Introduction. Unstable ankle fractures are routinely managed operatively. Due to soft-tissue and implant related complications, there has been recent literature reporting on the non-operative management of well-reduced medial malleolus fractures following fibular stabilisation, but with limited evidence supporting routine application. This trial assessed the superiority of internal fixation of well-reduced (displacement ≤2mm) medial malleolus fractures compared with non-fixation following fibular stabilisation. Methods and participants. Superiority, pragmatic, parallel, prospective randomised clinical trial conducted over a four year period. A total of 154 adult patients with a bi- or trimalleolar fractures were recruited from a single centre. Open injuries and vertical medial malleolar fractures were excluded. Following fibular stabilisation, patients were randomised intra-operatively on a 1:1 basis to fixation or non-fixation after satisfactory fluoroscopic fracture reduction was confirmed. The primary outcome was the Olerud Molander Ankle Score (OMAS) at one-year post-randomisation. Complications and radiographic outcomes were documented over the follow-up period. Results. Among 154 participants (mean age, 56.5 years; 119 women [77%]), 144 [94%] completed the trial. At one-year the median OMAS was 80 (IQR, 60–90) in the fixation group compared with 72.5 (IQR, 55–90) in the non-fixation group (p=0.17). Complication rates were comparable. Significantly more patients in the non-fixation group developed a radiographic non-union (20% vs 0%; p<0.001), with the majority (n=8/13) clinically asymptomatic and one patient required surgical re-intervention for this. Fracture type and
