Immobilization in external rotation after primary shoulder dislocation did not reduce the risk of recurrence: a randomized controlled trial.

BACKGROUND: The treatment of primary traumatic anterior shoulder dislocation varies widely from no immobilization, to two or three weeks of immobilization in internal rotation with the arm in a sling, to treatment with a brace in external rotation. The aim of the present clinical trial was to compare immobilization in internal and external rotation after anterior shoulder dislocation.

METHODS: One hundred and eighty-eight patients with a primary anterior traumatic dislocation of the shoulder were randomly assigned to treatment with immobilization in either internal rotation (ninety-five patients) or external rotation (ninety-three patients) for three weeks. The primary outcome measure was a recurrent dislocation within twenty-four months of follow-up.

RESULTS: The follow-up rate after a minimum period of two years was 97.9% (ninety-three of ninety-five) in the internal rotation group and 97.8% (ninety-one of ninety-three) in the external rotation group. The compliance rate with the immobilization was 47.4% (forty-five of ninety-five) in the internal rotation group and 67.7% (sixty-three of ninety-three) in the external rotation group. The intention-to-treat analyses showed that the recurrence rate was 24.7% (twenty-three of ninety-three) in the internal rotation group and 30.8% (twenty-eight of ninety-one) in the external rotation group (p = 0.36).

CONCLUSIONS: Immobilization in external rotation does not reduce the rate of recurrence for patients with first-time traumatic anterior shoulder dislocation.