Pectoralis major transfer for subscapular deficiency: anatomical study of the relationship between the transferred muscle and the musculocutaneous nerve

Tendon transfers for the management of irreparable subscapularis tears

Rotator cuff pathology is the main cause of shoulder pain and dysfunction in older adults. When a rotator cuff tear involves the subscapularis tendon, the symptoms are usually more severe and the prognosis after surgery must be guarded. Isolated subscapularis tears represent 18% of all rotator cuff tears and arthroscopic repair is a good alternative primary treatment. However, when the tendon is deemed irreparable, tendon transfers are the only option for younger or high-functioning patients. The aim of this review is to describe the indications, biomechanical principles, and outcomes which have been reported for tendon transfers, which are available for the treatment of irreparable subscapularis tears. The best tendon to be transferred remains controversial. Pectoralis major transfer was described more than 30 years ago to treat patients with failed surgery for instability of the shoulder. It has subsequently been used extensively to manage irreparable subscapularis tendon tears in many clinical settings. Although pectoralis major reproduces the position and orientation of the subscapularis in the coronal plane, its position in the axial plane - anterior to the rib cage - is clearly different and does not allow it to function as an ideal transfer. Consistent relief of pain and moderate recovery of strength and function have been reported following the use of this transfer. In an attempt to improve on these results, latissimus dorsi tendon transfer was proposed as an alternative and the technique has evolved from an open to an arthroscopic procedure. Satisfactory relief of pain and improvements in functional shoulder scores have recently been reported following its use. Both pectoralis minor and upper trapezius transfers have also been used in these patients, but the outcomes that have been reported do not support their widespread use.

Proportional localisation of the entry point of the coracobrachialis muscle by the musculocutaneous nerve along the humerus

PURPOSE

To project the distance between the tip of the greater tubercle (GT), respectively, the proximal border of the tip of the coracoid process (CP) and the entry point of the coracobrachialis by the musculocutaneous nerve (MCN) proportionally onto the humeral length.

METHODS

Sixty-six upper extremities were included in the study. The distance between the tip of the GT and the distal tip of the lateral humeral epicondyle (LE) was evaluated as the humeral length (HL). The interval between the tip of the GT and the entry point of the coracobrachialis muscle by the MCN was measured. The distance between the proximal border of the tip of the CP and the distal portion of the medial humeral epicondyle (ME) and the entry point of the MCN into the coracobrachialis were evaluated. Proportions were used to project the entry point of the coracobrachialis by the MCN along the HL, respectively, the interval between the proximal border of the tip of the CP and the distal tip of the ME.

RESULTS

The entry point of the MCN into the coracobrachialis muscle can be expected at an interval between 14.9 and 33.9% of the HL (between the tip of the GT and the LE), starting from the tip of the GT. Regarding the reference line between the proximal border of the CP and the ME, the nerve's entry point was located between 14.2 and 34.4%, starting from the CP.

CONCLUSION

Results represent easily applicable intervals for intraoperative localisation of the MCN.

Pectoralis major tendon transfer for management of subscapularis failure after anatomic total shoulder arthroplasty: technique and results

Background

Subscapularis tendon failure after anatomic total shoulder arthroplasty can lead to pain, dysfunction, and early component failure. The purpose of this study was to report on the results of pectoralis major tendon transfer for treatment of irreparable subscapularis tendon failure in the setting of prior shoulder arthroplasty.

Methods

Patients who underwent pectoralis major muscle transfer for treatment of subscapularis failure in the setting of prior total shoulder arthroplasty or hemiarthroplasty were included in the study. The entirety of the pectoralis major tendon was transferred superficial to the conjoined tendon and placed lateral to the bicipital groove.

Results

Eight patients were included in the study. All 7 patient who experienced pain in their shoulder had improvement in their pain postoperatively. Those patients with preserved active motion were able to regain that motion postoperatively. Radiographically, anterior translation was found to be temporarily improved; however, anterior instability would later recur in most cases, though this did not correlate with increased pain or decreased function.

Discussion

Management options ranging from continued observation, revision repair, pectoralis muscle transfer, or revision to reverse total shoulder arthroplasty should be considered in a setting of subscapularis failure after shoulder arthroplasty. Decision-making should be based on physiological age of the patient as well as symptoms present as well as the position and stability of the arthroplasty components.

Conclusion

Pectoralis muscle transfer can provide pain relief, improve subjective instability, and preserve function in physiological young patients with an irreparable subscapularis who have well-positioned and well-fixed anatomic shoulder arthroplasty components.

Outcome Comparison of Latissimus Dorsi Transfer and Pectoralis Major Transfer for Irreparable Subscapularis Tendon Tear: A Systematic Review

BACKGROUND

Latissimus dorsi transfer (LDT) and pectoralis major transfer (PMT) were developed to treat an irreparable subscapularis tendon tear (ISScT); however, the difference in their outcomes remains unclear.

PURPOSE

To systematically review and compare the outcomes of LDT and PMT for ISScT.

STUDY DESIGN

Systematic review; Level of evidence, 4.

METHODS

A systematic review was performed through a comprehensive search of Embase, PubMed, and the Cochrane Library. Studies of LDT or PMT were included according to the inclusion and exclusion criteria. The primary outcome was the Constant-Murley score (CMS) at the final follow-up. Secondary outcomes included the subjective shoulder value (SSV), visual analog scale (VAS) score for pain, active shoulder range of motion, and the belly-press and lift-off tests. Postoperative failure and complication rates were the safety outcome measures. Outcomes were summarized into the LDT and PMT groups, and results were compared statistically (P < .05).

RESULTS

Twelve studies were included in this review: 184 shoulders from 9 studies for the PMT group and 85 shoulders from 3 studies for the LDT group. For the PMT and LDT groups, the mean ages were 58.9 and 55.1 years, respectively, and the mean follow-up was 66.9 and 17.4 months, respectively. Overall, the LDT and PMT groups improved in the primary outcome (CMS) and secondary outcomes (SSV, VAS, ROM, and belly-press and lift-off tests), with low rates of failure and complication. When compared with the PMT group, the LDT group showed more significant improvements in CMS (35.2 vs 24.7; P < .001), active forward flexion (44.3° vs 14.7°; P < .001), abduction (35.0° vs 17.6°; P < .002), and positive belly-press test rate (45% vs 27%; P < .001). No statistically significant difference was seen between the groups in postoperative failure rate, complication rate, mean improvement of active internal rotation, VAS, or SSV.

CONCLUSION

In general, LDT showed significantly better clinical outcomes postoperatively than did PMT. The available fair-quality evidence suggested that LDT might be a better choice for ISScT. Further evaluations on the relative benefits of the 2 surgical approaches are required, with more high-quality randomized controlled studies.

Anterior Capsular Reconstruction Using a Dermal Allograft for an Irreparable Subscapularis Tear After Shoulder Arthroplasty: A Case Report

CASE

A 51-year-old man was noted to have an irreparable subscapularis tear after total shoulder arthroplasty (TSA). Owing to positive reported results with superior capsular reconstruction, his insufficiency was addressed with anterior capsular reconstruction with use of a dermal allograft. Two-year follow-up results demonstrate good functional outcomes, no recurrent instability, and excellent patient satisfaction.

CONCLUSIONS

Anterior shoulder insufficiency after TSA can significantly alter glenohumeral function and is an important cause of patient morbidity. This novel technique exhibits a good outcome and provides an alternative to previous methods of repair.

Biomechanical analysis of anterior capsule reconstruction and latissimus dorsi transfer for irreparable subscapularis tears

BACKGROUND

Anterior capsule reconstruction (ACR) and latissimus dorsi transfers (LTs) have been proposed as solutions for irreparable subscapularis tears. The purpose of this study was to biomechanically assess the effects of ACR and LT separately and together for treatment of irreparable subscapularis tears.

MATERIALS AND METHOD

Eight cadaveric shoulders underwent 5 testing conditions: (1) intact, (2) irreparable subscapularis tear, (3) ACR, (4) ACR+LT, and (5) LT alone. Anteroinferior translation loads of 20, 30, and 40 N were applied. Range of motion and magnitudes of glenohumeral anterior and inferior translation at 0°, 30°, and 60° of abduction and at 30° and 60° of external rotation were measured for each testing condition.

RESULTS

At 30° of abduction and 60° of external rotation, ACR and ACR+LT restored anterior and inferior translation to intact (P > .702) for 30 and 40 N of anteroinferiorly directed force. LT alone did not restore anteroinferior stability at 30 N of distraction force at 30° of glenohumeral abduction and 60° of external rotation (P < .001). However, ACR and ACR+LT led to significant decreases in total range of motion compared to intact at 0° and 30° of abduction (P < .007).

CONCLUSIONS

ACR with dermal allograft was able to restore anteroinferior stability in the setting of irreparable subscapularis tears but resulted in decreased total range of motion. LT alone was less effective than ACR in restoring glenohumeral stability. The addition of LT as a dynamic restraint did not increase the efficacy of ACR.

Anterior Capsule Reconstruction for Irreparable Subscapularis Tears

A subscapularis complete tear presents its own challenges in management. The glenohumeral biomechanics and force couple are reliant on a competent and functioning subscapularis muscle. An irreparable subscapularis makes those same challenges even more difficult to address. Traditionally, this problem has been addressed with tendon transfers, including pectoralis major or latissimus dorsi. These techniques can alter the ideal biomechanics of the shoulder and have high rates or failure. Iliotibial autograft or tibialis anterior have also been wrought with high failure rates. Recently, the superior capsular reconstruction has been described for irreparable tears of the supraspinatus and infraspinatus. Theoretically, this procedure can act as a check rein against subluxation, and may serve to reconnect the force couples of the rotator cuff. Anterior escape may represent a similar challenge when the irreparable rotator cuff tendon is the subscapularis. To address this, we describe an open anterior capsule reconstruction technique with an acellular dermal graft. We theorize that this procedure may serve in a similar capacity to its superior capsular counterpart.

Anterior Capsule Reconstruction Technique With an Acellular Dermal Allograft

An irreparable subscapularis may have a debilitating influence on glenohumeral joint biomechanics. Traditional treatment approaches are focused on tendon transfers, among which the most popular are pectoralis major and latissimus dorsi transfers. However, these techniques present significant retear rates, possible nerve injuries, and altered biomechanics. Other techniques like tibialis anterior or iliotibial autograft grafting also have many reported failures. We describe an all-arthroscopic anterior capsule reconstruction technique with an acellular dermal graft.

Anterior Capsular Reconstruction for Irreparable Subscapularis Tears

Chronic anterior shoulder instability due to structural failure of the subscapularis muscle and the anterior capsule is a rare and challenging diagnosis for surgeons to manage because poor-quality capsular, labral, and rotator cuff tissue often limits effective treatment options. If primary repair is not possible because of retraction and poor tissue quality, reconstruction with an allograft or autograft may be the only joint-preserving option. The purpose of this article is to describe a surgical technique for anterior capsular reconstruction using a human acellular dermal allograft for the treatment of irreparable subscapularis tears.

Long-Term Outcome After Pectoralis Major Transfer for Irreparable Anterosuperior Rotator Cuff Tears

BACKGROUND

Promising short-term outcomes after pectoralis major tendon transfer for the treatment of an irreparable anterosuperior rotator cuff tear have been reported. The purpose of this study was to evaluate the long-term outcome.

METHODS

Twenty-seven consecutive patients with irreparable anterosuperior rotator cuff tears without advanced cuff arthropathy or advanced humeral head migration were treated with a partial subcoracoid pectoralis major tendon transfer between 2004 and 2005. At an average of 10 years (range, 9 to 11 years) postoperatively, 22 patients (82%) with an average age of 62 years (range, 42 to 74 years) at the time of surgery had a long-term follow-up examination that included the pain score, strength and range-of-motion assessment, Constant score, Simple Shoulder Test (SST), as well as radiographic and ultrasonographic imaging. The long-term results were compared with the preoperative findings as well as the short-term results that were collected from a previous evaluation.

RESULTS

The adjusted Constant score increased from 54% to 87% at the short-term follow-up (p < 0.001) and remained improved at the long-term follow-up, with a mean score of 83% (p = 0.001). While the significant improvement of the pain level at the short-term follow-up was maintained at the time of final follow-up (p = 0.001), the increase in strength returned to the preoperative level (p = 0.178), and the improvement in range of motion diminished again over time despite remaining significantly improved (p = 0.029), especially with regard to internal rotation (p < 0.001). At the long-term follow-up, 77% of the patients were very satisfied with the procedure. A third of the patients had no progression of cuff arthropathy, a third had progression by 1 grade, and a third had progression by ≥2 grades. At the time of final follow-up, 1 patient (5%) had undergone revision surgery to reverse shoulder arthroplasty.

CONCLUSIONS

Pectoralis major tendon transfer for the treatment of irreparable anterosuperior rotator cuff tears results in a significant clinical improvement even 10 years after surgery, especially with respect to pain and internal rotation. Despite long-term radiographic progression of cuff arthropathy, patient satisfaction remains high over time, with a low rate of salvage with reverse shoulder arthroplasty.

LEVEL OF EVIDENCE

Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Pectoralis major transfer for treatment of irreparable subscapularis tear: a systematic review

PURPOSE

Irreparable ruptures of the subscapularis tendon lead to impaired function of the shoulder and presents a surgically complex problem. Transfer of the pectoralis major tendon has been reported as a possible treatment option. The purpose of this systematic review is to critically examine the outcomes of pectoralis major transfers for the treatment of irreparable subscapularis tears.

METHODS

A systematic review of the literature was performed using search of electronic databases. No language restrictions were applied. Case reports, review articles, and operative techniques without outcome data were excluded. All the outcomes reported by each study were analyzed and when possible, data were pooled to generate frequency-weighted values to summarize outcomes.

RESULTS

Eight studies with a total 195 shoulders were included in this systematic review. The mean age of patients was 58.8 years (range 18-81 years) and the mean follow-up was 33.4 months (range 6-80 months). Constant scores improved from a mean pre-operative score of 37.8 ± 6.8, to a mean postoperative score of 61.3 ± 6.5 (p < 0.0001). Pain scores could not be pooled as different scales were used. Nevertheless, a trend in pain reduction was noted in all papers. Functional outcomes were less favorable in patients with massive rotator cuff tears or previous shoulder replacements. Moreover, the Constant scores were significantly higher in patients following subcoracoid transfer of the pectoralis major tendon compared to patients who received supracoracoid transfer (p < 0.001). The overall reported incidence of postoperative nerve palsy is low (one transient musculocutaneous nerve palsy and one axillary nerve dysfunction out of 195 cases).

CONCLUSIONS

The systematic review based on frequency-weighted means demonstrated improvement in shoulder function, strength and pain relief after pectoralis major transfer for irreparable subscapularis tear.

LEVEL OF EVIDENCE

IV.

Arthroscopic transfer of the pectoralis major for irreparable tear of the subscapularis: a preliminary report

An irreparable tear of the subscapularis is a surgical challenge. Open approaches have been widely described to restore the anatomy and the function of the shoulder. Pectoralis major transfer is the most common technique used in this difficult clinical situation. Although this procedure has only been performed through an open approach, we describe a new arthroscopic technique for pectoralis major transfer. The critical part in this technique, in general, is the musculocutaneous nerve dissection, which is also possible through the arthroscopic approach. Together with an alternative method of harvesting using chips of bone and a minimal skin incision, this promising, less invasive technique presents all the advantages of the arthroscopic approach and provides a strong fixation to the lesser tuberosity.