Surgical Site Infection After Total Knee Arthroplasty: Risk Factors in Patients With Timely Administration of Systemic Prophylactic Antibiotics

BackgroundSurgical site infection (SSI) after total knee arthroplasty (TKA) is a catastrophic complication. Administration of prophylactic antibiotics within 60 minutes before surgery is a well-established strategy to prevent SSI. The study is aimed to identify the risk factors for SSI regarding primary TKA in patients with timely administration of systemic prophylactic antibiotics.MethodsA retrospective review of patients with primary TKA between 2009 and 2013 was conducted. Patients who had prophylactic antibiotics administered after skin incision or >60 minutes before skin incision were excluded.ResultsOf the 3152 patients enrolled, the incidence of SSI and deep-implant SSI was 1.52% and 0.79%, respectively. Charlson Comorbidity Index ≥3 was an independent risk factor for both SSI (odds ratio [OR], 2.34; 95% confidence interval [CI], 1.24-4.44, P = .01) and deep-implant SSI (OR, 3.46; 95% CI, 1.52-7.91, P < .01). Optimal dose of systemic antibiotics adjusted by patients' body weight for prophylaxis (OR, 0.29; 95% CI, 0.17-0.62, P < .01) and using antibiotic-laden bone cement (OR, 0.33; 95% CI, 0.17-0.64, P < .01) were significant protective factors for SSI. Meanwhile, using antibiotic-laden bone cement (OR, 0.31; 95% CI, 0.13-0.76, P = .01) also significantly decreased the risk of deep-implant SSI.ConclusionOur findings highlight the importance of appropriate dosage of prophylactic antibiotics and use of antibiotic-laden cement in preventing SSI after primary TKA. For prevention of deep-implant SSI, using antibiotic-laden bone cement seems to be an advisable strategy.