Recent reports highlighted the association between smoking and higher risk of postsurgical infections. The aim was to compare the incidence of prosthetic joint infection after primary total joint arthroplasty (TJA) according to smoking status.
A prospective hospital registry–based cohort study was performed including all primary knee and hip TJAs performed between March 1996 and December 2013. Smoking status preoperatively was classified into never, former, and current smoker. Incidence rates and hazard ratios (HRs) for prosthetic joint infection according to smoking status were assessed within the first year and beyond.
We included 8559 primary TJAs (mean age 69.5 years), and median follow-up was 67 months. There were 5722 never, 1315 former, and 1522 current smokers. Incidence rates of infection within the first year for never, former, and current smokers were, respectively, 4.7, 10.1, and 10.9 cases/1000 person-years, comparing ever vs never smokers, crude and adjusted HRs were 2.35 (95% confidence interval [CI] 1.39-3.98) and 1.8 (95% CI 1.04-3.2). Beyond the first year, crude and adjusted HRs were 1.37 (95% CI 0.78-2.39) and 1.12 (95% CI 0.61-2.04).
Smoking increased the infection risk about 1.8 times after primary hip or knee TJA in both current and former smokers. Beyond the first year, the infection risk was similar to never smokers.