Standard compared with fracture-specific components in reverse shoulder arthroplasty for proximal humerus fractures : a meta-analysis of clinical outcomes

Abstract

Aims: Reverse total shoulder arthroplasty (RSA) is a well-established treatment for proximal humerus fractures in elderly patients. However, the clinical advantages of standard humeral components compared to fracture-specific components remain unclear. This meta-analysis compares the clinical outcomes and complication rates of standard compared with fracture-specific components in RSA. Methods: A systematic review and meta-analysis were conducted according to the PRISMA guidelines. PubMed, Scopus, and Cochrane Library databases were searched from inception to 12 August 2024. Comparative studies reporting clinical outcomes between standard components and fracture-specific components in RSA for proximal humerus fractures were included. Data on functional scores, range of motion, tuberosity healing, and complications were extracted. Meta-analyses were performed using fixed or random-effects models based on heterogeneity, and risk of bias was assessed using the Newcastle-Ottawa Scale (NOS) and the Cochrane Risk of Bias Tool (RoB2). Weighted mean difference (WMD) was used as the effect size estimator for continuous outcomes, and risk ratio (RR) for dichotomous outcomes. Sensitivity analysis was performed to assess the robustness of the findings. Results: Six studies involving 436 patients (142 with standard components and 294 with fracture-specific components) were included. The pooled analysis found no significant differences between the two component types in functional outcomes (visual analogue scale (VAS): WMD 0.22; American Shoulder and Elbow Surgeons (ASES): WMD -7.43; Constant score: WMD -3.08) or postoperative range of motion (abduction: WMD 1.08°; internal rotation: WMD 0.35°; external rotation: WMD -2.76°; forward flexion: WMD -4.27°). Complication rates, including tuberosity failure (RR 1.34), scapular notching (RR 1.09), and component loosening (RR 1.64), were also comparable. Conclusion: This meta-analysis demonstrates no significant differences in clinical outcomes or complication rates between standard components and fracture-specific components in RSA, suggesting comparable performance in the treatment of proximal humerus fractures. While the findings offer potentially useful insights, they should be interpreted in the context of the limited number of included studies and possible risk of bias.