Surgical site infection in the elderly following orthopaedic surgery - Risk factors and outcomes

Background: Risk factor and outcomes data pertaining to surgical site infection in the elderly following orthopaedic operations are lacking. The aim of this study was to identify risk factors for surgical site infections and to quantify the impact of these infections on health outcomes in elderly patients following orthopaedic surgery. Methods: A risk factor and outcomes study was performed at Duke University Medical Center, a tertiary care center, and seven community hospitals in North Carolina and Virginia between 1991 and 2002. The study included elderly patients in whom a surgical site infection had developed following orthopaedic surgery and elderly patients in whom a surgical site infection had not developed following orthopaedic surgery (controls). Outcome measures included mortality during the one-year postoperative period and the total length of the hospital stay (including readmissions during the ninety-day postoperative period). Results: One hundred and sixty-nine patients with a surgical site infection were identified, and 171 controls were selected. The mean age of the patients was 74.7 years. The most frequent procedures were hip arthroplasty (n = 74, 22%) and open reduction of fractures (n = 55, 16%). The most common pathogen was Staphylococcus aureus (n = 95, 56%). A risk factor for surgical site infection, identified in the multivariate analysis, was admission from a health-care facility (odds ratio = 4.35; 95% confidence interval = 1.64, 11.11). Multivariate analysis also indicated that surgical site infection was a strong predictor of mortality (odds ratio = 3.80; 95% confidence interval = 1.49, 9.70) and an increased length of stay in the hospital (multiplicative effect = 2.49; 95% confidence interval = 2.10, 2.94; 9.31 mean attributable days per infection, 95% confidence interval = 6.88, 12.13). Conclusions: Measures for prevention of surgical site infection in elderly patients should target individuals who reside in health-care facilities prior to surgery. Future studies should be done to examine the effectiveness of such interventions in preventing infection and improving outcomes in elderly patients who undergo orthopaedic surgery.