Predicting surgical site infections after open reduction and internal fixation for ankle fractures

Surgical site infections (SSI) are one of the more severe complications following ankle surgery. It is associated with worse outcomes and re-admissions. Therefore, identification of risk factors is essential. The aim of this study was to identify risk factors for SSI in patients undergoing surgery for ankle fractures.

A retrospective study was performed in a large cohort (n = 929) of patients who underwent open reduction and internal fixation (ORIF) of ankle fractures between 2015 and 2020 in the Netherlands. The primary outcome variables included rate of SSI (superficial or deep) and deep SSI. Prediction factors were categorized as patient-related, injury-related and treatment-related.

The incidence rate was 9.36% for SSI and 3.55% for deep SSI. Univariate analysis showed significant associations for higher age (p < 0.001), DM (p = 0.018), ASA 2 and 3 (p = 0.013 and p < 0.001), bi- and trimalleolar fractures (p = 0.021 and p = 0.013), open fractures (p = 0.004) and small size plate compared to screw fixation (p = 0.027). The only independent significant risk factor for SSI in multivariate analysis was open fracture. For deep SSI the significant risk factors were DM (p = 0.039), ASA 3 and 4 (p = 0.001 and p = 0.005) and open fracture (p = 0.002). After multivariate analysis, the independent significant risk factors were open fracture and ASA 3 and 4.

Higher age, DM, ASA 2 and 3, bi- and trimalleolar fractures, open fractures and standard plate-size implant placement were identified as significant risk factors for SSI. Open fracture was the only significant independent risk factor for SSI after ORIF of ankle fractures. In deep SSI, there were different risk factors. DM, ASA 3 and 4, and open fractures were significantly associated. Although, open fracture and ASA 3 and 4 were the significant independent risk factors.