Subacromial spacer implantation for massive rotator cuff tears

BACKGROUND Massive rotator cuff tears (MRCT) can be treated arthroscopically by partial reconstruction, tenotomy/tenodesis of the long head of the biceps, and debridement. A new treatment option is the additional implantation of a biodegradable spacer (InSpace Balloon®; ISB) into the subacromial space, which reduces subacromial shear forces to keep the humeral head centered in the glenoid. The aim of this study is to investigate the clinical outcome of patients with MRCT who were treated arthroscopically with or without an additional ISB. METHODS The clinical outcome of patients treated with conventional arthroscopic techniques (n = 11, group A, partial repair, biceps tenotomy, and debridement) and that of patients treated with a supplementary ISB (n = 12, group B) was retrospectively analyzed. Preoperatively and postoperatively, shoulder function was assessed with the Constant and American Shoulder and Elbow Surgeons (ASES) scores. At follow-up after a mean of 22 months, patients filled out a questionnaire about their subjective satisfaction. RESULTS Preoperative shoulder function was lower in patients treated with an ISB (ASES score: group A, 59.1; group B, 31.5; Constant score: group A, 60.7; group B, 36.8). At follow-up, both groups had improved shoulder function (Constant score: group A, 60.7-77.6; p < 0.001; group B, 36.8-69.5; p < 0.001; ASES score: group A, 59.1-88.6; p < 0.001; group B, 31.5-85.7; p < 0.001). Patients in both groups were subjectively satisfied with their outcome. CONCLUSION The ISB is a feasible treatment option for MRCT, providing subjective pain relief and improved shoulder function. Further studies with larger patient collectives and longer follow-up are needed to confirm whether it is a safe and cost-effective treatment.