Risk factors for surgical site infection following orthopaedic surgery for fracture by trauma: a nested case–control study

Objective Surgical site infection (SSI) is associated with higher medical expenses and lower patient quality of life. This study aimed to identify specific modifiable risk factors for SSI after orthopaedic surgery for fractures caused by trauma. Design This nested case-control study used a nationwide trauma registry, the Japan Trauma Data Bank (JTDB) database. Methods Patient data from 280 hospitals between January 2004 and May 2019 were retrieved from the JTDB. We included patients with SSI and identified patients without SSI as control subjects using propensity score matching adjusted for unmodifiable factors. Risk factors associated with SSI after orthopaedic trauma surgery were assessed using multilevel mixed-effects logistic regression models. Results In total, 15,910 patients were included in the analysis. Of these patients, 377 (2.4%) had SSI. After propensity score matching, 258 patients with SSI and 2,580 matched patients without SSI were selected. In the multilevel mixed-effects logistic regression analysis, blood transfusion within 24 hours (odds ratio [OR], 1.51; 95% confidence interval [CI], 1.06–2.13) was a significant risk factor for SSI following orthopaedic fracture surgery. The OR of external fixation, transcatheter arterial embolization, and tourniquet for SSI following orthopaedic fracture surgery were 1.40 (95% CI, 0.96–2.03), 1.66 (95% CI, 0.81–3.38), and 2.99 (95% CI, 0.60–14.87), respectively. Conclusions These findings highlight the necessity of exercising caution when implementing blood transfusion within 24 hours as a risk factor associated with SSI following orthopaedic trauma surgery.