Background
The optimal duration of antibiotic therapy following debridement and implant retention (DAIR) for periprosthetic joint infections (PJI) is debated. Furthermore, the best antibiotic regimens for staphylococcal PJI, are also unclear. In this study, we evaluated the impact of antibiotic therapy duration on the risk of failure. We assessed the utility of rifampin-based regimens for staphylococcal PJI managed with DAIR.
Methods
We performed a retrospective cohort study of patients 18 years and older diagnosed with hip and knee PJI who underwent DAIR between January 1, 2008, and December 31, 2018, at Mayo Clinic, USA. The outcome was failure of DAIR. For statistical analysis, joint-stratified Cox regression models adjusted for age, sinus tract, symptom duration, and primary/revision arthroplasty were performed.
Results
We examined 247 cases of PJI with a median follow-up of 4.4 years (IQR 2.3-7) after DAIR. The estimated 5-year cumulative incidence of failure was 28.1% (n = 65). There was no association between the duration of intravenous (IV) antibiotics (median 42 days, IQR 38-42) and treatment failure (p = 0.119). A shorter duration of subsequent oral antibiotic therapy was associated with a higher risk of failure (p = 0.005; e.g., 90-day vs. 1-year duration, HR 3.50; 95% CI 1.48-8.25). For staphylococcal knee PJI, both the use and longer duration of a rifampin-based regimen were associated with a lower risk of failure (both p = 0.025). There was no significant association between FQ use and failure (HR 0.62; 95% CI 0.31 - 1.24; p = 0.172).
Conclusions
The duration of initial IV antibiotic therapy did not correlate with treatment failure in this cohort of patients. Rifampin use is recommended for staphylococcal knee PJI. There was no apparent benefit of FQ use in staphylococcal PJI.