Inter-observer reproducibility of diagnosis of diabetic foot osteomyelitis based on a combination of probe-to-bone test and simple radiography

Brazilian Society of Angiology and Vascular Surgery 2023 guidelines on the diabetic foot

The diabetic foot interacts with anatomical, vascular, and neurological factors that challenge clinical practice. This study aimed to compile the primary scientific evidence based on a review of the main guidelines, in addition to articles published on the Embase, Lilacs, and PubMed platforms. The European Society of Cardiology system was used to develop recommendation classes and levels of evidence. The themes were divided into six chapters (Chapter 1 - Prevention of foot ulcers in people with diabetes; Chapter 2 - Pressure relief from foot ulcers in people with diabetes; Chapter 3 -Classifications of diabetic foot ulcers; Chapter 4 - Foot and peripheral artery disease; Chapter 5 - Infection and the diabetic foot; Chapter 6 - Charcot's neuroarthropathy). This version of the Diabetic Foot Guidelines presents essential recommendations for the prevention, diagnosis, treatment, and follow-up of patients with diabetic foot, offering an objective guide for medical practice.

Diagnostic Performance of Atherogenic Index of Plasma for Predicting Diabetic Foot Osteomyelitis with Peripheral Artery Disease

Background: This study aims to assess the atherogenic index of plasma (AIP) diagnostic value in detecting diabetic foot osteomyelitis (DFO) among patients with diabetic foot ulcers (DFUs). Methods: A prospective cohort study was conducted on 80 patients with DFUs and suspected DFO between January 2022 and December 2023. The primary outcome measures included the diagnosis of DFO, determined by positive microbiological analysis results from bone samples and its correlation with the AIP. Receiver operating characteristic (ROC) curves were utilized to select the optimal diagnostic cut-off points for AIP and post hoc analysis was performed to evaluate the difference in the AIP for diagnosing DFO in patients with and without peripheral arterial disease (PAD). Results: The diagnostic potential for DFO in PAD patients of AIP-1 (Log TC/HDL) showed an AUC of 0.914 (p < 0.001 [0.832-0.996]), leading to a sensitivity of 83% and a specificity of 85%. By contrast, AIP-2 (Log TG/HDL) demonstrated a slightly lower AUC of 0.841 (p < 0.001 [0.716-0.967]), leading to a sensitivity of 76% and a specificity of 74%. Conclusions: The AIP tool, with its ideal blend of sensitivity and specificity, aids in predicting DFO effectively. Therefore, clinicians should consider using AIP for patients suffering from PAD and associated DFO.

IWGDF/IDSA guidelines on the diagnosis and treatment of diabetes-related foot infections (IWGDF/IDSA 2023)

The International Working Group on the Diabetic Foot (IWGDF) has published evidence-based guidelines on the management and prevention of diabetes-related foot diseases since 1999. The present guideline is an update of the 2019 IWGDF guideline on the diagnosis and management of foot infections in persons with diabetes mellitus. The Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) framework was used for the development of this guideline. This was structured around identifying clinically relevant questions in the P(A)ICO format, determining patient-important outcomes, systematically reviewing the evidence, assessing the certainty of the evidence, and finally moving from evidence to the recommendation. This guideline was developed for healthcare professionals involved in diabetes-related foot care to inform clinical care around patient-important outcomes. Two systematic reviews from 2019 were updated to inform this guideline, and a total of 149 studies (62 new) meeting inclusion criteria were identified from the updated search and incorporated in this guideline. Updated recommendations are derived from these systematic reviews, and best practice statements made where evidence was not available. Evidence was weighed in light of benefits and harms to arrive at a recommendation. The certainty of the evidence for some recommendations was modified in this update with a more refined application of the GRADE framework centred around patient important outcomes. This is highlighted in the rationale section of this update. A note is also made where the newly identified evidence did not alter the strength or certainty of evidence for previous recommendations. The recommendations presented here continue to cover various aspects of diagnosing soft tissue and bone infections, including the classification scheme for diagnosing infection and its severity. Guidance on how to collect microbiological samples, and how to process them to identify causative pathogens, is also outlined. Finally, we present the approach to treating foot infections in persons with diabetes, including selecting appropriate empiric and definitive antimicrobial therapy for soft tissue and bone infections; when and how to approach surgical treatment; and which adjunctive treatments may or may not affect the infectious outcomes of diabetes-related foot problems. We believe that following these recommendations will help healthcare professionals provide better care for persons with diabetes and foot infections, prevent the number of foot and limb amputations, and reduce the patient and healthcare burden of diabetes-related foot disease.

Clinical practice recommendations for infectious disease management of diabetic foot infection (DFI) - 2023 SPILF

In march 2020, the International Working Group on the Diabetic Foot (IWGDF) published an update of the 2015 guidelines on the diagnosis and management of diabetic foot infection (DFI). While we (the French ID society, SPILF) endorsed some of these recommendations, we wanted to update our own 2006 guidelines and specifically provide informative elements on modalities of microbiological diagnosis and antibiotic treatment (especially first- and second-line regiments, oral switch and duration). The recommendations put forward in the present guidelines are addressed to healthcare professionals managing patients with DFI and more specifically focused on infectious disease management of this type of infection, which clearly needs a multidisciplinary approach. Staging of the severity of the infection is mandatory using the classification drawn up by the IWGDF. Microbiological samples should be taken only in the event of clinical signs suggesting infection in accordance with a strict preliminarily established protocol. Empirical antibiotic therapy should be chosen according to the IWGDF grade of infection and duration of the wound, but must always cover methicillin-sensitive Staphylococcus aureus. Early reevaluation of the patient is a fundamental step, and duration of antibiotic therapy can be shortened in many situations. When osteomyelitis is suspected, standard foot radiograph is the first-line imagery examination and a bone biopsy should be performed for microbiological documentation. Histological analysis of the bone sample is no longer recommended. High dosages of antibiotics are recommended in cases of confirmed osteomyelitis.

IWGDF/IDSA Guidelines on the Diagnosis and Treatment of Diabetes-related Foot Infections (IWGDF/IDSA 2023)

The International Working Group on the Diabetic Foot (IWGDF) has published evidence-based guidelines on the management and prevention of diabetes-related foot diseases since 1999. The present guideline is an update of the 2019 IWGDF guideline on the diagnosis and management of foot infections in persons with diabetes mellitus. The Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) framework was used for the development of this guideline. This was structured around identifying clinically relevant questions in the P(A)ICO format, determining patient-important outcomes, systematically reviewing the evidence, assessing the certainty of the evidence, and finally moving from evidence to the recommendation. This guideline was developed for healthcare professionals involved in diabetes-related foot care to inform clinical care around patient-important outcomes. Two systematic reviews from 2019 were updated to inform this guideline, and a total of 149 studies (62 new) meeting inclusion criteria were identified from the updated search and incorporated in this guideline. Updated recommendations are derived from these systematic reviews, and best practice statements made where evidence was not available. Evidence was weighed in light of benefits and harms to arrive at a recommendation. The certainty of the evidence for some recommendations was modified in this update with a more refined application of the GRADE framework centred around patient important outcomes. This is highlighted in the rationale section of this update. A note is also made where the newly identified evidence did not alter the strength or certainty of evidence for previous recommendations. The recommendations presented here continue to cover various aspects of diagnosing soft tissue and bone infections, including the classification scheme for diagnosing infection and its severity. Guidance on how to collect microbiological samples, and how to process them to identify causative pathogens, is also outlined. Finally, we present the approach to treating foot infections in persons with diabetes, including selecting appropriate empiric and definitive antimicrobial therapy for soft tissue and bone infections; when and how to approach surgical treatment; and which adjunctive treatments may or may not affect the infectious outcomes of diabetes-related foot problems. We believe that following these recommendations will help healthcare professionals provide better care for persons with diabetes and foot infections, prevent the number of foot and limb amputations, and reduce the patient and healthcare burden of diabetes-related foot disease.

Analysis of the Influence of Diabetic Nephropathy in Patients with Diabetic Foot Osteomyelitis

This study analyzed the influence of diabetic nephropathy on the healing prognosis after conservative surgery in diabetic foot osteomyelitis (DFO). A retrospective observational study was carried out between January 2021 and December 2022 and involved 278 outpatients with a diagnosis of DFO at a specialized diabetic foot unit, including 74 (26.62%) patients with DN (group 2) and 204 (73.38%) patients without DN (group 1). There were 266 (95.70%) ulcers on the forefoot, 8 (2.90%) on the midfoot, and 4 (1.45%) on the hindfoot (p = 0.992). The healing rates were 85.1% (n = 63) for group 2 and 81.3% (n = 165) for group 1 (p = 0.457). When exploring the influence of DN on the risk of delayed ulcer healing, the results did not show a significant effect [12 (6; 28) weeks among patients with DN vs. 12 (6; 21) weeks among patients without DN; p = 0.576]. No significant differences were observed in complications, with one (2.59%) death occurring in group 1 (p = 0.296) and three minor amputations being performed in both groups [two (5.13%) amputations in group 1 vs. one amputation (9.09%) in group 2; p = 0.217]. Bone cultures were performed for a total of 190 patients (133 in group 1 and 57 in group 2). Of these, 176 positive bone cultures were isolated: 71 positive bone cultures (57.7%) were monomicrobial cultures in group 1, with 30 (56.6%) in group 2. There were 52 (42.3%) that had at least two microorganisms in group 1, and 23 (43.4%) in group 2 (p = 0.890). The most frequently prescribed oral antibiotic was amoxicillin/clavulanate (43.89%), followed by levofloxacin (28.4%), and trimethoprim/sulfamethoxazole (14.7%). This study shows that DN does not have a significant influence on the healing prognosis of patients with DFO after conservative surgery.

Is the Combination of Plain X-ray and Probe-to-Bone Test Useful for Diagnosing Diabetic Foot Osteomyelitis? A Systematic Review and Meta-Analysis

A systematic review and meta-analysis was conducted to assess the diagnostic accuracy of the combination of plain X-ray and probe-to-bone (PTB) test for diagnosing diabetic foot osteomyelitis (DFO). This systematic review has been registered in PROSPERO (a prospective international register of systematic reviews; identification code CRD42023436757). A literature search was conducted for each test separately along with a third search for their combination. A total of 18 articles were found and divided into three groups for separate analysis and comparison. All selected studies were evaluated using STROBE guidelines to assess the quality of reporting for observational studies. Meta-DiSc software was used to analyze the collected data. Concerning the diagnostic accuracy variables for each case, the pooled sensitivity (SEN) was higher for the combination of PTB and plain X-ray [0.94 (PTB + X-ray) vs. 0.91 (PTB) vs. 0.76 (X-ray)], as was the diagnostic odds ratio (DOR) (82.212 (PTB + X-ray) vs. 57.444 (PTB) vs. 4.897 (X-ray)). The specificity (SPE) and positive likelihood ratio (LR+) were equally satisfactory for the diagnostic combination but somewhat lower than for PTB alone (SPE: 0.83 (PTB + X-ray) vs. 0.86 (PTB) vs. 0.76 (X-ray); LR+: 5.684 (PTB + X-ray) vs. 6.344 (PTB) vs. 1.969 (X-ray)). The combination of PTB and plain X-ray showed high diagnostic accuracy comparable to that of MRI and histopathology diagnosis (the gold standard), so it could be considered useful for the diagnosis of DFO. In addition, this diagnostic combination is accessible and inexpensive but requires training and experience to correctly interpret the results. Therefore, recommendations for this technique should be included in the context of specialized units with a high prevalence of DFO.

Is fluoroscopy-guided percutaneous bone biopsy of diabetic foot with suspected osteomyelitis worthwhile? A retrospective study

BACKGROUND

Diabetic foot infection, particularly osteomyelitis, is a major risk factor of amputation in persons with diabetes. Bone biopsy with microbial examination is considered the gold standard of diagnosis of osteomyelitis, providing information about the offending pathogens as well as their antibiotics susceptibility. This allows targeting of these pathogens with narrow spectrum antibiotics, potentially reducing emergence of antimicrobial resistance. Percutaneous fluoroscopy guided bone biopsy allows accurate and safe targeting of the affected bone.

METHODS

In a single tertiary medical institution and over 9 year period, we performed 170 percutaneous bone biopsies. We retrosepctively reviewed the medical record of these patients including patients' demographics, imaging and biopsy microbiology and pathollogic results.

RESULTS

Microbiological cultures of 80 samples (47.1%) were positive with 53.8% of the positive culture showed monomicrobial growth and the remaining were polymicrobial. Of the positive bone samples 71.3% grew Gram-positive bacteria. Staphylococcus aureus was the most frequently isolated pathogen from positive bone cultures with almost one third showing methicillin resistence. Enterococcus species were the most frequently isolated pathogens from polymicrobial samples. Enterobacteriaceae species were the most common Gram-negative pathogens and were more common in polymicrobial samples.

CONCLUSIONS

Percutaneous image-guided bone biopsy is a low-risk, minimally invasive procedure that can provide valuable information about microbial pathogens and therefore enable targeting these pathogens with narrow spectrum antibiotics.

Bacterial Diversity and Antibiotic Resistance in Patients with Diabetic Foot Osteomyelitis

This study analysed the bacterial diversity, antibiotic susceptibility, and resistance in patients with complications of diabetic foot osteomyelitis (DFO). A retrospective observational study was carried out between September 2019 and September 2022 and involved 215 outpatients with a diagnosis of DFO at a specialized diabetic foot unit. A total of 204 positive bone cultures were isolated, including 62.7% monomicrobial cultures, and 37.3% were formed with at least two microorganisms. We observed that Proteus spp., Coagulase-negative staphylococci (CoNS), Staphylococcus aureus, Pseudomonas aeruginosa, Escherichia coli, and Corynebacterium were the most frequently isolated microorganisms and accounted for more than 10% of the DFO cases. With stratification by Gram-positive (GP) and Gram-negative (GN) bacteria, we observed that 91.6% of cultures presented at least one GP bacteria species, and 50.4% presented at least one GN bacteria species. The most common GP species were CoNS (29%), S. aureus (25.8%), and Corynebacterium spp. (14%). The most frequent GN species consisted of Proteus spp. (32%), P. aeruginosa (23.3%), and E. coli (17.5%). The main antibiotics with resistance to GP-dominated infections were penicillins without β-lactamase inhibitor, and those in GN-dominated infections were sulfonamides and penicillins without β-lactamase. Significant differences were not observed in mean healing time in DFU with acute osteomyelitis (12.76 weeks (4.50;18)) compared to chronic osteomyelitis (15.31 weeks (7;18.25); p = 0.101) and when comparing cases with soft tissue infection (15.95 (6;20)) and those without such an infection (16.59 (7.25;19.75), p = 0.618). This study shows that when treatment of DFO is based on early surgical treatment, the type of DFO and the presence of soft infection are not associated with different or worse prognoses.

Effectiveness of Sucrose Octasulfate Dressing in the Treatment of Neuro-Ischaemic Diabetic Foot Heel Ulcers: A Retrospective Single arm Study

The study aimed to evaluate the effectiveness of the use of sucrose octasulfate impregnated dressing (TLC-NOSF [Technology Lipido-Colloid-Nano-OligoSaccharide Factor]) in the management of persons with neuro-ischaemic heel diabetic foot ulcers (DFUs). Consecutive patients who referred for an active non-infected neuro-ischaemic heel DFU belonging to grade IC (superficial) or IIC (deep to tendons, muscle or capsule) according to Texas University Classification were included. All patients were managed by a pre-set limb salvage protocol in the respect of International guidelines and the TLC-NOSF dressing was used as primary and specific dressing. Patients were evaluated any 2 to 4 weeks until wound healing or different outcomes. Primary outcome was the rate of complete wound healing after 24 weeks of follow-up. The secondary outcomes assessed the healing time, the rate of wound regression, the re-ulceration in the case of complete healing and the safety. Thirty patients were included. The mean age was 67 ± 11 years, 17 (56.7%) were male, all of them were affected by type 2 diabetes with a mean duration of 18 ± 7 years. Twenty patients (66.7%) showed deep ulcers (grade 2 of Texas University Classification); the mean TcPO2 at the inclusion was 42 ± 7 mm Hg. Twenty-two patients (73.3%) healed by Week 24. The mean time of healing was 84 ± 32 days, 2 (6.7%) patients had ulcer relapse after healing, 28 (93.3%) had wound regression >50%, 2 (6.7%) had mild infection, 1 (3.3%) reported major amputation. No serious adverse events related to TLC-NOSF dressing or local reactions were reported. This current study showed the potential benefit of sucrose octasulfate for treating neuro-ischaemic heel DFUs in addition to the standard of care.

Culture Concordance in Different Sections of the Metatarsal Head: Interpretations of Microbiological Results

Microbiological cultures of per-wound bone biopsies have shown a lack of correlation and a high rate of false-negative results when compared with bone biopsy cultures in diabetic foot osteomyelitis. The selection of samples from the area of active osteomyelitis, which contains a complete census of the microorganisms responsible for the infection, is essential to properly guide antimicrobial treatment. We aimed to comparatively evaluate the quantitative and qualitative cultures taken from different areas, in metatarsal heads resected for osteomyelitis. For this purpose, we consecutively selected 13 metatarsal heads from 12 outpatients with plantar ulcers admitted to our diabetic foot unit. Metatarsal heads were divided transversally into 3 portions: plantar (A), central (B), and dorsal (C), and the 39 resulting samples were cultured. Qualitative and quantitative microbiological analysis was performed, and the isolated species and bacterial load, total and species specific, were compared between the 3 metatarsal bone segments. The primary outcome of the study was the bacterial diversity detected in the different bone sections. Cultures were positive in 12 of the 13 included metatarsal heads (92%). A total of 34 organisms were isolated from all specimens. Ten of the 12 cultures (83%) were polymicrobial. Ten of the 13 metatarsal heads (77%) had identical microbiological results in each of the 3 bone sections. The largest number of microorganisms was found in the central section. The overall concordance between sections was 91%. The predominant microorganisms were coagulase-negative staphylococci (41%). Statistical differences were not found in the bioburden between sections (range 3.25-3.41 log₁₀ colony-forming unit/g for all sections; P = .511). The results of our study suggest that microorganisms exhibit a high tendency to spread along the metatarsal bone and that the degree of progression along the bone is species dependent. The central portions of metatarsal bones tend to accumulate a higher diversity of species. Thus, we recommend this area of bone for targeted biopsy in patients with suspected osteomyelitis.

Medical Versus Surgical Treatment for the Management of Diabetic Foot Osteomyelitis: A Systematic Review

A systematic review and quality assessment was performed to assess the management of diabetic foot osteomyelitis by medical or surgical treatment. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) checklist was used. All selected studies were evaluated using the Cochrane Risk of Bias Tool to assess the risk of bias for randomized controlled trials. The literature was revised using PubMed (Medline) and Embase (Elsevier) up to September 2020 to identify clinical trials assessing medical or surgical treatment to manage diabetic foot osteomyelitis. A total of six clinical trials that met our inclusion criteria, with a total of 308 participants. Healing rate, complete closure of the wound, and type of complications were the outcomes evaluated. Risk of bias assessment showed that only two of the six clinical trials included in the systematic review had a low risk of bias. Based on our findings, we believe that the management of diabetic foot osteomyelitis remains challenging. There are few high-quality clinical trials that both stratify clinical presentations and compare these treatments. We conclude that the available evidence is insufficient to identify the best option to cure diabetic foot osteomyelitis.

State of the art of 18F-FDG PET/CT application in inflammation and infection: a guide for image acquisition and interpretation

AIM

The diagnosis, severity and extent of a sterile inflammation or a septic infection could be challenging since there is not one single test able to achieve an accurate diagnosis. The clinical use of 18F-fluorodeoxyglucose ([¹⁸F]FDG) positron emission tomography/computed tomography (PET/CT) imaging in the assessment of inflammation and infection is increasing worldwide. The purpose of this paper is to achieve an Italian consensus document on [¹⁸F]FDG PET/CT or PET/MRI in inflammatory and infectious diseases, such as osteomyelitis (OM), prosthetic joint infections (PJI), infective endocarditis (IE), prosthetic valve endocarditis (PVE), cardiac implantable electronic device infections (CIEDI), systemic and cardiac sarcoidosis (SS/CS), diabetic foot (DF), fungal infections (FI), tuberculosis (TBC), fever and inflammation of unknown origin (FUO/IUO), pediatric infections (PI), inflammatory bowel diseases (IBD), spine infections (SI), vascular graft infections (VGI), large vessel vasculitis (LVV), retroperitoneal fibrosis (RF) and COVID-19 infections.

METHODS

In September 2020, the inflammatory and infectious diseases focus group (IIFG) of the Italian Association of Nuclear Medicine (AIMN) proposed to realize a procedural paper about the clinical applications of [¹⁸F]FDG PET/CT or PET/MRI in inflammatory and infectious diseases. The project was carried out thanks to the collaboration of 13 Italian nuclear medicine centers, with a consolidate experience in this field. With the endorsement of AIMN, IIFG contacted each center, and the pediatric diseases focus group (PDFC). IIFG provided for each team involved, a draft with essential information regarding the execution of [¹⁸F]FDG PET/CT or PET/MRI scan (i.e., indications, patient preparation, standard or specific acquisition modalities, interpretation criteria, reporting methods, pitfalls and artifacts), by limiting the literature research to the last 20 years. Moreover, some clinical cases were required from each center, to underline the teaching points. Time for the collection of each report was from October to December 2020.

RESULTS

Overall, we summarized 291 scientific papers and guidelines published between 1998 and 2021. Papers were divided in several sub-topics and summarized in the following paragraphs: clinical indications, image interpretation criteria, future perspectivess and new trends (for each single disease), while patient preparation, image acquisition, possible pitfalls and reporting modalities were described afterwards. Moreover, a specific section was dedicated to pediatric and PET/MRI indications. A collection of images was described for each indication.

CONCLUSIONS

Currently, [¹⁸F]FDG PET/CT in oncology is globally accepted and standardized in main diagnostic algorithms for neoplasms. In recent years, the ever-closer collaboration among different European associations has tried to overcome the absence of a standardization also in the field of inflammation and infections. The collaboration of several nuclear medicine centers with a long experience in this field, as well as among different AIMN focus groups represents a further attempt in this direction. We hope that this document will be the basis for a "common nuclear physicians' language" throughout all the country.

SUPPLEMENTARY INFORMATION

The online version contains supplementary material available at 10.1007/s40336-021-00445-w.

Imaging tests for the detection of osteomyelitis: a systematic review

BACKGROUND

Osteomyelitis is an infection of the bone. Medical imaging tests, such as radiography, ultrasound, magnetic resonance imaging (MRI), single-photon emission computed tomography (SPECT) and positron emission tomography (PET), are often used to diagnose osteomyelitis.

OBJECTIVES

To systematically review the evidence on the diagnostic accuracy, inter-rater reliability and implementation of imaging tests to diagnose osteomyelitis.

DATA SOURCES

We conducted a systematic review of imaging tests to diagnose osteomyelitis. We searched MEDLINE and other databases from inception to July 2018.

REVIEW METHODS

Risk of bias was assessed with QUADAS-2 [quality assessment of diagnostic accuracy studies (version 2)]. Diagnostic accuracy was assessed using bivariate regression models. Imaging tests were compared. Subgroup analyses were performed based on the location and nature of the suspected osteomyelitis. Studies of children, inter-rater reliability and implementation outcomes were synthesised narratively.

RESULTS

Eighty-one studies were included (diagnostic accuracy: 77 studies; inter-rater reliability: 11 studies; implementation: one study; some studies were included in two reviews). One-quarter of diagnostic accuracy studies were rated as being at a high risk of bias. In adults, MRI had high diagnostic accuracy [95.6% sensitivity, 95% confidence interval (CI) 92.4% to 97.5%; 80.7% specificity, 95% CI 70.8% to 87.8%]. PET also had high accuracy (85.1% sensitivity, 95% CI 71.5% to 92.9%; 92.8% specificity, 95% CI 83.0% to 97.1%), as did SPECT (95.1% sensitivity, 95% CI 87.8% to 98.1%; 82.0% specificity, 95% CI 61.5% to 92.8%). There was similar diagnostic performance with MRI, PET and SPECT. Scintigraphy (83.6% sensitivity, 95% CI 71.8% to 91.1%; 70.6% specificity, 57.7% to 80.8%), computed tomography (69.7% sensitivity, 95% CI 40.1% to 88.7%; 90.2% specificity, 95% CI 57.6% to 98.4%) and radiography (70.4% sensitivity, 95% CI 61.6% to 77.8%; 81.5% specificity, 95% CI 69.6% to 89.5%) all had generally inferior diagnostic accuracy. Technetium-99m hexamethylpropyleneamine oxime white blood cell scintigraphy (87.3% sensitivity, 95% CI 75.1% to 94.0%; 94.7% specificity, 95% CI 84.9% to 98.3%) had higher diagnostic accuracy, similar to that of PET or MRI. There was no evidence that diagnostic accuracy varied by scan location or cause of osteomyelitis, although data on many scan locations were limited. Diagnostic accuracy in diabetic foot patients was similar to the overall results. Only three studies in children were identified; results were too limited to draw any conclusions. Eleven studies evaluated inter-rater reliability. MRI had acceptable inter-rater reliability. We found only one study on test implementation and no evidence on patient preferences or cost-effectiveness of imaging tests for osteomyelitis.

LIMITATIONS

Most studies included < 50 participants and were poorly reported. There was limited evidence for children, ultrasonography and on clinical factors other than diagnostic accuracy.

CONCLUSIONS

Osteomyelitis is reliably diagnosed by MRI, PET and SPECT. No clear reason to prefer one test over the other in terms of diagnostic accuracy was identified. The wider availability of MRI machines, and the fact that MRI does not expose patients to harmful ionising radiation, may mean that MRI is preferable in most cases. Diagnostic accuracy does not appear to vary with the potential cause of osteomyelitis or with the body part scanned. Considerable uncertainty remains over the diagnostic accuracy of imaging tests in children. Studies of diagnostic accuracy in children, particularly using MRI and ultrasound, are needed.

STUDY REGISTRATION

This study is registered as PROSPERO CRD42017068511.

FUNDING

This project was funded by the National Institute for Health Research Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 23, No. 61. See the NIHR Journals Library website for further project information.

Diabetic Foot Infections: The Diagnostic Challenges

Diabetic foot infections (DFIs) are severe complications of long-standing diabetes, and they represent a diagnostic challenge, since the differentiation between osteomyelitis (OM), soft tissue infection (STI), and Charcot’s osteoarthropathy is very difficult to achieve. Nevertheless, such differential diagnosis is mandatory in order to plan the most appropriate treatment for the patient. The isolation of the pathogen from bone or soft tissues is still the gold standard for diagnosis; however, it would be desirable to have a non-invasive test that is able to detect, localize, and evaluate the extent of the infection with high accuracy. A multidisciplinary approach is the key for the correct management of diabetic patients dealing with infective complications, but at the moment, no definite diagnostic flow charts still exist. This review aims at providing an overview on multimodality imaging for the diagnosis of DFI and to address evidence-based answers to the clinicians when they appeal to radiologists or nuclear medicine (NM) physicians for studying their patients.

Guidelines on the diagnosis and treatment of foot infection in persons with diabetes (IWGDF 2019 update)

The International Working Group on the Diabetic Foot (IWGDF) has published evidence-based guidelines on the prevention and management of diabetic foot disease since 1999. This guideline is on the diagnosis and treatment of foot infection in persons with diabetes and updates the 2015 IWGDF infection guideline. On the basis of patient, intervention, comparison, outcomes (PICOs) developed by the infection committee, in conjunction with internal and external reviewers and consultants, and on systematic reviews the committee conducted on the diagnosis of infection (new) and treatment of infection (updated from 2015), we offer 27 recommendations. These cover various aspects of diagnosing soft tissue and bone infection, including the classification scheme for diagnosing infection and its severity. Of note, we have updated this scheme for the first time since we developed it 15 years ago. We also review the microbiology of diabetic foot infections, including how to collect samples and to process them to identify causative pathogens. Finally, we discuss the approach to treating diabetic foot infections, including selecting appropriate empiric and definitive antimicrobial therapy for soft tissue and for bone infections, when and how to approach surgical treatment, and which adjunctive treatments we think are or are not useful for the infectious aspects of diabetic foot problems. For this version of the guideline, we also updated four tables and one figure from the 2016 guideline. We think that following the principles of diagnosing and treating diabetic foot infections outlined in this guideline can help clinicians to provide better care for these patients.

Evidence mapping of recommendations on diagnosis and therapeutic strategies for diabetes foot: an international review of 22 guidelines

To systematically review clinical practice guidelines (CPGs) on diabetes foot and assess the consistency of recommendations, quality of CPGs and to present an evidence-map for explicating research trends and gaps. We performed a literature search on PubMed, Embase, and Web of Science, guideline databases and websites of diabetes society to include the diabetic CPGs. The basic information, recommendations for the diabetic foot, methodological quality and reporting quality of diabetic CPGs were exacted by the Excel. Four researchers evaluated the methodological and reporting quality of diabetic foot CPGs by AGREE II instrument and RIGHT checklist. R3.5.1 software was used to create all bubble plots. A total of 22 diabetic CPGs were included, eight CPGs were from different professional diabetes societies. Recommendations on diabetic foot complications involve Diabetic foot ulcer (DFU), Charcot neuropathy (CN) and Osteomyelitis (OM). Eight DFU diagnostic systems presented in 22 CPGs. According to the recommendations of diabetic CPGs, the treatment of DFU can be summarized in four major items; six recommendations on CN diagnosis and six recommendations on treatment of CN were consistent among studies. However, there were inconsistencies in three OM diagnosis recommendations and four OM treatment recommendations. Some recommendations in CPGs were not very specific and clear, and hence they were not reliable for OM diagnosis and treatment. Once these inconsistencies are resolved, validated, accurate and effective diagnosis and treatment of diabetes foot will lead to reduced costs and adverse complications. The results of this review add to our knowledge and promote the development of trustworthy CPGs on diabetes.

What Is the Best Method to Differentiate Acute Charcot Foot From Acute Infection?

RECOMMENDATION

Differentiation between acute Charcot neuroarthropathy (CN) and acute infection/osteomyelitis is complex and requires multiple (>1) diagnostic criteria. These criteria include an emphasis on the presence of neuropathy, history, and physical examination. The absence of skin wounds and resolution of swelling/erythema with elevation makes the likelihood of infection very low. In unclear cases, laboratory testing, histologic examination and culturing of bone specimens, scintigraphy, and imaging, especially magnetic resonance imaging (MRI), may be of benefit.

LEVEL OF EVIDENCE

Moderate.

DELEGATE VOTE

Agree: 100%, Disagree: 0%, Abstain: 0% (Unanimous, Strongest Consensus).

Medical Imaging and Laboratory Analysis of Diagnostic Accuracy in 107 Consecutive Hospitalized Patients With Diabetic Foot Osteomyelitis and Partial Foot Amputations

The primary aim of our study was to compare the preoperative diagnostic accuracy of plain radiographic findings with the accuracy of magnetic resonance imaging (MRI) findings for diabetic foot osteomyelitis in hospitalized patients who underwent first-time partial foot amputations with confirmed histopathological specimens positive for osteomyelitis. Second, it was desired to determine whether certain variables within the initial clinical presentation and preoperative laboratory findings were associated with more accurate diagnosis of diabetic foot osteomyelitis in this study population. Finally, it was desired to determine the most common bacterial organisms found in bone and soft-tissue cultures taken intraoperatively and to determine how often the same organism was found in both. After applying the inclusion and exclusion criteria to the initial 329 patients identified through chart review, the final sample size for further analysis was n =107. In this study, after adjusting for the effects of covariates such as age, erythrocyte sedimentation rate (ESR) and C-reactive protein, plain radiographs seemed to have statistically more significant power than MRI in predicting and diagnosing diabetic foot osteomyelitis. In addition, higher ESR values were confirmed to predict a higher chance of positive diagnosis for diabetic foot osteomyelitis. Furthermore, the presence of positive bacterial identification from intraoperative bone cultures did not always indicate true osteomyelitis on histopathological examination.

LEVELS OF EVIDENCE

Level II: Diagnostic study.

Modern management of diabetic foot osteomyelitis. The when, how and why of conservative approaches

INTRODUCTION

Diabetic foot osteomyelitis (DFO) has long been considered a complex infection that is both difficult to diagnose and treat, and is associated with a high rate of relapse and limb loss. Areas covered: DFO can usually be diagnosed by a combination of clinical evaluation, serum inflammatory markers and plain X-ray. When the results of these procedures are negative or contradictory, advanced imaging tests or bone biopsy may be necessary. Staphylococcus aureus remains the most frequent microorganism isolated from bone specimens, but infection is often polymicrobial. Antibiotic therapy, preferably with oral agents guided by results of bone culture, for a duration of no more than six weeks, appears to be as safe and effective as surgery in cases of uncomplicated forefoot DFO. Surgery (which should be limb-sparing when possible) is always required for DFO accompanied by necrotizing fasciitis, deep abscess, gangrene or in cases not responding (either clinically or radiographically) to apparently appropriate antibiotic treatment. Expert commentary: Research in the past decade has improved diagnosis and treatment of DFO, and most cases can now be managed with a 'conservative' approach, defined as treatment either exclusively with antibiotics or with surgery removing as little bone and soft tissue as necessary.

Diabetic foot infection: Antibiotic therapy and good practice recommendations

BACKGROUND

Healthcare events related to diabetic foot disease carry a burden of morbidity, mortality and economic cost. Prompt identification of clinical infection with appropriate tissue sampling limits use of broad spectrum empirical antibiotics and improves antibiotic stewardship. Staphylococcus aureus remains the commonest infecting organism and high-dose flucloxacillin remains the empirical antibiotic of choice for antibiotic naïve patients. Barriers to microbe-specific treatment include: adequate tissue sampling, delays in culture results, drug allergies and the emergence of multidrug-resistant organisms which can complicate the choice of targeted antibiotics. Even appropriate antibiotic treatment carries a risk of adverse events including the selection of resistant organisms.

AIMS

Multidisciplinary clinical assessment of a diabetic foot infection is supported by the use of appropriate imaging modalities and deep tissue sampling, both of which are encouraged to enhance sampling accuracy. Narrow-spectrum, high dose, short duration antimicrobial therapy is ideal. Further clarity in these areas would be of benefit to clinicians involved in management of diabetic foot infections.

METHODS

A combination of literature review with expert discussion was used to generate consensus on management of diabetic foot infection, with a specific focus on empirical antimicrobial therapy.

RESULTS

Gram positive organisms represent the commonest pathogens in diabetic foot infection. However there are developing challenges in antimicrobial resistance and antibiotic availability.

DISCUSSION

Recommendations for empirical therapy, including the choice of alternative oral agents and use of outpatient antibiotics would be of benefit to those involved in diabetic foot care.

CONCLUSION

This paper provides advice on empirical antibiotic therapy that may be used as a framework for local guideline development to support clinicians in the management of diabetic foot infection.

Osteomyelitis in diabetic foot: A comprehensive overview

Foot infection is a well recognized risk factor for major amputation in diabetic patients. The osteomyelitis is one of the most common expression of diabetic foot infection, being present approximately in present in 10%-15% of moderate and in 50% of severe infectious process. An early and accurate diagnosis is required to ensure a targeted treatment and reduce the risk of major amputation. The aim of this review is to report a complete overview about the management of diabetic foot osteomyelitis. Epidemiology, clinical aspects, diagnosis and treatment are widely described according to scientific reccomendations and our experience.

Diagnostic and therapeutic update on diabetic foot osteomyelitis

Diabetic foot osteomyelitis (DFO) is the most common infection associated to diabetic foot ulcers (DFU). This review is designed to provide an update on the diagnosis and treatment of DFO based on an analysis of MEDLINE through PubMed using as search criterion "Diabetic Foot Osteomyelitis". Authors have included in this review the most relevant manuscripts regarding diagnosis and treatment of DFO. After review and critical analysis of publications, it may be concluded that diagnosis of DFO is not simple because of its heterogeneous presentation. Clinical inflammatory signs, probe-to-bone test, and plain X-rays are postulated as the basic tests for clinical diagnosis when DFO is suspected. Diagnosis should be supported by laboratory tests, of which ESR (>70mm/h) has been shown to be most precise. MRI is the most accurate imaging test, especially for differential diagnosis with Charcot foot. Pathogen isolation by bone culture is essential when the patient is treated with ATB only. Medical or surgical treatment should be based on the clinical characteristics of the patient and the lesion. Surgery should always be an option if medical treatment fails.

Optimising the quality and outcomes of treatments for diabetic foot infections

INTRODUCTION

Infection is the commonest foot complication that arises in people with diabetes and may lead to amputation and even death. The emergence of multidrug resistant bacteria, especially in Gram negative rods, may have a negative impact on the chances of cure in these patients.

AREAS COVERED

We searched the Medline and Pubmed databases for studies using the keywords 'diabetic foot infection' and 'diabetic foot osteomyelits' from 1980 to 2016. Expert commentary: Much has been done in the field of diabetic foot infection regarding pathophysiology, diagnosis and treatment. The construction of multidisciplinary teams is probably the most efficient way to improve the patients' outcome. The rational use of antibiotics and surgical skills are essential in these potentially severe infections. Each case of diabetic infection deserves to be discussed in the light of the current guidelines and the local resources. Because of the overal poor outcome of these infections, prevention remains a priority.

Challenges in the Treatment of Chronic Wounds

Significance: Chronic wounds include, but are not limited, to diabetic foot ulcers, venous leg ulcers, and pressure ulcers. They are a challenge to wound care professionals and consume a great deal of healthcare resources around the globe. This review discusses the pathophysiology of complex chronic wounds and the means and modalities currently available to achieve healing in such patients. Recent Advances: Although often difficult to treat, an understanding of the underlying pathophysiology and specific attention toward managing these perturbations can often lead to successful healing. Critical Issues: Overcoming the factors that contribute to delayed healing are key components of a comprehensive approach to wound care and present the primary challenges to the treatment of chronic wounds. When wounds fail to achieve sufficient healing after 4 weeks of standard care, reassessment of underlying pathology and consideration of the need for advanced therapeutic agents should be undertaken. However, selection of an appropriate therapy is often not evidence based. Future Directions: Basic tenets of care need to be routinely followed, and a systematic evaluation of patients and their wounds will also facilitate appropriate care. Underlying pathologies, which result in the failure of these wounds to heal, differ among various types of chronic wounds. A better understanding of the differences between various types of chronic wounds at the molecular and cellular levels should improve our treatment approaches, leading to better healing rates, and facilitate the development of new more effective therapies. More evidence for the efficacy of current and future advanced wound therapies is required for their appropriate use.

Management of hospitalized patients with diabetic foot infections

Diabetic foot infections (DFIs), which present with a variety of clinical manifestations, are commonly encountered by clinicians. They are associated with a high morbidity, a high amputation rate, a high mortality, and increased health care costs. An effective management of DFIs requires a multidisciplinary approach with a strong collaboration among all involved health care providers as well as patient involvement. Diagnosing DFIs appropriately requires consideration of the clinical symptoms and signs of infection in addition to supplementary laboratory testing such as inflammatory markers and imaging studies. The comprehensive patient assessment should include the predisposing risk factors for infection; the type, severity, and extent of the infection; and the assessment of neurologic and vascular status, comorbid conditions, and psychosocial factors. The comprehensive management of DFIs include not only effective antibiotic therapy but also surgical debridement, pressure offloading, wound care and moisture, maintaining good vascular perfusion, control of edema and pain, correction of metabolic abnormalities such as hyperglycemia, and addressing psychosocial and nutritional issues. Discharge planning that addresses full medical and social needs along with suitable follow-up, patient education and counseling, and clear communication with outpatient providers are critical for ensuring a safe and successful transition to outpatient management of hospitalized patients with DFIs.

Conservative Surgery of Diabetic Forefoot Osteomyelitis: How Can I Operate on This Patient Without Amputation?

Surgery is necessary in many cases of diabetic foot osteomyelitis. The decision to undertake surgery should be based on the clinical presentation of diabetic foot osteomyelitis. Surgery is required when the bone is protruding through the ulcer, there is extensive bone destruction seen on x-ray or progressive bone damage on sequential x-ray while undergoing antibiotic treatment, the soft tissue envelope is destroyed, and there is gangrene or spreading soft tissue infection. Several issues should be taken into account when considering surgery for treating diabetic foot osteomyelitis. It is necessary to have a surgeon available with diabetic foot expertise. Regarding location of diabetic foot osteomyelitis, it is important to consider whether isolated bone or a joint is involved. In cases in which osteomyelitis is associated with a bone deformity, surgery should be able to correct this. The surgeon should always reflect about whether extensive/radical surgery could destabilize the foot. The forefoot is the most frequent location of diabetic foot osteomyelitis and is associated with better prognosis than midfoot and hindfoot osteomyelitis. Many surgical procedures can be performed in patients with diabetes and forefoot ulcers complicated by osteomyelitis while avoiding amputations. Performing conservative surgeries without amputations of any part of the foot is not always feasible in cases in which the infection has destroyed the soft tissue envelope. Attempting conservative surgery in such cases risks infected tissues remaining in the wound bed leading to failure. The election of different surgical options depends on the expertise of the surgeons selected for the multidisciplinary teams. It is the aim of this article to provide a sample of surgical techniques in order to remove the bone infection from the forefoot while avoiding amputations.