Risk of Surgical Site Infection in Patients Undergoing Total Knee Arthroplasty

The aim of this study was to determine the participation of risk factors in the infection in patients who underwent total knee arthroplasty. This is a prospective longitudinal study, descriptive and analytical, that was carried out between January 2013 and December 2015. Eighty-one procedures were performed in 78 individuals, 16 males and 62 females. Three subjects underwent the procedure on both knees. The following predictive factors of infection were identified: Age, gender, comorbidities, evaluation of functional physical status using the American Society of Anesthesiologists Physical Status Classification System (ASAPS), length of hospital stay, use of prophylactic antibiotics and duration of surgery. The data was tabulated in a database using a Microsoft Excel spreadsheet. For statistical analysis, the chi-square test, chi-square test for independence and Fischer’s exact test were applied, all at a significance level of 5% (0.05). Surgical site infection was more prevalent in males (23.5%), age over 70 years (25.0%), for left gonarthrosis (17.9%), in the presence of comorbidities (17.9%), when hospital stay was 6 or more days (27.8%), in total arthroplasties of left knee (17,9%), in surgical times of up to 2 hours (20%), in the use of prophylactic antibiotics (16.7%) and in level II classification in the ASAPS (18.8%). The independence test was not significant in any of the evaluated factors (p-value greater than 0.05). The most prevalent bacteria identified in cases of infection was Staphylococcus aureus (33.2%). The risk factors studied were not statistically significant.