Factors affecting the incidence of surgical site infection after geriatric hip fracture surgery: a retrospective multicenter study

Background Geriatric hip fracture is a common type of osteoporotic fracture with high mortality and disability; surgical site infection (SSI) can be a devastating complication of this injury. By far, only a few studies identified easily remediable factors to reduce infection rates following hip fracture and less researches have focused on geriatric patients. The objective of this study was to identify potentially modifiable factors associated with SSI following geriatric hip fracture surgery. Methods This retrospective, multicenter study involves three level I hospitals. A total of 1240 patients (60 years or older) underwent hip surgery with complete data were recruited between January 2016 and June 2018. Demographics information, medications and additional comorbidities, operation-related variables, and laboratory indexes were extracted and analyzed. Receiver operating characteristic (ROC) analysis was performed to detect the optimum cut-off value for quantitative data. Univariate and multivariate logistic analysis model were performed respectively to identify the independent predictors. Results Ninety-four (7.58%) patients developed SSI in this study, and 76 (6.13%) had superficial infection, while 18 (1.45%) were diagnosed with deep infection. Results of univariate and multivariate analysis showed age > 79 years (OR, 2.60; p < 0.001), BMI > 26.6 kg/m2 (OR, 2.97; p < 0.001), operating time > 107 min (OR, 2.18; p = 0.001), and ALB < 41.6 g/L (OR, 2.01; p = 0.005) were associated with an increased incidence of SSI; drainage use (OR, 0.57; p = 0.007) could reduce the incidence of wound infection for patients after geriatric hip fracture. Conclusion Accurate modifiable variables, operating time > 107 min, serum albumin < 41.6 g/L, BMI > 26.6 kg/m2, and age > 79 years could be applied to distinguish geriatric patients with high-risk of postoperative surgical site infection.