Transfer of the clavicular portion of the pectoralis major for treatment of irreparable tears of the subscapularis

Purpose of the study Old tears of the subscapular muscle situated in the glenoid area are not ac cessible to direct repair and require locoregional muscle plasty. The clavi cular portion of the pectoralis major can be used for reconstruction. The p urpose of this study was to describe the operative technique and examine sh ort-term outcome. Material and methods Five patients, mean age 54 years (45-71 years) with an irreparable tear of the subscapularis in the glenoid area with fatty degeneration greater than grade two in the Goutallier classification were treated. Four had had previ ous surgery for acromioplasty associated with rotator cuff repair in two or implantation of a humeral prosthesis in one. The preoperative Constant sco re was 27.5 (mean, range = 8.5-54) due td invalidating pain,limited active mobility and reduced muscle force. Gerber's lift-off test was positive for those patients for whom it could be performed. Plain x-rays evidenced anter ior subdislocation of the humeral head in one case. Subscapular reconstruct ion was achieved using the entire clavicular portion of the pectoralis majo r which was dissected and sectioned at its distal insertion on the humerus then reinserted by transosseous suture onto the lesser tuberosity. The reha bilitation program started with active and passive mobility against gravity within a few days of surgery using biofeedback contraction of the muscle f lap then active contractions two months postoperatively. Patients were revi ewed at a mean 19 months (6-42 months) for clinical and radiological assess ment. Results Four patients had a painless shoulder with a negative lift-off test . The gain in active mobility was predominantly achieved with anterior elev ation and abduction. Muscle force was weak leading to a low overall Constan t score at revision (mean = 50, range = 30-63). Radiographically, the humer al head was centered exactly as on the preoperative films. There were no ca ses with a new anterior subdislocation nor an aggravation of a former subdi slocation. Functional outcome was better in cases with a unique tear of the subscapularis. Discussion and conclusion Open surgery is used for primary repair of recent tears of the subscapulari s. This technique gives 80 p. 100 good and very good results. In case of sy mptomatic acromioclavicular osteoarthtisis, better long-term results can be obtained by using a tendodesis of the long biceps and resecting the latera l centimeter of the clavicle. In case of irreparable tears in the glenoid a rea, reconstruction by transfer of the clavicular portion of the pectoralis major can produce a stable painless shoulder with improved active moblity and normal clinical tests. This method provides anterior stability of the g lenohumeral articulation and prevents any anterior subdislocation of the hu meral head, thus protecting the joint from secondary degeneration.