Alpha-defensin for the intra-operative diagnosis of prosthetic joint infections

A single-center prospective study was conducted over one-year period to determine the performance (sensitivity, specificity, positive and negative predictive values) of the synovasure test for the diagnosis of prosthetic joint infection using the MSIS consensus criteria as the reference. The study included all patients admitted for resumption of hip or knee prosthesis whatever the reason, all couples of friction, patients under antibiotic treatment, immuno-compromised or with systemic inflammatory diseases. 62 consecutive patients were preoperatively distributed into three groups (infected, uninfected and questionable). In order to determine MSIS criteria, pre-operative blood tests, as well as bacteriological, cytological and histological analyses of intraoperative tissues were performed. The synovasure test was performed following the protocol on articular fluid intraoperatively and showed a sensitivity of 83.3%, a specificity of 95.7%, a positive predictive value of 83.3% and a negative predictive value of 95.7%.