Irreparable Posterosuperior Rotator Cuff Tears Treated With InSpace Balloon With or Without Arthroscopic Subscapularis Repair: Short-Term Clinical Outcomes in a Multicenter Retrospective Study.

Purpose: To evaluate the short-term clinical outcomes of subacromial balloon implantation and concomitant procedures including subscapularis repair for irreparable posterosuperior rotator cuff tears. Methods: This retrospective multicenter study included patients aged ≥40 years who underwent InSpace Balloon implantation between September 2021 and October 2024, with a minimum 12-month follow-up. Patients undergoing posterosuperior cuff repair were excluded. The primary outcome was the American Shoulder and Elbow Surgeons score. Secondary outcomes included Single Assessment Numeric Evaluation, Simple Shoulder Test, visual analog scale-pain, range of motion, complications, and reoperations. Subgroup analyses compared patients with versus without subscapularis repair, those aged <65 versus ≥65, and those who underwent implantation as a revision procedure. Minimal clinically important difference and Patient Acceptable Symptom State rates were calculated using cohort-specific thresholds. Results: Sixty patients met inclusion criteria (mean age: 68.9 ± 8.5 years; mean follow-up: 22.3 ± 7.9 months). Statistically significant improvements were observed across all patient-reported outcome measures (American Shoulder and Elbow Surgeons: 46.5-72.2; Single Assessment Numeric Evaluation: 37.1-67.7; Simple Shoulder Test: 4.6-7.4; visual analog scale-pain: 5.2-2.3; all Conclusions: Subacromial balloon implantation provides significant short-term functional and pain improvements for massive, irreparable posterosuperior rotator cuff tears, regardless of subscapularis repair. Higher clinical outcome scores were observed in patients over age 65. Level of Evidence: Level IV, retrospective therapeutic case series.