Periprosthetic Hip and Knee Infection: Is An Ipsilateral Uninfected Total Joint Arthroplasty at Risk?

Introduction Periprosthetic joint infections (PJI) of total hip arthroplasty (THA) or total knee arthroplasty (TKA) may occur in the setting of an uninfected ipsilateral prosthetic joint. However, the risk to that uninfected ipsilateral joint is unknown. We analyzed the survivorship free from PJI in at risk THAs and TKAs following treatment of an ipsilateral knee or hip PJI, respectively. Methods Using our institutional total joint registry, we identified 205 patients who underwent treatment for PJI (123 THAs, 83 TKAs) with an at risk ipsilateral in situ knee or hip, respectively between 2000 and 2019. In total, 54% of index PJIs were chronic and 46% were acute. The mean age was 70 years, 47% were female, and the mean BMI was 32 kg/m2. Kaplan-Meier survivorship analyses were performed. Mean follow-up was 6 years. Results The 5-year survivorship free of PJI in an at-risk THA after an ipsilateral TKA was treated for PJI was 97%. The 5-year survivorship free of PJI in an at risk TKA when the ipsilateral THA was treated for PJI was 99%. Three PJIs occurred (2 THAs and 1 TKA), all over 1 year from the index ipsilateral PJI treatment. One hip PJI was an acute hematogenous infection that resulted from a pneumonia. The other two new PJIs were caused by the same organism as the index PJI and were due to a failure of source control at the index joint. Conclusions When diagnosed with PJI in a single joint, the risk of developing PJI in an ipsilateral prosthetic joint within 5 years was low (1-3% risk). In the rare event of an ipsilateral infection, all occurred greater than one year from the index PJI and 2 of 3 were with the same organism when source infection control failed.