Effect of Medial or Lateral Graft Failure on Graft Volume and Clinical Outcomes After Superior Capsule Reconstruction for Irreparable Rotator Cuff Tears

Background:Graft failure is a common complication after superior capsule reconstruction (SCR). The graft in SCR is fixed on the greater tuberosity and superior glenoid, and graft failure has been reported on both sides.Purpose:To evaluate the clinical manifestations of patients with graft failure after SCR and identify the clinical and radiological differences between medial and lateral graft failure.Study Design:Cohort study; Level of evidence, 3.Methods:Patients who underwent SCR with a dermal allograft for symptomatic irreparable rotator cuff tears between March 2018 and September 2021 were retrospectively reviewed. All patients had minimum 2-year follow-up and underwent magnetic resonance imaging at 6 months postoperatively. Patients with graft failure were divided into 2 groups: those with lateral graft failure on the greater tuberosity side (group I) and those with medial graft failure on the glenoid side (group II). Patients with intact grafts were included in group III as a control group. Intergroup differences in clinical and radiological characteristics were analyzed, and multiple regression analysis was performed.Results:Among the 93 patients included, there were 18 patients in group I, 15 in group II, and 60 in group III. Overall, 11 patients (61.1%) in group I and 9 patients (60.0%) in group II had a partial graft rupture at one anchor. The postoperative graft volume was significantly lower in group I than in groups II and III (2514.0 ± 564.3 mm3, 3183.5 ± 547.1 mm3, and 3198.0 ± 584.8 mm3, respectively; P = .002 for group I vs II; P < .001 for group I vs III). The acromiohumeral distance (AHD) was significantly increased at 6 months postoperatively compared with before surgery in group I (6.6 ± 1.6 mm vs 4.3 ± 1.9 mm, respectively; P < .001) and group II (7.4 ± 1.3 mm vs 5.7 ± 1.7 mm, respectively; P = .002). However, group I exhibited a significantly greater decrease in the AHD over time than group II ( P < .001) and a significantly lower AHD at the final follow-up than the other groups ( P < .001). The postoperative American Shoulder and Elbow Surgeons score was significantly lower in group I than in the other groups ( P < .001). On multiple regression analysis, fatty infiltration of the infraspinatus muscle, Hamada grade, and graft width were independent factors for lateral graft failure.Conclusion:Patients with lateral graft failure had inferior clinical outcomes and lower postoperative graft volumes than those with medial graft failure after SCR using a dermal allograft. The AHD of patients with lateral graft failure improved postoperatively; however, it deteriorated over time.