Protective effect of N-acetylcysteine in prosthetic joint infection: A nationwide population-based cohort study

PurposeThis nationwide population-based retrospective cohort study evaluated the protective effect of N-acetylcysteine against prosthetic joint infection after hip or knee joint replacement.MethodsPatients receiving N-acetylcysteine after hip or knee joint replacement between 2000 and 2015 were identified from the Taiwan National Health Insurance Research Database. Each patient receiving N-acetylcysteine was matched to four controls based on age, sex, and index year. All subjects were followed-up from the index date to December 31, 2015. The Cox proportional hazards regression model was used to assess the risk of prosthetic joint infection.ResultsA total of 1478 patients were included in the study group, and 5912 matched subjects not receiving N-acetylcysteine were included in the control group. After adjusting for age, sex, insured premium, comorbidities, and immunosuppressive agent use, no significant difference in the risk of prosthetic joint infection was found between the two groups. A higher N-acetylcysteine dose (>360 cumulative defined daily dose) significantly decreased the risk of prosthetic joint infection (adjusted hazard ratio = 0.891; 95% confidence interval = 0.599–0.989; p = 0.042). The protective effect of N-acetylcysteine was observed only in the group of prosthetic joint infection within 5 years (adjusted hazard ratio = 0.801; 95% confidence interval = 0.581–0.980; p = 0.040).ConclusionsHigh cumulative dose of N-acetylcysteine (>360 cumulative defined daily dose) can effectively reduce the risk of prosthetic joint infection in patients undergoing knee or hip joint replacement surgery within 5 years.