Combined Superior Capsular Reconstruction and Lower Trapezius Transfer Using an Achilles Tendon Allograft Show Better Clinical Outcomes and Lower Graft Tear Rates Versus Isolated Superior Capsular Reconstruction for Chronic Posterosuperior Irreparabl

PURPOSE: To compare the surgical outcomes of superior capsular reconstruction (SCR) combined with lower trapezius transfer (LTT) using an Achilles tendon allograft versus isolated SCR for the treatment of posterosuperior irreparable massive rotator cuff tears with severe infraspinatus fatty infiltration (Goutallier grades 3-4). METHODS: Between 2016 and 2023, patients who underwent SCR + LTT or SCR alone for posterosuperior irreparable massive rotator cuff tears with severe infraspinatus fatty infiltration and had ≥24-month follow-up were retrospectively reviewed. Clinical evaluation included American Shoulder and Elbow Surgeons (ASES), Constant, visual analog scale (VAS) scores, and active external rotation (ER) were evaluated. Radiographs assessed the acromiohumeral distance, while magnetic resonance imaging at 3 and 12 months evaluated graft integrity for all patients. The minimal clinically important difference (MCID) was calculated as half the standard deviation of score change from baseline to the latest follow-up for the SCR group. The frequency of MCID achievements was then calculated in both groups, based on the SCR-derived thresholds. RESULTS: Thirty-six patients were analyzed (SCR + LTT group, n = 15; SCR, n = 21) with a mean follow-up time of 30.5 ± 6.9 and 36.5 ± 9.2 months, respectively (P = .067). The dataset was disaggregated by sex according to the Sex and Gender Equity in Research guidelines. Clinical and radiologic outcomes did not differ significantly between sexes, except for the preoperative Constant score, which was higher in the male group (male vs female: 60.4 ± 8.1 vs 54.4 ± 8.4, P = .017). At the final follow-up, SCR + LTT yielded superior ASES, Constant scores, lower VAS scores, and better ER than the SCR group (87.7 ± 5.0 vs 74.0 ± 18.3, P = .042; 66.5 ± 4.3 vs 55.6 ± 12.5, P = .004; 0.7 ± 0.6 vs 1.8 ± 1.6, P = .033; and 47.3 ± 13.7 vs 36.0 ± 12.1, P = .049, respectively). Graft tear rates were significantly lower in the SCR + LTT group compared with the SCR group (13.3% vs 47.6%, P = .040), with greater acromiohumeral distance (7.9 vs 6.3 mm, P = .033). At 6 months postoperatively, the SCR + LTT group showed higher ASES score, ER, and lower VAS scores than the SCR group (65.8 ± 13.7 vs 56.4 ± 13.6, P = .036; 37.3 ± 15.3 vs 24.8 ± 17.9, P = .036; and 1.0 ± 0.9 vs 3.5 ± 2.0, P < .001, respectively). The SCR + LTT group showed comparable MCID achievements for the ASES, Constant, VAS scores compared with the SCR groups (86.7% vs 66.7%, P = .252; 46.7% vs 33.3%, P = .449; 66.7% vs 71.4%, P = >.999, respectively). CONCLUSIONS: Both SCR + LTT and SCR improved pain and function at ≥24 months postoperatively in patients with posterosuperior irreparable massive rotator cuff tears with severe infraspinatus fatty infiltration. However, SCR + LTT provided superior clinical outcomes, greater ER restoration, lower graft tear rates, and comparable MCID achievements compared with isolated SCR. LEVEL OF EVIDENCE: Level III, retrospective cohort study.