Periprosthetic joint infection (PJI) is considered one of the most feared causes of implant failure, due to the difficulty in formulating a proper and timely diagnosis. In the diagnostic workup are often used test with a low specificity, such as the dosage of ESR and CRP, or sensitivity, such as cultures or the leukocyte count of the synovial fluid. Radiological investigations are expensive and unreliable to play a direct role in the diagnosis of PJI. The alpha-defensin is an antimicrobial peptide released by neutrophils in response to pathogens and it is an ideal biomarker for the diagnosis of PJI. It is now possible to verify the presence of alpha-defensin in periprosthetic synovial fluid with an ELISA (Synovasure® PJI, Zimmer) that provides results in 10 minutes, with a sensitivity of 97% and a specificity of 96%, without being affected by systemic inflammatory diseases or by the assumption of antibiotics. The purpose of this study is to assess the applicability and reliability of Synovasure® PJI, correlating its results with microbiological analyzes, laboratory tests and imaging studies of the patient. Patients recruited are those who have undergone a previous total hip or knee arthroplasty where there is suspicion of PJI. The test can be performed either during surgery or during the diagnostic iter, through the execution of an arthrocentesis. The synovial fluid is partly used for Synovasure® PJI and partly put in culture for microbiological analyzes. Once ready, culture results are compared with the results of the test to get a confirmation of its reliability or reference to identify the microorganism responsible for PJI. These data are then compared, with laboratory tests and radiological investigations performed by the patient.Introduction
Materials and Methods
