The value of repeated debridement, antibiotics, and implant retention (DAIR) for early periprosthetic joint infection.

Background and purpose: Debridement, antibiotics, and implant retention (DAIR) is the proposed initial treatment of early periprosthetic joint infection (PJI), but it may fail to provide infection control. Subsequently, either implant removal or repeated DAIR may be considered. This study aims to identify the failure rate of repeated DAIR for early PJI in primary total knee arthroplasty (TKA) and total hip arthroplasty (THA). Methods: All DAIRs performed following primary THA or TKA for early PJI from 2010 to 2019 were retrospectively analysed. Patient demographics, comorbidities, surgical details, and pre-DAIR C-reactive protein (CRP) levels were recorded. Failure of early infection control (within 1 month after DAIR) prompted a second DAIR. Follow-up was performed up to 2 years post-surgery. A Kaplan-Meier survival analysis was performed in single- and repeated-DAIR groups. Cox regression analyses explored potential risk factors for implant failure after repeated DAIR. Results: A total of 124 cases of early PJI were included. Single DAIR achieved adequate infection control in 69.4 % ( $n=86$ ) of cases, while 30.6 % ( $n=38$ ) of cases underwent repeated DAIR within 3-23 d. After 2 years, implant removal was performed in 8 cases (9.9 %; 95 %CI 3.0 %-16.0 %) in the single-DAIR group and in 8 cases (22.2 %; 95 %CI 7.3 %-34.7 %) in the repeated-DAIR group. No statistically significant associations between the failure of repeated DAIR and its potential risk factors were found. Conclusion: If initial DAIR does not achieve early PJI control, repeated DAIR can still be considered, as it may avoid implant removal in 77.8 % of cases. The authors advocate for tailored decisions considering implant revisability, patient comorbidity, and pathogen susceptibility.