Achievement of minimal clinically important difference in shoulder function after reverse shoulder arthroplasty: a retrospective cohort study

Abstract

Purpose

Reverse shoulder arthroplasty (RSA) is a surgical procedure to relieve pain and improve shoulder function. This study aimed to investigate the percentage of patients achieving a minimal clinically important difference (MCID) in the American Shoulder and Elbow Surgeons (ASES) score following RSA and to examine factors associated with MCID achievement.

Methods

This study included 74 patients (26 males and 48 females; mean age 76.9 ​± ​4.7 years) who underwent RSA between January 2019 and July 2022. Patients were grouped based on the change in ASES total score from pre-operative to 1 year post-operative as follows: not achieved group (<16 point change); and improvement criteria achieved group (≥16 point change).

Results

Overall, 81% of patients achieved an ASES score change of ≥16 points. There were no significant differences in demographic characteristics between the two groups. However, the not achieved group had a significantly lower pre-operative pain visual analog scale score and a significantly higher pre-operative ASES total score than the improvement criteria achieved group. Logistic regression analysis identified pre-operative ASES total score as significantly associated with MCID achievement (odds ratio ​= ​0.91, 95% confidence interval 0.87–0.96; p ​= ​0.0007).

Conclusions

The rate of patients achieving a ≥16 point improvement in the ASES total score after RSA was 81%. A high pre-operative ASES total score was identified as a factor limiting MCID achievement, suggesting that patients with a high pre-operative function may experience less significant post-operative improvement.