Mechanical supports for acute, severe ankle sprain: a pragmatic, multicentre, randomised controlled trial.

Lamb SE, Marsh JL, Hutton JL, Nakash R, Cooke MW; Collaborative Ankle Support Trial (CAST Group)

This study aimed to assess the effectiveness of three different mechanical supports (Aircast brace, Bledsoe boot, or 10-day below-knee cast) compared with that of a double-layer tubular compression bandage in promoting recovery after severe ankle sprains. 584 participants with severe ankle sprain were provided with a mechanical support within the first 3 days of attendance by a trained health-care professional, and given advice on reducing swelling and pain. Patients who received the below-knee cast had a more rapid recovery than those given the tubular compression bandage. The clinically important benefits were noted at 3 months in quality of ankle function with the cast compared with tubular compression bandage as well as in pain, symptoms, and activity. There were no significant differences between tubular compression bandage and the other treatments at 9 months.

A short period of immobilisation in a below-knee cast or Aircast results in faster recovery than if the patient is only given tubular compression bandage. This study recommends below-knee casts because they show the widest range of benefit.

Lancet, 2009, 373(9663), 575-81.

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