A prospective randomized study comparing the effectiveness of midlateral and posterior subacromial steroid injections

Abstract

Copyright © SLACK inCorporAted The authors sought to compare the accuracy and effectiveness of the midlateral and posterior routes of subacromial injection. They conducted a prospective randomized study involving 50 shoulders scheduled to receive subacromial injection via the midlateral or posterior route. After injection, a blinded musculoskeletal radiologist interpreted the radiographs. Age, sex, body mass index, side of shoulder involved, circumference of the proximal humerus, and acromial type were assessed. The accuracy rates of the injections, modified University of California Los Angeles shoulder scores, and visual analog scale pain scores were compared. The accuracy rate of the midlateral route was significantly higher than that of the posterior route (92% vs 68%; P<.034). Although there were significantly improved modified University of California Los Angeles shoulder and visual analog scale pain scores in both groups after injection, differences in functional outcomes were not statistically significant (P>.05). Univariate analysis showed no correlation between accuracy and age, sex, body mass index, or circumference of the proximal humerus. However, injection route had some influence on accuracy, with a crude odds ratio of 5.41 (95% confidence interval, 1.017-28.791; P=.048) for the midlateral route. Midlateral was the preferred route for subacromial injection.