Subacromial balloon spacer implantation for patients with massive irreparable rotator cuff tears achieves satisfactory clinical outcomes in the short and middle of follow-up period: a meta-analysis

Purpose This meta-analysis was performed systematically to evaluate the efficacy of subacromial balloon spacers for patients with massive, irreparable rotator cuff tears. Methods Electronic databases, including Medline/PubMed, Embase and Cochrane Library, were systematically searched to identify studies evaluating the efficacy of subacromial spacers for patients with irreparable or massive rotator cuff tears. Meta-analyses were performed to pool the outcome estimates of interest, such as the total constant score (TCS) and its sub-score (pain, activities of daily living [ADL], range of motion [ROM], and strength), Oxford shoulder score (OSS), American Shoulder and Elbow Society scores (ASES) and numeric rating scale (NRS), as well as different outcomes at different time points in the follow-up period. Results Ten studies with a total of 261 patients involving 270 shoulders were deemed viable for inclusion in the meta-analysis. The combined results demonstrated significant improvements in the TCS at the final follow-up (pooled mean difference = 26.4, 95% confidence intervals [CIs] 23.3 to 29.5). A sensitivity analysis and subgroup analysis, which were implemented based on two factors, different follow-up points and sub-scores (pain, ADL, ROM, and strength), revealed a consistent trend. The combined shoulder motion results demonstrated significant improvements in the forward flexion and external rotation (0° abduction) variables rather than in the abduction and external rotation (90° abduction) variables. Additionally, significant improvements in the OSS and ASES and a decrease in the NRS were observed in the middle of the follow-up period. Conclusion This meta-analysis indicated that subacromial balloon spacer implantation for patients with massive irreparable rotator cuff tears may achieve satisfactory outcomes between 3 months and 3 years of follow-ups. Although the short- and middle- term effect is significant, the long-term effect needs to be confirmed by large-sample randomized controlled trial. Level of evidence IV.