Abstract
INTRODUCTION: Middle trapezius tendon (MTT) transfer has emerged as a viable treatment option for isolated irreparable supraspinatus tears (IIST). This study aimed to compare the clinical outcomes of MTT transfer between patients with intact subscapularis and those with concomitant subscapularis tears. METHODS: A retrospective review was conducted on patients who underwent arthroscopically assisted MTT transfer for IISTs between January 2018 and December 2023, with a minimum follow-up of 24 months. Patients were stratified into two groups: subscapularis intact and subscapularis tear (Lafosse type I-III, treated with debridement or repair). Patients with incomplete follow-up or missing data were excluded. Clinical outcomes-including pain (VAS), functional scores (Constant and ASES), active range of motion (ROM), and strength-were evaluated pre- and postoperatively. Radiologic assessments included acromiohumeral distance (AHD) and Hamada grade for glenohumeral arthritis. Minimal clinically important differences (MCID) and complications were also recorded. RESULTS: After excluding five patients, 61 patients were included (48 Subscapularis-intact, 13 Subscapularis-tear). Both groups demonstrated significant postoperative improvements in VAS, Constant, ASES scores, ROM and strength in forward elevation and abduction. Preoperative internal rotation ROM and strength were lower in the subscapularis-tear group, but postoperative values were comparable between the groups. MCID achievement rates exceeded 90 % in both groups. Complications included one retear and one minor progression of arthritis in the subscapularis-tear group, one infection in the subscapularis-tear group, and one retear in the subscapularis-intact group. CONCLUSION: MTT transfer provides significant improvements in pain, function, forward elevation, and abduction in patients with IISTs, regardless of preoperative subscapularis integrity. Although preoperative internal rotation ROM and strength were lower in the subscapularis-tear group, postoperative recovery restored these measures to levels comparable with the subscapularis-intact group, supporting the efficacy of MTT transfer even in the presence of concomitant subscapularis pathology.