Outcomes of operative and non-operative management of acromial and scapular spine fractures after reverse shoulder arthroplasty: a systematic review.

Background: Reverse total shoulder arthroplasty (rTSA) use is rising. Acromial stress fractures (ASFs) are infrequent but significant complication associated with pain and functional limitation. Optimal management remains uncertain. This review compared union, functional outcomes, and complication between non-operative and operative management of ASF post-rTSA. Methods: Systematic review was conducted in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. MEDLINE, Embase, Scopus, Web of Science, and the Cochrane Library were searched. Randomized controlled trials, observational studies, and case series including ≥3 adult patients with post-rTSA ASFs reporting management and outcomes were eligible. A descriptive quantitative synthesis was undertaken. Results: Fourteen studies (376 fractures in 374 patients; mean age 72.9 years; 78% female) were included. ASF incidence (from 4 studies) ranged from 3.1 to 7.2%. Seventy percent of fractures occurred atraumatically; mean time to diagnosis was 11.3 months; mean follow-up was 41.1 months. Levy type II predominated. Management was non-operative (73.9%) or operative (26.1%). Overall union was 68%, higher after fixation (78% vs. 59.8%; Conclusion: ASFs post-rTSA remains challenging. Surgical fixation demonstrates higher union, but functional outcomes are comparable to non-operative management and surgery carries notable complication burden. Given the descriptive, Level IV evidence, findings are hypothesis-generating; treatment should be individualized, and prospective comparative studies using standardized classifications/outcomes are required.