Outcomes after revision total shoulder arthroplasty with pectoralis major transfer

Irreparable tears of the subscapularis muscle pose a difficult problem to patients and the treating physician. Pectoralis major transfers (PMTs) are often used in patients with irreparable tears of the subscapularis muscle with good outcomes. Similarly, PMT used in conjunction with shoulder arthroplasty has been proposed for patients with deficient subscapularis muscles and end stage glenohumeral arthritis. The data for PMT done in the setting of shoulder arthroplasty is sparse in the literature. This study aims to be among the first to report on long-term outcomes for arthroplasty done concomitantly with PMT.

This is a retrospective case series of patients who underwent PMT for subscapularis tendon deficiency in conjunction with revision total shoulder arthroplasty (TSA) by a single surgeon between 2000 and 2017. Patients indicated for shoulder arthroplasty who had an irreparable subscapularis tear were considered for pectoralis major transfer. Exclusion criteria were lack of postoperative radiographic imaging and follow-up time of less than 12 months. Primary endpoints included shoulder range of motion and patient reported outcomes.

5 patients were included. The mean time to the last follow-up visit for revision TSA was 10.0 years (range 3.3-15.1). Only one patient had increased passive external rotation at final follow-up. Implant survivorship was 100 %; there were no further revisions or surgical interventions. Forward elevation increased from 69 ± 57° to 100 ± 69°, external rotation was 42 ± 19° to 42 ± 26°, and internal rotation improved from L4 to L2. ASES scores improved from 25 ± 11 to 39 ± 26, SST scores increased from 3 ± 3 to 6 ± 3, and VAS scores decreased 8 ± 1 to 6 ± 2.

PMT with revision shoulder arthroplasty provides satisfactory range of motion and shoulder function in patients with irreparable subscapularis tears. This study evaluated mid-to long-term data and demonstrated favorable outcomes in revision TSA with PMT patients. TSA concomitant with PMT for a deficient subscapularis was particularly effective in improving stability, internal rotation, and reducing passive external rotation.

IV, retrospective case series.