Surgical site infection incidence and risk factors in knee arthroplasty: A 9-year prospective cohort study at a university teaching hospital in Spain

Abstract

Surgical site infection (SSI) is one of the complications posed by knee replacement surgery. Hospital-based infection surveillance systems may provide indicators of improvement and allow the characterization of risk factors critical to reduce infection. The aims of this study were to compare the incidence of SSI in our center with rates in the Madrid Region, Spain, and the United States, and to evaluate any possible SSI-related risk factor in knee replacement surgery. All patients who underwent knee replacement surgery at a tertiary hospital in 2008-2016 were included. SSI was defined according to Centers for Disease Control and Prevention criteria. Infection rate was calculated. The association between risk factors and SSI incidence was assessed by reference to odds ratio (OR) with multivariate analysis. The study population (n = 1969) had a global SSI risk of 1.0%. We found a declining trend in the follow-up period, from an SSI risk of 1.8% in 2009 to 0.4% in 2016. Independent risk factors included hair removal (OR: 3.09, 95% confidence interval [CI]: 1.27-7.50) and National Healthcare Safety Network risk index ≥ 2 (OR: 9.37, 95% CI: 2.90-30.26). This study identified risk factors that showed the necessity to strictly comply with wound decontamination and patient preparation protocols, reduce surgery duration, and identify patients who require comprehensive monitoring.