Mid-term outcomes following reverse and anatomic shoulder arthroplasty: a systematic review and meta-analysis

Background: Reverse total shoulder arthroplasty (rTSA), is increasingly used worldwide to treat a growing number of pathologies. By the reversing the native joint configuration, rTSA has been shown to significantly alleviate pain and restore motion even for patients with end-stage pathology. Despite this, there is a lack of evidence substantiating the comparative effectiveness of rTSA vs. anatomic arthroplasty, particularly in the mid-to long-term. Methods: This systematic review and meta-analysis followed Preferred Reporting Items for Systematic Reviews and Meta-Analysesguidelines. The PubMed, Embase, and Scopus databases were searched on February 12, 2024, without date restrictions. Studies in English comparing outcomes of rTSA and anatomic total shoulder arthroplasty (aTSA) with a mean follow-up of at least 4 years were included. Meta-analyses employed random effects models to assess differences in functional outcomes, complication rates, and revision rates between the surgeries. Results: The search yielded 8 comparative studies involving 3453 patients, revealing significant functional improvements in aTSA over rTSA at midterm follow-ups, such as better forward flexion, abduction, and external rotation. However, rTSA resulted in a significantly lower rate of revision surgeries. No significant differences were found in total complication rates, instability, or infection rates between the groups. Both surgeries showed similar patient-reported outcome measures. Discussion: The meta-analysis finds a lack of high-quality trials comparing aTSA and rTSA. Current evidence suggests that aTSA may offer better functional outcomes, while rTSA may provide a more durable construct with lower revision rates. These results are at a significant risk of bias, and robust trials are needed to validate these interpretations.