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 fixation.

Aims: This study compares functional outcomes and patient experience between cast immobilization and early mobilization in a removable boot after ankle fracture fixation, 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 difference 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 difference, and failed to detect a difference between groups. Boot participants had better dorsiflexion, particularly those with comminuted fractures, and better plantarflexion, 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 differences 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 fixation. Boots provided improved dorsiflexion and plantarflexion for some subgroups, but higher complication rates. Treatment modality decisions could therefore be informed by individual patient preference.