Subacromial balloon spacer massive rotator cuff tear treatment systematic review and meta-analysis: Patient selection and physical therapy may be keys to outcome success.

Purpose: Subacromial balloon spacer implantation (SBSI) efficacy for massive rotator cuff tear treatment was evaluated based on perceived shoulder function, active shoulder mobility, pain, complications and research study methodological quality. The purpose was to better discern the efficacy of this device from both surgical and rehabilitative perspectives to improve patient outcomes.

Methods: PubMed, EMBASE and Cochrane Library databases were searched (1 January 2010 to 1 June 2024) using 'balloon spacer', 'subacromial spacer', 'subacromial balloon spacer', 'shoulder spacer' and 'inspace' terms. Pre-surgery (baseline), 12-month (12-m) and 24-month (24-m) post-SBSI mean changes were compared using one-way ANOVA and Scheffe post hoc tests, and comparative study effect sizes were calculated (p ≤ 0.05).

Results: This review consists of 27 studies with 894 patients (67.8 ± 5 years of age) and 29.4 ± 17-month follow-up. Modified Coleman Methodology Scores (MCMS) revealed fair overall quality (mean = 61.4 ± 11). Constant-Murley scores improved from 34.8 ± 6 (baseline), to 64.2 ± 9 (12-m) and 67.9 ± 8 (24-m) (12-m, 24-m > baseline, p < 0.001). ASES scores improved from 35.1 ± 14 (baseline), to 83.3 ± 7 (12-m) and 81.8 ± 5 (24-m)(12-m, 24-m > baseline, p < 0.001). VAS pain scores improved from 6.6 ± 1 (baseline), to 2.6 ± 1 (12-m) and 2.0 ± 1 (24-m) (12-m, 24-m < baseline, p < 0.001). Flexion increased from 108.5 ± 25° (baseline), to 128.5 ± 30° (12-m) and 151.2 ± 14° (24-m) (24-m > 12-m, baseline, p = 0.01). Abduction increased from 97.7 ± 24° (baseline) to 116.3 ± 23° (12-m) and 142.3 ± 15° (24-m) (24-m > 12-m, baseline, p = 0.02). External rotation (ER) in adduction changed from 33.1 ± 7° (baseline) to 32.5 ± 4° (12-m) and 53.9 ± 9° (24-m)(24-m > 12-m, baseline, p = 0.01). ER at 90° abduction increased from 56.3 ± 3° (baseline) to 83.5 ± 5° (12-m) and 77.1 ± 4° (24-m) (24-m, 12-m > baseline, p = 0.01). Comparison studies, however, displayed insignificant results with small effect sizes.

Conclusion: Despite overall fair MCMS scores, at 24-m post-SBSI, shoulder function improved and pain decreased. More rigorous comparative studies, however, revealed insignificant findings. Patients with the potential to re-establish the essential glenohumeral joint force couple that depresses the humeral head on the glenoid fossa and who comply with physical therapy may be more likely to achieve success following SBSI.

Level Of Evidence: Level IV.