Clinical Outcome of Arthroscopic Partial Repair of Large to Massive Posterosuperior Rotator Cuff Tears: Medialization of the Attachment Site of the Rotator Cuff Tendon

BACKGROUD: The goal of this study was to evaluate the clinical and radiological outcomes of arthroscopic partial repair with medialization of the attachment site of the rotator cuff tendon and to identify prognostic factors affecting rotator cuff healing in patients with irreparable large to massive posterosuperior rotator cuff tears. METHODS: Between July 2012 and March 2016, 42 patients with irreparable large to massive posterosuperior rotator cuff tears underwent an arthroscopic partial repair with medialization of the attachment site of the rotator cuff tendon. All patients had a minimum of 2-year follow-up (mean, 35.4 ± 7.3 months). Clinical evaluation was performed using the visual analog scale, the University of California, Los Angeles shoulder rating scale, Constant score, and active range of motion. Radiological evaluation was performed using magnetic resonance imaging and simple radiography. RESULTS: Clinical outcomes at the final follow-up improved significantly compared with the preoperative values (all p < 0.001). The failure rate was 23.8% (10/42); however, clinical outcomes significantly improved regardless of cuff healing (all p < 0.001). The mean acromiohumeral distance was 6.5 ± 1.7 mm (range, 3.2–9.7 mm) before surgery and 6.3 ± 1.6 mm (range, 2.8–9.5 mm) at the final follow-up. Preoperative acromiohumeral distance was associated with failure of cuff healing in the univariate analysis (p = 0.043) and multivariate analysis (p = 0.048). A receiver operating characteristic curve was used to determine the predictive cutoff value for the smallest preoperative acromiohumeral distance for successful healing, which was calculated as 5.3 mm. CONCLUSIONS: Despite healing failure, arthroscopic partial repair with medialization can be a possible treatment option for irreparable large to massive posterosuperior rotator cuff tears because of the improvement in clinical outcome. The shorter preoperative acromiohumeral distance was the single most important factor negatively affecting cuff healing, and the likelihood of success of healing might be improved if a repair is performed when the preoperative acromiohumeral distance is < 5.3 mm.