Aim

Apart from other biomarkers isolated in the synovial fluid, alpha-defensin appears to be a promising diagnostic tool to confirm a periprosthetic joint infection (PJI) in the hip or knee. The purpose of this study was to evaluate the sensitivity and specificity of an alpha defensin lateral flow (ADLF) test compared to usual standard classifications in the diagnostic management of PJI.

Aim

Accurate diagnosis is key in correctly managing prosthetic joint infection (PJI). Our aim is to compare the preoperative performance of three PJI definitions comparing it to definitive postoperative classification.

Aims

This study evaluated the definitions developed by the European Bone and Joint Infection Society (EBJIS) 2021, the International Consensus Meeting (ICM) 2018, and the Infectious Diseases Society of America (IDSA) 2013, for the diagnosis of periprosthetic joint infection (PJI).

Aim

There have been many attempts to define the criteria by which prosthetic joint infection (PJI) is diagnosed. Our aim is to validate the 2021 European Bone and Joint Infection Society (EBJIS) definition of PJI.

Introduction

Accurate diagnosis of peri-prosthetic joint infection is critical to allow adequate treatment. Currently, the criteria of the Musculo-Skeletal Infection Society (MSIS) serve as a validated reference tool. More recently, these criteria have been modified for better accuracy. The goal of this study was to compare retrospectively the diagnostic accuracy of these two different tools in cases of known peri-prosthetic hip or knee infection or in aseptic cases and to analyze one additional criterion: presence of an early loosening (prior to 2 years after implantation).

Aim

Synovial fluid investigation is the best alternative to diagnose prosthetic joint infection (PJI) before adequate microbiological/histology sampling during revision surgery. Although accurate preoperative diagnosis is certainly recommended, puncturing every patient before revision arthroplasty raises concerns about safety and feasibility issues especially in difficult to access joint (e.g., hip), that often require OR time and fluoroscopy/ultrasound guidance.

Currently there is no clear guidelines regarding optimal indications to perform preoperative joint aspiration to diagnose PJI before revision surgery. The main goal of this study is to determine the accuracy of our institutional criteria using the new European Bone and Joint Infection Society (EBJIS) PJI definition.

Aim. Diagnosing periprosthetic joint infections (PJI) can be very challenging, especially infections caused by low virulence microorganisms. No single test with a 100% accuracy is available yet. Hence, different infection definitions were introduced to improve the diagnostic confidence and quality of research articles. Due to constant developments in this field, infection definitions are adopted continuously. The aim of our study was to find the most sensitive currently available infection definition among three currently used criteria (International Consensus Meeting – criteria 2018 (ICM), Infectious Diseases Society of America - criteria 2013 (IDSA), and European Bone and Joint Infection Society – criteria 2021 (EBJIS)) for the diagnosis of PJI. Method. Between 2015 and 2020, patients with an indicated revision surgery due to septic or aseptic failure after a total hip or knee replacement were included in this retrospective analysis of prospectively collected data. A standardized diagnostic workup was done in all patients. The components of the IDSA-, ICM-, and EBJIS- criteria for the diagnosis of PJI were identified in each patient. Results. Overall, 206 patients (hip: n=104 (50%); knee: n=102 (50%)) with a median age of 74 years (IQR 65 – 80y) were included. 101 patients (49%) were diagnosed with PJI when using the EBJIS- criteria. Based on the IDSA- and ICM- criteria, 99 patients (48%, IDSA) and 86 patients (42%, ICM) were classified as septic. Based on all three criteria, 84 cases (41%) had an infection. 15 septic cases (n=15/206; 7%) were only identified by the IDSA- and EBJIS- criteria. In 2 patients (n=2/206, 1%), an infection was present based on only the ICM and EBJIS criteria. No case was classified as infected by one infection definition alone. A statistically significant higher number of inconclusive cases was observed when the ICM criteria (n=30/206; 15%) were used in comparison to the EBJIS criteria (likely infections: n=16/206; 8%) (Fisher's exact test, p=0.041). The EBJIS definition showed a better preoperative performance in comparison to the other two definitions (p<0.0001). Conclusions. The most sensitive infection definition seems to be the novel EBJIS– criteria covering all infections diagnosed by the IDSA- and ICM-criteria without detecting any further infection. In addition, less inconclusive (infection likely) cases were detected by the EBJIS-criteria in comparison with the ICM-criteria reducing the so called ‘grey zone’ significantly which is of utmost importance in clinical routine

Aims. Histology is an established tool in diagnosing periprosthetic joint infections (PJIs). Different thresholds, using various infection definitions and histopathological criteria, have been described. This study determined the performance of different thresholds of polymorphonuclear neutrophils (≥ 5 PMN/HPF, ≥ 10 PMN/HPF, ≥ 23 PMN/10 HPF) , when using the European Bone and Joint Infection Society (EBJIS), Infectious Diseases Society of America (IDSA), and the International Consensus Meeting (ICM) 2018 criteria for PJI. Methods. A total of 119 patients undergoing revision total hip (rTHA) or knee arthroplasty (rTKA) were included. Permanent histology sections of periprosthetic tissue were evaluated under high power (400× magnification) and neutrophils were counted per HPF. The mean neutrophil count in ten HPFs was calculated (PMN/HPF). Based on receiver operating characteristic (ROC) curve analysis and the z-test, thresholds were compared. Results. Using the EBJIS criteria, a cut-off of ≥ five PMN/HPF showed a sensitivity of 93% (95% confidence interval (CI) 81 to 98) and specificity of 84% (95% CI 74 to 91). The optimal threshold when applying the IDSA and ICM criteria was ≥ ten PMN/HPF with sensitivities of 94% (95% CI 79 to 99) and 90% (95% CI 76 to 97), and specificities of 86% (95% CI 77 to 92) and 92% (95% CI 84 to 97), respectively. In rTKA, a better performance of histopathological analysis was observed in comparison with rTHA when using the IDSA criteria (p < 0.001). Conclusion. With high accuracy, histopathological analysis can be supported as a confirmatory criterion in diagnosing periprosthetic joint infections. A threshold of ≥ five PMN/HPF can be recommended to distinguish between septic and aseptic loosening, with an increased possibility of detecting more infections caused by low-virulence organisms. However, neutrophil counts between one and five should be considered suggestive of infection and interpreted carefully in conjunction with other diagnostic test methods. Cite this article: Bone Joint Res 2021;10(8):536–547

Aim. One of the surgical therapeutic options for periprosthetic joint infection (PJI) includes debridement, antibiotics, and implant retention (DAIR). Prognostically favorable criteria for DAIR include short duration of symptoms, stable implant, pathogen susceptible to a ‘biofilm-active’ antimicrobial agent, and intact soft-tissue conditions. Despite this, there is a proportion of failures after DAIR, possibly because the duration of infection is underestimated. With the hypothesis that the duration of infection correlates with the bacterial load, and hence, the bacterial load is associated with failure after DAIR, we aimed to investigate the association of bacterial load in the sonication fluid of mobile parts and clinical outcome after DAIR. Method. From our PJI cohort (2010–2021), patients with DAIR (both palliative and curative approaches) were reviewed retrospectively. Patients with hip, knee or shoulder arthroplasties fulfilling infection definition, available sonication results, and ≥2 years follow-up were included. Sonication results were categorized in ≤ or >1000 cfu/mL. Univariate analysis was performed to identify predictors for DAIR failure. Results. Out of 209 PJIs, we identified 96 patients (100 PJIs, 47.8%) with DAIR. In 67 (69.8%) patients with 71 PJIs, there was a follow-up of ≥2 years. The mean age was 72.7 (SD 12.99) years, 50% were male. The infection affected 36 hips (50.7%), 32 knees (45.1%) and 3 shoulders (4.2%). At follow-up, there were 29 (40.8%) cured and 42 (59.2%) failed cases. When comparing failed and cured cases, we found no difference in comorbidities and previously defined risk factors for PJI, ASA score, Charlson score, anatomic location, no. of previous surgeries, pathogenesis of infection or laboratory values. The proportion of patients with high bacterial load on mobile parts (i.e. >1000 cfu/mL) was significantly higher in the failed DAIR group than it was in the cured group (61.9% vs 20.7%, p<0.001). Conclusions. In this study, a high bacterial load in sonication fluid of mobile parts was associated with failure after DAIR in patients with PJI. Sonication may help to differentiate acute hematogenous seeding to the implant and late reactivation of a previously silent implant-associated infection

Aims. Fungal periprosthetic joint infections (fPJIs) are rare complications, constituting only 1% of all PJIs. Neither a uniform definition for fPJI has been established, nor a standardized treatment regimen. Compared to bacterial PJI, there is little evidence for fPJI in the literature with divergent results. Hence, we implemented a novel treatment algorithm based on three-stage revision arthroplasty, with local and systemic antifungal therapy to optimize treatment for fPJI. Methods. From 2015 to 2018, a total of 18 patients with fPJI were included in a prospective, single-centre study (DKRS-ID 00020409). The diagnosis of PJI is based on the European Bone and Joint Infection Society definition of periprosthetic joint infections. The baseline parameters (age, sex, and BMI) and additional data (previous surgeries, pathogen spectrum, and Charlson Comorbidity Index) were recorded. A therapy protocol with three-stage revision, including a scheduled spacer exchange, was implemented. Systemic antifungal medication was administered throughout the entire treatment period and continued for six months after reimplantation. A minimum follow-up of 24 months was defined. Results. Eradication of infection was achieved in 16 out of 18 patients (88.8%), with a mean follow-up of 35 months (25 to 54). Mixed bacterial and fungal infections were present in seven cases (39%). The interval period, defined as the period of time from explantation to reimplantation, was 119 days (55 to 202). In five patients, a salvage procedure was performed (three cementless modular knee arthrodesis, and two Girdlestone procedures). Conclusion. Therapy for fPJI is complex, with low cure rates according to the literature. No uniform treatment recommendations presently exist for fPJI. Three-stage revision arthroplasty with prolonged systemic antifungal therapy showed promising results. Cite this article: Bone Jt Open 2021;2(8):671–678

Aims

The aim of this study was to evaluate the optimal deep tissue specimen sample number for histopathological analysis in the diagnosis of periprosthetic joint infection (PJI).

Aims

Serum inflammatory parameters are widely used to aid in diagnosing a periprosthetic joint infection (PJI). Due to their limited performances in the literature, novel and more accurate biomarkers are needed. Serum albumin-to-globulin ratio (AGR) and serum CRP-to-albumin ratio (CAR) have previously been proposed as potential new parameters, but results were mixed. The aim of this study was to assess the diagnostic accuracy of AGR and CAR in diagnosing PJI and to compare them to the established and widely used marker CRP.

Aims

This study aims to determine difference in annual rate of early-onset (≤ 90 days) deep surgical site infection (SSI) following primary total knee arthroplasty (TKA) for osteoarthritis, and to identify risk factors that may be associated with infection.

Aims

The aim of this study was to determine the consensus best practice approach for the investigation and management of children (aged 0 to 15 years) in the UK with musculoskeletal infection (including septic arthritis, osteomyelitis, pyomyositis, tenosynovitis, fasciitis, and discitis). This consensus can then be used to ensure consistent, safe care for children in UK hospitals and those elsewhere with similar healthcare systems.

Introduction. Wound surveillance has been reported to result in a significant fall in the incidence of wound sepsis in total knee arthroplasty (TKA). However, there is currently little guidance on the definition of surgical wound infection that is best to be used for surveillance. The purpose of this study was to assess the agreement between three common definitions of surgical wound infection as a performance indicator in TKA; (a) the CDC 1992 definition, (b) the NINSS modification of the CDC definition and (c) the ASEPSIS scoring method applied to the same series of surgical wounds. Methods. A prospective study of 500 surgical wounds in patients who underwent knee arthroplasties between May 2002 and December 2004 from a single tertiary centre were assessed according to the different definitions of surgical wound infection. Results. A total of 500 wounds were assessed in 482 patients. Mean age of patients was 70+/−11 years, 61.6% were females, duration of surgery was 101+/−49 minutes and mean follow-up was 35.2+/−25.7 months. The most commonly isolated species were Coagulase negative staphylococci (33.3%), Staphylococcus aureus (25%) and Pseudomonas aeruginosa (16.6%). The mean percentage of wounds classified as infected differed substantially with different definitions: 5.8% with the CDC definition, 3.6% with the NINSS version and 2.2% with an ASEPSIS score > 20. When superficial infections (according to CDC category) were included, 5.2% (26) of all observed wounds received conflicting diagnoses, and 1.4% (7) were classified as infected by both ASEPSIS and CDC definitions. When superficial infections were excluded, the two definitions estimated about the same overall percentage infection (2.2% and 2.6% respectively), but there were almost three times as many conflicting infection diagnoses (n=14) as concordant ones (n=5). Conclusion. Distinctions in surgical wound infection definitions contribute to notable differences in how infections are classified after TKA. Even small changes made to the CDC definition, as with the NINSS version, caused major variation in estimated percentage of wound infection. A single definition used consistently can show changes in wound infection rates over time at a single centre. However, differences in interpretation prevent comparison between different centres

Aims

This study aims to estimate economic outcomes associated with 30-day deep surgical site infection (SSI) from closed surgical wounds in patients with lower limb fractures following major trauma.

Aims: To determine the rate of orthopaedic wound infection using ASEPSIS and compare this to the rate of infection as defined by the US Centres for Disease Control (CDC) and the UK Surgical Site Infection Surveillance Service (SSISS). Background: It is a common misconception that reported rates of orthopaedic wound infection are accurate, reliable and reproducible. Most definitions of infection, including CDC and SSISS, are subjective and depend on the interpretation of the surgeon. ASEPSIS. 1. is a method of wound scoring which grades wounds as uninfected, disturbed healing, minor infection, moderate infection and severe infection. ASEPSIS scoring has been proven to be both objective and repeatable. 2. . Method: Over 4 years, 1113 orthopaedic wounds were prospectively evaluated using the CDC definition for surgical site infections, the SSISS definition and the ASEPSIS scoring method. Patients were seen pre-operatively and at 3 and 5 days post-operatively. They also completed a wound surveillance questionnaire at 2 months post-discharge. Results: The overall infection rates were 8% as defined by CDC, 4% as defined by SSISS and 3% as defined by ASEPSIS. Further classification of the wounds as defined by ASEPSIS revealed that 91% of wounds showed no evidence of infection (score < 10), 6.6% showed a disturbance of healing (score 11–20), 2.3% had a minor infection (score 21–30), 0.4% had a moderate infection (score 31–40) and 0.3% had severe infection (score > 40). Conclusion: This study illustrates that accurate wound surveillance is not simple. Different wound infection definitions give very different rates of infection and make comparisons between surgeons and hospitals impossible. We propose that ASEPSIS provides the most accurate and reproducible results and also provides more information with the grading of wound infection. The overall rate of orthopaedic wound infection using the ASEPSIS method is 3%. If all hospitals used this scoring method, more accurate comparisons of infection rates could be made

Introduction. Despite recent advances in the diagnosis of periprosthetic joint infection(PJI), identifying the infecting organism continues to be a challenge, with up to a third of PJIs reported to have negative cultures. Current molecular techniques have thus far been unable to replace culture as the gold standard for isolation of the infecting pathogen. Next- generation sequencing(NGS) is a well-established technique for comprehensively sequencing the entire pathogen DNA in a given sample and has recently gained much attention in many fields of medicine. Our aim was to evaluate the ability of NGS in identifying the causative organism(s) in patients with PJI. Methods. After obtaining Institutional Review Board approval and informed consent for all study participants, samples were prospectively collected from 148 revision total joint arthroplasty procedures (83 knees, 65 hips). Synovial fluid, deep tissue and swabs were obtained at the time of surgery and shipped to the laboratory for NGS analysis (MicroGenDx). Deep tissue specimens were also sent to the institutional laboratory(Thomas Jefferson University Hospital) for culture. PJI was diagnosed using the Musculoskeletal Infection Society(MSIS) definition of PJI. Statistical analysis was performed using SPSS software. Results. Fifty-five revisions were considered infected; culture was positive in 40 of these (40/55, 72.7%), while NGS was positive in 47 (47/55, 85.5%). Among the positive cultures, complete concordance between NGS and culture was observed in 33 cases (33/40, 82.5%). One case was partially discordant between NGS and culture, with culture detecting three organisms as opposed to one organism on NGS. One case showed complete discordance with NGS and culture detecting different organisms. Three patients with negative NGS results had positive cultures. In another two cases culture simply reported the gross morphology of the organism but the phenotype was not identified, while NGS was able to definitively identify an organism. Among the 15 cases of culture-negative PJI, NGS was able to identify an organism in 10 cases (10/15, 66.7%). These data are summarized in Figure 1. Ninety-three revisions were considered to be aseptic; NGS exclusively identified microbes in 15 of 93 “aseptic” revisions (16.1%) and culture exclusively isolated an organism in 4 of 93 cases(5.3%). One case was positive on both NGS and culture, however the results were discordant from each other. The remaining cases (73/93, 78.5%) were both NGS and culture negative. NGS detected several organisms in most positive samples, with a greater number of organisms detected in aseptic compared to septic cases (6.8 vs. 4.0, respectively). Discussion. NGS was able to detect a pathogen in two-thirds of culture-negative cases and demonstrated a high rate of concordance with culture in culture-positive cases. The rate of false positives was low compared to earlier studies using molecular techniques. Our findings also suggest that some cases of PJI may be polymicrobial and escape detection using conventional culture. NGS may be a useful adjunct for identifying the causative organism(s) in PJI, particularly in the setting of negative cultures. Further study is required to determine the significance of isolated organisms in samples from patients who are not thought to be infected

Aim. Dexamethasone is often used as part of multimodal analgesia to prevent postoperative nausea and vomiting (PONV) and also to reduce postoperative pain. Because glucocorticoids have immunosuppressive and glucose-rising effects, the aim of current study was to examine if dexamethasone may be used safely in arthroplasty surgery. Methods. All consecutive total primary and revision hip and knee arthroplasties performed in the Hospital District of Helsinki and Uusimaa, Peijas Hospital were analyzed (n=18 872). Emergency operations, for example total hip arthroplasties for femur fractures, were also included. Prospective surveillance for postoperative infections was performed. All infections meeting the Musculoskeletal Infection Society definition for prosthetic joint infection (PJI) were included. Results. A total of 189 (1.0%) PJIs occurred: 0.8% after all primary arthroplasties and 1.9% after revision arthroplasties. The PJI rate after the emergency operations was 2.3 % (19/796). The PJI rate in the dexamethasone group was 1.0% (30/2 922) and in the non-dexamethasone group 1.0% (159/15 950), with no significant difference in the PJI incidence (P=0.849). The median time from the index operation to the infection was 16.0 (Q1–Q3 13.0–23.0) days. Total of 35 causative bacteria were cultured from the 30 PJI in dexamethasone group and 169 bacteria from the 159 PJI in non-dexamethasone group with no significant difference: Staphylococcus aureus (40.0% and 45.0%, respectively, P=1.000), Staphylococcus epidermidis (14.3% and 10.7%, P=0.375), other coagulase-negative staphylococci (11.4% and 11.8%, P=0.200), Streptococcus agalactiae (11.4% and 11.8%, P=0.695), Streptococcus betahemolyticus G (8.6% and 2.4%, P=0.081), other streptococci (0.0% and 4.1%, P=0.599), Enterococcus faecalis (2.9% and 5.3%, P=1.000), Enterobacter cloacae (2.9% and 3.6%, P=1.000), Pseudomonas aeruginosa (2.9% and 1.8%, P=0.502), and other bacteria (14.3% and 8.8%, P=0.544). Only one methicillin-resistant Staphylococcus aureus (MRSA) was detected in dexamethasone group. The proportion of polymicrobial PJIs was similar in both groups: 13.3% and 8.8%, respectively (p=0.495). Conclusions. In our study material, the use of 5–10mg dose of dexamethasone did not increase the incidence of postoperative PJI. The single 5–10 dose of dexamethasone may be safely used to prevent PONV and as part of multimodal analgesia on patients undergoing arthroplasty operation

Aims

The aim of this study was to analyze the prevalence of culture-negative periprosthetic joint infections (PJIs) when adequate methods of culture are used, and to evaluate the outcome in patients who were treated with antibiotics for a culture-negative PJI compared with those in whom antibiotics were withheld.