Antibiotic-loaded calcium sulphate beads in in debridement, antibiotics, and implant retention (DAIR) for acute hip and knee periprosthetic joint infection: a retrospective comparative cohort study.

BACKGROUND: The role of antibiotic-loaded calcium sulphate (CaS) beads as an adjunct to debridement, antibiotics, and implant retention (DAIR) for acute periprosthetic joint infection (PJI) remains controversial. This study compared outcomes between standard DAIR and DAPRI (DAIR plus antibiotic-loaded CaS beads). METHODS: A retrospective single-center cohort study was conducted on 51 consecutive patients treated for acute hip or knee PJI between 2022 and 2025. Thirty-three patients underwent standard DAIR and 18 underwent DAPRI. The primary endpoint was septic failure, defined as recurrent infection requiring surgical intervention. The secondary endpoints were identification of clinical and surgical predictors of failure. Univariable logistic regression analysis was performed to evaluate factors associated with septic failure following implant-retention treatment for acute PJI. RESULTS: Overall septic failure occurred in 13/51 patients (25.5%). Failure rates were 27.3% in the DAIR group and 22.2% in the DAPRI group, a difference that did not reach statistical significance (p = 0.750). Recurrence with the same pathogen was less frequent after DAPRI (5.6% vs. 15.2%). In subgroup analyses, failure in acute hematogenous PJI was 25% with DAPRI versus 62% with DAIR (p = 0.099), and in hip arthroplasty no failures occurred with DAPRI (0/7) versus 25% with DAIR (6/24; p = 0.293). On univariable analysis, significant predictors of failure were acute hematogenous infection (OR 7.22; p = 0.008), preoperative fistula (OR 5.66; p = 0.018), and higher BMI (OR 1.15; p = 0.015). Among aseptic complication we reported 2/31 (6.5%) cases of hip dislocation. CONCLUSION: DAPRI was not associated with a statistically significant reduction in septic failure compared with standard DAIR (27.3% vs. 22.2%; p = 0.750) in this small, underpowered cohort. Exploratory subgroup analyses suggested a possible benefit in acute hematogenous PJI and hip arthroplasty, but these findings are hypothesis-generating and require confirmation in larger studies. Acute hematogenous infection, preoperative fistula, and higher BMI were significant univariable predictors of septic failure.