Fracture-related infection after lateral versus posterolateral approaches in AO/OTA type 44B fractures: A retrospective cohort study.

BACKGROUND: Postoperative wound complications remain a relevant concern after open reduction and internal fixation (ORIF) of ankle fractures. The posterolateral approach has gained popularity for AO/OTA type 44B ankle fractures due to improved access to the posterior malleolus; however, concerns persist regarding a potentially increased risk of fracture-related infection (FRI) compared with the traditional lateral approach. The aim of this study was to compare postoperative infection rates between lateral and posterolateral approaches using the international FRI consensus definition.

METHODS: A retrospective cohort study was conducted including patients with AO/OTA type 44B ankle fractures treated surgically with ORIF at a Level I trauma center between 2019 and 2024. Median follow-up was 14 months. Patients were grouped according to surgical approach (lateral vs. posterolateral). The primary outcome was FRI. Secondary outcomes included minor wound complications, reoperation, and identification of patient and surgery-related risk factors. Multivariate logistic regression analyses were performed to identify factors independently associated with FRI. A predefined subgroup analysis evaluated the impact of posterior malleolar fixation in patients with a posterior malleolar fracture.

RESULTS: A total of 427 patients were included: 300 treated with a lateral approach and 127 with a posterolateral approach. The overall FRI rate was 3.3% (14/427). Infection rates were comparable between the lateral (3.3%) and posterolateral (3.1%) approaches (p = 0.92). Rates of minor wound complications and reoperation were also comparable. The posterolateral approach was predominantly used in fractures requiring posterior malleolar fixation. In the subgroup analysis of patients with a posterior malleolar fracture (n = 198), neither fragment fixation nor surgical approach was independently associated with FRI, despite longer operative in patients undergoing fragment fixation.

CONCLUSION: In AO/OTA type 44B ankle fractures treated with ORIF, the posterolateral approach was not associated with a higher risk of fracture-related infection compared with the lateral approach. These findings support selecting the surgical approach according to fracture morphology rather than concerns regarding postoperative infection.