The FRI classification - A new classification of fracture-related infections.

AIM: To identify the most relevant factors with respect to the management of fracture-related infection (FRI) and to develop a comprehensive FRI classification that guides decision-making and allows scientific comparison. METHOD: An international group of FRI experts determined the preconditions, purpose, primary factors for inclusion, format and detailed description of the elements of an FRI classification through a consensus driven process. RESULTS: Three major elements were identified and grouped together in the FRI Classification: Fracture (F), Related patient factors (R) and Impairment of soft tissues (I). Each element was divided into five levels of complexity. Fractures can be healed (F1) or unhealed (F2-5). Patients may be fully healthy (R1) or have 4 levels of compromise, with and without end-organ damage (R2-5). Soft tissue condition ranges from well vascularized and easily closed (I1) to major skin defects requiring free flaps (I4). In all three elements, the fifth level (F5, R5 or I5) describes a patient who has an unreconstructible bone, soft tissue envelope or is not fit for surgery. CONCLUSION: The FRI classification, which is based on the three major elements Fracture (F), Related patient factors (R) and Impairment of soft tissues (I) is intended to guide decision-making and improve the quality of scientific reporting for FRIs in the future. The proposed classification is based on expert opinion and therefore an essential next step is clinical validation, in order to realize the ultimate goal of improving outcomes in the management of FRI.

Prosthetic Joint Infections due to Candida Species: A Multicenter International Study.

BACKGROUND: Prosthetic joint infection (PJI) caused by Candida spp is a severe complication of arthroplasty. We investigated the outcomes of Candida PJI. METHODS: This was a retrospective observational multinational study including patients diagnosed with Candida-related PJI between 2010 and 2021. Treatment outcome was assessed at 2-year follow-up. RESULTS: A total of 269 patients were analyzed. Median age was 73.0 (interquartile range [IQR], 64.0-79.0) years; 46.5% of patients were male and 10.8% were immunosuppressed. Main infection sites were hip (53.0%) and knee (43.1%), and 33.8% patients had fistulas. Surgical procedures included debridement, antibiotics, and implant retention (DAIR) (35.7%), 1-stage exchange (28.3%), and 2-stage exchange (29.0%). Candida spp identified were Candida albicans (55.8%), Candida parapsilosis (29.4%), Candida glabrata (7.8%), and Candida tropicalis (5.6%). Coinfection with bacteria was found in 51.3% of cases. The primary antifungal agents prescribed were azoles (75.8%) and echinocandins (30.9%), administered for a median of 92.0 (IQR, 54.5-181.3) days. Cure was observed in 156 of 269 (58.0%) cases. Treatment failure was associated with age >70 years (OR, 1.811 [95% confidence interval {CI}: 1.079-3.072]), and the use of DAIR (OR, 1.946 [95% CI: 1.157-3.285]). Candida parapsilosis infection was associated with better outcome (OR, 0.546 [95% CI: .305-.958]). Cure rates were significantly different between DAIR versus 1-stage exchange (46.9% vs 67.1%, P = .008) and DAIR versus 2-stage exchange (46.9% vs 69.2%, P = .003), but there was no difference comparing 1- to 2-stage exchanges (P = .777). CONCLUSIONS: Candida PJI prognosis seems poor, with high rate of failure, which does not appear to be linked to immunosuppression, use of azoles, or treatment duration.

Local Antimicrobial Therapy with Combined Aminoglycoside and Vancomycin Compared to Aminoglycoside Monotherapy in the Surgical Management of Osteomyelitis and Fracture-Related Infection.

We investigated the effect of combination aminoglycoside and vancomycin local antibiotic treatment compared to aminoglycoside alone in the surgical management of bone infection. Data including patient demographics, type of surgery, microbiological characteristics, BACH score, duration of antibiotic treatment and clinical outcomes were collected. Failure of therapy was a composite of recurrence of infection, continued or new antimicrobial therapy, or reoperation with suspected or confirmed infection at one year after index surgery. A total of 266 patients met the inclusion criteria. 252 patients reached the final follow-up and were included in the final analysis. 113 patients had treatment with aminoglycoside alone and 139 patients had combination aminoglycoside and vancomycin. There was no difference in the failure rate between groups; 10/113 (8.8%) in the aminoglycoside alone and 12/139 (8.6%) in the combination group, p = 0.934. Multivariate analysis showed that there was no added benefit of combination therapy (OR 1.54: 95% CI 0.59-4.04, p = 0.38). BACH score and low BMI were associated with increased risk of failure (BACH OR 3.49: 95% CI 1.13-10.76, p = 0.03; Low BMI OR 0.91: 95% CI 0.84-0.99, p = 0.037). The form of the carrier material (pellets or injectable paste) had no effect on failure rate (p = 0.163). The presence of aminoglycoside resistance had no effect on failure rate (OR 0.39: 95% CI 0.05-3.01, p = 0.37). Clinical outcome was not improved by the addition of vancomycin to aminoglycoside alone as local therapy for the management of bone infection.

Clinical Outcome following Management of Severe Osteomyelitis due to Pin Site Infection.

Aim: This study has investigated cases of pin site infection (PSI) which required surgery for persistent osteomyelitis (OM) despite pin removal. Materials and methods: Patients requiring surgery for OM after PSI between 2011 and 2021 were included in this retrospective cohort study. Single-stage surgery was performed in accordance with a protocol at one institution. This involved deep sampling, debridement, implantation of local antibiotics, culture-specific systemic antibiotics and soft tissue closure. A successful outcome was defined as an infection-free interval of at least 24 months following surgery. Results: Twenty-seven patients were identified (the sites were 22 tibias, 2 humeri, 2 calcanei, 1 radius); about 85% of them were males with a median age of 53.9 years. The majority of infections (21/27) followed fracture treatment. Fifteen patients were classified as BACH uncomplicated and 12 were BACH complex. Staphylococci were the most common pathogens, polymicrobial infections were detected in five cases (19%). Seven patients required flap coverage which was performed in the same operation.After a median of 3.99 years (2.00-8.05) follow-up, all patients remained infection free at the site of the former OM. Wound leakage after local antibiotic treatment was seen in 3/27 (11.1%) cases but did not require further treatment. Conclusion: Osteomyelitis after PSI is uncommon but has major implications for the patient as 7 patients needed flap coverage. This reinforces the need for careful pin placement and pin site care to prevent deep infection. These infections were treated in accordance with a protocol and were not managed simply by curettage. All patients treated in this manner remained infection-free after a minimum follow-up of 2 years suggesting that this protocol is effective. Clinical significance: Pin site infection is a very common complication in external fixation. The sequela of a chronic pin site OM is rare but the implications to the patient are huge. In this series, more than a quarter of patients required flap coverage as part of the treatment of the deep infection. How to cite this article: Frank FA, Pomeroy E, Hotchen AJ, et al. Clinical Outcome following Management of Severe Osteomyelitis due to Pin Site Infection. Strategies Trauma Limb Reconstr 2024;19(1):21-25.

The Microbiological Profile and Antibiotic Susceptibility of Fracture Related Infections in a Low Resource Setting Differ from High Resource Settings: A Cohort Study from Cameroon.

Fracture-related infection (FRI) is a common and devastating complication of orthopedic trauma in all settings. Data on the microbiological profile and susceptibility of FRI to antibiotics in low-income countries are scarce. Therefore, this study aimed to investigate the microbial patterns and antimicrobial susceptibility of FRI in a sub-Saharan African setting in order to provide guidance for the formulation of evidence-based empirical antimicrobial regimens. We conducted a retrospective analysis of patients treated for FRI with deep tissue sampling for microbiological culture from January 2016 to August 2023 in four tertiary-level hospitals in Yaoundé, Cameroon. There were 246 infection episodes in 217 patients. Cultures were positive in 209 (84.9%) cases and polymicrobial in 109 (44.3%) cases. A total of 363 microorganisms from 71 different species were identified, of which 239 (65.8%) were Gram-negative. The most commonly isolated pathogens were Staphylococcus aureus (n = 69; 19%), Enterobacter cloacae (n = 43; 11.8%), Klebsiella pneumoniae (n = 35; 9.6%), Escherichia coli (n = 35; 9.6%), and Pseudomonas aeruginosa (n = 27; 7.4%). Coagulase-negative staphylococci (CoNS) were isolated in only 21 (5.9%) cases. Gram-negative bacteria accounted for the majority of the infections in early (70.9%) and delayed (73.2%) FRI, but Gram-positive bacteria were prevalent in late FRI (51.7%) (p < 0.001). Polymicrobial infections were more frequent in the early (55.9%) and delayed (41.9%) groups than in the late group (27.6%) (p < 0.001). Apart from Staphylococcus aureus, there was no significant difference in the proportions of causative pathogens between early, delayed, and late FRI. This study found striking resistance rates of bacteria to commonly used antibiotics. MRSA accounted for 63% of cases. The most effective antibiotics for all Gram-positive bacteria were linezolid (96.4%), vancomycin (92.5%), clindamycin (85.3%), and fucidic acid (89.4%). For Gram-negative bacteria, only three antibiotics displayed a sensitivity >50%: amikacin (80.4%), imipenem (74.4%), and piperacillin + tazobactam (57%). The most effective empirical antibiotic therapy (with local availability) was the combination of vancomycin and amikacin or vancomycin and imipenem. In contrast to the literature from high-resource settings, this study revealed that in a sub-Saharan African context, Gram-negative bacteria are the most common causative microorganisms of FRI. This study revealed striking resistance rates to commonly used antibiotics, which will require urgent action to prevent antimicrobial resistance in low and middle-income countries.

Key aspects of soft tissue management in fracture-related infection: recommendations from an international expert group.

A judicious, well-planned bone and soft tissue debridement remains one of the cornerstones of state-of-the-art treatment of fracture-related infection (FRI). Meticulous surgical excision of all non-viable tissue can, however, lead to the creation of large soft tissue defects. The management of these defects is complex and numerous factors need to be considered when selecting the most appropriate approach. This narrative review summarizes the current evidence with respect to soft tissue management in patients diagnosed with FRI. Specifically we discuss the optimal timing for tissue closure following debridement in cases of FRI, the need for negative microbiological culture results from the surgical site as a prerequisite for definitive wound closure, the optimal type of flap in case of large soft tissue defects caused by FRI and the role of negative pressure wound therapy (NPWT) in FRI. Finally, recommendations are made with regard to soft tissue management in FRI that should be useful for clinicians in daily clinical practice.Level of evidence Level V.

A practical definition of pin site infection.

Pin Site Infection (PSI) is the most common complication of external fixation treatment. Several classifications and diagnostic approaches have been used with reported incidences varying widely from 1 to 100 %. The quality of the existing literature is limited by the absence of a definition. This renders comparing literature and developing evidence-based algorithms for prevention, diagnostics, and treatment difficult to impossible. Similar problems were identified with prosthetic joint infection (PJI) and fracture-related infection (FRI) in recent years, resulting in new, validated definitions. PSI is complicated by the complexity of the issue. Numerous factors in PSI need consideration. Factors may be related to the patient, the surgical technique, the pin-bone interface, the pin-skin interface, the choice of external fixation device and/or the material used and its properties. Reliably diagnosing PSI is one of the most pressing issues. New definitions for FRI or PJI have diagnostic criteria which can be either confirmatory or suggestive. Any positive finding of a confirmatory criterion constitutes an infection. Although PSI resembles PJI and FRI, distinct differences are present. The skin is never closed, and bacterial colonization is inevitable along the treatment duration. The external fixator is only temporarily in place; thus, the goal of all measures is to continue the external fixator until the intended indication is reached. This paper proposes the principles of a definition of PSI. This definition is not designed to guide any treatment of PSI. Its purpose is to create common ground for clinical investigations and publishing further research.

The global burden of fracture-related infection: can we do better?

Fracture-related infection is a major complication related to musculoskeletal injuries that not only has important clinical consequences, but also a substantial socioeconomic impact. Although fracture-related infection is one of the oldest disease entities known to mankind, it has only recently been defined and, therefore, its global burden is still largely unknown. In this Personal View, we describe the origin of the term fracture-related infection, present the available data on its global impact, and discuss important aspects regarding its prevention and management that could lead to improved outcomes in both high-resource and low-resource settings. We also highlight the need for health-care systems to be adequately compensated for the high cost of human resources (trained staff) and well-equipped facilities required to adequately care for these complex patients. Our aim is to increase awareness among clinicians and policy makers that fracture-related infection is a disease entity that deserves prioritisation in terms of research, with the goal to standardise treatment and improve patient outcomes on a global scale.

A natural history of untreated chronic osteomyelitis of the tibia over 20 years, with evolving squamous cell carcinoma: a case report.

Squamous cell carcinoma (SCC) is a rare but potentially life-threatening complication of chronic osteomyelitis. Whilst there have been over 100 cases of chronic osteomyelitis with malignant transformation reported in the literature between 1999 and 2020, this is the first case report to document transformation with 20 years of concordant imaging and clinical review.

A comparison of clinical and radiological outcomes between two different biodegradable local antibiotic carriers used in the single-stage surgical management of long bone osteomyelitis.

Aims: Dead-space management, following dead bone resection, is an important element of successful chronic osteomyelitis treatment. This study compared two different biodegradable antibiotic carriers used for dead-space management, and reviewed clinical and radiological outcomes. All cases underwent single-stage surgery and had a minimum one-year follow-up. Methods: A total of 179 patients received preformed calcium sulphate pellets containing 4% tobramycin (Group OT), and 180 patients had an injectable calcium sulphate/nanocrystalline hydroxyapatite ceramic containing gentamicin (Group CG). Outcome measures were infection recurrence, wound leakage, and subsequent fracture involving the treated segment. Bone-void filling was assessed radiologically at a minimum of six months post-surgery. Results: The median follow-up was 4.6 years (interquartile range (IQR) 3.2 to 5.4; range 1.3 to 10.5) in Group OT compared to 4.9 years (IQR 2.1 to 6.0; range 1.0 to 8.3) in Group CG. The groups had similar defect sizes following excision (both mean 10.9 cm3 (1 to 30)). Infection recurrence was higher in Group OT (20/179 (11.2%) vs 8/180 (4.4%), p = 0.019) than Group CG, as was early wound leakage (33/179 (18.4%) vs 18/180 (10.0%), p = 0.024) and subsequent fracture (11/179 (6.1%) vs 1.7% (3/180), p = 0.032). Group OT cases had an odds ratio 2.9-times higher of developing any one of these complications, compared to Group CG (95% confidence interval 1.74 to 4.81, p < 0.001). The mean bone-void healing in Group CG was better than in Group OT, in those with ≥ six-month radiological follow-up (73.9% vs 40.0%, p < 0.001). Conclusion: Local antibiotic carrier choice affects outcome in chronic osteomyelitis surgery. A biphasic injectable carrier with a slower dissolution time was associated with better radiological and clinical outcomes compared to a preformed calcium sulphate pellet carrier.

A Survey of Orthopedic Surgical Management of Pressure Ulcer-Related Pelvic Osteomyelitis.

Pressure-ulcer related pelvic osteomyelitis is managed with little high-quality evidence. We undertook an international survey of orthopedic surgical management, covering diagnostic parameters, multidisciplinary input, and surgical approaches (indications, timing, wound closure, and adjunctive therapies). This identified areas of consensus and disagreement, representing a starting point for future discussion and research.

Diagnosis of fracture-related infection in patients without clinical confirmatory criteria: an international retrospective cohort study.

Background: fracture-related infection (FRI) remains a serious complication in orthopedic trauma. To standardize daily clinical practice, a consensus definition was established, based on confirmatory and suggestive criteria. In the presence of clinical confirmatory criteria, the diagnosis of an FRI is evident, and treatment can be started. However, if these criteria are absent, the decision to surgically collect deep tissue cultures can only be based on suggestive criteria. The primary study aim was to characterize the subpopulation of FRI patients presenting without clinical confirmatory criteria (fistula, sinus, wound breakdown, purulent wound drainage or presence of pus during surgery). The secondary aims were to describe the prevalence of the diagnostic criteria for FRI and present the microbiological characteristics, both for the entire FRI population. Methods: a multicenter, retrospective cohort study was performed, reporting the demographic, clinical and microbiological characteristics of 609 patients (with 613 fractures) who were treated for FRI based on the recommendations of a multidisciplinary team. Patients were divided in three groups, including the total population and two subgroups of patients presenting with or without clinical confirmatory criteria. Results: clinical and microbiological confirmatory criteria were present in 77 % and 87 % of the included fractures, respectively. Of patients, 23 % presented without clinical confirmatory criteria, and they mostly displayed one (31 %) or two (23 %) suggestive clinical criteria (redness, swelling, warmth, pain, fever, new-onset joint effusion, persisting/increasing/new-onset wound drainage). The prevalence of any suggestive clinical, radiological or laboratory criteria in this subgroup was 85 %, 55 % and 97 %, respectively. Most infections were monomicrobial (64 %) and caused by Staphylococcus aureus. Conclusion: clinical confirmatory criteria were absent in 23 % of the FRIs. In these cases, the decision to operatively collect deep tissue cultures was based on clinical, radiological and laboratory suggestive criteria. The combined use of these criteria should guide physicians in the management pathway of FRI. Further research is needed to provide guidelines on the decision to proceed with surgery when only these suggestive criteria are present.

Making the diagnosis in prosthetic joint infection: a European view.

Prosthetic joint infections (PJI) can be difficult to diagnose. Studies have shown that we are missing many infections, possibly due to poor diagnostic workup and the presence of culture-negative infection. PJI diagnosis requires a methodical approach and a standardised set of criteria. Multiple PJI definitions have been published with improved accuracy in recent years. The new European Bone and Joint Infection Society definition offers some advantages in clinical practice. It identifies more clinically important infections and accurately defines those with the highest risk of treatment failure. It reduces the number of patients with uncertain diagnoses. Classification of PJIs may offer a better understanding of treatment outcomes and risk factors for failure.

The Sinus Tract in Bone and Joint Infection: Minimally Invasive Salvation or Prolonged Suffering? A Multicenter Study.

This study assessed the quality of life (QOL) and the functional outcome in daily living in patients with a chronic, treatment-resistant periprosthetic joint infection (PJI) or osteomyelitis, living with a natural or iatrogenic sinus tract. METHODS: A follow-up examination in three national reference centers for septic bone and joint surgery was performed utilizing the Hospital Anxiety and Depression Scale (HADS-D/A), the Visual Analogue Scale (VAS), and the Short Form-36 (SF-36) score, including patients with a chronic sinus tract due to treatment-resistant PJI or osteomyelitis. RESULTS: In total, 48 patients were included, with a mean follow-up time of 43.1 ± 23.9 months. The mean SF-36 Mental Component Summary (MCS) was 50.2 (±12.3) and the Physical Component Summary (PCS) was 33.9 (±11.3). The mean HADS-D was 6.6 (±4.4) and HADS-A was 6.2 (±4.6), and the VAS was 3.4 (±2.6). The SF-36 MCS showed no significant differences between the study group and the standard population (47.0, p = 0.10), as well as the HADS-A. The PCS in the study population was significantly worse (50.0, p < 0.001), as was the HADS-D. CONCLUSIONS: A sinus tract represents a treatment option in selected cases with an acceptable QOL. The treatment should be considered for multimorbid patients with a high perioperative risk or if the bone or soft tissue quality prevents surgery.

Predictive factors for fracture-related infection in open tibial fractures in a Sub-Saharan African setting.

INTRODUCTION: The management of open tibial fractures (OTF) is challenging in low and middle-income countries (LMICs) where appropriate human resources and infrastructure (including equipment, implants and surgical supplies) are not readily available and medical care is not readily accessible. OTF are not rarely associated with a subsequent fracture-related infection (FRI), which is one of the most devastating and difficult to cure complications in orthopaedic trauma care. The aim of this study was to determine the rate and the predictive factors of FRI in OTF in a limited-resource setting of sub-Saharan Africa. METHODS: Patients with OTF who underwent surgery from July 2015 to December 2020 and followed-up for at least 12 months in a tertiary care teaching hospital in Yaoundé (Cameroon) were retrospectively investigated. Diagnosis of FRI was based on the confirmatory criteria of the International FRI Consensus definition. All patients with bone infections, occurring at any time point during follow-up, were included. Logistic regression was used to determine the predictive factors for FRI. RESULTS: One hundred and five patients with OTF were studied. With a mean follow-up period of 29.5 ± 16.6 months, 33 patients (31.4%) presented with FRI. Gustilo-Anderson type of OTF, compliance with antibiotics, blood transfusion, time to first washing of the wounds and method of bone fixation were factors associated with the occurrence of FRI. In multivariable logistic regression, 6-hours delay to first washing of the wounds (OR=8.07, 95% CI: 1.43-45.31, p = 0.01), and compliance with antibiotics (OR=11.33, 95%CI: 1.11-115.6, p = 0.04) were the only independent predictors of FRI. CONCLUSION: The overall rate of FRI in open tibial fracture is still high in the sub-Saharan African context. For similar low-resources settings, this study supports the recommendations (1) to perform a very early washing-dressing-splinting of OTF on admission of the patient, (2) to administer antibiotics early, and (3) to perform surgery as soon as reasonably possible, once appropriate personnel, equipment, implants and surgical supplies are available.

Microbial Persistence, Replacement and Local Antimicrobial Therapy in Recurrent Bone and Joint Infection.

We report microbiological results from a cohort of recurrent bone and joint infection to define the contributions of microbial persistence or replacement. We also investigated for any association between local antibiotic treatment and emerging antimicrobial resistance. Microbiological cultures and antibiotic treatments were reviewed for 125 individuals with recurrent infection (prosthetic joint infection, fracture-related infection, and osteomyelitis) at two UK centres between 2007 and 2021. At re-operation, 48/125 (38.4%) individuals had an organism from the same bacterial species as at their initial operation for infection. In 49/125 (39.2%), only new species were isolated in culture. In 28/125 (22.4%), re-operative cultures were negative. The most commonly persistent species were Staphylococcus aureus (46.3%), coagulase-negative Staphylococci (50.0%), and Pseudomonas aeruginosa (50.0%). Gentamicin non-susceptible organisms were common, identified at index procedure in 51/125 (40.8%) and at re-operation in 40/125 (32%). Gentamicin non-susceptibility at re-operation was not associated with previous local aminoglycoside treatment (21/71 (29.8%) vs. 19/54 (35.2%); p = 0.6). Emergence of new aminoglycoside resistance at recurrence was uncommon and did not differ significantly between those with and without local aminoglycoside treatment (3/71 (4.2%) vs. 4/54 (7.4%); p = 0.7). Culture-based diagnostics identified microbial persistence and replacement at similar rates in patients who re-presented with infection. Treatment for orthopaedic infection with local antibiotics was not associated with the emergence of specific antimicrobial resistance.

Three to six tissue specimens for histopathological analysis are most accurate for diagnosing periprosthetic joint infection.

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). METHODS: In this retrospective diagnostic study, patients undergoing revision surgery after total hip or knee arthroplasty (n = 119) between January 2015 and July 2018 were included. Multiple specimens of the periprosthetic membrane and pseudocapsule were obtained for histopathological analysis at revision arthroplasty. Based on the Infectious Diseases Society of America (IDSA) 2013 criteria, the International Consensus Meeting (ICM) 2018 criteria, and the European Bone and Joint Infection Society (EBJIS) 2021 criteria, PJI was defined. Using a mixed effects logistic regression model, the sensitivity and specificity of the histological diagnosis were calculated. The optimal number of periprosthetic tissue specimens for histopathological analysis was determined by applying the Youden index. RESULTS: Based on the EBJIS criteria (excluding histology), 46 (39%) patients were classified as infected. Four to six specimens showed the highest Youden index (four specimens: 0.631; five: 0.634; six: 0.632). The sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of five tissue specimens were 76.5% (95% confidence interval (CI) 67.6 to 81.4), 86.8% (95% CI 81.3 to 93.5), 66.0% (95% CI 53.2 to 78.7), and 84.3% (95% CI 79.4 to 89.3), respectively. The area under the curve (AUC) was calculated with 0.81 (as a function of the number of tissue specimens). Applying the ICM and IDSA criteria (excluding histology), 40 (34%) and 32 (27%) patients were categorized as septic. Three to five specimens had the highest Youden index (ICM 3: 0.648; 4: 0.651; 5: 0.649) (IDSA 3: 0.627; 4: 0.629; 5: 0.625). CONCLUSION: Three to six tissue specimens of the periprosthetic membrane and pseudocapsule should be collected at revision arthroplasty and analyzed by a pathologist experienced and skilled in interpreting periprosthetic tissue.Cite this article: Bone Joint J 2023;105-B(2):158-165.

UK consensus definitions for necrotising otitis externa: a Delphi study.

OBJECTIVE: To establish consensus definitions for necrotising otitis externa (NOE) to facilitate the diagnosis and exclusion of NOE in clinical practice and expedite future high-quality study of this neglected condition. DESIGN: The work comprised of a systematic review of the literature, five iterative rounds of consultation via a Delphi process and open discussion within the collaborative. An expert panel analysed the results to produce the final outputs which were shared with and endorsed by national specialty bodies. SETTING: Secondary care in the UK. PARTICIPANTS: UK clinical specialists practising in infection, ear nose and throat (ENT) surgery or radiology. MAIN OUTCOME MEASURES: Definitions and statements meeting the following criteria were accepted: (a) minimum of 70% of respondents in agreement or strong agreement with a definition/statement AND (b) <15% of respondents in disagreement or strong disagreement with a definition/statement. RESULTS: Seventy-four UK clinicians specialising in ENT, Infection and Radiology with a special interest in NOE took part in the work which was undertaken between 2019 and 2021. The minimum response rate for a Round was 76%. Consensus criteria for all proposed case definitions, outcome definitions and consensus statements were met in the fifth round. CONCLUSIONS: This work distills the clinical opinion of a large group of multidisciplinary specialists from across the UK to create practical definitions and statements to support clinical practice and research for NOE. This is the first step in an iterative process. Further work will seek to validate and test these definitions and inform their evolution.

The European Bone and Joint Infection Society definition of periprosthetic joint infection is meaningful in clinical practice: a multicentric validation study with comparison with previous definitions.

BACKGROUND AND PURPOSE: A new periprosthetic joint infection (PJI) definition has recently been proposed by the European Bone and Joint Infection Society (EBJIS). The goals of this paper are to evaluate its diagnostic accuracy and compare it with previous definitions and to assess its accuracy in preoperative diagnosis. PATIENTS AND METHODS: We retrospectively evaluated a multicenter cohort of consecutive revision total hip and knee arthroplasties. Cases with minimum required diagnostic workup were classified according to EBJIS, 2018 International Consensus Meeting (ICM 2018), Infectious Diseases Society of America (IDSA), and modified 2013 Musculoskeletal Infection Society (MSIS) definitions. 2 years' minimum follow-up was required to assess clinical outcome. RESULTS: Of the 472 cases included, PJI was diagnosed in 195 (41%) cases using EBJIS; 188 (40%) cases using IDSA; 172 (36%) using ICM 2018; and 145 (31%) cases using MSIS. EBJIS defined fewer cases as intermediate (5% vs. 9%; p = 0.01) compared with ICM 2018. Specificity was determined by comparing risk of subsequent PJI after revision surgery. Infected cases were associated with higher risk of subsequent PJI in every definition. Cases classified as likely/confirmed infections using EBJIS among those classified as not infected in other definitions showed a significantly higher risk of subsequent PJI compared with concordant non-infected cases using MSIS (RR = 3, 95% CI 1-6), but not using ICM 2018 (RR = 2, CI 1-6) or IDSA (RR = 2, CI 1-5). EBJIS showed the highest agreement between pre-operative and definitive classification (k = 0.9, CI 0.8-0.9) and was better at ruling out PJI with an infection unlikely result (sensitivity 89% [84-93], negative predictive value 90% [85-93]). CONCLUSION: The newly proposed EBJIS definition emerged as the most sensitive of all major definitions. Cases classified as PJI according to the EBJIS criteria and not by other definitions seem to have increased risk of subsequent PJI compared with concordant non-infected cases. EBJIS classification is accurate in ruling out infection preoperatively.