The influence of sex: A Deep Dive into Reverse Total Shoulder Arthroplasty Outcomes

Abstract

Background: The increasing prevalence of Reverse Total Shoulder Arthroplasty (RTSA) highlights the need for detailed analyses of sex-based outcomes. This study aims to elucidate the differences in functional, pain, and radiological outcomes between sexes following RTSA, addressing a crucial gap in understanding how sex influences recovery and overall results.

Methods: We analyzed data from RTSA procedures recorded between 2006 and 2022 in a local registry, with an average age of 72 years. Linear mixed models and Logistic Regression models were utilized to explore associations between clinical outcomes (range of motion, function, pain), radiological outcomes (scapular notching, bone resorption, implant loosening) and sex up to 24 months. A mediation analysis was conducted to assess the mediating effects of negative affect between sex and pain.

Results: Out of 2,747 RTSA cases, 1,804 (65%) were performed on female patients. Differences were noted over the 24 month follow-up with males demonstrating better overall function compared to females (p<0.001). Females demonstrated increased preoperative pain levels compared to males without significant differences post-surgery. Linear mixed models revealed significant effects of sex on pain, function, flexion and internal rotation over time. No differences were noted in any of the radiological outcomes over time. Mediation analysis showed a significant indirect effect (b=-0.107 (95% CI [ -0.145, -0.07], p < 0.001) between sex and postsurgical pain.

Conclusions: Although radiological outcomes were comparable, a detailed analysis reveals sex differences in clinically important outcomes. These differences should be considered during preoperative counseling and in risk stratification for patients undergoing RTSA.

Level of evidence: Level III; Retrospective Cohort Study.

Keywords: Shoulder Arthroplasty; clinical outcomes; radiological outcomes; sex differences.