Smoking is not closely related to revision for periprosthetic joint infection after primary total knee and hip arthroplasty

Background: The influence of smoking on the risk of periprosthetic joint infection (PJI) remains unclear. The objective was to explore the impact of smoking on PJI after primary total knee (TKA) and hip (THA) arthroplasty. Hypothesis: Current smoking patients should have an increased risk of PIJ compared with nonsmoking patients. Patients and methods: A prospective registry-based observational cohort study was performed. A total of 4591 patients who underwent primary TKA (3076 patients) or THA (1515) were included. According to the smoking status at the time of arthroplasty, patients were classified as nonsmokers (3031 patients), ex-smokers (688), and smokers (872). Multivariate analysis included smoking status, age, gender, education level, body mass index, American Society of Anesthesiologists class, diagnosis (osteoarthritis, rheumatism), diabetes, chronic obstructive pulmonary disease, perioperative blood transfusion, site of arthroplasty (knee, hip), length of operation, and length of stay. Results: There were PJI after 59 (1.9%) TKA and 27 (1.8%) THA (p=0.840). There were PJI in 47 (1.6%) nonsmokers, 12 (1.7%) ex-smokers, and 17 (1.9%) smokers (p=0.413). There were wound complications (delayed wound healing and superficial wound infection) in 34 (0.7%) nonsmokers, 9 (1.3%) in ex-smokers, and 17 (1.9%) in smokers (p=0.045). In multivariate analysis, only the female gender was a significant predictor of PJI (OR 1.3, 95% CI 1.1-2.4 [p=0.039]). Specifically, the categories of ex-smokers (OR 0.8, 95% CI 0.2-1.7 [p=0.241]) and smokers (OR 1.1, 95% CI 0.6-1.5 [p=0.052]) were not significant predictors. The 4-year arthroplasty survival with PJI as the endpoint was 99.1% (95% CI: 99.0-99.7) for nonsmokers, 99.0% (95% CI: 98.8-99.2) for ex-smokers, and 98.7% (95% CI: 98.2-99.0) for smokers was not significantly different between smoking status groups (p=0.318). Discussion: Smoking was not identified as a significant predictor for PJI following primary TKA or THA.