The diagnosis of periprosthetic joint infection (PJI) can be difficult. All current diagnostic tests have problems with accuracy and interpretation of results. Many new tests have been proposed, but there is no consensus on the place of many of these in the diagnostic pathway. Previous attempts to develop a definition of PJI have not been universally accepted and there remains no reference standard definition. This paper reports the outcome of a project developed by the European Bone and Joint Infection Society (EBJIS), and supported by the Musculoskeletal Infection Society (MSIS) and the European Society of Clinical Microbiology and Infectious Diseases (ESCMID) Study Group for Implant-Associated Infections (ESGIAI). It comprised a comprehensive review of the literature, open discussion with Society members and conference delegates, and an expert panel assessment of the results to produce the final guidance.Aims
Methods
Synovial fluid white blood cell (WBC) count and percentage of polymorphonuclear cells (%PMN) are elevated at periprosthetic joint infection (PJI). Leucocytes produce different interleukins (IL), including IL-6, so we hypothesized that synovial fluid IL-6 could be a more accurate predictor of PJI than synovial fluid WBC count and %PMN. The main aim of our study was to compare the predictive performance of all three diagnostic tests in the detection of PJI. Patients undergoing total hip or knee revision surgery were included. In the perioperative assessment phase, synovial fluid WBC count, %PMN, and IL-6 concentration were measured. Patients were labeled as positive or negative according to the predefined cut-off values for IL-6 and WBC count with %PMN. Intraoperative samples for microbiological and histopathological analysis were obtained. PJI was defined as the presence of sinus tract, inflammation in histopathological samples, and growth of the same microorganism in a minimum of two or more samples out of at least four taken.Aims
Methods
Prosthetic joint infections (PJI) are caused by a variety of microorganisms but most frequently by staphylococci. The results of treatment of PJI due to organisms other than staphylococci are less known. The aim of this study is to evaluate the outcomes after streptococcal PJI. The data of 26 streptococcal (13 hip and 13 knee PJI from 24 patients) were retrieved from hospital based PJI register, and analyzed. There were 15 female and 11 male patients (mean age 66 y). Most (13) PJI were hematogenous. 15 PJI had been treated with debridement and retention (D&R) of the infected joint, 1 with permanent resection arthroplasty, 9 had two stage revision and 1 patient had one stage partial replacement. After the microbiological diagnosis was established most patients received 2–3 weeks of penicillin G or ceftriaxone followed by 2–6 months of oral amoxicillin. All patients had regular follow-ups after the procedure at least at 1 month, three months and one year. The results were classified as: PJI cure (in absence of clinical signs and symptoms of infection and with negative CRP), probable failure (in absence of clinical signs and symptoms of infection but with elevated CRP), definite failure (if a new treatment was necessary), and mechanical failure (aseptic loosening, periprosthetic fracture, quadriceps rupture). One foreign patient was lost to follow up. The mean follow up time for the rest was 60 months (from 16 to 167) months. There was probable prosthesis failure in 1 case, definite prosthesis failure in 7 cases and mechanical failure in 3 cases. The mean survival time of the failed prostheses was 28 (range from 2 to 83) months. 6 failures (40 %) occurred in group of cases that had undergone D&R, and 1 (6 %) in the two stage revision group. Among the 7 definite failures in 4 patients antibiotic treatment was empirically started after the symptoms reappeared resulting in long remission periods. Comparing to the published results of staphylococcal PJI it seems that D&R of the prosthesis for streptococcal PJI is considerably less successful. Rifampicin as a proven treatment of choice for staphylococcal infections is probably the main reason for the difference. An unexpected feature of streptococcal PJI is that definite failures are easily suppressed for long time with a short course of oral antibiotics.
