Mechanical Supports for Acute, Severe Ankle Sprain: A Pragmatic, Multicentre, Randomised Controlled Trial 

SLR - January 2010 - Yuko Miyazaki

Reference: 
Lamb, S.E., Marsh, J.L., Hutton, J.L., Nakash, R., Cooke, M.W. (2009).  Mechanical supports for acute, severe ankle sprain: A pragmatic, multicentre, randomised controlled trial. Lancet, 373: 575-81.

Scientific Literature Reviews

Reviewed by:  Yuko Miyazaki, DPM
Residency Program: Kaiser North Bay Consortium, Vallejo

Podiatric Relevance:
Severe ankle sprains are commonly treated by foot and ankle surgeons, but there is a relative lack of evidence to aid in clinical decision making, specifically with respect to which types of braces are the most effective.

Methods:
In this multicenter randomized trial with blinded assessment of outcome, 584 participants with severe ankle sprains were recruited between April 2003 and July 2008 from eight emergency departments across England.  The supports to promote early recovery and mobilization were tubular compression (double layer of tubegrip) as the reference treatment, the Bledsoe boot, the Aircast and a below-knee cast with weight bear as tolerated (applied for 10 days).  Severity of sprain was identified by the inability to fully bear the weight for at least 3 days after the injury.  All participants had a radiograph to rule out fracture.  Participants were provided with the mechanical support by a trained health-care professional and given advice on reducing swelling and pain.  The primary outcome was quality of ankle function at 3months and final outcome at 9 months, measured with the Foot and Ankle Score.

Results: 
At 3 months the below –knee cast had a more rapid recovery than the compression bandage.  There were significant benefits in quality of ankle function with the cast compared with the compression bandage (mean difference 9%, P <0.007) as well as in pain, symptoms and activity.  The Aircast did not offer as wide a range of benefits as a cast, but the effect on quality of ankle function at 3months was similar to what the cast offered.    There was no benefit with Bledsoe boot compared to the tubular compression bandage, which was the least effective treatment during the entire recovery course.  There were no significant differences between a compression bandage and the other treatments at 9 months. 

Conclusions:
With severe ankle sprains, the authors concluded that a short duration (10 days) of immobilization in a below-knee cast ( weight bear as tolerated) or Aircast provides a faster recovery compared to treating with only a compression bandage or Bledsoe boot.   There was a limitation of their study in that compliance with the various supports was not measured; however, below-knee casts demonstrated a wide range of positive effects at the 3 month interval.