[CRITICAL EVALUATION OF THE ABILITY TO DIAGNOSE PERIPROSTHETIC INFECTION IN A MEDICAL SYSTEM IN ISRAEL].

Introduction: Prosthetic joint infection is a dangerous complication of joint replacement arthroplasty. Besides its catastrophic consequences, differentiating a deep infection from other complications is not always trivial due to lack of clinical signs of infection, inaccurate tests, lab-dependent analysis, variable normal values and ongoing dispute in the literature regarding the recommended diagnosis algorithm.

Aims: The purpose of this study was to examine the diagnosis algorithm in our medical center.

Methods: We reviewed all patients who underwent hip or knee replacement and developed prosthetic joint infection between January 2005 and December 2012. The data collected included the patient's demographics, lab and imaging results such as white blood cells (WBC) and C reactive protein (CRP) levels in serum, as well as leukocytes scan and microbiological culture results. In addition, our diagnosis algorithm was compared to those suggested in the literature.

Results: Out of 1142 patients who underwent knee or hip replacement arthroplasty, we included 34 patients (2.97%) who were diagnosed with prosthetic joint infection, including 21 knee joints (61.8%) and 13 hip joints (38.2%). Twelve patients (35.3%) had a positive culture, six (50%) grew a gram-negative bacterium. In addition, a significant association was found between CRP levels in the serum at diagnosis, hospital release and at 1 month post hospitalization (p<0.0001).

Discussion: The study raises questions in regards to the diagnostic technique used and suggests it may lead to under-diagnosis, maltreatment and inefficient use of resources. We suggest evaluating these algorithms in other departments.