18), nonunion (9), underlying cognitive disability or psychiatric illness (4), and insufficient follow-up to clinical or radiographic healing (22). Ninety-one patients were eligible for study inclusion. Radiographs at time of final clinical visit were reviewed to assess for evidence of malunion at the fracture site, as defined by previously reported criteria³ (>20° angulation in anterior/posterior or varus/valgus plane of motion or shortening of ≥2.5 cm). Fifteen patients met all the inclusion criteria for further evaluation.

Medical records were retrospectively reviewed for information on age at injury, sex, comorbidities (eg, diabetes, osteoporosis, smoking), body mass index, type and duration of immobilization, complications, return to work, cosmetic perception, time to final clinical follow-up, and symptoms at final clinical follow-up. Incidence of potential risk factors associated with malunion—obesity, noncompliance, and comorbidities such as smoking and diabetes—was compared between the 15 patients with malunion and the other study patients, who healed without malunion.

For long-term postoperative follow-up, patients were contacted to be seen in clinic to complete an updated physical examination, self-reported questionnaire, and the DASH form. Physical examination included measurements of range of motion (ROM) and strength involving the shoulder, elbow, and forearm, with ROM reported as the difference between the injured and contralateral upper extremities. Neurovascular status and focal tenderness to palpation were also assessed on examination. When in-person examination was not possible, the questionnaire and DASH form were completed over the telephone. The self-reported questionnaire asked for information on smoking status, pain, functional limitations, cosmetic perception, satisfaction, and whether or not the patient would still opt for nonoperative management if presented with the same injury again. Pain and satisfaction were measured on numerical scales: Pain scores ranged from 0 (no pain) to 10 (worst possible pain), and satisfaction scores ranged from 1 (not satisfied) to 5 (very satisfied). Data are presented as mean values.

Results

Of the 91 study-eligible patients, 15 (16%) met the radiographic criteria for the diagnosis of malunion. Retrospective data were available for all 15 patients from time of injury to final clinical follow-up (mean, 19 weeks; range, 7-53 weeks). Mean age at injury was 39 years (range, 20-79 years). Additional demographics are listed in Table 1. Incidence of potential risk factors, such as body mass index (26.5 vs 25.4), smoking (33% vs 33%), and diabetes (0% vs 8%), was not significantly different between the malunion and healed-without-malunion groups, respectively. Furthermore, all malunion patients were compliant with their treatment protocol.

Radiographs were assessed at time of final follow-up to confirm healing and to document malunion. Varus malunion was found in 13 patients (mean, 24°; range, 20.5°-35.5°), and shortening was documented in the other 2 patients (mean, 4 cm; range, 3-5 cm). Patients were immobilized a mean of 10 weeks (range, 6-13 weeks). Initial fracture management consisted of coaptation splinting for 1 to 2 weeks (12 patients), hanging arm cast for 1 week (1 patient), and posterior splint for 1 week (1 patient). Patients were then transitioned to Sarmiento fracture bracing for the duration of their treatment (range, 5-12 months). One patient, followed initially at an outside institution, was managed in a sling throughout the duration of treatment (12 weeks) (Table 1). All 15 patients were neurovascularly intact at time of final clinical examination, with return of full upper extremity ROM in all but 3 patients. Only 1 of these 3 patients reported residual pain and functional limitations 4 months after injury (Table 2). Twelve patients were evaluated for return to work, with all successfully returning to work without restrictions at time of final follow-up. The 1 minor complication noted during the treatment period involved medial-sided elbow skin breakdown from brace wear, which resolved with local wound care. No patient required or requested surgical intervention for their residual malunion.

Of the 15 patients, 8 (53%) were reached for in-person examination (6 patients) or telephone interview (2 patients) for follow-up assessment by means of DASH form and self-reported questionnaire a mean of 47 months (range, 12-99 months) after initial injury. The 6 patients who had a physical examination were neurovascularly intact, lacked focal tenderness to palpation, and demonstrated full (5/5) strength within the deltoid, biceps, triceps, pronator, and supinator musculature. Each patient had equal ROM compared with the contralateral uninjured extremity on shoulder forward flexion and abduction, elbow flexion and extension, and forearm pronation and supination. Three patients (50%) had mild residual loss of ROM, with 2 demonstrating decreased shoulder external rotation of 10° and 15°, respectively, and 1 demonstrating decreased shoulder internal rotation of 10°.

Mean DASH score was 10.4 (range, 0-49.2). Evaluation of the self-reported questionnaire revealed a mean pain score of 1.1 (range, 0-7), with only 2 patients reporting any ongoing pain. In addition, 2 patients reported functional limitations, both related to overhead activities. However, 6 (75%) of the 8 patients reported noticeable cosmetic deformity, most commonly varus angulation (4 patients), as well as palpable bony prominence (2) and muscle atrophy (1). The majority of patients were satisfied with the outcome of their treatment (mean, 4; range, 2-5), with 6 patients reporting being satisfied or very satisfied, and all 6 indicating they would undergo nonoperative management again if presented with the same injury. Two patients reported being dissatisfied with their outcome, 1 because of cosmetic appearance and 1 because of cosmetic appearance and functional limitations. Both patients indicated they would choose operative management if presented with the same injury. There was no apparent relationship between outcome and degree of residual deformity, as both patients with varus angulation of more than 30° reported no residual pain or functional limitation and were very satisfied with the outcome of their treatment (Table 2).

Of the 7 patients who could not be reached for final follow-up, 2 on initial contact expressed overall satisfaction with their outcome and denied functional limitations. However, both asked to complete the study at a later date. Subsequently, these 2 patients could not be reached to complete the formal follow-up.

Discussion

Humeral shaft fractures are usually managed nonoperatively. One of the most commonly cited disadvantages of nonoperative management is its higher incidence of residual angular deformity, up to 13% in previous studies.⁴ Our study found a slightly higher incidence, 16%, on review of 91 nonoperatively managed humeral shaft fractures treated over an 11.5 year period. Although previous studies have reported acceptable functional and cosmetic outcomes with residual angular deformity of less than 20°,^2,3,5,8,9 only observational reports have suggested acceptable function in patients with a documented malunion.⁸

To our knowledge, ours is the first study to correlate malunion with functional parameters and subjective patient-reported outcomes. We found that malunion was not associated with significant pain or functional limitation after nonoperative management of humeral shaft fractures. Furthermore, 75% of patients were satisfied or very satisfied with the outcome of their treatment and indicated they would undergo nonoperative management if presented with the same injury again. However, 75% of patients reported a noticeable cosmetic deformity, and one-third of these patients cited it as a major reason for dissatisfaction with their overall outcome. Regarding function, all patients returned to full strength and ROM of the affected extremity, aside from small losses of internal or external shoulder rotation on the magnitude of 10° to 15° in 50% of those patients tested. In addition, 75% of patients returned to regular activity without functional limitations; the other 25% reported trouble with overhead activities. There were no significant complications during the treatment or follow-up period, once the fracture had healed.

The major limitation of this study was its small patient population. (Obtaining a larger series of patients with malunion after nonoperative treatment of humeral shaft fractures likely would require a multicenter study.) Some of our study findings, such as lack of correlation between degree of malunion and subsequent functional or subjective outcomes, would require a larger sample size for verification and more definitive conclusions. Another limitation is that the study was not designed to evaluate the cause of malunion. Therefore, we cannot draw any definitive conclusions regarding what may have contributed to the development of malunion in our study population. However, all our malunion patients were compliant with their treatment protocol, and they showed no significant difference in incidence of potential risk factors (eg, obesity, comorbidities) compared with the patients who healed without malunion.

Conclusion

Malunion after nonoperative management of humeral shaft fractures does not appear to result in significant pain, dissatisfaction, or functional limitation as measured on physical examination and with validated objective outcome measures in the majority of patients. Furthermore, no patients in this study required surgical intervention for any residual limitations or complications after malunion. The majority of patients reported a noticeable cosmetic deformity, which left a small subset of patients dissatisfied. Overall, our study findings can be used to help counsel patients before and during nonoperative management—particularly patients who appear to be healing with some malunion. Our findings suggest that operative intervention to prevent malunion is not necessary, as it likely would not result in any overall improvement in patient function or satisfaction, but patients should be counseled regarding the high likelihood of cosmetic deformity, which may or may not be bothersome.

Polymer matrix composite materials have been widely promoted for orthopedic use in a variety of settings, including surgical instruments, medical devices, implants, and bone models.^1-13 These types of composites are engineered from 2 or more constituent materials with significantly different physical or chemical properties; these materials remain separate and distinct on a macroscopic level within the finished composite structure. As a result of ongoing biomaterial research, polymer matrix composite materials can be engineered with a wide range of physical, mechanical, and surface properties, tailored to their application. Given their advantages (eg, high strength-to-weight ratio, radiolucency), these polymer matrix composite materials have gained popularity over traditional metallic materials.

Sterilization is an essential day-to-day procedure in the health care sector, both for single- and multiple-use devices or instruments, and thus a composite material used in medical components should remain unaffected by the process. The type of sterilization most commonly performed is steam sterilization, which achieves microbiological death by moist heat and pressure. Steam is created in an autoclave at a temperature of 132°C (270°F) in typical hospital settings. Steam sterilization cycles last 5 to 14 minutes based on specific manufacturer recommendations. Most medical-grade plastics used in health care have been designed and formulated to withstand the required sterilization cycles without sacrificing key properties. The structure integrity and overall performance of polymer matrix composites may be strongly influenced by the stability of the fiber/polymer interfacial region in terms of physical, chemical, and mechanical characteristics of the material at different scales.¹⁴ Absorption of moisture causes dilatational expansion and induces stresses, which are associated with the moisture-induced expansion resulting in degradation of structure stability.¹⁵ Thus, steam sterilization could affect the properties of the polymer matrix composite materials by excessive absorption of moisture by the polymer.

To our knowledge, no one has studied whether polymer matrix material properties degrade from long-term, repeated steam sterilization followed by mechanical loading. We conducted a study to evaluate the structural properties (short-beam strength, SBS) of several composite materials exposed to repeated sterilization as compared with traditional metal materials: SS-316L (stainless steel 316L) and Al-7075-T6 (aluminum 7075-T6).

Materials and Methods

We evaluated 3 types of composite materials: Tepex (Tepex Dynalite 201; HiPer Technology Inc.), CFR-PPS (carbon-fiber–reinforced polyphenylene sulfide, Cetex PPS; TenCate Advanced Composites USA Inc.), and HTN-53 (Zytel HTN53G50HSLR NC010; HiPer Technology Inc.) (Figure 1). Tepex is being used for orthopedic applications (knee braces, orthoses, insoles) and sporting goods applications. The performance of this material is superior to that of unreinforced thermoplastics. CFR-PPS represented the state of the art in composite materials for aerospace applications (eg, airframe structures, engine nacelles, fan casings, floorboards, interior parts). This is a high-performance material with exceptional high temperature and aggressive chemical resistance characteristics. CFR-PPS is also used to make filter fabric for coal boilers, papermaking felts, electrical insulation, specialty membranes, gaskets, and packing. It is not solubilized by any known solvents, even in long-term exposure, at temperatures up to 200°C. In addition, it exhibits exceptional resistance to organic and inorganic solutions, acids and alkali solutions, and a wide array of miscellaneous chemicals. HTN-53 is a 50% glass-reinforced, lubricated, high-performance polyamide resin with improved flow, developed for applications requiring excellent surface appearance with water-heated molds. This material has specifically shown survivability in hot, cold, chemically aggressive, and load-bearing environments. In addition, it has shown superior moisture and temperature resistance. These 3 composite materials were compared with SS-316L and Al-7075-T6. SS-316L is commonly used for implants in orthopedics, and Al-7075-T6 is a relatively radiolucent alternative for medical applications. Two different tests were performed to evaluate and validate these composite materials: (1) radiographic density evaluation and (2) structural property tests (short-beam load-to-failure [LTF] test, short-beam cyclic compression loading [CCL] test) before and after sterilization cycling.

Radiographic Density Evaluation

The radiographic density of the 5 materials was evaluated with radiographic images of a cadaveric knee specimen (Figure 2). Radiographic image intensification is the gold standard for repeated radiographic imaging in the operating room. Six different radiographic images were obtained for each material superimposed over a cadaveric knee to recreate potential instrument positioning during surgery: posterior to subject (1 piece), posterior to subject (2 pieces), anterior to subject (1 piece), anterior to subject (2 pieces), anterior and posterior to subject in alignment (1 piece), and anterior and posterior to subject in alignment (2 pieces). Image-Pro Plus software (Media Cybernetics) was used to measure the radiographic density of the materials from the grayscale of the images.

Structural Properties Testing Before and After Sterilization Cycling

We used a standard SBS testing method to determine whether any degradation of structural properties resulted from standard repeated sterilization. The material geometries of the test specimens were 18.96×6.50×3.37 mm (length × width × thickness). Standard sterilization procedures were performed with steam sterilization using an autoclave at a temperature of 132°C (270°F) for at least 5 minutes (range, 5-14 minutes). Sample interval testing ran at 0, 200, and 400 sterilization cycles for structural properties in terms of SBS and moisture retention, with the structural properties at the 0th sterilization cycle (material before sterilization was performed) used as a baseline for comparison. Materials were subjected to 400 sterilization cycles, which is representative of the number of sterilization cycles per year an instrument or device would be subjected to.

Three structural tests were performed for each sample interval: moisture retention, LTF, and CCL. Moisture retention was investigated before and after repeated sterilization by measuring the weight of the test materials, as steam sterilization is known to affect the amount of moisture that is absorbed by a material. Twelve specimens of each proposed material were weighed at each sample interval, with the structural weight at the 0th sterilization cycle (material before sterilization is performed) serving as a baseline for comparison.

SBS testing was based on the ASTM (American Society for Testing and Materials) D2344 standard¹⁶ for LTF and CCL tests (Figure 3). Six samples of material were used for each test at every sample interval, yielding 180 samples. Seven servohydraulic material testing system instruments (1 MTS 810 and 6 MTS 858 Mini Bionix) were used to test the SBS of each material. For LTF testing, each specimen was loaded in compression from 30 N to complete structural failure at a constant displacement rate of 1.0 mm/min (0.05 in/min). Testing was initiated with 5 preconditioning loading cycles from 30 to 100 N at 1 Hz. The load was then applied continuously until failure occurred; force and displacement data were collected every 0.02 second. This procedure was performed for 6 replicates for each sample interval for each test material.

The calculation for SBS, F_sbs (MPa), for the constant loading rate until structural failure is:

                            Fsbs = 0.75 ×   Pm
                                                b × h

where P_m (N) is the maximum applied load observed during the test, b is the measured specimen width (mm), and h is the measured specimen thickness (mm).

CCL testing consisted of each test material axially loaded with 100 to 500 N at a frequency of 1 Hz for 100,000 cycles. The maximum load of 500 N was chosen as a standard based on 80% of the minimum ultimate failure load from previous LTF tests. Displacement and force data were collected every 5 cycles at the maximum compressive load. Degradation of the material was calculated using the difference between the deflection of the initial cycle and the deflection of the final cycle (50th cycle and 100,000th cycle). This procedure was performed for 6 replicates for each sample interval for each test material.

Statistical Analysis

LTF and CCL testing data were analyzed for any differences among the test materials using 1-way analysis of variance with the least significant difference multiple comparisons post hoc test method using SPSS Version 16.0, with P < .05 denoting significance. These analyses were used to determine the statistical relevance of the difference between the SBS (LTF and CCL) of each test material. Means and standard deviations were calculated for all tests.

Results

Radiographic Density Evaluation

Overall, all the tested composite materials were significantly more radiolucent than either SS-316L or Al-7075-T6. Figure 4 shows the 6 different radiographic images obtained for each material superimposed over a cadaveric knee to recreate potential instrument positioning during surgery: posterior to subject (1 piece), posterior to subject (2 pieces), anterior to subject (1 piece), anterior to subject (2 pieces), anterior and posterior to subject in alignment (1 piece), and anterior and posterior to subject in alignment (2 pieces). SS-316L can be considered radiopaque, and Al-7075-T6 has been used as a relatively radiolucent alternative. Tepex was statistically more radiolucent than the other 2 tested composite materials (Table 1). Even with 2 pieces placed anterior to the subject and 2 placed posterior, the radiodensity compared to the cortical bone was still lower than 1 piece of Al-7075-T6 either anterior or posterior to the subject.

Structural Properties Testing

Moisture Retention. Moisture retention was evaluated by weighing the test materials before and after repeated sterilization. There was no significant difference in moisture retention, as weight differences for all the tested materials were less than 0.5 weight percentage compared to the 0th sterilization cycle (Table 2). Therefore, the results of this study showed that all the tested materials exhibited good moisture/temperature resistance after 400 sterilization cycles.

Load to Failure. In the LTF test, significant differences were detected in SBS between all 5 tested materials (P < .05). Figure 5 shows the comparison of the structural properties in terms of SBS between the 5 tested materials, and Figure 6 shows the failure modes for the tested materials. There was no SBS for SS-316L, as the material did not exhibit complete structural failure even after 400 sterilization cycles; however, SS-316L was observed in inelastic deformation failure (Figure 6D). Al-7075-T6 had much higher SBS compared with the other composite materials, and it also resulted in an inelastic deformation failure mode only after 400 sterilization cycles; otherwise, flexure failure modes were observed. Tepex and CFR-PPS exhibited interlaminar shear failure, and HTN-53 exhibited complete structural failure.

Every composite material tested using the short-beam test for LTF showed a decrease in SBS with increased sterilization cycles (Figure 5). This decrease ranged from 17% to 57% compared with the 0th sterilization cycle. SBS was higher for CFR-PPS than for the other 2 composites. No statistically significant difference was found between CFR-PPS and Tepex except at the 200th sterilization cycle. HTN-53 was brittle at the 0th sterilization cycle but performed more like a ductile material at the 200th cycle. In addition, HTN-53 had the lowest SBS in terms of LTF testing when compared with the other 2 composites.

During the complete structural failure test, the failure modes for Tepex and CFR-PPS were visually identified as interlaminar shear failure (Figures 6A, 6B), whereas HTN-53 visually exhibited pure flexure failure (Figure 6C). As for the metals, SS-316L exhibited plastic deformation, and Al-7075-T6 exhibited flexure failure (Figures 6D, 6E).

Cyclic Compression Loading. Tepex was the only material to pass the 100,000 loading cycle without failure (Table 3). HTN-53 had the poorest performance of all: Its failure rates were 33% (2/6 samples) before sterilization (average cycle, 22,213; range, 21,500-22,925), 83% (5/6 samples) at the 200th sterilization cycle (average cycle, 4,210; range, 0-14,360), and 100% after 400 sterilization cycles (average cycle, 12,725; range, 1,190-21,900). CFR-PPS had no failures before the 400th sterilization cycle, and its failure rate after 400 sterilization cycles (average cycle, 50,735; range, 50,270-51,200) was 33% (2/6 samples).

Discussion

The success of a reusable composite material for use in orthopedic surgery depends not only on radiographic density, fabrication methods, and design but also on the ability to withstand repeated sterilization. Over the past 3 decades, investigators have explored several high-performance polymer matrix composite materials for use in orthopedics, especially in trauma, hip stems, and spinal implants.^1,3,4,17-34 According to Evans and Gregson,³⁵ composite materials have been widely promoted as possible orthopedic biomaterials but to date have found few successful commercial applications, because of the many challenging problems encountered in fabrication and testing. One of the most important factors in the mechanical properties of many composite materials is the influence of the cooling and loading rates on fiber-matrix interface adhesion.^36-38 Our results tended to agree with the findings of Evans and Gregson,³⁵ as some of these composite materials did not withstand repeated sterilizations well.

Guan and colleagues³⁹ evaluated the influence of sterilization treatment on continuous carbon-fiber–reinforced polyolefin composite. Their 3-point bending test results showed that the levels of maximum load of all the specimens undergoing sterilization by autoclave were lower than those of the control group. For these composites, they concluded that autoclave sterilization and Co-60 gamma ray irradiation sterilization should be avoided and that ethylene oxide is the best method. Our results support their findings with a different set of composites.

Although HTN-53 has shown promise in other orthopedic applications because of its superior moisture and temperature resistance, we found that its performance after repeated sterilization was relatively poor. Tepex showed the greatest potential for durability after repeated sterilization; its mechanical properties were stable after 200 steam sterilization cycles.

Clinical Applications

The composite materials investigated in the present study have potential for use in either instrumentation or long-term implantation applications because of their versatility, mechanical strength, fatigue resistance, and biocompatibility. Akay and Aslan⁴⁰ stated that carbon-fiber–filled composite implants can be designed with more appropriate modulus, strength, toughness, or stiffness by the arrangement of reinforcing fiber volume and orientation, and can provide better fatigue resistance. A notable advantage of using a composite plate with metal screws is that the potential for corrosion of metallic components is eliminated. Another major advantage of composite medical implants (eg, DiPhos-RM) is radiolucency, which allows direct visualization of osseous callus formation as well as monitoring of fracture healing, thereby improving clinical assessment and accuracy.

Numerous studies have documented the successful clinical performance of composite materials in orthopedic, trauma, and spinal surgery applications.^41-45 Bagheri and colleagues⁴¹ developed a new carbon fiber–flax–epoxy composite plate and biomechanically compared it with a standard clinical metal plate. Their results confirmed that the carbon fiber–flax–epoxy material represents a potential candidate for bone fracture plate applications, as it can simultaneously provide similar mechanical stiffness and lower stress shielding (higher bone stress) compared with a standard clinical metal bone plate. Tarallo and colleagues⁴⁵ evaluated the clinical results of 40 cases at 12-month follow-up using a new plate made of carbon-fiber–reinforced polyetheretherketon (DiPhos-RM, Lima Corporate) for the treatment of distal radius fractures. They reported good clinical results for this device at early follow-up, and its use allowed maintenance of reduction in complex AO (Arbeitsgemeinschaft für Osteosynthesefragen) fractures.

The main advantage in using composites for surgical instruments is their radiolucency. These materials do not obscure images or radiographs during fluoroscopic visualization. Surgery often requires fluoroscopic visualization of internal organs or bones, which may require temporary removal of radiopaque devices (eg, retractors, clamps, forceps, hooks, distractors). Aside from being inconvenient, removal and subsequent reinsertion consume valuable time and interfere with the smooth flow of an operation.

The shortcomings of using composite materials for surgical instruments involve detectability and sterilization. A significant issue in surgery is the accidental leaving behind of instruments in patients, which can cause serious problems ranging from organ perforation and blood infection to death. Although instrument counting and other safety protocols can reduce the risk of overlooking an instrument, mistakes are bound to happen. The other shortcoming is the influence of repeated sterilization on the mechanical properties of the composite materials, as sterilization is mandatory for surgical instruments used in the operation room. The structural integrity and overall performance of the polymer composite materials—especially the stability of the interface and the interphase zones—are strongly influenced by repeated sterilization.

On the other hand, composite materials have potential advantages that may support their introduction into long-term medical implant applications, as sterilization commonly is performed only once, during packaging. The effects of sterilization by radiation or steam are much less pronounced on composite implants than on composite surgical instruments. However, composite implants require careful consideration with respect to the bioactivity of wear particles that may be produced from articulation. Further, carbon-fiber–reinforced polymer implants are still substantially more difficult to manufacture and more costly than their metallic counterparts.⁴⁶

Limitations

This study has some limitations. Most important, studies of this nature do not account for biological factors such as corrosion, biological wear, and the soft-tissue attachment effects on structural properties for potential in vivo use. Another limitation was that the study tested only the mechanical properties in terms of SBS and provided no information about other mechanical properties, such as tensile, compression, and torsion strengths. We think SBS testing adequately evaluates challenging scenarios like thin and narrow instruments/devices that are anticipated in application, and information regarding other modes of failure and mechanical properties (compression, tension, torsion) would be a further area of research. An additional limitation was that our model used a relatively small number of samples. A larger study with more samples and varying layout patterns and layers of the carbon fibers may more clearly demonstrate the effect of steam sterilization on composite materials.

Conclusion

This study provided new information on 3 selected composite materials and their structural properties after repeated steam sterilization. We discovered that these composites were similar in radiographic density and water retention but behaved very differently in terms of mechanical durability after repeated steam sterilization. All selected composites demonstrated deterioration of mechanical properties after repeated steam sterilization. Knowing these results could aid in making decisions about the design and manufacturing of operative instruments and orthopedic biomaterials. Although our preliminary findings are intriguing, further study is warranted to seek specific applications for these composite materials in orthopedic surgery.

Polymer matrix composite materials have been widely promoted for orthopedic use in a variety of settings, including surgical instruments, medical devices, implants, and bone models.^1-13 These types of composites are engineered from 2 or more constituent materials with significantly different physical or chemical properties; these materials remain separate and distinct on a macroscopic level within the finished composite structure. As a result of ongoing biomaterial research, polymer matrix composite materials can be engineered with a wide range of physical, mechanical, and surface properties, tailored to their application. Given their advantages (eg, high strength-to-weight ratio, radiolucency), these polymer matrix composite materials have gained popularity over traditional metallic materials.

Sterilization is an essential day-to-day procedure in the health care sector, both for single- and multiple-use devices or instruments, and thus a composite material used in medical components should remain unaffected by the process. The type of sterilization most commonly performed is steam sterilization, which achieves microbiological death by moist heat and pressure. Steam is created in an autoclave at a temperature of 132°C (270°F) in typical hospital settings. Steam sterilization cycles last 5 to 14 minutes based on specific manufacturer recommendations. Most medical-grade plastics used in health care have been designed and formulated to withstand the required sterilization cycles without sacrificing key properties. The structure integrity and overall performance of polymer matrix composites may be strongly influenced by the stability of the fiber/polymer interfacial region in terms of physical, chemical, and mechanical characteristics of the material at different scales.¹⁴ Absorption of moisture causes dilatational expansion and induces stresses, which are associated with the moisture-induced expansion resulting in degradation of structure stability.¹⁵ Thus, steam sterilization could affect the properties of the polymer matrix composite materials by excessive absorption of moisture by the polymer.

To our knowledge, no one has studied whether polymer matrix material properties degrade from long-term, repeated steam sterilization followed by mechanical loading. We conducted a study to evaluate the structural properties (short-beam strength, SBS) of several composite materials exposed to repeated sterilization as compared with traditional metal materials: SS-316L (stainless steel 316L) and Al-7075-T6 (aluminum 7075-T6).

Materials and Methods

We evaluated 3 types of composite materials: Tepex (Tepex Dynalite 201; HiPer Technology Inc.), CFR-PPS (carbon-fiber–reinforced polyphenylene sulfide, Cetex PPS; TenCate Advanced Composites USA Inc.), and HTN-53 (Zytel HTN53G50HSLR NC010; HiPer Technology Inc.) (Figure 1). Tepex is being used for orthopedic applications (knee braces, orthoses, insoles) and sporting goods applications. The performance of this material is superior to that of unreinforced thermoplastics. CFR-PPS represented the state of the art in composite materials for aerospace applications (eg, airframe structures, engine nacelles, fan casings, floorboards, interior parts). This is a high-performance material with exceptional high temperature and aggressive chemical resistance characteristics. CFR-PPS is also used to make filter fabric for coal boilers, papermaking felts, electrical insulation, specialty membranes, gaskets, and packing. It is not solubilized by any known solvents, even in long-term exposure, at temperatures up to 200°C. In addition, it exhibits exceptional resistance to organic and inorganic solutions, acids and alkali solutions, and a wide array of miscellaneous chemicals. HTN-53 is a 50% glass-reinforced, lubricated, high-performance polyamide resin with improved flow, developed for applications requiring excellent surface appearance with water-heated molds. This material has specifically shown survivability in hot, cold, chemically aggressive, and load-bearing environments. In addition, it has shown superior moisture and temperature resistance. These 3 composite materials were compared with SS-316L and Al-7075-T6. SS-316L is commonly used for implants in orthopedics, and Al-7075-T6 is a relatively radiolucent alternative for medical applications. Two different tests were performed to evaluate and validate these composite materials: (1) radiographic density evaluation and (2) structural property tests (short-beam load-to-failure [LTF] test, short-beam cyclic compression loading [CCL] test) before and after sterilization cycling.

Radiographic Density Evaluation

The radiographic density of the 5 materials was evaluated with radiographic images of a cadaveric knee specimen (Figure 2). Radiographic image intensification is the gold standard for repeated radiographic imaging in the operating room. Six different radiographic images were obtained for each material superimposed over a cadaveric knee to recreate potential instrument positioning during surgery: posterior to subject (1 piece), posterior to subject (2 pieces), anterior to subject (1 piece), anterior to subject (2 pieces), anterior and posterior to subject in alignment (1 piece), and anterior and posterior to subject in alignment (2 pieces). Image-Pro Plus software (Media Cybernetics) was used to measure the radiographic density of the materials from the grayscale of the images.

Structural Properties Testing Before and After Sterilization Cycling

We used a standard SBS testing method to determine whether any degradation of structural properties resulted from standard repeated sterilization. The material geometries of the test specimens were 18.96×6.50×3.37 mm (length × width × thickness). Standard sterilization procedures were performed with steam sterilization using an autoclave at a temperature of 132°C (270°F) for at least 5 minutes (range, 5-14 minutes). Sample interval testing ran at 0, 200, and 400 sterilization cycles for structural properties in terms of SBS and moisture retention, with the structural properties at the 0th sterilization cycle (material before sterilization was performed) used as a baseline for comparison. Materials were subjected to 400 sterilization cycles, which is representative of the number of sterilization cycles per year an instrument or device would be subjected to.

Three structural tests were performed for each sample interval: moisture retention, LTF, and CCL. Moisture retention was investigated before and after repeated sterilization by measuring the weight of the test materials, as steam sterilization is known to affect the amount of moisture that is absorbed by a material. Twelve specimens of each proposed material were weighed at each sample interval, with the structural weight at the 0th sterilization cycle (material before sterilization is performed) serving as a baseline for comparison.

SBS testing was based on the ASTM (American Society for Testing and Materials) D2344 standard¹⁶ for LTF and CCL tests (Figure 3). Six samples of material were used for each test at every sample interval, yielding 180 samples. Seven servohydraulic material testing system instruments (1 MTS 810 and 6 MTS 858 Mini Bionix) were used to test the SBS of each material. For LTF testing, each specimen was loaded in compression from 30 N to complete structural failure at a constant displacement rate of 1.0 mm/min (0.05 in/min). Testing was initiated with 5 preconditioning loading cycles from 30 to 100 N at 1 Hz. The load was then applied continuously until failure occurred; force and displacement data were collected every 0.02 second. This procedure was performed for 6 replicates for each sample interval for each test material.

The calculation for SBS, F_sbs (MPa), for the constant loading rate until structural failure is:

                            Fsbs = 0.75 ×   Pm
                                                b × h

where P_m (N) is the maximum applied load observed during the test, b is the measured specimen width (mm), and h is the measured specimen thickness (mm).

CCL testing consisted of each test material axially loaded with 100 to 500 N at a frequency of 1 Hz for 100,000 cycles. The maximum load of 500 N was chosen as a standard based on 80% of the minimum ultimate failure load from previous LTF tests. Displacement and force data were collected every 5 cycles at the maximum compressive load. Degradation of the material was calculated using the difference between the deflection of the initial cycle and the deflection of the final cycle (50th cycle and 100,000th cycle). This procedure was performed for 6 replicates for each sample interval for each test material.

Statistical Analysis

LTF and CCL testing data were analyzed for any differences among the test materials using 1-way analysis of variance with the least significant difference multiple comparisons post hoc test method using SPSS Version 16.0, with P < .05 denoting significance. These analyses were used to determine the statistical relevance of the difference between the SBS (LTF and CCL) of each test material. Means and standard deviations were calculated for all tests.

Results

Radiographic Density Evaluation

Overall, all the tested composite materials were significantly more radiolucent than either SS-316L or Al-7075-T6. Figure 4 shows the 6 different radiographic images obtained for each material superimposed over a cadaveric knee to recreate potential instrument positioning during surgery: posterior to subject (1 piece), posterior to subject (2 pieces), anterior to subject (1 piece), anterior to subject (2 pieces), anterior and posterior to subject in alignment (1 piece), and anterior and posterior to subject in alignment (2 pieces). SS-316L can be considered radiopaque, and Al-7075-T6 has been used as a relatively radiolucent alternative. Tepex was statistically more radiolucent than the other 2 tested composite materials (Table 1). Even with 2 pieces placed anterior to the subject and 2 placed posterior, the radiodensity compared to the cortical bone was still lower than 1 piece of Al-7075-T6 either anterior or posterior to the subject.

Structural Properties Testing

Moisture Retention. Moisture retention was evaluated by weighing the test materials before and after repeated sterilization. There was no significant difference in moisture retention, as weight differences for all the tested materials were less than 0.5 weight percentage compared to the 0th sterilization cycle (Table 2). Therefore, the results of this study showed that all the tested materials exhibited good moisture/temperature resistance after 400 sterilization cycles.

Load to Failure. In the LTF test, significant differences were detected in SBS between all 5 tested materials (P < .05). Figure 5 shows the comparison of the structural properties in terms of SBS between the 5 tested materials, and Figure 6 shows the failure modes for the tested materials. There was no SBS for SS-316L, as the material did not exhibit complete structural failure even after 400 sterilization cycles; however, SS-316L was observed in inelastic deformation failure (Figure 6D). Al-7075-T6 had much higher SBS compared with the other composite materials, and it also resulted in an inelastic deformation failure mode only after 400 sterilization cycles; otherwise, flexure failure modes were observed. Tepex and CFR-PPS exhibited interlaminar shear failure, and HTN-53 exhibited complete structural failure.

Every composite material tested using the short-beam test for LTF showed a decrease in SBS with increased sterilization cycles (Figure 5). This decrease ranged from 17% to 57% compared with the 0th sterilization cycle. SBS was higher for CFR-PPS than for the other 2 composites. No statistically significant difference was found between CFR-PPS and Tepex except at the 200th sterilization cycle. HTN-53 was brittle at the 0th sterilization cycle but performed more like a ductile material at the 200th cycle. In addition, HTN-53 had the lowest SBS in terms of LTF testing when compared with the other 2 composites.

During the complete structural failure test, the failure modes for Tepex and CFR-PPS were visually identified as interlaminar shear failure (Figures 6A, 6B), whereas HTN-53 visually exhibited pure flexure failure (Figure 6C). As for the metals, SS-316L exhibited plastic deformation, and Al-7075-T6 exhibited flexure failure (Figures 6D, 6E).

Cyclic Compression Loading. Tepex was the only material to pass the 100,000 loading cycle without failure (Table 3). HTN-53 had the poorest performance of all: Its failure rates were 33% (2/6 samples) before sterilization (average cycle, 22,213; range, 21,500-22,925), 83% (5/6 samples) at the 200th sterilization cycle (average cycle, 4,210; range, 0-14,360), and 100% after 400 sterilization cycles (average cycle, 12,725; range, 1,190-21,900). CFR-PPS had no failures before the 400th sterilization cycle, and its failure rate after 400 sterilization cycles (average cycle, 50,735; range, 50,270-51,200) was 33% (2/6 samples).

Discussion

The success of a reusable composite material for use in orthopedic surgery depends not only on radiographic density, fabrication methods, and design but also on the ability to withstand repeated sterilization. Over the past 3 decades, investigators have explored several high-performance polymer matrix composite materials for use in orthopedics, especially in trauma, hip stems, and spinal implants.^1,3,4,17-34 According to Evans and Gregson,³⁵ composite materials have been widely promoted as possible orthopedic biomaterials but to date have found few successful commercial applications, because of the many challenging problems encountered in fabrication and testing. One of the most important factors in the mechanical properties of many composite materials is the influence of the cooling and loading rates on fiber-matrix interface adhesion.^36-38 Our results tended to agree with the findings of Evans and Gregson,³⁵ as some of these composite materials did not withstand repeated sterilizations well.

Guan and colleagues³⁹ evaluated the influence of sterilization treatment on continuous carbon-fiber–reinforced polyolefin composite. Their 3-point bending test results showed that the levels of maximum load of all the specimens undergoing sterilization by autoclave were lower than those of the control group. For these composites, they concluded that autoclave sterilization and Co-60 gamma ray irradiation sterilization should be avoided and that ethylene oxide is the best method. Our results support their findings with a different set of composites.

Although HTN-53 has shown promise in other orthopedic applications because of its superior moisture and temperature resistance, we found that its performance after repeated sterilization was relatively poor. Tepex showed the greatest potential for durability after repeated sterilization; its mechanical properties were stable after 200 steam sterilization cycles.

Clinical Applications

The composite materials investigated in the present study have potential for use in either instrumentation or long-term implantation applications because of their versatility, mechanical strength, fatigue resistance, and biocompatibility. Akay and Aslan⁴⁰ stated that carbon-fiber–filled composite implants can be designed with more appropriate modulus, strength, toughness, or stiffness by the arrangement of reinforcing fiber volume and orientation, and can provide better fatigue resistance. A notable advantage of using a composite plate with metal screws is that the potential for corrosion of metallic components is eliminated. Another major advantage of composite medical implants (eg, DiPhos-RM) is radiolucency, which allows direct visualization of osseous callus formation as well as monitoring of fracture healing, thereby improving clinical assessment and accuracy.

Numerous studies have documented the successful clinical performance of composite materials in orthopedic, trauma, and spinal surgery applications.^41-45 Bagheri and colleagues⁴¹ developed a new carbon fiber–flax–epoxy composite plate and biomechanically compared it with a standard clinical metal plate. Their results confirmed that the carbon fiber–flax–epoxy material represents a potential candidate for bone fracture plate applications, as it can simultaneously provide similar mechanical stiffness and lower stress shielding (higher bone stress) compared with a standard clinical metal bone plate. Tarallo and colleagues⁴⁵ evaluated the clinical results of 40 cases at 12-month follow-up using a new plate made of carbon-fiber–reinforced polyetheretherketon (DiPhos-RM, Lima Corporate) for the treatment of distal radius fractures. They reported good clinical results for this device at early follow-up, and its use allowed maintenance of reduction in complex AO (Arbeitsgemeinschaft für Osteosynthesefragen) fractures.

The main advantage in using composites for surgical instruments is their radiolucency. These materials do not obscure images or radiographs during fluoroscopic visualization. Surgery often requires fluoroscopic visualization of internal organs or bones, which may require temporary removal of radiopaque devices (eg, retractors, clamps, forceps, hooks, distractors). Aside from being inconvenient, removal and subsequent reinsertion consume valuable time and interfere with the smooth flow of an operation.

The shortcomings of using composite materials for surgical instruments involve detectability and sterilization. A significant issue in surgery is the accidental leaving behind of instruments in patients, which can cause serious problems ranging from organ perforation and blood infection to death. Although instrument counting and other safety protocols can reduce the risk of overlooking an instrument, mistakes are bound to happen. The other shortcoming is the influence of repeated sterilization on the mechanical properties of the composite materials, as sterilization is mandatory for surgical instruments used in the operation room. The structural integrity and overall performance of the polymer composite materials—especially the stability of the interface and the interphase zones—are strongly influenced by repeated sterilization.

On the other hand, composite materials have potential advantages that may support their introduction into long-term medical implant applications, as sterilization commonly is performed only once, during packaging. The effects of sterilization by radiation or steam are much less pronounced on composite implants than on composite surgical instruments. However, composite implants require careful consideration with respect to the bioactivity of wear particles that may be produced from articulation. Further, carbon-fiber–reinforced polymer implants are still substantially more difficult to manufacture and more costly than their metallic counterparts.⁴⁶

Limitations

This study has some limitations. Most important, studies of this nature do not account for biological factors such as corrosion, biological wear, and the soft-tissue attachment effects on structural properties for potential in vivo use. Another limitation was that the study tested only the mechanical properties in terms of SBS and provided no information about other mechanical properties, such as tensile, compression, and torsion strengths. We think SBS testing adequately evaluates challenging scenarios like thin and narrow instruments/devices that are anticipated in application, and information regarding other modes of failure and mechanical properties (compression, tension, torsion) would be a further area of research. An additional limitation was that our model used a relatively small number of samples. A larger study with more samples and varying layout patterns and layers of the carbon fibers may more clearly demonstrate the effect of steam sterilization on composite materials.

Conclusion

This study provided new information on 3 selected composite materials and their structural properties after repeated steam sterilization. We discovered that these composites were similar in radiographic density and water retention but behaved very differently in terms of mechanical durability after repeated steam sterilization. All selected composites demonstrated deterioration of mechanical properties after repeated steam sterilization. Knowing these results could aid in making decisions about the design and manufacturing of operative instruments and orthopedic biomaterials. Although our preliminary findings are intriguing, further study is warranted to seek specific applications for these composite materials in orthopedic surgery.

Polymer matrix composite materials have been widely promoted for orthopedic use in a variety of settings, including surgical instruments, medical devices, implants, and bone models.^1-13 These types of composites are engineered from 2 or more constituent materials with significantly different physical or chemical properties; these materials remain separate and distinct on a macroscopic level within the finished composite structure. As a result of ongoing biomaterial research, polymer matrix composite materials can be engineered with a wide range of physical, mechanical, and surface properties, tailored to their application. Given their advantages (eg, high strength-to-weight ratio, radiolucency), these polymer matrix composite materials have gained popularity over traditional metallic materials.

Sterilization is an essential day-to-day procedure in the health care sector, both for single- and multiple-use devices or instruments, and thus a composite material used in medical components should remain unaffected by the process. The type of sterilization most commonly performed is steam sterilization, which achieves microbiological death by moist heat and pressure. Steam is created in an autoclave at a temperature of 132°C (270°F) in typical hospital settings. Steam sterilization cycles last 5 to 14 minutes based on specific manufacturer recommendations. Most medical-grade plastics used in health care have been designed and formulated to withstand the required sterilization cycles without sacrificing key properties. The structure integrity and overall performance of polymer matrix composites may be strongly influenced by the stability of the fiber/polymer interfacial region in terms of physical, chemical, and mechanical characteristics of the material at different scales.¹⁴ Absorption of moisture causes dilatational expansion and induces stresses, which are associated with the moisture-induced expansion resulting in degradation of structure stability.¹⁵ Thus, steam sterilization could affect the properties of the polymer matrix composite materials by excessive absorption of moisture by the polymer.

To our knowledge, no one has studied whether polymer matrix material properties degrade from long-term, repeated steam sterilization followed by mechanical loading. We conducted a study to evaluate the structural properties (short-beam strength, SBS) of several composite materials exposed to repeated sterilization as compared with traditional metal materials: SS-316L (stainless steel 316L) and Al-7075-T6 (aluminum 7075-T6).

Materials and Methods

We evaluated 3 types of composite materials: Tepex (Tepex Dynalite 201; HiPer Technology Inc.), CFR-PPS (carbon-fiber–reinforced polyphenylene sulfide, Cetex PPS; TenCate Advanced Composites USA Inc.), and HTN-53 (Zytel HTN53G50HSLR NC010; HiPer Technology Inc.) (Figure 1). Tepex is being used for orthopedic applications (knee braces, orthoses, insoles) and sporting goods applications. The performance of this material is superior to that of unreinforced thermoplastics. CFR-PPS represented the state of the art in composite materials for aerospace applications (eg, airframe structures, engine nacelles, fan casings, floorboards, interior parts). This is a high-performance material with exceptional high temperature and aggressive chemical resistance characteristics. CFR-PPS is also used to make filter fabric for coal boilers, papermaking felts, electrical insulation, specialty membranes, gaskets, and packing. It is not solubilized by any known solvents, even in long-term exposure, at temperatures up to 200°C. In addition, it exhibits exceptional resistance to organic and inorganic solutions, acids and alkali solutions, and a wide array of miscellaneous chemicals. HTN-53 is a 50% glass-reinforced, lubricated, high-performance polyamide resin with improved flow, developed for applications requiring excellent surface appearance with water-heated molds. This material has specifically shown survivability in hot, cold, chemically aggressive, and load-bearing environments. In addition, it has shown superior moisture and temperature resistance. These 3 composite materials were compared with SS-316L and Al-7075-T6. SS-316L is commonly used for implants in orthopedics, and Al-7075-T6 is a relatively radiolucent alternative for medical applications. Two different tests were performed to evaluate and validate these composite materials: (1) radiographic density evaluation and (2) structural property tests (short-beam load-to-failure [LTF] test, short-beam cyclic compression loading [CCL] test) before and after sterilization cycling.

Radiographic Density Evaluation

The radiographic density of the 5 materials was evaluated with radiographic images of a cadaveric knee specimen (Figure 2). Radiographic image intensification is the gold standard for repeated radiographic imaging in the operating room. Six different radiographic images were obtained for each material superimposed over a cadaveric knee to recreate potential instrument positioning during surgery: posterior to subject (1 piece), posterior to subject (2 pieces), anterior to subject (1 piece), anterior to subject (2 pieces), anterior and posterior to subject in alignment (1 piece), and anterior and posterior to subject in alignment (2 pieces). Image-Pro Plus software (Media Cybernetics) was used to measure the radiographic density of the materials from the grayscale of the images.

Structural Properties Testing Before and After Sterilization Cycling

We used a standard SBS testing method to determine whether any degradation of structural properties resulted from standard repeated sterilization. The material geometries of the test specimens were 18.96×6.50×3.37 mm (length × width × thickness). Standard sterilization procedures were performed with steam sterilization using an autoclave at a temperature of 132°C (270°F) for at least 5 minutes (range, 5-14 minutes). Sample interval testing ran at 0, 200, and 400 sterilization cycles for structural properties in terms of SBS and moisture retention, with the structural properties at the 0th sterilization cycle (material before sterilization was performed) used as a baseline for comparison. Materials were subjected to 400 sterilization cycles, which is representative of the number of sterilization cycles per year an instrument or device would be subjected to.

Three structural tests were performed for each sample interval: moisture retention, LTF, and CCL. Moisture retention was investigated before and after repeated sterilization by measuring the weight of the test materials, as steam sterilization is known to affect the amount of moisture that is absorbed by a material. Twelve specimens of each proposed material were weighed at each sample interval, with the structural weight at the 0th sterilization cycle (material before sterilization is performed) serving as a baseline for comparison.

SBS testing was based on the ASTM (American Society for Testing and Materials) D2344 standard¹⁶ for LTF and CCL tests (Figure 3). Six samples of material were used for each test at every sample interval, yielding 180 samples. Seven servohydraulic material testing system instruments (1 MTS 810 and 6 MTS 858 Mini Bionix) were used to test the SBS of each material. For LTF testing, each specimen was loaded in compression from 30 N to complete structural failure at a constant displacement rate of 1.0 mm/min (0.05 in/min). Testing was initiated with 5 preconditioning loading cycles from 30 to 100 N at 1 Hz. The load was then applied continuously until failure occurred; force and displacement data were collected every 0.02 second. This procedure was performed for 6 replicates for each sample interval for each test material.

The calculation for SBS, F_sbs (MPa), for the constant loading rate until structural failure is:

                            Fsbs = 0.75 ×   Pm
                                                b × h

where P_m (N) is the maximum applied load observed during the test, b is the measured specimen width (mm), and h is the measured specimen thickness (mm).

CCL testing consisted of each test material axially loaded with 100 to 500 N at a frequency of 1 Hz for 100,000 cycles. The maximum load of 500 N was chosen as a standard based on 80% of the minimum ultimate failure load from previous LTF tests. Displacement and force data were collected every 5 cycles at the maximum compressive load. Degradation of the material was calculated using the difference between the deflection of the initial cycle and the deflection of the final cycle (50th cycle and 100,000th cycle). This procedure was performed for 6 replicates for each sample interval for each test material.

Statistical Analysis

LTF and CCL testing data were analyzed for any differences among the test materials using 1-way analysis of variance with the least significant difference multiple comparisons post hoc test method using SPSS Version 16.0, with P < .05 denoting significance. These analyses were used to determine the statistical relevance of the difference between the SBS (LTF and CCL) of each test material. Means and standard deviations were calculated for all tests.

Results

Radiographic Density Evaluation

Overall, all the tested composite materials were significantly more radiolucent than either SS-316L or Al-7075-T6. Figure 4 shows the 6 different radiographic images obtained for each material superimposed over a cadaveric knee to recreate potential instrument positioning during surgery: posterior to subject (1 piece), posterior to subject (2 pieces), anterior to subject (1 piece), anterior to subject (2 pieces), anterior and posterior to subject in alignment (1 piece), and anterior and posterior to subject in alignment (2 pieces). SS-316L can be considered radiopaque, and Al-7075-T6 has been used as a relatively radiolucent alternative. Tepex was statistically more radiolucent than the other 2 tested composite materials (Table 1). Even with 2 pieces placed anterior to the subject and 2 placed posterior, the radiodensity compared to the cortical bone was still lower than 1 piece of Al-7075-T6 either anterior or posterior to the subject.

Structural Properties Testing

Moisture Retention. Moisture retention was evaluated by weighing the test materials before and after repeated sterilization. There was no significant difference in moisture retention, as weight differences for all the tested materials were less than 0.5 weight percentage compared to the 0th sterilization cycle (Table 2). Therefore, the results of this study showed that all the tested materials exhibited good moisture/temperature resistance after 400 sterilization cycles.

Load to Failure. In the LTF test, significant differences were detected in SBS between all 5 tested materials (P < .05). Figure 5 shows the comparison of the structural properties in terms of SBS between the 5 tested materials, and Figure 6 shows the failure modes for the tested materials. There was no SBS for SS-316L, as the material did not exhibit complete structural failure even after 400 sterilization cycles; however, SS-316L was observed in inelastic deformation failure (Figure 6D). Al-7075-T6 had much higher SBS compared with the other composite materials, and it also resulted in an inelastic deformation failure mode only after 400 sterilization cycles; otherwise, flexure failure modes were observed. Tepex and CFR-PPS exhibited interlaminar shear failure, and HTN-53 exhibited complete structural failure.

Every composite material tested using the short-beam test for LTF showed a decrease in SBS with increased sterilization cycles (Figure 5). This decrease ranged from 17% to 57% compared with the 0th sterilization cycle. SBS was higher for CFR-PPS than for the other 2 composites. No statistically significant difference was found between CFR-PPS and Tepex except at the 200th sterilization cycle. HTN-53 was brittle at the 0th sterilization cycle but performed more like a ductile material at the 200th cycle. In addition, HTN-53 had the lowest SBS in terms of LTF testing when compared with the other 2 composites.

During the complete structural failure test, the failure modes for Tepex and CFR-PPS were visually identified as interlaminar shear failure (Figures 6A, 6B), whereas HTN-53 visually exhibited pure flexure failure (Figure 6C). As for the metals, SS-316L exhibited plastic deformation, and Al-7075-T6 exhibited flexure failure (Figures 6D, 6E).

Cyclic Compression Loading. Tepex was the only material to pass the 100,000 loading cycle without failure (Table 3). HTN-53 had the poorest performance of all: Its failure rates were 33% (2/6 samples) before sterilization (average cycle, 22,213; range, 21,500-22,925), 83% (5/6 samples) at the 200th sterilization cycle (average cycle, 4,210; range, 0-14,360), and 100% after 400 sterilization cycles (average cycle, 12,725; range, 1,190-21,900). CFR-PPS had no failures before the 400th sterilization cycle, and its failure rate after 400 sterilization cycles (average cycle, 50,735; range, 50,270-51,200) was 33% (2/6 samples).

Discussion

The success of a reusable composite material for use in orthopedic surgery depends not only on radiographic density, fabrication methods, and design but also on the ability to withstand repeated sterilization. Over the past 3 decades, investigators have explored several high-performance polymer matrix composite materials for use in orthopedics, especially in trauma, hip stems, and spinal implants.^1,3,4,17-34 According to Evans and Gregson,³⁵ composite materials have been widely promoted as possible orthopedic biomaterials but to date have found few successful commercial applications, because of the many challenging problems encountered in fabrication and testing. One of the most important factors in the mechanical properties of many composite materials is the influence of the cooling and loading rates on fiber-matrix interface adhesion.^36-38 Our results tended to agree with the findings of Evans and Gregson,³⁵ as some of these composite materials did not withstand repeated sterilizations well.

Guan and colleagues³⁹ evaluated the influence of sterilization treatment on continuous carbon-fiber–reinforced polyolefin composite. Their 3-point bending test results showed that the levels of maximum load of all the specimens undergoing sterilization by autoclave were lower than those of the control group. For these composites, they concluded that autoclave sterilization and Co-60 gamma ray irradiation sterilization should be avoided and that ethylene oxide is the best method. Our results support their findings with a different set of composites.

Although HTN-53 has shown promise in other orthopedic applications because of its superior moisture and temperature resistance, we found that its performance after repeated sterilization was relatively poor. Tepex showed the greatest potential for durability after repeated sterilization; its mechanical properties were stable after 200 steam sterilization cycles.

Clinical Applications

The composite materials investigated in the present study have potential for use in either instrumentation or long-term implantation applications because of their versatility, mechanical strength, fatigue resistance, and biocompatibility. Akay and Aslan⁴⁰ stated that carbon-fiber–filled composite implants can be designed with more appropriate modulus, strength, toughness, or stiffness by the arrangement of reinforcing fiber volume and orientation, and can provide better fatigue resistance. A notable advantage of using a composite plate with metal screws is that the potential for corrosion of metallic components is eliminated. Another major advantage of composite medical implants (eg, DiPhos-RM) is radiolucency, which allows direct visualization of osseous callus formation as well as monitoring of fracture healing, thereby improving clinical assessment and accuracy.

Numerous studies have documented the successful clinical performance of composite materials in orthopedic, trauma, and spinal surgery applications.^41-45 Bagheri and colleagues⁴¹ developed a new carbon fiber–flax–epoxy composite plate and biomechanically compared it with a standard clinical metal plate. Their results confirmed that the carbon fiber–flax–epoxy material represents a potential candidate for bone fracture plate applications, as it can simultaneously provide similar mechanical stiffness and lower stress shielding (higher bone stress) compared with a standard clinical metal bone plate. Tarallo and colleagues⁴⁵ evaluated the clinical results of 40 cases at 12-month follow-up using a new plate made of carbon-fiber–reinforced polyetheretherketon (DiPhos-RM, Lima Corporate) for the treatment of distal radius fractures. They reported good clinical results for this device at early follow-up, and its use allowed maintenance of reduction in complex AO (Arbeitsgemeinschaft für Osteosynthesefragen) fractures.

The main advantage in using composites for surgical instruments is their radiolucency. These materials do not obscure images or radiographs during fluoroscopic visualization. Surgery often requires fluoroscopic visualization of internal organs or bones, which may require temporary removal of radiopaque devices (eg, retractors, clamps, forceps, hooks, distractors). Aside from being inconvenient, removal and subsequent reinsertion consume valuable time and interfere with the smooth flow of an operation.

The shortcomings of using composite materials for surgical instruments involve detectability and sterilization. A significant issue in surgery is the accidental leaving behind of instruments in patients, which can cause serious problems ranging from organ perforation and blood infection to death. Although instrument counting and other safety protocols can reduce the risk of overlooking an instrument, mistakes are bound to happen. The other shortcoming is the influence of repeated sterilization on the mechanical properties of the composite materials, as sterilization is mandatory for surgical instruments used in the operation room. The structural integrity and overall performance of the polymer composite materials—especially the stability of the interface and the interphase zones—are strongly influenced by repeated sterilization.

On the other hand, composite materials have potential advantages that may support their introduction into long-term medical implant applications, as sterilization commonly is performed only once, during packaging. The effects of sterilization by radiation or steam are much less pronounced on composite implants than on composite surgical instruments. However, composite implants require careful consideration with respect to the bioactivity of wear particles that may be produced from articulation. Further, carbon-fiber–reinforced polymer implants are still substantially more difficult to manufacture and more costly than their metallic counterparts.⁴⁶

Limitations

This study has some limitations. Most important, studies of this nature do not account for biological factors such as corrosion, biological wear, and the soft-tissue attachment effects on structural properties for potential in vivo use. Another limitation was that the study tested only the mechanical properties in terms of SBS and provided no information about other mechanical properties, such as tensile, compression, and torsion strengths. We think SBS testing adequately evaluates challenging scenarios like thin and narrow instruments/devices that are anticipated in application, and information regarding other modes of failure and mechanical properties (compression, tension, torsion) would be a further area of research. An additional limitation was that our model used a relatively small number of samples. A larger study with more samples and varying layout patterns and layers of the carbon fibers may more clearly demonstrate the effect of steam sterilization on composite materials.

Conclusion

This study provided new information on 3 selected composite materials and their structural properties after repeated steam sterilization. We discovered that these composites were similar in radiographic density and water retention but behaved very differently in terms of mechanical durability after repeated steam sterilization. All selected composites demonstrated deterioration of mechanical properties after repeated steam sterilization. Knowing these results could aid in making decisions about the design and manufacturing of operative instruments and orthopedic biomaterials. Although our preliminary findings are intriguing, further study is warranted to seek specific applications for these composite materials in orthopedic surgery.