Comparison of lesser tuberosity osteotomy to subscapularis peel in shoulder arthroplasty: A randomized controlled trial

Abstract

Background: Controversy exists regarding the optimal technique of subscapularis tendon mobilization during shoulder arthroplasty. The purpose of the present randomized double-blind study was to compare two of these techniques - lesser tuberosity osteotomy and subscapularis peel - with regard to muscle strength and functional outcomes. Methods: Patients undergoing shoulder arthroplasty were randomized to undergo either a lesser tuberosity osteotomy or a subscapularis peel. The primary outcome was subscapularis muscle strength as measured with an electronic handheld dynamometer at twenty-four months postoperatively. Secondary outcomes included the Western Ontario Osteoarthritis of the Shoulder Index and American Shoulder and Elbow Surgeons scores. A sample size calculation determined that eighty-six patients provided 90% power with a 0.79 effect size to detect a significant difference between groups. Results: Forty-three patients were allocated to subscapularis osteotomy, and forty-four patients were allocated to subscapularis peel. Eighty-three percent of the study cohort returned for the twenty-four-month follow-up. The primary outcome of subscapularis muscle strength at twenty-four months revealed no significant difference (p = 0.131) between the lesser tuberosity osteotomy group (mean [and standard deviation], 4.4 ± 2.9 kg) and the subscapularis peel group (mean, 5.5 ± 2.6 kg). Comparison of secondary outcomes, including the Western Ontario Osteoarthritis of the Shoulder Index and American Shoulder and Elbow Surgeons scores, demonstrated no significant differences between groups at any time point. Compared with baseline measures, mean subscapularis muscle strength, Western Ontario Osteoarthritis of the Shoulder Index score, and American Shoulder and Elbow Surgeons score all improved significantly in both groups at twenty-four months (p < 0.001). Discussion: No significant differences in the primary or secondary outcomes of function were identified between the lesser tuberosity osteotomy group and the subscapularis peel group. For the parameters investigated, this trial does not demonstrate any clear advantage of one subscapularis treatment technique over the other. Level of Evidence: Therapeutic Level I. See Instructions for Authors for a complete description of levels of evidence. Copyright © 2012 by the Journal of Bone and Joint Surgery, Incorporated.