The Fate of Failed Debridement, Antibiotics, and Implant Retention in Infected Knee Arthroplasties: Nothing to Lose

Purpose The frequency of periprosthetic knee infections increases yearly because of the popularity of the total knee prostheses. Revision knee arthroplasty is an annoying problem for both the surgeons and the patients. Debridément, antibiotics, and implant retention (DAIR) is a popular alternative for the treatment of periprosthetic knee infections. Little is known about the fate of the failed DAIR patients. This study aims to investigate the effect of the failed DAIR on the clinical result after two-staged revision arthroplasty. Method Ninety-nine two-staged revision arthroplasties and 85 DAIR patients from two reference clinics were retrospectively analyzed. The minimum follow-up was 36 months. Patients were grouped according to the treatment as, two-staged revision without DAIR, two-staged revision after failed DAIR, and successful DAIR. Their Knee Society Scores (KSS), functional KSS (KSS-f) and Western Ontario and McMaster Universities Arthritis Index (WOMAC) scores were analyzed and compared. Results DAIR has a 52.9% success rate for the treatment of infection. Elevated erythrocyte sedimentation rates and C-reactive peptide levels are not risk factors for failure, but the time passed since the index surgery is a risk factor for worse outcome scores. Failed DAIR is not a risk factor for reinfection after two-staged revision. Last KSS after failed DAIR, successful DAIR, and two-staged revision were 83.98±7.033, 91.89±4.386, and 91.38±4.735, respectively. Last KSS-f after failed DAIR, successful DAIR, and two-staged revision were 86.25±9.524, 94.56±8.106, and 94.85±5.996, respectively. Last WOMAC after failed DAIR, successful DAIR, and two-staged revision were 86.16±7.745, 94.750±4.964, and 93.319±5.961, respectively. Conclusion Failed DAIR is associated with lesser, but still good, or excellent clinical scores. DAIR is suggested as a promising treatment option for periprosthetic knee infections in well-selected patients.