Elevated Infection and Complication Rates in Patients Undergoing a Primary THA with a History of a PJI in a Prior Hip or Knee Arthroplasty: A Matched Cohort Study

Abstract Introduction There are little data on the outcomes of primary total hip arthroplasties (THAs) in patients with a prior surgically treated hip or knee periprosthetic joint injection (PJI). The goal of this study was to compare the risk of infection in this population to matched controls. Methods We retrospectively reviewed 48 patients whom underwent 50 primary THAs from 2000-2014 with a history of a PJI in a total knee arthroplasty (TKA) or contralateral THA. Thirteen patients (27%) were on chronic antibiotic suppression at the time of primary THA. Mean age was 67 years and mean body mass index (BMI) was 35 kg/m2. Mean follow-up was 6 years. We 1:3 matched (age, sex, BMI, cemented vs. cementless femoral fixation, and surgical year) these cases to 150 primary THAs. Competing risk analysis, with death as the competing risk, was performed. Results The cumulative incidence of PJI with death as a competing risk was 1.5-fold higher in the study cohort (2.0%) compared to matched controls (1.4%) (HR=1.5, p=0.75). The cumulative incidence of any infection with death as a competing risk was 2-fold higher in the study cohort (4.0%) compared to matched controls (2.1%) (HR=2.0, p=0.45). However, these were both statistically similar given the relatively small cohort. The overall complication rate, including infections and reoperations, was 17% in the study cohort. Conclusion Patients undergoing a clean primary THA with a history of a TKA or contralateral THA PJI in another joint have a 2% and 4% risk of PJI and any infection, respectively. Moreover, nearly 1-in-5 patients experience at least one complication. Level of Evidence Level III