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Pectoralis major transfer for anterior-superior subluxation in massive rotator cuff insufficiency
Pectoralis major transfer for anterior-superior subluxation in massive rotator cuff insufficiency Leesa M. Galatz, MD,a Patrick M. Connor, MD,b Ryan P. Calfee, MD,a Jim C. Hsu, MD,a and Ken Yamaguchi, MD,a St Louis, MO, and Charlotte, NC
The purpose of this study was to evaluate the outcome after subcoracoid pectoralis major transfer for anteriorsuperior shoulder instability in massive rotator cuff insufficiency. Fourteen patients underwent subcoracoid pectoralis major transfer for this debilitating surgical complication. At a mean 17.5-month follow-up, there were 11 satisfactory and 3 unsatisfactory results. Nine of the patients were satisfied with the procedure and would repeat the operation under similar circumstances. Pain scores, as measured on a visual analog scale, decreased from 6.9 to 3.2 postoperatively. Mean forward flexion increased from 24.4° to 60.8°. American Shoulder and Elbow Society functional outcome score increased from 27.2 preoperatively to 47.7 postoperatively. Thirteen of the fourteen patients had improved humeral head containment and improved ability to perform activities of daily living at waist level. A subcoracoid pectoralis major muscle transfer has a low complication rate and is a viable option in this difficult patient population, with better results than those previously reported. (J Shoulder Elbow Surg 2003;12:1-5.)
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o date, anterior-superior shoulder instability has left the surgeon with few surgical options. Resulting from a combination of rotator cuff deficiency, loss of the coracoacromial arch, and anterior deltoid compromise, this surgical complication has proved exceedingly difficult to treat. Several procedures have been described by which to attempt reconstruction of the coracoacromial arch in order to contain the humeral head.1,7 The procedures focus on head containment From the Department of Orthopaedic Surgery, Barnes-Jewish Hospital, Washington University School of Medicine, St. Louis, MO,a and Miller Orthopaedic Clinic, Charlotte, NCb Reprint requests: Leesa M. Galatz, MD, Department of Orthopaedic Surgery, Washington University School of Medicine, BarnesJewish Hospital, One Barnes-Jewish Hospital Plaza, Suite 11300, West Pavilion St. Louis, MO 63110 (E-mail: [email protected]). Copyright © 2003 by Journal of Shoulder and Elbow Surgery Board of Trustees. 1058-2746/2003/$35.00 ⫹ 0 32/1/128137 doi:10.1067/mse.2003.128137
by static reconstruction of the coracoacromial arch. They include bone grafting and fascia lata allograft, as well as other soft-tissue reconstructions of the coracoacromial ligament. Some patients have moderate relief of pain with some restoration of strength, but the majority continued to have chronic pain and severely limited function. We used an alternative technique in which a dynamic, rather than static, reconstruction was performed. A subcoracoid pectoralis major muscle transfer to the humeral head, as originally described by Resch et al,5 was used in 14 patients with a diagnosis of anterior-superior shoulder instability. The rationale for the pectoralis major transfer was to provide a muscle transfer that would provide dynamic stability to the humeral head by exerting a downward and internal rotation vector. This was accomplished by routing the pectoralis tendon deep to the conjoint tendon so that the coracoid base acted as a pulley to optimize strength in the inferior direction of pull. The purpose of this study was to review the preliminary results of a subcoracoid pectoralis major muscle transfer for the treatment of anterior-superior shoulder instability. MATERIALS AND METHODS Clinical criteria From 1996 to 1999, 23 patients underwent a subcoracoid pectoralis major transfer at two centers. Fourteen patients with anterior-superior shoulder instability were identified from this group. Final follow-up averaged 17.5 months (range, 12-31 months). The diagnosis of anteriorsuperior instability was made by clinical examination revealing (1) severely deficient rotator cuff function, (2) compromised coracoacromial arch, (3) superior migration of the humeral head upon attempted elevation, and (4) compromised anterior deltoid (Figure 1). Inclusion criteria were that patients had the following: (1) diagnosis of anteriorsuperior instability as defined above, (2) one or more previous surgical procedures on the involved shoulder, and (3) a minimum of 12 months’ follow-up. Patients were excluded if they had a functioning rotator cuff and/or deltoid, had not had previous surgery, or did not meet the minimum follow-up requirement. Patients who had a pectoralis major transfer for a diagnosis other than anteriorsuperior instability were not studied.
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Figure 1 A, Radiograph of patient with pathologic anterior-superior instability of the right shoulder who presented after a hemiarthroplasty with an excessively large head, deficient rotator cuff, and deltoid dehiscence. B, Postoperative radiograph after revision hemiarthroplasty and subcoracoid pectoralis major muscle transfer demonstrating containment within the coracoacromial arch.
Patient assessment Three women and eleven men were identified. The mean age was 67.5 years (range, 40-80 years). Ten procedures were performed on the dominant and four on the nondominant extremity. The medical records, operative reports, and preoperative and postoperative imaging studies of all patients were reviewed retrospectively. All patients were examined at the time of final follow-up. The patients were evaluated preoperatively and at final follow-up with a standard physical examination according to the guidelines established by the American Shoulder and Elbow Surgeons (ASES) and an ASES shoulder outcome questionnaire.6 The standardized data were available on all patients at both time points. The patients had undergone a mean of 2.3 prior surgical procedures (range, 1-4). These included 3 total shoulder arthroplasties, 1 revision total shoulder arthroplasty, 6 rotator cuff repairs, 2 irrigation and debridement procedures for postoperative shoulder infection, 3 hemiarthroplasties for rotator cuff deficiency, 1 open reduction/internal fixation for a proximal humerus fracture, 1 hemiarthroplasty for a proximal humerus fracture, and 1 hemiarthroplasty for a proximal humerus nonunion. All had massive rotator cuff tears with subscapularis tendon deficiency prior to the shoulder reconstruction we performed. Postoperative anterior-superior instability was rated as follows: contained, intermediate instability (some instability at the initiation of elevation); and severe (the humeral head luxated at rest and becoming subcutaneous with elevation attempts). The final results were rated as satisfactory or unsatisfactory according to Neer’s criteria for the evalua-
tion of patients with limited goals.4 According to these criteria, for a result to be satisfactory, there had to be nearly total pain relief and the patient had to be able to use the arm at the side for daily activities. Pain was graded on a scale from 0 (no pain) to 10 (totally incapacitating) on a visual analog scale. Range of motion was assessed according to the standards set by ASES. Motion was measured with the patient in a sitting position with the use of a goniometer. Function was also assessed on the basis of the patient’s ability to perform 10 different tasks of everyday living. Each task was graded on a scale of 0 (could not perform) to 3 (no difficulty).6
Operative treatment All patients underwent a subcoracoid pectoralis major muscle transfer. In addition, the following procedures were also performed: 1 deltoidplasty (an attempt to repair an attenuated anterior deltoid), 2 attempted rotator cuff repairs, 2 biceps tenodeses, 1 heterotopic ossification removal, 1 revision total shoulder arthroplasty, 1 hemiarthroplasty, 3 revision hemiarthroplasties, 2 repeat irrigation and debridement procedures, 1 intercalary allograft of the proximal humerus, and 1 Achilles tendon allograft reconstruction of the anterior-superior glenoid bone and coracoacromial arch. Two patients underwent a concomitant PDS weave procedure to augment perioperative humeral head containment. Three No. 1 polydioxanone (PDS) (Ethicon, Somerville, NJ) sutures were weaved tightly, passed through a drill hole in the scapular spine and around the
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Figure 2 The extended deltopectoral approach is shown with the pectoralis major insertion exposed, inserting into the humeral cortex. The insertion of the pectoralis major is incised as shown. (Reprinted with permission from Klepps et al. Tech Shoulder Elbow Surg 2001;2:85-91.)
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Figure 3 The entire pectoralis major is released from the humerus and retracted medially. Both the medial and lateral pectoral nerves are visualized, inserting into the undersurface of the pectoralis major. However, during the surgical technique, these nerves are not visualized. n., Nerve. (Reprinted with permission from Klepps et al. Tech Shoulder Elbow Surg 2001;2:85-91.)
proximal humerus, and then tied with the humeral head in a reduced position.
Surgical technique The pectoralis major transfer was performed essentially as described by Resch et al.5 Two modifications were made: (1) the entire pectoralis major muscle was transferred and (2) the tendon was attached to the greater tuberosity. The surgery was performed with patients in the 45° beachchair position. They were always under general anesthesia and usually had an interscalene block for postoperative analgesia. The surgery was performed through a deltopectoral approach. The lateral border of the conjoined tendon of the short head of the biceps and the coracobrachialis was identified, and the entire conjoined tendon was dissected. The musculocutaneous nerve was identified and dissected free so that it could be visualized as it penetrated the muscle approximately 5 cm distal to the coracoid.2 The pectoralis major tendon was isolated at its insertion onto the lateral aspect of the biceps groove of the humerus. One or two stay sutures were placed in the tendon for traction. The tendon was released in its entirety from the humerus and mobilized medially (Figure 2). Care was taken not to mobilize more than 8 cm from the lateral border of the muscle in order to protect the lateral pectoral nerve (Figure 3).3 The tendon was passed from medial to lateral, deep to the conjoined tendon but superficial to the musculocutaneous nerve (Figure 4),3,5 with the use of stay sutures in the tendon for traction. In 4 cases, the transfer was felt to place the musculocutaneous nerve under tension. To remedy this, the small proximal branch of the musculocutaneous nerve, which entered the muscle of the coracobrachialis superior to the main body of the nerve, was released in these cases. The main innervation to the biceps was unaffected by this release. The lateral end of the tendon was secured over the lesser tuberosity to the greater tuberosity as superiorly as possible in order to maximize the downward vector and place the musculotendinous unit under some tension. Transosseous sutures were placed at the attachment site on the greater
Figure 4 The entire pectoralis is transferred deep to the conjoined tendon and superficial to the musculocutaneous nerve. The pectoralis major tendon is subsequently inserted into the greater tuberosity. n., Nerve. (Reprinted with permission from Klepps et al. Tech Shoulder Elbow Surg 2001;2:85-91.)
tuberosity. A Mason-Allen stitch was placed through the tendon to secure it to bone. Asymmetric posterior and inferior capsular contractures were released in 3 patients in order to allow the humeral head to remain in the reduced position without tension. The wound was closed over suction drainage. The arm was placed in a sling and abduction pillow with the arm anterior to the midcoronal plane of the body.
Postoperative rehabilitation The shoulder was kept immobilized in an abduction orthosis with the arm anterior to the mid plane of the body
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for the first 6 weeks after surgery. The rationale for the prolonged immobilization in this position was to allow scarring with the humeral head in a captured position under the acromion and not to allow it to move into a subluxed anterior-superior position. After 6 weeks, motion was started with passive forward flexion, passive external rotation with the arm at the side, and pendulum exercises. External rotation was limited to approximately 10° to 20° or an amount determined by intraoperative assessment of tension on the transfer. Patients were allowed active motion of the elbow, wrist, and hand. Active range of motion exercises were initiated at 12 weeks. Load bearing was allowed soon thereafter as required. Limited goals rehabilitation guidelines were used; thus emphasis was placed on strength at waist level and elevation to 90°.
RESULTS Outcome
At the final follow-up of 17.5 months (range, 12-31 months), results were satisfactory in 11 patients and unsatisfactory in 3 patients, according to Neer’s limited goals criteria.4 Satisfaction with the operation was assessed on a scale from 0 to 10 (in which 0 is not satisfied at all and 10 is completely satisfied). Postoperative satisfaction averaged 5.7. Patients were asked if they were satisfied with the operation and would repeat the procedure under the same circumstances. Nine stated that they were satisfied and would repeat the operation. Five were not satisfied. The ASES functional outcome scores improved from a mean of 27.2 points preoperatively (range, 10-56) to a mean of 47.7 postoperatively (range, 10-80). The mean increase was 20.5 points (range, 5-50). When the activities of daily living functional score was examined separately, the score, expressed as a percentage of maximal score, averaged 39% preoperatively. The mean percentage of maximal score was 48% postoperatively. Pain scores, as assessed on a visual analog scale from 0 (no pain) to 10 (the worst pain), decreased from 6.9 preoperatively (range, 4-10) to 3.2 postoperatively (range, 0-9). Function
Active forward flexion increased from 28.4° (range, 0°-160°) to 60° (range, 15°-170°). Three patients were able to elevate above the horizontal plane. Passive external rotation decreased from a mean of 32° preoperatively (range, 0°-75°) to 28° postoperatively (range, 0°-45°). No patient had increased passive external rotation at the time of final follow-up. All patients had an abnormal abdominal compression test result preoperatively. At the time of final follow-up, 6 patients had a normal abdominal compression test result.
J Shoulder Elbow Surg January/February 2003
Anterior-superior instability
Anterior-superior instability was graded in all patients. In 7 patients, the humeral head was graded as contained. Three of these patients were able to elevate their arms above the horizontal plane. Six patients had intermediate instability, defined as some instability at initiation of elevation. One patient’s humeral head was not contained, and he had humeral head elevation at rest. His shoulder was never captured within the coracoacromial arch. Two patients underwent procedures for static reconstruction in addition to pectoralis major muscle transfer for treatment of anterior-superior instability. One patient had an Achilles tendon reconstruction of the coracoacromial arch as well as a PDS weave. He had intermediate instability at final follow-up and attained 110° of forward elevation. The second patient had a PDS weave only in addition to his pectoralis major muscle transfer and was able to elevate to 80°. His humeral head was graded as contained. Complications
There were no intraoperative complications. Postoperatively, 1 patient had transient musculocutaneous nerve neuropraxia. The musculocutaneous nerve was functioning in all other patients. At the time of final follow-up, only 1 patient had a definite failure of the pectoralis major transfer. The transfer failed at the site of reattachment and could be palpated in its retracted position. The patient’s humeral head was not contained within the coracoacromial arch postoperatively, as determined by clinical examination. He declined further surgery. DISCUSSION Anterior-superior shoulder instability is a devastating complication of shoulder surgery that can leave patients with considerable pain and disability. Surgical procedures for the treatment of this condition are considered salvage operations, and to date, there is no reliable option that leads to predictable satisfactory results. The difficulty arises from loss of both the primary and secondary constraints to superior migration of the humeral head. The primary constraint, the rotator cuff, is irreparable in cases of anterior-superior instability and often includes loss of the subscapularis. The coracoacromial arch acts as a secondary constraint to superior migration, its role increasing in a rotator cuffdeficient shoulder. The loss of constraint is complicated by compromise of the anterior portion of the deltoid muscle. The anterior deltoid compromise results from thinning, dehiscence, or denervation resulting from surgical procedures. The intact posterior and lateral portions of the deltoid exert a posterior vector on the mid shaft of the humerus during contrac-
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tion, intensifying the anterior escape of the humeral head. Anterior-superior subluxation can also be exacerbated by asymmetric posterior capsular contracture. Taken together, loss of the rotator cuff, coracoacromial arch, and anterior deltoid results in a dynamic anterior-superior instability that occurs during attempt at elevation. Historical solutions for this problem have included static reconstruction of the coracoacromial arch. Wiley7 was the first to report this disabling complication. In his review of 4 cases, he described static reconstruction of the coracoacromial arch in which bone graft from the iliac crest was used. This procedure was performed in 2 patients. There was some initial pain relief; however, long-term follow-up was not available. Flatow et al1 reported a series of 6 patients. All had coracoacromial ligament reconstruction with autologous fascia lata graft. In addition, 3 had concomitant latissimus dorsi and teres major transfers. One patient also had an iliac crest reconstruction of the previously resected anterior acromion. One had a revision hemiarthroplasty, in which the head was changed to a wider component in order to achieve stability. Only 2 of the 6 patients were satisfied with the outcome of their surgical procedure, and all 6 were graded as having unsatisfactory results by Neer’s limited goals criteria. The primary goal of treatment for anterior-superior instability was pain relief. Given the loss of important musculature about the shoulder, limited goals were anticipated in terms of function. However, there were some important aspects of waist-level function that could be improved and make a large difference in quality of life. One of these is the obligate extension that occurs in many of these patients with attempt at elevation. The intact posterior and lateral deltoid muscles cause the shoulder to extend in the absence of the anterior deltoid and subscapularis to counteract that force. As a result, the patient is unable to get the hand to the mouth. The subcoracoid pectoralis major muscle transfer exerts force to counteract the strong functioning deltoid and helps to avoid the obligate extension, allowing the patient to get the hand to the mouth and improving stability for other waist-level activities. The rationale for use of a dynamic reconstruction was based in part on the failures of previously described static reconstructions of secondary constraints for anterior-superior instability. Historically, static reconstruction led to unfavorable results in the majority of patients. Second, dynamic reconstruction with a pectoralis major transfer provides a critical anterior muscular contribution to offset the loss of both the subscapularis9 and deltoid. A subcoracoid pectoralis major muscle transfer provides an appropriate inferior and internal rotation vector to counter the anterior
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and superior displacement of the humeral head. In addition, the pectoralis major muscle contracts in phase with the subscapularis and, therefore, is an appropriate substitute for this muscle. Our study has some inherent weaknesses. Most of the patients had multiple different types of procedures both prior to and in conjunction with the pectoralis transfer. However, this reflects the complex nature of anterior-superior instability.8,10 It occurs as a complication of numerous and/or difficult shoulder procedures. Second, this study is a retrospective review. However, both preoperative and final follow-up data were gathered in a consistent, standardized fashion at both institutions. Our series included 2 patients who underwent static reconstructive procedures in addition to pectoralis major transfers. These patients both had a satisfactory result. One had a contained humeral head at follow-up and one had intermediate instability. We could not attribute their results solely to the muscle transfer. A subcoracoid pectoralis muscle transfer appeared to be a reasonable option in salvage situations for this difficult problem. The transfer provided a better outcome than procedures that reconstruct the secondary static constraints of the coracoacromial arch. Although limited goals may be expected in most cases, the majority of patients obtained good pain relief and improved function at waist level. REFERENCES
1. Flatow E, Connor P, Levine W, et al. Coracoacromial arch reconstruction for anterosuperior subluxation after failed rotator cuff surgery. J Shoulder Elbow Surg 1997;6:228. 2. Flatow EL, Bigliani LU, April EW. An anatomic study of the musculocutaneous nerve and its relationship to the coracoid. Clin Orthop 1989;244:166-71. 3. Klepps SJ, Goldfarb C, Flatow E, et al. Anatomic evaluation of the sub-coracoid pectoralis major transfer in human cadavers. J Shoulder Elbow Surg 2001;10:453-9. 4. Neer CS II, Morrison DS. Glenoid bone grafting in total shoulder arthroplasty. J Bone Joint Surg Am 1988;70:1154-62. 5. Resch H, Povacz P, Ritter E, Matschi W. Transfer of the pectoralis major muscle for the treatment of irreparable rupture of the subscapularis tendon. J Bone Joint Surg Am 2000;82:372-82. 6. Richards RR, An K, Bigliani LU, et al. A standard method for the assessment of shoulder function. J Shoulder Elbow Surg 1994;3: 347-52. 7. Wiley AM. Superior humeral dislocation. A complication following decompression and debridement for rotator cuff tears. Clin Orthop 1991;263:135-41. 8. Williams GR Jr. Complications of rotator cuff surgery. In: Iannotti JP, Williams GR Jr, editors. Disorders of the shoulder: diagnosis and management. Philadelphia: Lippincott Williams & Wilkins; 1999. p. 93-127. 9. Wirth MA, Rockwood CA Jr. Operative treatment of irreparable rupture of the subscapularis. J Bone Joint Surg Am 1997;79:72231. 10. Yamaguchi K. Complications of rotator cuff repair. Tech Orthop 1997;12:33-41.
The purpose of this study was to evaluate the outcome after subcoracoid pectoralis major transfer for anteriorsuperior shoulder instability in massive rotator cuff insufficiency. Fourteen patients underwent subcoracoid pectoralis major transfer for this debilitating surgical complication. At a mean 17.5-month follow-up, there were 11 satisfactory and 3 unsatisfactory results. Nine of the patients were satisfied with the procedure and would repeat the operation under similar circumstances. Pain scores, as measured on a visual analog scale, decreased from 6.9 to 3.2 postoperatively. Mean forward flexion increased from 24.4° to 60.8°. American Shoulder and Elbow Society functional outcome score increased from 27.2 preoperatively to 47.7 postoperatively. Thirteen of the fourteen patients had improved humeral head containment and improved ability to perform activities of daily living at waist level. A subcoracoid pectoralis major muscle transfer has a low complication rate and is a viable option in this difficult patient population, with better results than those previously reported. (J Shoulder Elbow Surg 2003;12:1-5.)
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o date, anterior-superior shoulder instability has left the surgeon with few surgical options. Resulting from a combination of rotator cuff deficiency, loss of the coracoacromial arch, and anterior deltoid compromise, this surgical complication has proved exceedingly difficult to treat. Several procedures have been described by which to attempt reconstruction of the coracoacromial arch in order to contain the humeral head.1,7 The procedures focus on head containment From the Department of Orthopaedic Surgery, Barnes-Jewish Hospital, Washington University School of Medicine, St. Louis, MO,a and Miller Orthopaedic Clinic, Charlotte, NCb Reprint requests: Leesa M. Galatz, MD, Department of Orthopaedic Surgery, Washington University School of Medicine, BarnesJewish Hospital, One Barnes-Jewish Hospital Plaza, Suite 11300, West Pavilion St. Louis, MO 63110 (E-mail: [email protected]). Copyright © 2003 by Journal of Shoulder and Elbow Surgery Board of Trustees. 1058-2746/2003/$35.00 ⫹ 0 32/1/128137 doi:10.1067/mse.2003.128137
by static reconstruction of the coracoacromial arch. They include bone grafting and fascia lata allograft, as well as other soft-tissue reconstructions of the coracoacromial ligament. Some patients have moderate relief of pain with some restoration of strength, but the majority continued to have chronic pain and severely limited function. We used an alternative technique in which a dynamic, rather than static, reconstruction was performed. A subcoracoid pectoralis major muscle transfer to the humeral head, as originally described by Resch et al,5 was used in 14 patients with a diagnosis of anterior-superior shoulder instability. The rationale for the pectoralis major transfer was to provide a muscle transfer that would provide dynamic stability to the humeral head by exerting a downward and internal rotation vector. This was accomplished by routing the pectoralis tendon deep to the conjoint tendon so that the coracoid base acted as a pulley to optimize strength in the inferior direction of pull. The purpose of this study was to review the preliminary results of a subcoracoid pectoralis major muscle transfer for the treatment of anterior-superior shoulder instability. MATERIALS AND METHODS Clinical criteria From 1996 to 1999, 23 patients underwent a subcoracoid pectoralis major transfer at two centers. Fourteen patients with anterior-superior shoulder instability were identified from this group. Final follow-up averaged 17.5 months (range, 12-31 months). The diagnosis of anteriorsuperior instability was made by clinical examination revealing (1) severely deficient rotator cuff function, (2) compromised coracoacromial arch, (3) superior migration of the humeral head upon attempted elevation, and (4) compromised anterior deltoid (Figure 1). Inclusion criteria were that patients had the following: (1) diagnosis of anteriorsuperior instability as defined above, (2) one or more previous surgical procedures on the involved shoulder, and (3) a minimum of 12 months’ follow-up. Patients were excluded if they had a functioning rotator cuff and/or deltoid, had not had previous surgery, or did not meet the minimum follow-up requirement. Patients who had a pectoralis major transfer for a diagnosis other than anteriorsuperior instability were not studied.
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Figure 1 A, Radiograph of patient with pathologic anterior-superior instability of the right shoulder who presented after a hemiarthroplasty with an excessively large head, deficient rotator cuff, and deltoid dehiscence. B, Postoperative radiograph after revision hemiarthroplasty and subcoracoid pectoralis major muscle transfer demonstrating containment within the coracoacromial arch.
Patient assessment Three women and eleven men were identified. The mean age was 67.5 years (range, 40-80 years). Ten procedures were performed on the dominant and four on the nondominant extremity. The medical records, operative reports, and preoperative and postoperative imaging studies of all patients were reviewed retrospectively. All patients were examined at the time of final follow-up. The patients were evaluated preoperatively and at final follow-up with a standard physical examination according to the guidelines established by the American Shoulder and Elbow Surgeons (ASES) and an ASES shoulder outcome questionnaire.6 The standardized data were available on all patients at both time points. The patients had undergone a mean of 2.3 prior surgical procedures (range, 1-4). These included 3 total shoulder arthroplasties, 1 revision total shoulder arthroplasty, 6 rotator cuff repairs, 2 irrigation and debridement procedures for postoperative shoulder infection, 3 hemiarthroplasties for rotator cuff deficiency, 1 open reduction/internal fixation for a proximal humerus fracture, 1 hemiarthroplasty for a proximal humerus fracture, and 1 hemiarthroplasty for a proximal humerus nonunion. All had massive rotator cuff tears with subscapularis tendon deficiency prior to the shoulder reconstruction we performed. Postoperative anterior-superior instability was rated as follows: contained, intermediate instability (some instability at the initiation of elevation); and severe (the humeral head luxated at rest and becoming subcutaneous with elevation attempts). The final results were rated as satisfactory or unsatisfactory according to Neer’s criteria for the evalua-
tion of patients with limited goals.4 According to these criteria, for a result to be satisfactory, there had to be nearly total pain relief and the patient had to be able to use the arm at the side for daily activities. Pain was graded on a scale from 0 (no pain) to 10 (totally incapacitating) on a visual analog scale. Range of motion was assessed according to the standards set by ASES. Motion was measured with the patient in a sitting position with the use of a goniometer. Function was also assessed on the basis of the patient’s ability to perform 10 different tasks of everyday living. Each task was graded on a scale of 0 (could not perform) to 3 (no difficulty).6
Operative treatment All patients underwent a subcoracoid pectoralis major muscle transfer. In addition, the following procedures were also performed: 1 deltoidplasty (an attempt to repair an attenuated anterior deltoid), 2 attempted rotator cuff repairs, 2 biceps tenodeses, 1 heterotopic ossification removal, 1 revision total shoulder arthroplasty, 1 hemiarthroplasty, 3 revision hemiarthroplasties, 2 repeat irrigation and debridement procedures, 1 intercalary allograft of the proximal humerus, and 1 Achilles tendon allograft reconstruction of the anterior-superior glenoid bone and coracoacromial arch. Two patients underwent a concomitant PDS weave procedure to augment perioperative humeral head containment. Three No. 1 polydioxanone (PDS) (Ethicon, Somerville, NJ) sutures were weaved tightly, passed through a drill hole in the scapular spine and around the
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Figure 2 The extended deltopectoral approach is shown with the pectoralis major insertion exposed, inserting into the humeral cortex. The insertion of the pectoralis major is incised as shown. (Reprinted with permission from Klepps et al. Tech Shoulder Elbow Surg 2001;2:85-91.)
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Figure 3 The entire pectoralis major is released from the humerus and retracted medially. Both the medial and lateral pectoral nerves are visualized, inserting into the undersurface of the pectoralis major. However, during the surgical technique, these nerves are not visualized. n., Nerve. (Reprinted with permission from Klepps et al. Tech Shoulder Elbow Surg 2001;2:85-91.)
proximal humerus, and then tied with the humeral head in a reduced position.
Surgical technique The pectoralis major transfer was performed essentially as described by Resch et al.5 Two modifications were made: (1) the entire pectoralis major muscle was transferred and (2) the tendon was attached to the greater tuberosity. The surgery was performed with patients in the 45° beachchair position. They were always under general anesthesia and usually had an interscalene block for postoperative analgesia. The surgery was performed through a deltopectoral approach. The lateral border of the conjoined tendon of the short head of the biceps and the coracobrachialis was identified, and the entire conjoined tendon was dissected. The musculocutaneous nerve was identified and dissected free so that it could be visualized as it penetrated the muscle approximately 5 cm distal to the coracoid.2 The pectoralis major tendon was isolated at its insertion onto the lateral aspect of the biceps groove of the humerus. One or two stay sutures were placed in the tendon for traction. The tendon was released in its entirety from the humerus and mobilized medially (Figure 2). Care was taken not to mobilize more than 8 cm from the lateral border of the muscle in order to protect the lateral pectoral nerve (Figure 3).3 The tendon was passed from medial to lateral, deep to the conjoined tendon but superficial to the musculocutaneous nerve (Figure 4),3,5 with the use of stay sutures in the tendon for traction. In 4 cases, the transfer was felt to place the musculocutaneous nerve under tension. To remedy this, the small proximal branch of the musculocutaneous nerve, which entered the muscle of the coracobrachialis superior to the main body of the nerve, was released in these cases. The main innervation to the biceps was unaffected by this release. The lateral end of the tendon was secured over the lesser tuberosity to the greater tuberosity as superiorly as possible in order to maximize the downward vector and place the musculotendinous unit under some tension. Transosseous sutures were placed at the attachment site on the greater
Figure 4 The entire pectoralis is transferred deep to the conjoined tendon and superficial to the musculocutaneous nerve. The pectoralis major tendon is subsequently inserted into the greater tuberosity. n., Nerve. (Reprinted with permission from Klepps et al. Tech Shoulder Elbow Surg 2001;2:85-91.)
tuberosity. A Mason-Allen stitch was placed through the tendon to secure it to bone. Asymmetric posterior and inferior capsular contractures were released in 3 patients in order to allow the humeral head to remain in the reduced position without tension. The wound was closed over suction drainage. The arm was placed in a sling and abduction pillow with the arm anterior to the midcoronal plane of the body.
Postoperative rehabilitation The shoulder was kept immobilized in an abduction orthosis with the arm anterior to the mid plane of the body
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for the first 6 weeks after surgery. The rationale for the prolonged immobilization in this position was to allow scarring with the humeral head in a captured position under the acromion and not to allow it to move into a subluxed anterior-superior position. After 6 weeks, motion was started with passive forward flexion, passive external rotation with the arm at the side, and pendulum exercises. External rotation was limited to approximately 10° to 20° or an amount determined by intraoperative assessment of tension on the transfer. Patients were allowed active motion of the elbow, wrist, and hand. Active range of motion exercises were initiated at 12 weeks. Load bearing was allowed soon thereafter as required. Limited goals rehabilitation guidelines were used; thus emphasis was placed on strength at waist level and elevation to 90°.
RESULTS Outcome
At the final follow-up of 17.5 months (range, 12-31 months), results were satisfactory in 11 patients and unsatisfactory in 3 patients, according to Neer’s limited goals criteria.4 Satisfaction with the operation was assessed on a scale from 0 to 10 (in which 0 is not satisfied at all and 10 is completely satisfied). Postoperative satisfaction averaged 5.7. Patients were asked if they were satisfied with the operation and would repeat the procedure under the same circumstances. Nine stated that they were satisfied and would repeat the operation. Five were not satisfied. The ASES functional outcome scores improved from a mean of 27.2 points preoperatively (range, 10-56) to a mean of 47.7 postoperatively (range, 10-80). The mean increase was 20.5 points (range, 5-50). When the activities of daily living functional score was examined separately, the score, expressed as a percentage of maximal score, averaged 39% preoperatively. The mean percentage of maximal score was 48% postoperatively. Pain scores, as assessed on a visual analog scale from 0 (no pain) to 10 (the worst pain), decreased from 6.9 preoperatively (range, 4-10) to 3.2 postoperatively (range, 0-9). Function
Active forward flexion increased from 28.4° (range, 0°-160°) to 60° (range, 15°-170°). Three patients were able to elevate above the horizontal plane. Passive external rotation decreased from a mean of 32° preoperatively (range, 0°-75°) to 28° postoperatively (range, 0°-45°). No patient had increased passive external rotation at the time of final follow-up. All patients had an abnormal abdominal compression test result preoperatively. At the time of final follow-up, 6 patients had a normal abdominal compression test result.
J Shoulder Elbow Surg January/February 2003
Anterior-superior instability
Anterior-superior instability was graded in all patients. In 7 patients, the humeral head was graded as contained. Three of these patients were able to elevate their arms above the horizontal plane. Six patients had intermediate instability, defined as some instability at initiation of elevation. One patient’s humeral head was not contained, and he had humeral head elevation at rest. His shoulder was never captured within the coracoacromial arch. Two patients underwent procedures for static reconstruction in addition to pectoralis major muscle transfer for treatment of anterior-superior instability. One patient had an Achilles tendon reconstruction of the coracoacromial arch as well as a PDS weave. He had intermediate instability at final follow-up and attained 110° of forward elevation. The second patient had a PDS weave only in addition to his pectoralis major muscle transfer and was able to elevate to 80°. His humeral head was graded as contained. Complications
There were no intraoperative complications. Postoperatively, 1 patient had transient musculocutaneous nerve neuropraxia. The musculocutaneous nerve was functioning in all other patients. At the time of final follow-up, only 1 patient had a definite failure of the pectoralis major transfer. The transfer failed at the site of reattachment and could be palpated in its retracted position. The patient’s humeral head was not contained within the coracoacromial arch postoperatively, as determined by clinical examination. He declined further surgery. DISCUSSION Anterior-superior shoulder instability is a devastating complication of shoulder surgery that can leave patients with considerable pain and disability. Surgical procedures for the treatment of this condition are considered salvage operations, and to date, there is no reliable option that leads to predictable satisfactory results. The difficulty arises from loss of both the primary and secondary constraints to superior migration of the humeral head. The primary constraint, the rotator cuff, is irreparable in cases of anterior-superior instability and often includes loss of the subscapularis. The coracoacromial arch acts as a secondary constraint to superior migration, its role increasing in a rotator cuffdeficient shoulder. The loss of constraint is complicated by compromise of the anterior portion of the deltoid muscle. The anterior deltoid compromise results from thinning, dehiscence, or denervation resulting from surgical procedures. The intact posterior and lateral portions of the deltoid exert a posterior vector on the mid shaft of the humerus during contrac-
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J Shoulder Elbow Surg Volume 12, Number 1
tion, intensifying the anterior escape of the humeral head. Anterior-superior subluxation can also be exacerbated by asymmetric posterior capsular contracture. Taken together, loss of the rotator cuff, coracoacromial arch, and anterior deltoid results in a dynamic anterior-superior instability that occurs during attempt at elevation. Historical solutions for this problem have included static reconstruction of the coracoacromial arch. Wiley7 was the first to report this disabling complication. In his review of 4 cases, he described static reconstruction of the coracoacromial arch in which bone graft from the iliac crest was used. This procedure was performed in 2 patients. There was some initial pain relief; however, long-term follow-up was not available. Flatow et al1 reported a series of 6 patients. All had coracoacromial ligament reconstruction with autologous fascia lata graft. In addition, 3 had concomitant latissimus dorsi and teres major transfers. One patient also had an iliac crest reconstruction of the previously resected anterior acromion. One had a revision hemiarthroplasty, in which the head was changed to a wider component in order to achieve stability. Only 2 of the 6 patients were satisfied with the outcome of their surgical procedure, and all 6 were graded as having unsatisfactory results by Neer’s limited goals criteria. The primary goal of treatment for anterior-superior instability was pain relief. Given the loss of important musculature about the shoulder, limited goals were anticipated in terms of function. However, there were some important aspects of waist-level function that could be improved and make a large difference in quality of life. One of these is the obligate extension that occurs in many of these patients with attempt at elevation. The intact posterior and lateral deltoid muscles cause the shoulder to extend in the absence of the anterior deltoid and subscapularis to counteract that force. As a result, the patient is unable to get the hand to the mouth. The subcoracoid pectoralis major muscle transfer exerts force to counteract the strong functioning deltoid and helps to avoid the obligate extension, allowing the patient to get the hand to the mouth and improving stability for other waist-level activities. The rationale for use of a dynamic reconstruction was based in part on the failures of previously described static reconstructions of secondary constraints for anterior-superior instability. Historically, static reconstruction led to unfavorable results in the majority of patients. Second, dynamic reconstruction with a pectoralis major transfer provides a critical anterior muscular contribution to offset the loss of both the subscapularis9 and deltoid. A subcoracoid pectoralis major muscle transfer provides an appropriate inferior and internal rotation vector to counter the anterior
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and superior displacement of the humeral head. In addition, the pectoralis major muscle contracts in phase with the subscapularis and, therefore, is an appropriate substitute for this muscle. Our study has some inherent weaknesses. Most of the patients had multiple different types of procedures both prior to and in conjunction with the pectoralis transfer. However, this reflects the complex nature of anterior-superior instability.8,10 It occurs as a complication of numerous and/or difficult shoulder procedures. Second, this study is a retrospective review. However, both preoperative and final follow-up data were gathered in a consistent, standardized fashion at both institutions. Our series included 2 patients who underwent static reconstructive procedures in addition to pectoralis major transfers. These patients both had a satisfactory result. One had a contained humeral head at follow-up and one had intermediate instability. We could not attribute their results solely to the muscle transfer. A subcoracoid pectoralis muscle transfer appeared to be a reasonable option in salvage situations for this difficult problem. The transfer provided a better outcome than procedures that reconstruct the secondary static constraints of the coracoacromial arch. Although limited goals may be expected in most cases, the majority of patients obtained good pain relief and improved function at waist level. REFERENCES
1. Flatow E, Connor P, Levine W, et al. Coracoacromial arch reconstruction for anterosuperior subluxation after failed rotator cuff surgery. J Shoulder Elbow Surg 1997;6:228. 2. Flatow EL, Bigliani LU, April EW. An anatomic study of the musculocutaneous nerve and its relationship to the coracoid. Clin Orthop 1989;244:166-71. 3. Klepps SJ, Goldfarb C, Flatow E, et al. Anatomic evaluation of the sub-coracoid pectoralis major transfer in human cadavers. J Shoulder Elbow Surg 2001;10:453-9. 4. Neer CS II, Morrison DS. Glenoid bone grafting in total shoulder arthroplasty. J Bone Joint Surg Am 1988;70:1154-62. 5. Resch H, Povacz P, Ritter E, Matschi W. Transfer of the pectoralis major muscle for the treatment of irreparable rupture of the subscapularis tendon. J Bone Joint Surg Am 2000;82:372-82. 6. Richards RR, An K, Bigliani LU, et al. A standard method for the assessment of shoulder function. J Shoulder Elbow Surg 1994;3: 347-52. 7. Wiley AM. Superior humeral dislocation. A complication following decompression and debridement for rotator cuff tears. Clin Orthop 1991;263:135-41. 8. Williams GR Jr. Complications of rotator cuff surgery. In: Iannotti JP, Williams GR Jr, editors. Disorders of the shoulder: diagnosis and management. Philadelphia: Lippincott Williams & Wilkins; 1999. p. 93-127. 9. Wirth MA, Rockwood CA Jr. Operative treatment of irreparable rupture of the subscapularis. J Bone Joint Surg Am 1997;79:72231. 10. Yamaguchi K. Complications of rotator cuff repair. Tech Orthop 1997;12:33-41.