This study aims to compare the efficacy of the posterolateral and posteromedial approaches in the surgical treatment of trimalleolar ankle fractures involving the posterior malleolus.

A total of 120 patients with trimalleolar ankle fractures (Haraguchi type II posterior malleolar fractures confirmed by computed tomography scans involving >30% of the tibial articular surface) admitted to our hospital were separated into two subgroups according to different intervention methods. The posterolateral approach subgroup had 60 patients (finally, 58 patients were included), and the posteromedial approach subgroup had 60 patients (finally, 57 patients were included). Open reduction and internal fixation (ORIF) were conducted in all patients, addressing the fibula through the same posterolateral incision or through a separate lateral incision in the posteromedial group. The general operation, fracture healing and complication rate of the two subgroups were compared.

The operation time, intraoperative bleeding, incision length and postoperative hospitalisation time of the posterolateral approach subgroup were significantly shorter than those of the posteromedial approach subgroup. The fracture healing time in the posterolateral approach subgroup was significantly shorter than that in the posteromedial approach subgroup, and the complication rate was significantly less than that in the posteromedial approach subgroup. At a mean follow-up of 14.3 months (range: 12–18 months), there was no notable distinction in the excellent and good rates for the posterolateral approach subgroup (94.83%) and the posteromedial approach subgroup (87.72%).

The posterolateral approach for the treatment of trimalleolar ankle fractures shortens the operation time, promotes fracture healing through improved visualisation and reduction quality, lessens the incidence of complications and, compared with posteromedial ORIF, does not affect the functional recovery of the ankle joint.

Trimalleolar ankle fracture

Posterior malleolar fracture

Posterolateral approach

Open reduction and internal fixation operation

Ankle function

Complication

© 2026 The Authors. Published by Elsevier Ltd.