Published: 06 July 2021
A study funded by the NIHR has discovered little difference in the clinical effectiveness of two treatments for ankle fractures, the traditional cast and the removable brace. The researchers behind the Ankle Injury Rehabilitation (AIR) Trial at Warwick Clinical Trials Unit conclude therefore that the choice of treatment method should be down to cost and patient preference.
The trial was led by NIHR Career Development Fellow Professor Rebecca Kearney, of Warwick Medical School at the University of Warwick. The team’s findings are published today in The BMJ.
Ankle fractures are very common, affecting 184 people per 100,000 annually. Use of the removable brace, a plastic boot constructed in two halves secured by Velcro, has become more common in recent years to treat broken ankles, as an alternative to the familiar cast.
The four-year study aimed to compare the cast to the brace in the treatment of ankle fractures and involved 669 patients. Selected at random, half of the trial participants were given a removable brace and the others a cast which fully immobilises the foot. Those with the brace were advised to remove it three times a day and perform ankle movement exercises.
Four months later patients completed a questionnaire to report on pain and functional limitations, such as stiffness, swelling, or pain when walking, climbing stairs, running or doing other activities. Researchers scored their responses, and found no statistically significant difference between either group and between those who had or had not received surgery.
Professor Kearney said: “With cast not being better, it comes down to a decision on the cost of the interventions, patient preferences and if there’s a difference in complications, which we did not find evidence of. Patients should discuss their preference with their clinician, who should take into account these factors.
“If you keep the ankle really still it allows the bones to heal, but that’s not great if all the joints around it stiffen up and the muscles weaken. The idea behind the boot is that you can do movement exercises with the ankle and walk on it to encourage weight-bearing. In theory, that could result in decreased muscle wastage and joint stiffness. In practice though, it didn’t result in better functional outcomes.
“It was also clear in the quantitative data that when patients swapped treatments, they swapped in predominantly one direction – from the cast to the brace.”
The study, Use of cast immobilisation versus removable brace in adults with an ankle fracture: multicentre randomised controlled trial findings is published in The BMJ.