Outcomes of Debridement, Antibiotics, and Implant Retention in the Management of Infected Total Knee Arthroplasty: Analysis of 5,178 Cases From the National Australian Registry

Background: Periprosthetic joint infection is a devastating and severe complication of total knee arthroplasty (TKA). The Australian Joint Registry reports an increasing number of debridement, antibiotics, and implant retention (DAIR) procedures, underscoring the need to comprehend outcomes for informed treatment decisions. This study aimed to determine the outcome of DAIR procedures, evaluate time since primary TKA, and identify patient-related factors associated with DAIR failure. Methods: We conducted a national registry-based cohort study using data from 1999 to 2021. We included 8,642 revisions for infection, of which 5,178 were DAIR procedures (60%) predominantly performed within four weeks of primary surgery. We assessed the outcomes using Kaplan-Meier estimates and Cox proportional hazard models. Results: Post-DAIR, the cumulative percent second revision cumulative percent revision in the DAIR cohort was 20% at year 1, increasing to 36% at year 17. Early DAIR procedures had a lower post-DAIR revision rate until three months after primary TKA. A DAIR performed within 2 weeks after primary TKA compared to three months had an hazard ratio [HR]: 0.74 (95% CI [confidence interval]: 0.62 to 0.88). After four weeks, the post-DAIR revision rate did not deteriorate and was similar for further time periods from the primary. Men had an age-adjusted HR of 1.28 (95% CI: 1.14 to 1.43, P < 0.001) for DAIR failure compared to women. There was a significantly higher HR for post-DAIR revision in patients younger than 75 years of age, compared to patients aged ≥ 75 years. Conclusions: These findings underscore the critical influence of patient-related factors and the timing of DAIR treatment on the need for additional surgery. DAIR after four weeks had an increased risk of subsequent revision, and older women undergoing early DAIR interventions had more favorable outcomes. Understanding these nuances aids in optimizing periprosthetic joint infection management strategies, offering insights for decision-making.