Impact of a Prior Debridement, Antibiotics, and Implant Retention on Outcomes of Two-Stage Exchange Knee Arthroplasty in Periprosthetic Joint Infection

BACKGROUND: In periprosthetic joint infection (PJI), prior studies evaluating failed debridement, antibiotics, and implant retention (DAIR) before two-stage exchange arthroplasty report conflicting outcomes and exclude initially successful DAIR cases. This study (1) compared two-stage exchange arthroplasty success with and without a preceding failed DAIR and (2) evaluated outcomes with initially successful DAIR cases included. METHODS: This multihospital retrospective cohort study evaluated patients with PJI ≥ one year after primary total knee arthroplasty treated with initial DAIR or two-stage between 2015 and 2022. All patients met Musculoskeletal Infection Society (MSIS) or 2018 International Consensus Meeting criteria. We excluded patients who had prior PJI in the same joint or those who underwent more than one DAIR or two-stage exchange prior. Patients were categorized based on initial treatment: DAIR (n = 94) or two-stage exchange (n = 99). A subset of the DAIR cohort requiring later two-stage exchange (n = 22) was analyzed separately. Treatment success was defined as no reoperation and a MSIS Tier 1 or 2 outcome. Statistical analyses included t-tests, Chi-squares, Kaplan-Meier curves, and Cox models adjusted for key covariates (P < 0.05). RESULTS: Prior DAIR for acute PJI was not significantly associated with reduced success rates when comparing primary two-stage exchange arthroplasty to two-stage exchange arthroplasty following failed DAIR (P = 0.21), though 24-months survival probability was consistently lower. Similarly, when including initial DAIR successes in this analysis, there were no statistical differences in survival, although success rates favored two-stage exchange arthroplasty (P = 0.27). CONCLUSIONS: Our results suggest that, when PJI appears acute, DAIR should be completed. Although DAIR success may be low, it does not appear to substantially impact the success of subsequent two-stage exchange arthroplasty.