It still remains unclear whether postoperative antibiotic treatment is advantageous in presumed aseptic revision-arthroplasties of the hip (rTHA) and knee (rTKA) with unexpected-positive-intraoperative-cultures (UPIC). The aim of this study was to evaluate if there is a difference in the septic and/or aseptic re-revision rate in patients with or without postoperative antibiotics. In this retrospective propensity-score (PS) matched cohort-study we compared the re-revision rate and the microbiological spectrum in rTHA and rTKA treated with (AB-Group; n=70) and without (non-AB-Group; n=70) antibiotic treatment in patients with UPIC. Baseline covariates for PS-matching were type of revision, sex, Body-Mass-Index, age, Surgical-Site-Infection-Score, American-Society-of-Anesthesiologists-Classification, serum C-reactive-protein. All patients received routine antibiotic prophylaxis, but empiric AB treatment was started only in patients in the AB-Group. Post-operative treatment was decided on an individual basis according to the preference of the surgeon and the infectious disease specialist for a minimum duration of two weeks. In total, 90 rTHA (45 AB-Group, 45 in non-AB-Group) patients with UPICs and 50 rTKA (25 AB-Group, 25 in non-AB-Group) were included in the study. There was no significant variation in patient demographics.Aim
Method
Patients with EBJIS Definition confirmed PJI, due to Aim
Methods
Unexpected negative-cultures (UNC) are a common diagnostic problem in periprosthetic joint infection (PJI) of the hip and knee when using culture-based methods. A novel molecular approach (MC)1 based on the identification of the vast majority of bacterial species in a single assay using species-specific bacterial interspacing region length polymorphisms and phylum-specific 16S rDNA sequence polymorphisms has demonstrated clinical utility in PJI diagnostics (1). In addition, MC provides an estimate of the leukocyte concentration in the specimen analysed. The aim of this retrospective, blinded study was to evaluate the performance of MC in identifying the microbiological content and determining the leukocyte count in synovial fluid (SF) collected from hip and knee revision arthroplasty cases with UNC. It was also assessed whether antibiotic treatment would have been changed if the result from MC had been known. A total of 89 SF samples from 70 patients (43 female; 27 male) who underwent revision arthroplasty (14 hip; 75 knee) were included. Using European and Bone Joint Infection Society (EBJIS) criteria, 82 cases were classified as infected (77 UNC and 5 septic culture-positive controls), five as non-infected (aseptic culture-negative controls), and two as likely infected, but infected by clinical observation. MC was performed and evaluated together with SF parameters. Antibiotic treatment, clinical outcome, patient demographics and surgical details were analysed.Aim
Method
Synovial calprotectin point-of-care test (POC) has shown promising clinical value in diagnosing periprosthetic joint infections (PJIs). However, limited data are available in unclear cases. Moreover, cut-off values for calprotectin lateral flow assay (LFA) and enzyme-linked immunosorbent assay (ELISA) need to be adapted. The aim of this study was to evaluate the performance of an upgraded and more sensitive version of a synovial calprotectin LFA along with ELISA immunoassay in patients with septic, aseptic, and unclear cases. Overall, 206 prospectively collected periprosthetic synovial fluid samples from 169 patients (106f/63m; 38 hip/131 knee) who underwent revision surgeries were retrospectively evaluated for calprotectin concentration. The following groups were analyzed: unexpected negative cultures (UNC; 32/206), unexpected positive cultures (UPC; 28/206), and unclear cases (65/206) with conflicting clinical results. In addition, we added a true aseptic (40/206), and true septic (41/206) control groups according to the international consensus meeting (ICM) 2018 PJI classification. Calprotectin concentration was determined by a rapid quantitative LFA (n=206) (Lyfstone®, Norway), and compared to calprotectin ELISA immunoassay (171/206). For the determination of a new calprotectin cut-off value, analysis of the area under the curve (AUC) followed by Youden's J statistic were performed using the calproctectin values from clear septic and aseptic cases. Sensitivity and specificity for calprotectin were calculated. All statistical analyses were performed using IBM-SPSS® version 25 (Armonk, NY, USA).Aim
Methods
To evaluate the clinical success and hip pain and function of patients with infected hip replacement treated by two-stage exchange using a temporary implant with high dose vancomycin added to the antibiotic cement at the first stage revision. Thirty-three hips in 32 patients (median 67 yrs) underwent first stage revision using the PROSTALAC™ system (n=27) or a self-made system using an Elite long stem (n=6). Infection was diagnosed after 19 primary, 11 revision and 3 hemiarthroplasty hip replacements. Patients were reviewed regularly clinically and by questionnaire. The median follow-up was 3 years.Introduction
Method
