Journal of Bone and Joint Infection最新文献

Introduction: Infection remains a major complication of open fractures, with rates reaching up to 70 % after severe injury. Systemic antibiotics often fail to achieve the therapeutic levels needed to disrupt biofilm at the wound site due to compromised blood flow and systemic dilution. This study investigates the efficacy of systemic antibiotics against Staphylococcus aureus and Pseudomonas aeruginosa monomicrobial biofilms in an ovine model of simulated fracture-related infection (FRI). Methods: An established model of long-bone FRI in the right hind limb of mature Rambouillet sheep was adapted. Local soft tissue trauma was induced, the periosteum was stripped from the tibial surface, and a simulated fracture was created on the bone surface. The site was inoculated with mature biofilm grown on fracture fixation plates. Sheep were assigned to a treatment group receiving 10 d of systemic antibiotic therapy or a positive control group that received no treatment. All animals were sacrificed at 21 d, and microbiological and histological analysis was performed. Results: Systemic antibiotics failed to produce a statistically significant reduction in S. aureus biofilm compared to the positive control. Systemic therapy significantly reduced P. aeruginosa bioburden compared to the positive control, but levels remained above the clinical threshold for infection. The histological analysis revealed moderate improvement from systemic treatment. Conclusions: This investigation established the limitations of systemic antibiotic therapy in this model of long-bone FRI against S. aureus and P. aeruginosa biofilms. Microbiological and histological analyses revealed hallmark features of recalcitrance to systemic treatment, validating the utility of this model to study anti-infective therapies. These findings highlight the need for new antibiotic delivery strategies to manage biofilm-associated infections.

Purpose: Periprosthetic joint infection (PJI) represents a major complication of total joint arthroplasty (TJA). The joint-specific bone involvement, antimicrobial options, coverage of the soft tissues, and host status (JS-BACH) classification of 2021 aims to categorize PJI severity and predict PJI recurrence and quality of life following surgical PJI treatment. Until now, only one external validation has confirmed its predictive value for treatment failure. This study aimed to further validate the classification in an external cohort and to compare outcomes between different pathogen groups. Methods: We applied the JS-BACH classification to a cohort of 249 consecutive gram-positive (staphylococci) and gram-negative PJIs in hip and knee joints treated at our institution between 2010 and 2022 (Staphylococcus aureus $n=62$ ; coagulase-negative staphylococci $n=115$ ; gram-negative organisms $n=72$ ). According to the JS-BACH classification, we divided cases into uncomplicated ( $n=35$ ), complex ( $n=155$ ), and limited options ( $n=59$ ). The median (interquartile range, IQR) follow-up was 25.0 (3-59) and at least 12 months. Outcomes were assessed based on the 2013 Delphi consensus on PJI outcome. PJI was defined following the EBJIS classification. Results: A higher JS-BACH category correlated significantly with a lower infection-free survival. Using uncomplicated cases as baseline, the hazards ratio (HR) was 3.2 (95 %-CI 1.3-7.9) for complex and 6.6 (95 %-CI 2.6-16.7) for limited options cases. Similarly, higher JS-BACH categories were associated with lower revision-free survival for recurrent PJI, again with uncomplicated cases as baseline: complex HR 2.2 (95 %-CI 0.9-5.5); limited options HR 4.1 (95 %-CI 1.6-10.8). The mean infection-free survival was 85.7 %, 58.7 %, and 33.9 % for uncomplicated, complex, and limited options cases ( $p<0.001$ ). Conclusion: The novel JS-BACH classification provides reliable predictions of treatment outcome for the proposed subgroups. It provides a structured and simple-to-use option for classifying PJI in daily clinical practice and for scientific purposes.

Introduction: Historically, isolating patients diagnosed with musculoskeletal infections (MSIs) from the general orthopaedic population has been regarded a fundamental aspect of effective infection control. However, this remains controversial. Evolving perspectives on infection prevention, resource constraints, and staffing shortages necessitate a reassessment of current practices. This scoping review examines existing isolation policies for MSIs in orthopaedic practice and provides expert recommendations for hospital policymakers. Materials and methods: A systematic search of seven databases identified 23 320 articles. After deduplication and screening of 10 621 abstracts, 119 full texts were reviewed and 14 studies met the inclusion criteria. A total of 9 studies involved surgical wards, 5 examined general hospital wards, and 2 addressed orthopaedic patients. Results: Evidence indicates that individual isolation measures can reduce methicillin-resistant Staphylococcus aureus infections, whereas additional contact precautions or isolation showed no reduction of transmission risk for extended-spectrum beta-lactamase-producing Enterobacterales in endemic settings. For vancomycin-resistant Enterococcus (VRE), one study found a reduction in infections after implementing individual isolation, while another study reported no impact. No evidence supports separating patients with non-resistant MSIs from elective orthopaedic patients. Similarly, no data support the routine use of dedicated septic wards in orthopaedic practice. Conclusions: Effective infection control relies on hospital-wide strategies, provided that appropriate preventive measures and a high level of compliance with standard precautions are in place. Isolation practices should be selectively tailored to local epidemiology to balance infection prevention with optimal resource utilization. Managing MSIs in specialized centres, instead of dedicated septic wards, may deliver more effective care and adherence to standard precautions.

Chronic periprosthetic joint infections (PJIs) complicated by severe bone loss are challenging cases that require complex and specialized treatment approaches. Megaprosthetic replacement has gained in popularity in the setting of chronic hip and knee PJI; however, only a limited number of studies reporting on its utility are available. Thus, we aimed to review our cohort of patients with this specific condition who received modular megaprosthesis (MMP) as a limb salvage option in order to assess the failure rates, infection control, and implant longevity. We retrospectively reviewed electronic medical records of 61 patients who received MMPs for chronic hip and knee PJI between 2012 and 2024. The mean follow-up was $6.6\pm 3.5$  years. Failures were classified according to the Henderson classification. Kaplan-Meier survival curves were used to assess failure-free, infection-free, and overall implant survival. Cox regression analysis was performed to identify variables associated with MMP failure. Among the 61 patients, 37.7 % experienced any type of MMP failure, with infection recurrence being the most common reason for failure (60.9 %), followed by structural failure of the implant (17.4 %). At the 5-year follow-up, failure-free survival, infection-free survival, and revision-free survival were 65.8 %, 80.0 %, and 70.5 %, respectively. McPherson host grade C was significantly associated with implant failure (hazard ratio (HR) 3.1; 95 % confidence interval 1.4-7.6; $P=0.024$ ). Conclusively, MMPs represent a valuable treatment option for patients with chronic hip and knee PJI and large bone defects. While infection control is acceptable, the rates of any-type failure are high. These findings should be considered during preoperative patient counseling.

Background: Periprosthetic joint infections (PJIs) are a devastating complication following oncologic endoprosthetic reconstruction (EPR). Despite significant efforts to characterize the microbiologic profile of PJI in traditional joint arthroplasty, data are lacking in orthopedic oncology. Our study analyzed the causative microorganisms and time to positivity (TTP) of PJI in oncologic EPR and conventional joint arthroplasty (C-TJA). Methods: We retrospectively compared sample cultures for lower-extremity oncologic EPR and C-TJA patients diagnosed with PJI between 2000 and 2022. All positive microorganisms were assessed, along with clinical and culture method data. Comparisons utilized the Mann-Whitney $U$  test. Results: We included 70 oncologic EPR and 153 C-TJA patients diagnosed with PJIs. Staphylococcus epidermidis (16.8 % vs. 10.6 %, $p=0.01$ ), Enterococcus spp. (12.6 % vs. 4 %, $p<0.001$ ), and Peptostreptococcus spp. (5.3 % vs. 1.3 %, $p<0.001$ ) were common and more frequently isolated in oncologic EPR than C-TJA PJI. Conversely, Staphylococcus aureus predominated in samples from C-TJA patients (31.7 % vs. 15.1 %, $p<0.001$ ). Differences in endoprosthetic microorganism prevalence were observed between primary versus metastatic bone disease and bone versus soft tissue sarcoma. TTP was highly variable among microorganisms and was significantly faster ( $p<0.05$ ) for bone and soft tissue vs. synovial fluid (3 d vs. 4 d) and for broth and solid media vs. broth only (2.5 d vs. 4.5 d). Conclusion: The microorganism profile in oncologic EPR PJI was distinct from C-TJA PJI. The oncologic EPR population highlighted variability in the prevalence of Gram-negative rods and slower TTP for broth-only cultures. Further investigation of the mechanisms behind these differences will allow care teams to provide prompt, individualized, and targeted antimicrobial therapy.

Background: Prosthetic joint infection (PJI) is an uncommon but serious complication of joint arthroplasty, associated with significant morbidity and healthcare costs. Anaerobic organisms are an under-recognized cause of PJI, either as sole pathogens or within polymicrobial infections, and data on their clinical impact are limited. This study compared clinical presentation and outcomes of anaerobic vs. aerobic PJIs. Methods: This is a retrospective review of 284 patients who met Musculoskeletal Infection Society (MSIS) criteria for PJI from 2014 to 2020 at the University of Iowa Hospitals and Clinics (UIHC). A total of 38 had anaerobic PJI; 268 had aerobic PJI. Statistical analyses were performed using Pearson's ${\chi }^2$ , a Fisher exact test, and a $t$ test. Results: Anaerobic PJIs represented 13.4 % of PJIs in our institution. Compared to aerobic cases, anaerobic PJIs had longer symptom duration (19.4 vs. 10.9 weeks, $p=0.005$ ), more sinus tracts (23.7 % vs. 6.1 %, $p<0.001$ ), fewer fevers (13.2 % vs. 31.3 %, $p=0.022$ ), more radiographic abnormalities (44.7 % vs. 29.3 %, $p=0.024$ ), and lower ESR and CRP (ESR: 49.0 vs. 67.4 mm h^-1; CRP: 6.6 vs. 12.3 mg dL^-1; both $p=0.003$ ). Shoulder PJIs were more often anaerobic (39.5 % vs. 4.9 %, $p<0.001$ ). Anaerobic PJIs were more likely to be treated with two-stage exchange (65.8 %), while aerobic cases more often underwent debridement and implant retention (44.7 %). Recurrence rates were similar. Conclusion: Anaerobic PJIs tend to present with features such as shoulder involvement, prolonged or chronic symptoms, sinus tract formation, and radiographic signs of infection, whereas aerobic PJIs are more commonly linked to acute presentations. For this reason, both aerobic and anaerobic cultures should be performed routinely to optimize diagnostic yield.

The absence of a standardized definition for postoperative spinal infections (PSIs) hinders both diagnosis and research. Using a meta-epidemiological approach, we analyzed 101 studies, with most relying on predefined criteria but with a minority creating their own definition (mainly clinical). Establishing a universal definition is crucial to enhancing PSI management and facilitating research.

Awaiting final microbiology results can delay discharge in musculoskeletal (MSK) infections. We developed a novel process based on electronic medical records reviewing post-discharge results. Among 1662 encounters, 35.6 % had $\ge$ 1 intervention, often therapy modification. Multidisciplinary review by an orthopaedic infectious diseases team improved antimicrobial optimization through timely action on culture results after discharge.

Aim: The aim of this study was to investigate the diagnostic performance of a novel rapid multiplex polymerase chain reaction (mPCR) in adults with suspected acute native joint infection. Methods: This retrospective single-centre study included 143 patients with suspected acute native joint infection from February 2023 to May 2024. A septic arthritis was classified based on institutional criteria. The agreement between mPCR and conventional culture of synovial fluid (SF) was assessed by calculating the Cohen's $\kappa$ coefficient. The diagnostic performance of mPCR was calculated, and the area under the curve (AUC) was compared with conventional culture of synovial fluid by using the $z$ test. Results: When considering only microorganisms targeted by mPCR, this method detected 13 novel microorganisms in 13 cases compared to conventional culture, resulting in an overall agreement of 91 %, a positive agreement of 100 %, a negative agreement of 88 %, and a Cohen's $\kappa$  coefficient of 0.780. Of these 13 cases, 9 were classified as septic, with 6 ( $n=6/9$ , 67 %) on antibiotics prior to aspiration. When considering all microorganisms (including off-panel microorganisms), the overall percentage agreement between mPCR and conventional culture was 89 %, with a Cohen's $\kappa$  coefficient of 0.735, indicating substantial agreement. Sensitivity, specificity, PPV, NPV, LR $+$ , LR $-$ , accuracy, and AUC of mPCR were 45 %, 89 %, 90 %, 44 %, 4.21, 0.62, 59 %, and 0.671, and those of conventional culture were 40 %, 100 %, 100 %, 45 %, 0.60, 59 %, and 0.698. No difference in performance was observed between both methods ( $p=0.183$ ). The combination of both techniques showed a sensitivity, specificity, PPV, NPV, LR $+$ , LR $-$ , accuracy, and AUC of 48 %, 89 %, 90 %, 46 %, 4.5, 0.58, 62 %, and 0.686. Conclusion: Given its comparable diagnostic performance and faster turnaround time relative to conventional synovial fluid culture, this novel mPCR can be recommended as a valuable adjunct in the diagnosis of septic arthritis in adults, particularly in patients with prior antimicrobial treatment.

Background: Native vertebral osteomyelitis and infective endocarditis (NVO $+$ IE) are increasingly recognized as overlapping entities, sharing common risk factors (e.g., advanced age, immunosuppression) and similar pathogen profiles, most commonly Staphylococcus aureus and streptococci. Concurrent infection presents unique diagnostic and therapeutic challenges, leading to uncertainty regarding clinical outcomes and mortality. Therefore, we aimed to systematically evaluate the combined mortality associated with concomitant NVO $+$ IE and to summarize the available clinical characteristics from published studies. Methods: A systematic review was conducted following the PRISMA framework. The databases searched included MEDLINE, Embase, Cochrane Library, and Scopus from 1970 to October 2023. Studies were included if they involved at least 10 adult patients diagnosed with NVO and IE and provided mortality data. Two reviewers independently screened the references, extracted the data, and evaluated the methodological quality using a dedicated tool. A random-effects meta-analysis was performed to aggregate in-hospital, 1-month, 1-year, and 3-year mortality rates. Results: A total of 16 studies (12 retrospective, 3 prospective, 1 mixed) were included, involving 641 patients (mean age 67.1 years) with NVO $+$ IE. In-hospital mortality was 14.0 % (95 % CI: 10.0 %-20.0 %). At 1 month, mortality was 9.0 % (95 % CI: 5.0 %-17.0 %), rising to 18.0 % (95 % CI: 13.0 %-24.0 %) by 1 year and 16.0 % (95 % CI: 3.0 %-50.0 %) by 3 years. Significant between-study heterogeneity was observed ( $I^2$  range: 3 %-70 %). Common co-morbidities included diabetes mellitus (23.7 %), chronic renal failure (15.0 %), and immunosuppression (15.0 %). Streptococci (31.5 %), S. aureus (25.2 %), and enterococci (17.7 %) were the primary pathogens. Cardiac valve surgery and spinal surgery were reported in 47.5 % and 29.9 % of patients, respectively. A subgroup analysis on 1-month mortality showed that S. aureus predominance was associated with a significantly higher mortality compared to streptococci. Certainty in the estimates was low due to imprecision and methodological limitations. Conclusions: Concomitant NVO $+$ IE is associated with substantial mortality, especially for S. aureus, underscoring the need for earlier diagnosis, coordinated multidisciplinary management, and standardized treatment protocols. Future prospective, high-quality studies are needed to clarify optimal strategies for diagnostic workup and surgical intervention for this complex clinical scenario.