Differences and Similarities in Hip and Knee Acute Periprosthetic Joint Infections After Primary Arthroplasty Treated with Irrigation and Debridement: An International, Multicenter Retrospective Study

BACKGROUND: Debridement, antibiotics, and implant retention (DAIR) are the recommended surgical treatments for acute periprosthetic joint infections (PJI). The success of DAIR has been variable due to the patient heterogeneity. This multinational study evaluated the success rate and risk factors of failure of a DAIR procedure after primary arthroplasty and was separated for total hip arthroplasty (THA) and total knee arthroplasty (TKA). METHODS: Patients diagnosed with acute postoperative PJI between 1999 and 2017 and treated with DAIR after primary THA or TKA were included. In total, 643 patients from five European centers and one in the United States were analyzed. Acute postoperative PJI was defined as infections occurring within three months after primary arthroplasty. Treatment failure was defined as any subsequent surgical intervention to control the infection, including a repeated DAIR procedure, and death related to infection within one year. RESULTS: The success rate for DAIR after primary THA was 66.4% (253 of 381). Stepwise logistic regression identified significant independent risk factors for DAIR failure in THA: preoperative C-reactive protein levels (CRP) over 71 mg/L (odds ratio (OR) 2.48, P = 0.004), men (OR 2.17, P < 0.013), and an indication for arthroplasty other than osteoarthritis (OR 4.23, P <0.001). The overall success rate for DAIR after primary TKA was 68.7% (180 of 262). Significant independent risk factors for failure were chronic renal failure (OR 4.02, P = 0.034), preoperative serum CRP levels over 116 (OR 5.39, P <0.001), and polymicrobial infections (OR 2.22, P <0.043). Polyethylene exchange was an independent success factor in this population (OR 0.39, P = 0.018). CONCLUSION: The DAIR failure rates in acute postoperative PJI were similar for primary TKA and THA, but risk factors differed; high preoperative CRP was the only shared independent predictor. Host factors for DAIR failure differ between hips and knees.