The Ankle Recovery Trial (ART): clinical outcomes and patient experience of a pragmatic multicentre RCT comparing cast with removable boot for early mobilization after ankle fracture surgical fxation

Abstract

Aims This study compares functional outcomes and patient experience between cast immobilization and early mobilization in a removable boot after ankle fracture fxation, with early weightbearing encouraged in both groups. Methods This pragmatic multicentre randomized controlled trial with qualitative component and economic evaluation was conducted across eight UK NHS hospitals. Adults with acute ankle fractures were randomized to receive a plaster cast or removable support boot two weeks post-surgery. The primary outcome was ankle function measured by the Olerud and Molander Ankle Symptom Score (OMAS) seven weeks post-surgery. Secondary outcomes included function at 12 weeks, mechanistic measures, quality of life, complications, and resource use. Subgroup analyses included fracture complexity and age. Patients’ views on both treatments were collected through semi-structured telephone interviews. Results In total, 243 participants consented to be randomized (120 cast; 123 boot), of whom 173 (71.2%) completed the primary outcome. The mean diference in OMAS at seven weeks between groups was 4.9 points favouring the boot (95% CI-1.0 to 10.7), which is below the minimal clinically important diference, and failed to detect a diference between groups. Boot participants had better dorsifexion, particularly those with comminuted fractures, and better plantarfexion, particularly older patients. Complication rates were low, albeit higher in the boot group (cast eight/112; boot 18/117); all were minor, except one case of deep vein thrombosis in the boot group. Overall, we found low wound complication rates (7%). There were no diferences for all other secondary measures. Patients expressed preference for boots at randomization, point of withdrawal from the trial, and during interviews. Conclusion Patients managed in casts and boots had similar functional outcomes following ankle fracture fxation. Boots provided improved dorsifexion and plantarfexion for some subgroups, but higher complication rates. Treatment modality decisions could therefore be informed by individual patient preference.