Prevalence and risk factors of surgical site infection after closed isolated patella fracture surgery: A prospective cohort study

Purpose Surgical site infection (SSI) after patella fracture surgery could be devastating and challenging. There is no large sample size study to investigate the prevalence and risk factors of it. The purpose of this study was to address this clinical issue. Methods A total of 820 patients who underwent patella fracture surgery between October 2014 and December 2018, were included. Demographic data, fracture type, injury mechanism, pre-operative stay, surgery-related variables, and pre-operative laboratory indexes were obtained from a prospective database. The optimum cutoff value of surgery duration was detected by receiver operating characteristic analysis. Univariate analysis and multivariate analysis were performed to determine the risk factors. Results A total of 17 patients developed SSI after patella fracture surgery, indicating a prevalence of 2.1%, with 11 cases (1.3%) for superficial infection and six cases (0.8%) for deep infection. After adjustment of multiple variables, current smoking, (OR, 18.6, CI, 3.5-99.0); albumin < 35 g/L, (OR, 7.4, CI, 1.1-52.3); diabetes mellitus, (OR, 8.8, CI, 1.3-59.4) and surgery duration > 79.5 minutes, (OR, 13.2, CI, 1.5-117.3) were identified to be independent risk factors of SSI after patella fracture surgery (p < 0.05). Conclusion The prevalence of SSI in patients with closed isolated patella fracture was 2.1%, with 1.3% for superficial and 0.8% for deep infection. We recommend individualized risk stratification and targeted interventions for patients with risk factors (current smoking, albumin < 35 g/L, diabetes mellitus, and surgery duration > 79.5 minutes).