TIMING FROM ADMISSION TO DEBRIDEMENT, ANTIBIOTIC, AND IMPLANT RETENTION (DAIR) AFFECTS TREATMENT SUCCESS IN TOTAL KNEE ARTHROPLASTY PROSTHETIC JOINT INFECTION

Prosthetic joint infection (PJI) represents a devastating complication associated with increased patient morbidity, mortality and a decreased quality of life. DAIR is an attractive treatment option in patients presenting with acute PJI due to its reduced morbidity, cost and technical ease of the procedure. Time from hospital admission to surgery is a factor known to be associated with outcomes for several orthopaedic procedures, notably in the care of hip fractures. Little is known, however, with regards to whether time from admission to DAIR affects outcomes. As such, we developed a study to assess the association of factors associated with failure of DAIR in total knee arthroplasty (TKA). This is a retrospective, consecutive series from a single academic, tertiary referral centre specializing in the treatment of PJI. A search of our institutional PJI registry was conducted between 2008 and 2021 for patients having undergone DAIR following TKA at a minimum 2-year follow-up. Baseline patient and surgical characteristics were collected. The primary outcome assessed was reoperation for recalcitrant PJI. Secondary outcomes assessed were: 90-day readmission, 90- day and 1- year mortality, Post-operative complications, and use of chronic suppressive antibiotic therapy. Multivariate regression analysis was performed to determine the effect of variables on outcomes and reported as odds ratios (OR) and confidence intervals (CI) with p < 0 .05 considered statistically significant. A total of 121 patients satisfied final inclusion criteria for this study, consisting of 89 primary TKAs and 22 revision TKAs. Mean age at time of DAIR was 67.8 ­+ 11 years. Multivariate regression analysis of our primary outcome demonstrated that time from admission to DAIR > 48 hours was associated with a substantial increase in risk for reoperation for PJI (OR: 8.7, CI95% 1.5-51.1, p = 0.017). Post-operative complications were positively associated with DAIR >48 hours from admission (OR: 47.7, CI95% 2.7 – 827.1, p = 0.008). 90-day readmission was associated with lower preoperative Hb (OR: 1.04, CI95% 1.01 – 1.07, p = 0.014). Similarly, 1-year all-cause mortality was associated with lower preoperative Hb (OR: 1.06, CI95% 0.99 – 1.14, p = 0.082). The results of this study suggest that the timing of hospital admission to DAIR has both a significant impact on reoperation for recalcitrant PJI and one-year mortality risk. Akin to the treatment of hip fractures, care should be provided within 48 hours of admission to reduce treatment failure and mortality. In lieu of these findings, surgeons should advocate for rapid OR access when performing DAIR in the treatment of TKA PJI. Further research is required to delineate more specific time cut-offs in DAIR for TKA PJI.