Immobilisation in external rotation after first-time traumatic anterior shoulder instability reduces recurrent instability: A meta-analysis

Abstract

Importance Cadaveric and MRI findings have demonstrated significantly less labral separation and displacement when the shoulder is placed in external rotation as compared with internal rotation. Objective The purpose of the current study is to meta-analyse the randomised controlled trials in the literature to compare immobilisation in external versus internal rotation after first-time anterior shoulder dislocation. Evidence review A literature search of MEDLINE, EMBASE and the Cochrane Library was performed based on the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Randomised controlled trials comparing immobilisation in external rotation versus internal rotation for first-time anterior shoulder dislocation were included. Findings Nine randomised controlled trials with 795 patients were included. The mean age of included patients was 29 years, 82.4% were male and the mean follow-up was 25.5 months. As compared with immobilisation in internal rotation, compliance was significantly higher (74.5% vs 67.4%, p=0.01), and the rate of recurrent dislocations was significantly lower (22.2% vs 33.4%, p=0.02) with immobilisation in external rotation. Additionally, in patients 20-40 years old the rate of recurrent dislocations was significantly lower in those treated with immobilisation in external rotation than internal rotation (12.1% vs 31.4%, p=0.006). Immobilisation in external rotation also resulted in a higher rate of return to preinjury level of play (60.1% vs 42.6%, p=0.0001). Conclusions and relevance Immobilisation of the shoulder in external rotation after a traumatic first-time anterior shoulder dislocation results in a higher compliance rate, a lower recurrent dislocation rate and a higher rate of return to play as compared with immobilisation in internal rotation. Level of evidence Level I.