Retrospective Study from a Single Center to Identify Risk Factors Associated with Reinfection in Patients Undergoing 2-Stage Revision Surgery for Periprosthetic Joint Infection.

BACKGROUND This study identified risk factors associated with reinfection and created a scoring system designed for patients with periprosthetic joint infection (PJI) who have undergone prosthetic resection and spacer implantation. MATERIAL AND METHODS Patients who underwent 2-stage revision for PJI from January 2010 to December 2017 were retrospectively analyzed in this study. Patients were divided into 2 groups: infection recurrence and infection cure. Demographic and clinical information, laboratory test results, and radiological images that were potentially associated with infection were obtained and analyzed. RESULTS Seven independent risk (protective) factors for infection recurrence in patients with PJI who underwent 2-stage hip revision surgery were identified: C-reactive protein level, type of bacterial infection, age, immunosuppression, albumin/globulin ratio, glucose level, and magnetic resonance imaging findings. Finally, a weighted scoring system of 100-mark system was established and the area under the curve was 0.965 (95% confidential interval=0.947-0.983). The predictive scores for low risk (≤30%), moderate risk (31-69%), and high risk (≥70%) of infection recurrence were ≤45, 46-77, and ≥78, respectively. CONCLUSIONS For patients with PJI who had already undergone joint resection and spacer implantation, this newly established scoring system might help determine the accurate risk of infection recurrence after a definitive new prosthesis implantation. Patients with scores greater than 78 points would be considered very likely to have an infection recurrence. Therefore, the second-stage revision surgery should be changed to an additional anti-infection treatment or a debridement surgery instead of a definitive prosthesis implantation surgery.