Outcomes of subacromial balloon spacer implantation for irreparable rotator cuff tears: a systematic review and meta-analysis

Background: The management of irreparable rotator cuff tears remains a topic of considerable debate among orthopedic surgeons. Currently, there is little consensus regarding the gold-standard treatment; however, an emerging option involves the use of a biodegradable subacromial spacer. The purpose of this study, therefore, was to systematically review and synthesize the current literature reporting on the clinical outcomes following implantation of a subacromial balloon spacer (SABS) for the treatment of patients with irreparable rotator cuff tears. Methods: A systematic review of the PubMed Central, MEDLINE, Embase, Scopus, and Cochrane Library databases from inception through December 2022 was performed. Clinical outcome studies reporting on functional and clinical outcomes, as well as postoperative complications, were included. Results: A total of 127 studies were initially identified, of which 28 were deemed eligible for inclusion in our review. Of these studies, 17 reported adequate preoperative and postoperative data (mean and a measure of variance) and thus were included in the meta-analysis. Among the included studies, a total of 894 shoulders (886 patients) were included; the mean age was 67.4 years (range, 61.7-76.2 years). The average follow-up period was 30.4 months (range, 12-56 months). All postoperative patient-reported outcomes improved significantly from baseline, including the Constant score (mean difference, 33.53; P < .001), American Shoulder and Elbow Surgeons score (mean difference, 40.38; P < .001), Oxford Shoulder Score (mean difference, 12.05; P = .004), and visual analog scale pain score or Numeric Pain Rating Scale score (mean difference, -3.79; P < .001). Forward elevation (mean difference, 24 degrees; P < .001), abduction (mean difference, 52 degrees; P = .02), and external rotation (mean difference, 15 degrees; P <.001) improved. Device-related complications occurred at a rate of 3.6%, the most common of which were balloon migration (1.0%) and synovitis (0.6%). Ultimately, 5% of patients required salvage reverse shoulder arthroplasty. Conclusion: Short-term outcomes suggest that SABS implantation can be a safe and effective treatment and appears to be associated with early improvements in postoperative pain and function. Clinical heterogeneity, use of concomitant procedures, and variations in patient selection limit our ability to conclusively interpret the available evidence. We do not yet know the potential therapeutic value of SABS implantation relative to other currently accepted treatment strategies, the length of symptomatic improvement that can be expected, or the long-term implications of SABS use on the outcomes of further salvage procedures. Level of evidence: Level IV; Systematic Review (c) 2023 Journal of Shoulder and Elbow Surgery Board of Trustees. All rights reserved.