Predicting Outcomes of Periprosthetic Joint Infection Treated with Debridement, Antibiotics, and Implant Retention (DAIR): An External Validation of the KLIC (Kidney, Liver, Index Surgery, Cemented Prosthesis, C-reactive Protein) Score.

Abstract

Debridement, antibiotics, and implant retention (DAIR) is a treatment option for selected patients who have periprosthetic joint infection (PJI) and well-fixed prostheses. The KLIC (Kidney, Liver, Index Surgery, Cemented Prosthesis, C-reactive Protein) score has been developed to aid in patient selection, but it is unclear if it does so reliably. We aimed to externally validate the KLIC score in a cohort of patients who have early and late acute PJI. Retrospective data were used from five sites across four countries. In total, 199 had an infected hip prosthesis and 376 had an infected knee prosthesis. Treatment failure was defined as: (i) prosthesis removal for any reason, (ii) infection relapse determined by the treating clinician, or (iii) additional DAIR performed > seven days after the initial procedure. Non-parametric estimation of the area under the receiver operating curve (AUC) was used to establish discriminative performance. A total of 240 of 575 (42%) patients met the criteria of treatment failure, with similar failure rates among hip (84 of 199, 42%) and knee (156 of 376, 41%) infections. There was no significant difference when comparing discriminative performance in patients who had infections of the hip (AUC 0.53, 95% confidence interval (CI) 0.45 to 0.61) or knee (AUC 0.55, 95% CI 0.50 to 0.60) (P = 0.25), with limited discriminative performance in both cohorts. Performance did not differ in patients who had early acute (AUC 0.55, 95% CI 0.49 to 0.60) or late acute infections (AUC 0.51, 95% CI 0.43 to 0.59) (P = 0.81). The KLIC score has a limited ability to discriminate between patients who fail treatment with DAIR and those who do not. This was consistent across patients who had early and late acute infections. Further work is needed to improve its performance before recommending its use in clinical practice.