Incidence and risk factors associated with postoperative surgical site infection in younger adults with hip fractures: a case-control study

Purpose Hip fracture is associated with high morbidity and mortality. The most common complication after hip fracture is surgical site infection (SSI). The goal was to investigate risks associated with SSI in young adults who underwent surgery for hip fractures. Methods We conducted a case-control study enrolling 1243 patients from Jan 2015 to Dec 2019. This study investigated the multifaceted factors including demographics, lifestyles, comorbidities, surgical variables, and laboratory test results. Patients were divided into the case group (developed SSI) and control group (not developed SSI). Univariate analyses and multivariate logistic regression analyses were used to identify the risk factors independently associated with SSI. Results A total of 25 patients including 16 (1.8%) in femoral neck fracture and nine (2.5%) in intertrochanteric fracture developed SSI post-operatively, with an accumulated incidence rate of 2.0%. Among them, four cases (1.6%) were deep SSI and 21 cases (98.4%) were superficial SSI. In most cases, Staphylococcus aureus caused the infections. Diabetes mellitus (OR 4.05, 95%CI: 1.08-15.23, P = 0.038), cerebrovascular disease (OR 3.71, 95%CI: 1.14-12.03, P = 0.029), heart disease (OR 6.23, 95%CI: 1.81-21.48, P = 0.004), and operative time (OR 1.01, 95%CI: 1.01-1.02, P = 0.002) in femoral neck fractures while ALP (> upper limit) (OR 33.39, 95%CI: 2.21-504.89, P = 0.011) and CK (> upper limit) (OR 40.97, 95%CI: 1.70-989.31, P = 0.022) in intertrochanteric fractures were found to be significantly associated with SSI. Conclusion Targeted pre-operative management, depending on the patients' fracture type and risk factors, should be developed to reduce post-operative SSI rates of younger adults with hip fracture.