Objective: Surgical site infection (SSI) following hip fractures represents an important complication. This study aimed to investigate the incidence rate after surgery of hip fractures in the elderly and to identify the associated risk factors. Patients: Patients' demographic, injury, and surgery-related data and biochemical indexes were retrospectively reviewed and recorded during their hospitalization, between July 2015 and June 2017. After their discharge from hospital, patients were prospectively followed up at postoperative 1, 3, 6, and 12 months. SSIs were identified by review of patients' medical records and post-discharge telephone follow-up. Univariate and multivariate analyses were performed to determine the independent risk factors associated with SSI. Results: A total of 611 patients undergoing surgery for hip fractures with complete data were included for analysis. During the postoperative one year, 27 SSIs (19 superficial and 8 deep SSIs) developed, indicating the cumulative incidence of 4.4% (95%CI, 2.8-6.0%). Of them, 21 (77.8%) SSIs were detected during patients' hospitalization, and the 6 (22.2%) cases were confirmed via telephone during the post-discharge follow-up. After adjustment of multiple variables, BMI, current smoking, surgical duration, preoperative hospital stay, ASA class of III-IV, ALB <35g/L, and FBG > 110mg/dL were identified as independent risk factors for SSI. Conclusions: Three modifiable factors as smoking, preoperative ALB <35g/L, and FBG > 110mg/dL should be optimized preoperatively to reduce the SSIs. Other factors, although not modifiable, could be used for screening of at-risk patients, patient risk stratification, or for counseling of patients.
Keywords: SSI; elderly hip fracture; incidence; modifiable; multivariate analysis; risk factor.