Sonographic features and acquisition protocols for Charcot neuro-osteoarthropathy in diabetes: a scoping review protocol

Adam McIlwaine; Ellen Kirwan; Leo Quinlan; Caroline McIntosh

doi:10.12688/hrbopenres.14368.1

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Study Protocol

Sonographic features and acquisition protocols for Charcot neuro-osteoarthropathy in diabetes: a scoping review protocol

[version 1; peer review: 1 approved]

Adam McIlwaine ¹, Ellen Kirwan¹, Leo Quinlan¹, Caroline McIntosh¹

PUBLISHED 19 Mar 2026

Author details Author details

¹ University of Galway, Galway, County Galway, Ireland

Adam McIlwaine
Roles: Conceptualization, Methodology, Project Administration, Writing – Original Draft Preparation, Writing – Review & Editing

Ellen Kirwan
Roles: Formal Analysis

Leo Quinlan
Roles: Supervision, Writing – Review & Editing

Caroline McIntosh
Roles: Methodology, Supervision, Writing – Review & Editing

OPEN PEER REVIEW

REVIEWER STATUS

Abstract

Background

Charcot neuro-osteoarthropathy (CNO; Charcot foot) is an uncommon but serious complication of diabetes and is frequently misdiagnosed or recognised late. Delayed recognition is associated with severe consequences, including progressive deformity, ulceration, amputation and substantial morbidity. Imaging is central to recognition and monitoring. While magnetic resonance imaging is commonly used for early disease where radiographs are non-diagnostic, musculoskeletal ultrasound offers a portable, non-ionising modality that may depict cortical surface irregularity, effusion, synovitis, tenosynovitis and periarticular hypervascularity. However, reported sonographic findings and acquisition protocols are heterogeneous, and to date no scoping review has systematically mapped this evidence in CNO.

Methods

This protocol has been developed in accordance with JBI guidance for scoping reviews and is reported in accordance with PRISMA-P. The completed scoping review will be reported in accordance with PRISMA-ScR. A populated PRISMA-P checklist is provided (Extended data 2). Using the Population–Concept–Context framework, we will include studies of adults with diabetes and confirmed or clinically suspected CNO of the foot/ankle that report musculoskeletal ultrasound findings and/or acquisition protocol details. Studies focused solely on vascular/perfusion ultrasound without musculoskeletal assessment will be excluded. MEDLINE, Embase, CINAHL and Scopus will be searched from inception, with grey literature and citation tracking, and no language restrictions. Two reviewers will independently screen titles/abstracts and full texts. Data will be charted by one reviewer using a prespecified form and independently verified by a second reviewer. Findings will be synthesised using narrative summary and tables, mapping reported sonographic features and protocol parameters. No formal risk-of-bias assessment is planned.

Discussion

This scoping review will provide an evidence map of reported sonographic features and ultrasound acquisition protocols in CNO, identify gaps and inconsistencies in reporting, and inform future research including protocol standardisation and reproducibility-focused evaluation.

Systematic review registration Open Science Framework: 10.17605/OSF.IO/ZRXWD

Keywords

Charcot neuro-osteoarthropathy; Charcot foot; diabetes mellitus; musculoskeletal ultrasound; sonography; Doppler ultrasound; scoping review; protocol

Corresponding author: Adam McIlwaine

Competing interests: No competing interests were disclosed.

Grant information: University of Galway Further Education Policy studentship

Copyright: © 2026 McIlwaine A et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

How to cite: McIlwaine A, Kirwan E, Quinlan L and McIntosh C. Sonographic features and acquisition protocols for Charcot neuro-osteoarthropathy in diabetes: a scoping review protocol [version 1; peer review: 1 approved]. HRB Open Res 2026, 9:24 (https://doi.org/10.12688/hrbopenres.14368.1) First published: 19 Mar 2026, 9:24 (https://doi.org/10.12688/hrbopenres.14368.1) Latest published: 19 Mar 2026, 9:24 (https://doi.org/10.12688/hrbopenres.14368.1)

Introduction

Charcot neuro-osteoarthropathy (CNO), commonly referred to as Charcot foot, is a destructive complication of diabetes characterised by progressive bone and joint breakdown of the foot and ankle in the presence of peripheral neuropathy.⁴ Although relatively uncommon, CNO carries a disproportionate clinical burden; reported prevalence varies depending on the population studied and case definition but estimates typically fall within the sub-1% to low single-digit percentage range among people with diabetes (NICE NG19,⁵ IWGDF 2023⁶). Clinically, early CNO often presents with swelling, warmth and erythema, frequently with minimal pain due to neuropathy, while plain radiographs may initially appear normal, contributing to diagnostic uncertainty.^6,7

Despite its severity, delayed or missed diagnosis remains a major challenge. CNO is frequently misdiagnosed as cellulitis, gout, fracture, sprain or deep infection, leading to inappropriate management and delayed immobilisation/off-loading.^6,8 Such delays are associated with progressive deformity and substantial morbidity.^6,8,9 These challenges are not confined to single healthcare systems. Irish evaluations of diabetic-foot services, including the HSE Diabetic foot Model of Care, have highlighted variable access to multidisciplinary care and diagnostic imaging, reflecting broader system-level barriers to early recognition of complex foot pathology.^10,11 Together, these findings reinforce the need for accessible imaging approaches that can support timely recognition of active disease.

The pathophysiology of CNO is multifactorial and is commonly conceptualised as an interaction between neurotraumatic and neurovascular mechanisms. Repetitive, unperceived trauma in an insensate foot may trigger a pro-inflammatory cascade, while autonomic dysfunction may increase local perfusion, contributing to bone resorption and structural failure.^4,6 International guidance emphasises that early recognition of active CNO and prompt immobilisation/off-loading are central to management, underscoring the clinical importance of timely identification.⁶

Several classification systems are used to describe disease stage and anatomical distribution. The Eichenholtz classification describes three radiographic stages—development, coalescence and reconstruction—later expanded to include a Stage 0 phenotype, in which radiographs are normal but clinical and advanced imaging findings indicate active disease.^12,13 Anatomical classification is commonly described using the Sanders–Frykberg system, with complementary frameworks such as the Brodsky classification linking disease location to mechanical and prognostic implications.^14,15 In clinical practice, stage and site are often combined to guide management decisions and communication.⁶

Although midfoot involvement is most commonly reported, distal and forefoot presentations may introduce additional diagnostic complexity. The so-called diabetic sausage toe may represent inflammatory Charcot change but may also reflect osteomyelitis, with contemporary series demonstrating a high prevalence of infection in this phenotype.¹⁶ Other inflammatory conditions, such as psoriatic dactylitis, may present with diffuse soft-tissue swelling and tenosynovitis on imaging, overlapping clinically with Charcot presentations.¹⁷ These overlaps highlight the importance of understanding how ultrasound findings are described across anatomical regions and tissue types.

Imaging plays a central role in diagnosis and monitoring. Weight-bearing radiographs are widely used for assessing alignment and chronic structural change but lack sensitivity in early active disease.^6,7 Magnetic resonance imaging (MRI) is generally regarded as the preferred modality where radiographs are normal, due to its ability to demonstrate bone marrow oedema, joint effusion and soft-tissue involvement, and to assist in differentiation from infection.^6,18,19 Computed tomography may be valuable for detailed cortical assessment and surgical planning, while nuclear imaging techniques have more limited roles due to radiation exposure and variable availability.⁷

Ultrasound has been proposed as a complementary, non-ionising and portable imaging modality, particularly where access to MRI is limited. Published case series and observational studies describe sonographic features in active CNO including joint effusion, synovitis, periarticular soft-tissue oedema, cortical surface irregularity and tenosynovitis, with musculoskeletal Doppler used to demonstrate periarticular hypervascularity as a marker of inflammatory activity.^20–22 In parallel, calcaneal quantitative ultrasound has been explored in the assessment of active Charcot neuroarthropathy, reflecting acoustic properties of bone rather than local inflammatory change.²³ Despite this emerging literature, there remains no validated sonographic scoring system, consensus on anatomical regions to be assessed, or standardised approach to acquisition parameters or musculoskeletal Doppler reporting in CNO.^7,21,22 To date, no scoping review has systematically mapped the sonographic features and ultrasound acquisition protocols reported in the literature for CNO in people with diabetes.

Aim and objectives

Review question

This protocol is for a scoping review and is therefore framed using the Population–Concept–Context (PCC) approach rather than a PICO intervention-effect framework.¹ The review will address the following question: In adults with diabetes and confirmed or clinically suspected Charcot neuro-osteoarthropathy of the foot/ankle (Population), what sonographic features and ultrasound acquisition protocol parameters (Concept) have been reported across clinical and research settings (Context) Where studies include comparator imaging or post-intervention monitoring, these details will be charted descriptively but are not prespecified as mandatory PICO elements. Specifically, the review will:

(i) Identify which anatomical sites and tissue types are assessed by ultrasound in CNO;
(ii) Describe variation in acquisition protocols, including probe characteristics, patient positioning, scanning technique and musculoskeletal Doppler reporting; and
(iii) Identify gaps and inconsistencies in reporting to inform future research and potential protocol standardisation.

Protocol

Design, reporting standards and registration

This protocol has been developed in accordance with the Joanna Briggs Institute (JBI) methodology for scoping reviews¹ and will be reported in line with PRISMA-P² and PRISMA-ScR.³ A populated PRISMA-P checklist is provided (Extended data 2). For transparency, the PRISMA-ScR checklist to be used for the final scoping review report is provided (Extended data 3). Items relating to results will be completed in the final review report.

Protocol eligibility statement: At the time of submission, this review has not started the final data extraction stage.

Amendments

Any amendments to the protocol after registration will be documented with dates, rationale and version history within OSF and described in the final publication.

Eligibility criteria

Eligibility criteria are defined using the Population–Concept–Context (PCC) framework.¹ The population comprises adults (≥18 years) with diabetes mellitus (any type) and confirmed or clinically suspected CNO of the foot or ankle, including those with or without prior surgical intervention. The concept is musculoskeletal ultrasound/sonography used to report features of CNO and/or acquisition protocols, including assessment of bone, joints, soft tissue, tendons or fascia, and associated descriptions of musculoskeletal Doppler signal where reported. The context is unrestricted by healthcare setting, and studies from outpatient, inpatient, specialist diabetic foot clinics, community and tertiary services will be eligible.

Primary studies presenting original ultrasound findings or protocol information will be eligible, including observational studies, case series and case reports. Review articles and imaging atlases will not be treated as primary evidence unless they contain extractable original sonographic images or primary data relevant to the review objectives; otherwise, they will be used for citation tracking only. Studies will be excluded if they do not specifically address CNO/Charcot, do not include ultrasound/sonography, focus solely on vascular/perfusion ultrasound without musculoskeletal assessment of CNO, are non-human studies, or are unavailable as full text. No language restrictions will be applied. Where full texts are not in English, translation will be undertaken using machine translation to support eligibility assessment and data charting, with verification by a second reviewer where feasible.

Information sources and search strategy

The following bibliographic databases will be searched from inception: MEDLINE (PubMed), Embase (Ovid), CINAHL (EBSCOhost) and Scopus (Elsevier). Grey literature will be sought via ProQuest Dissertations & Theses, and relevant conference proceedings where accessible. Supplementary searching will include backward reference screening of included studies and forward citation tracking using Scopus and Google Scholar.¹ No language restrictions will be applied.

Search strategies have been developed to capture Charcot neuro-osteoarthropathy terms combined with ultrasound/sonography terms and diabetes terms and will be adapted for each database interface. Full electronic search strategies for all databases (including limits) are provided in Extended data 1. Search validation will be undertaken using a set of known relevant studies to ensure sensitivity; if key studies are not retrieved, strategies will be iteratively refined prior to final execution. All search results will be exported to EndNote for deduplication and then imported into Covidence for screening and data charting. Covidence will be used to manage screening decisions, reviewer conflicts, and the audit trail of decisions. Data charting will be exported from Covidence to spreadsheet software for descriptive synthesis. Study materials will be maintained with version control on OSF (DOI: 10.17605/OSF.IO/ZRXWD). If more than six months elapse between initial searching and synthesis, searches will be rerun prior to final analysis to capture newly published studies.

Selection of sources of evidence

Following deduplication, two reviewers will independently screen titles and abstracts in Covidence against the eligibility criteria.¹ Records judged potentially eligible by either reviewer will proceed to full-text review. Two reviewers will then independently assess full-text articles for inclusion, with reasons for exclusion recorded at this stage. Disagreements at any stage will be resolved through discussion; if consensus cannot be reached, a third reviewer will adjudicate.

A pilot screening phase of approximately 25–50 records will be conducted to calibrate the team and refine operational definitions. Inter-rater agreement during pilot screening will be quantified using Cohen’s kappa, and calibration will continue until acceptable agreement is achieved before proceeding to full screening. The selection process will be reported using a PRISMA-ScR flow diagram in the final review report.³ Screening operational definitions and decision rules are provided in the screening manual (Extended data 5).

Data charting process

Data will be charted using a standardised form developed a priori and piloted on a subset of included studies to ensure clarity and completeness.¹ Consistent with scoping review methodology and pragmatic resourcing, charting will be undertaken by the primary reviewer (AM) and independently verified by a second reviewer (EK) against the source publications. Any discrepancies identified during verification will be resolved through discussion, with adjudication by a third reviewer (CM) if required. The final charting form and coding guidance are provided in Extended data 4.

The charted variables will include: study characteristics (author, year, country, design), participant characteristics (age, sex, diabetes type/duration, neuropathy, surgical status), Charcot classification (Eichenholtz stage and Sanders–Frykberg location where reported), diagnostic confirmation approach and diagnostic certainty (e.g., MRI-confirmed, radiographic stage, multidisciplinary diagnosis, surgical/histopathological confirmation, or author-defined/unclear), whether osteomyelitis/infection is co-reported or explicitly excluded, anatomical sites/tissues scanned, sonographic features (e.g., effusion, synovitis, cortical irregularity, periarticular oedema, tendon/fascia involvement), acquisition parameters (transducer type, frequency, patient position, scanning planes/approach, equipment details if available), use and reporting of musculoskeletal Doppler, comparator imaging modalities, and key findings relevant to protocol variation and feature reporting. Missing or unclear methodological details will be noted; where essential details are absent, study authors may be contacted to request clarification.

Data items and coding assumptions

Variables will be operationalised using the data charting form and coding guidance (Extended data 4). Where information is not reported, items will be coded as not reported (NR) and will not be imputed. Disease status will be charted as active/acute, chronic/reconstructive, mixed, or not stated, based on the authors’ definitions and/or reported classification where available. When studies report multiple anatomical sites or mixed cohorts, data will be charted at study level and, where feasible, summarised descriptively by anatomical region and tissue type. Comparator imaging modalities will be recorded when reported but are not required for inclusion. Diagnostic confirmation will be charted using prespecified categories (e.g., MRI-confirmed, radiograph-confirmed/staged, multidisciplinary clinical diagnosis, surgical confirmation and/or histopathology/microbiology, author-defined/unclear, or mixed), and any explicit statements regarding osteomyelitis/infection (present, excluded, or not reported) will be recorded.

Charting domains and prioritisation

As this is a scoping review, data will be charted as predefined domains rather than intervention outcomes. Primary domains (mapped to the review objectives) are: (i) sonographic features reported in CNO and how these are defined; and (ii) ultrasound acquisition and reporting parameters, including transducer type/frequency, patient positioning, anatomical coverage/scan planes, and musculoskeletal Doppler use and reporting, including whether settings/technique are described. Secondary domains are: anatomical region and tissue type assessed, CNO stage/location classification (where reported), comparator imaging modalities (where reported), and study/participant characteristics relevant to interpreting protocol variation. Prioritisation is justified to ensure the review primarily maps what is scanned and how it is performed/reported, consistent with the aims of protocol standardisation and reproducibility-focused research.

Synthesis of results

Findings will be synthesised descriptively, using narrative summary and structured tables to map the range and frequency of reported sonographic features and the variability of acquisition protocols.¹ Where feasible, results will be grouped by anatomical region, tissue type, and whether the reported CNO is active versus chronic/reconstructive, and by pre- versus post-surgical context. Counts and proportions will be presented where appropriate. No meta-analysis is planned.

Consistent with JBI guidance for scoping reviews, no formal risk-of-bias assessment will be conducted (therefore not assessed at study or outcome level); however, we will narratively describe key methodological limitations of included studies (e.g., study design and sample size, diagnostic confirmation approach, and presence/absence of comparator imaging) and summarise completeness and transparency of reporting of ultrasound acquisition parameters (e.g., transducer characteristics, patient positioning, anatomical coverage/scan planes, and musculoskeletal Doppler technique) to contextualise findings and avoid overinterpretation.¹

Consultation exercise

To support interpretive validity and clinical relevance, a consultation exercise will be undertaken after preliminary synthesis.¹ A small panel comprising clinicians with expertise in diabetic foot care and musculoskeletal imaging will review draft summary tables to confirm interpretive accuracy and assist in contextualising gaps in reporting and protocol heterogeneity. Any consultation feedback will be documented and incorporated into the discussion.

Ethics and dissemination

Ethical approval is not required because this study will synthesise data from publicly available literature and will not involve human participants. Results will be disseminated through peer-reviewed publication and presentation at relevant national and international meetings, with supporting materials (e.g., search strategies, screening logs and charting templates) made available via OSF in line with open science practices.

Conclusions/Discussion

The evidence base describing ultrasound use in Charcot neuro-osteoarthropathy (CNO) remains heterogeneous and comparatively early in its development, spanning small observational studies and case series, with variable reporting of acquisition parameters and sonographic findings.^7,20–22 A scoping review is therefore methodologically appropriate, as it is designed to map the breadth and nature of an emerging literature, clarify key concepts and definitions, and identify gaps in methods and reporting rather than estimate effects or comparative accuracy.¹ By synthesising the reported sonographic features alongside the technical and procedural details of scan acquisition, this review will clarify what has been described to date, where reporting converges, and where inconsistency is most pronounced.

A key anticipated contribution is the structured identification of variability in both the content and reporting of ultrasound examinations in CNO. Published work suggests that ultrasound may depict periarticular and soft-tissue features such as effusion, synovitis, oedema and tenosynovitis, and may demonstrate periarticular hypervascularity using musculoskeletal Doppler, but the extent to which these findings are consistently described, and the degree to which they are linked to reproducible acquisition methods, is unclear.^20–22 Mapping acquisition parameters—including transducer characteristics, patient positioning, scanning approach/planes and use of Doppler—will highlight whether essential methodological details are routinely reported, and will support more standardised reporting in future studies.

This scoping review is positioned within a clinically relevant diagnostic context. Diagnostic delay in CNO is well described and carries significant consequences, including deformity and downstream ulceration risk.^6,8 Contemporary clinical guidance emphasises early identification of active disease and prompt immobilisation/off-loading.⁶ Although MRI is commonly regarded as the preferred modality where radiographs are normal, constraints in access and service pathways may influence real-world feasibility, including within Irish diabetic foot services.^10,11 In that context, ultrasound may represent a practical adjunct in some settings; however, its potential role cannot be meaningfully evaluated without clearer understanding of what has been reported, how examinations are performed, and what methodological gaps exist.⁷ The outputs of this review will therefore provide an evidence map to inform the design of robust evaluative studies, including future work on standardised acquisition protocols, reproducibility, and the clinical utility of ultrasound within diagnostic pathways.

Several methodological considerations should be noted. In keeping with JBI guidance for scoping reviews, a formal risk-of-bias assessment is not planned because the primary purpose is evidence mapping and characterisation of reporting rather than effect estimation.¹ Nonetheless, the review will summarise completeness of acquisition reporting and highlight limitations in the underlying literature, including small sample sizes, heterogeneity in case definitions and disease staging, and variable comparator imaging.^7,20–22 Data charting will be conducted by the primary reviewer with independent verification by a second reviewer, balancing methodological rigour with pragmatic resourcing while maintaining transparency through prespecified forms and open materials.¹ No language restrictions will be applied; where translation is required, the approach used and any uncertainties will be documented. Machine translation may risk loss of nuance, which will be considered when interpreting the evidence map.

In summary, this scoping review will systematically map sonographic features and acquisition protocols reported for CNO in diabetes, identify gaps in methodological reporting, and provide a structured foundation for future work aimed at standardisation and rigorous evaluation of ultrasound within clinical pathways.¹

Data availability

Underlying data

No data are associated with this article.

Extended data

Open Science Framework (OSF): Sonographic features and acquisition protocols for Charcot neuro-osteoarthropathy in diabetes: a scoping review protocol. https://doi.org/10.17605/OSF.IO/XZ7NK .²⁴

This project contains:

• Extended data 1 (full electronic search strategies); Extended data 2 (completed PRISMA-P checklist)
• Extended data 3 (PRISMA-ScR checklist)
• Extended data 4 (data charting (extraction) form and coding guidance)
• Extended data 5 (screening manual and operational definitions)

Data are available under the terms of the Creative Commons Zero (CC0 1.0) Public Domain Dedication.

Reporting guidelines

This protocol was developed using JBI guidance for scoping reviews and is reported in accordance with PRISMA-P. The completed scoping review will be reported in accordance with PRISMA-ScR. Completed checklists are available as extended data on OSF (https://doi.org/10.17605/OSF.IO/XZ7NK).²⁴ Sex and gender will be charted where reported in included studies in line with SAGER guidance.

Acknowledgments

Not applicable.

References

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2. Moher D, Shamseer L, Clarke M, et al.: Preferred reporting items for systematic review and meta-analysis protocols (PRISMA-P) 2015 statement. Syst. Rev. 2015; 4: 1. Publisher Full Text
3. Tricco AC, Lillie E, Zarin W, et al.: PRISMA extension for scoping reviews (PRISMA-ScR): checklist and explanation. Ann. Intern. Med. 2018; 169(7): 467–473. Publisher Full Text
4. Vella S, Cachia MJ: Charcot neuroarthropathy: pathogenesis, diagnosis and medical management. Malta Med. J. 2008; 20(3): 13–19.
5. National Institute for Health and Care Excellence (NICE): Diabetic foot problems: prevention and management (NG19). London: NICE; 2015 [updated 2019 Oct 11; cited 2025 Dec 28].
6. Wukich DK, Schaper NC, Gooday C, et al.: Guidelines on the diagnosis and treatment of active Charcot neuro-osteoarthropathy in persons with diabetes mellitus (IWGDF 2023). Diabetes Metab. Res. Rev. 2024; 40(3): e3646. PubMed Abstract | Publisher Full Text
7. Mascio A, Comisi C, Cinelli V, et al.: Radiological assessment of Charcot neuro-osteoarthropathy in diabetic foot: a narrative review. Diagnostics (Basel). 2025; 15(6): 767. PubMed Abstract | Publisher Full Text | Free Full Text
8. Korst GS, Jimoh R, Jupiter DC: Delayed diagnosis of Charcot foot: a systematic review. J. Foot Ankle Surg. 2022; 61(5): 1109–1113. Publisher Full Text
9. Armstrong DG, Boulton AJM, Bus SA: Diabetic foot ulcers and their recurrence. N. Engl. J. Med. 2017; 376(24): 2367–2375. Publisher Full Text
10. Health Service Executive (HSE) National Clinical Programme for Diabetes: Diabetic Foot Model of Care. Dublin: HSE; 2021 [cited 2025 Dec 28].
11. Pallin JA, Buckley-O’Farrell K, Riordan F, et al.: Implementing an integrated diabetic foot care programme in Ireland: podiatrists’ experience. BMC Health Serv. Res. 2023; 23: 1157. PubMed Abstract | Publisher Full Text | Free Full Text
12. Eichenholtz SN: Charcot joints. Springfield (IL): Charles C Thomas; 1966.
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14. Sanders LJ, Frykberg RG: Diabetic neuropathic osteoarthropathy: the Charcot foot. The high risk foot in diabetes mellitus. Frykberg RG, editor. New York (NY): Churchill Livingstone; 1991; 297–338.
15. Brodsky JW: The diabetic foot. Surgery of the foot and ankle. Mann RA, Coughlin MJ, editors. St Louis (MO): Mosby; 7th ed. 1999; 895–969.
16. Yammine K, Mouawad J, Abou Orm G, et al.: The diabetic sausage toe: prevalence, presentation and outcomes. Int. Wound J. 2024; 21(7): e70002. PubMed Abstract | Publisher Full Text | Free Full Text
17. Bakewell CJ, Olivieri I, Aydin SZ, et al.: Ultrasound and magnetic resonance imaging in the evaluation of psoriatic dactylitis: status and perspectives. J. Rheumatol. 2013; 40(12): 1951–1957. PubMed Abstract | Publisher Full Text
18. Tsang KWK, Morrison WB: Update: imaging of lower extremity infection. Semin. Musculoskelet. Radiol. 2016; 20(2): 175–191. Publisher Full Text
19. Chantelau EA, Richter A: The acute diabetic Charcot foot managed on the basis of magnetic resonance imaging—a review of 71 cases. Swiss Med. Wkly. 2013; 143: w13831. PubMed Abstract | Publisher Full Text
20. Mortada M, Ezzeldin N, Hammad M: Ultrasonographic features of acute Charcot neuroarthropathy of the foot: a pilot study. Clin. Rheumatol. 2020; 39(12): 3787–3793. PubMed Abstract | Publisher Full Text
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22. Sanverdi SE, Ergen BF, Oznur A: Current challenges in imaging of the diabetic foot. Diabet Foot Ankle. 2012; 3: 18754. Publisher Full Text
23. Piaggesi A, Romanelli M, Carnicelli L, et al.: Biochemical and ultrasound tests for early diagnosis of active neuro-osteoarthropathy (Charcot foot) in diabetes. Diabetes Res. Clin. Pract. 2002; 58(1): 1–9. Publisher Full Text
24. McIlwaine A, Kirwan E, Quinlan L, et al.: Sonographic features and acquisition protocols for Charcot neuro-osteoarthropathy in diabetes: a scoping review protocol. [Dataset]. Open Science Framework. 2025. Publisher Full Text

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Version 1

VERSION 1 PUBLISHED 19 Mar 2026

Author details Author details

¹ University of Galway, Galway, County Galway, Ireland

Adam McIlwaine
Roles: Conceptualization, Methodology, Project Administration, Writing – Original Draft Preparation, Writing – Review & Editing

Ellen Kirwan
Roles: Formal Analysis

Leo Quinlan
Roles: Supervision, Writing – Review & Editing

Caroline McIntosh
Roles: Methodology, Supervision, Writing – Review & Editing

Competing interests

No competing interests were disclosed.

Grant information

University of Galway Further Education Policy studentship

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Published: 19 Mar 2026, 9:24

https://doi.org/10.12688/hrbopenres.14368.1

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© 2026 McIlwaine A et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

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McIlwaine A, Kirwan E, Quinlan L and McIntosh C. Sonographic features and acquisition protocols for Charcot neuro-osteoarthropathy in diabetes: a scoping review protocol [version 1; peer review: 1 approved]. HRB Open Res 2026, 9:24 (https://doi.org/10.12688/hrbopenres.14368.1)

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Reviewer Report 24 Apr 2026

Ingrid T Sabbagh, School of Clinical Medicine, University of the Witwatersrand Johannesburg School of Clinical Medicine (Ringgold ID: 56399), Johannesburg, Gauteng, South Africa

Approved

https://doi.org/10.21956/hrbopenres.15826.r54511

This is a well-constructed and clinically relevant protocol. The rationale is clear, the choice of scoping review appropriate, and methods generally sound and transparent with good availability of extended data. There are 2 somewhat related points that I believe could ... Continue reading

This is a well-constructed and clinically relevant protocol. The rationale is clear, the choice of scoping review appropriate, and methods generally sound and transparent with good availability of extended data. There are 2 somewhat related points that I believe could benefit from some further attention:

Although the authors highlight the absence of a scoping review on the topic, it would benefit the reader to have a better sense of exactly how sparse the literature is in this space, to better understand the novelty of the approach and the need for synthesis of the evidence. Is there only a small number of scattered case studies or a broader base of evidence that just lacks a systematic analysis.
Related to this, the inclusion criteria are quite broad, particularly in allowing clinically suspected as well as confirmed cases. If the evidence base is indeed very limited then this may be necessary, but should be more clearly justified as such. Given the broad criteria, it is necessary to explain more fully how diagnostically uncertain cases will be distinguished from confirmed cases in the final synthesis as this can add significant noise to your evidence map.

And a few minor points that the authors may choose to address at their discretion:

Calcaneal quantitative ultrasound is mentioned in the introduction and treated as conceptually distinct from musculoskeletal imaging but is not mentioned again. It is not entirely clear to me whether both are in scope.
The proposed consultation exercise appears reasonable as an advisory step but its scope could be more clearly specified. Will the feedback influence only interpretation and discussion, or also coding or categorisation?
The approach to do single-extractor data charting is pragmatic, but if you do end up with a small and technically nuanced data set it may be worth the rigour of duplicate extraction.

Is the rationale for, and objectives of, the study clearly described?

Yes
Is the study design appropriate for the research question?

Yes
Are sufficient details of the methods provided to allow replication by others?

Yes
Are the datasets clearly presented in a useable and accessible format?

Not applicable

Competing Interests: No competing interests were disclosed.

Reviewer Expertise: Epidemiology, quantitative analysis, systematic reviews

I confirm that I have read this submission and believe that I have an appropriate level of expertise to confirm that it is of an acceptable scientific standard.

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Ingrid T Sabbagh, University of the Witwatersrand Johannesburg School of Clinical Medicine (Ringgold ID: 56399), Johannesburg, South Africa

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Ingrid T Sabbagh, School of Clinical Medicine, University of the Witwatersrand Johannesburg School of Clinical Medicine (Ringgold ID: 56399), Johannesburg, Gauteng, South Africa

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This is a well-constructed and clinically relevant protocol. The rationale is clear, the choice of scoping review appropriate, and methods generally sound and transparent with good availability of extended data. There are 2 somewhat related points that I believe could benefit from some further attention:

Although the authors highlight the absence of a scoping review on the topic, it would benefit the reader to have a better sense of exactly how sparse the literature is in this space, to better understand the novelty of the approach and the need for synthesis of the evidence. Is there only a small number of scattered case studies or a broader base of evidence that just lacks a systematic analysis.
Related to this, the inclusion criteria are quite broad, particularly in allowing clinically suspected as well as confirmed cases. If the evidence base is indeed very limited then this may be necessary, but should be more clearly justified as such. Given the broad criteria, it is necessary to explain more fully how diagnostically uncertain cases will be distinguished from confirmed cases in the final synthesis as this can add significant noise to your evidence map.

And a few minor points that the authors may choose to address at their discretion:

Calcaneal quantitative ultrasound is mentioned in the introduction and treated as conceptually distinct from musculoskeletal imaging but is not mentioned again. It is not entirely clear to me whether both are in scope.
The proposed consultation exercise appears reasonable as an advisory step but its scope could be more clearly specified. Will the feedback influence only interpretation and discussion, or also coding or categorisation?
The approach to do single-extractor data charting is pragmatic, but if you do end up with a small and technically nuanced data set it may be worth the rigour of duplicate extraction.

Is the rationale for, and objectives of, the study clearly described?

Yes
Is the study design appropriate for the research question?

Yes
Are sufficient details of the methods provided to allow replication by others?

Yes
Are the datasets clearly presented in a useable and accessible format?

Not applicable

Competing Interests

No competing interests were disclosed.

Reviewer Expertise

Epidemiology, quantitative analysis, systematic reviews

I confirm that I have read this submission and believe that I have an appropriate level of expertise to confirm that it is of an acceptable scientific standard.

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Sonographic features and acquisition protocols for Charcot neuro-osteoarthropathy in diabetes: a scoping review protocol

Abstract

Background

Methods

Discussion

Keywords

Introduction

Aim and objectives

Review question

Protocol

Design, reporting standards and registration

Amendments

Eligibility criteria

Information sources and search strategy

Selection of sources of evidence

Data charting process

Data items and coding assumptions

Charting domains and prioritisation

Synthesis of results

Consultation exercise

Ethics and dissemination

Conclusions/Discussion

Data availability

Underlying data

Extended data

Reporting guidelines

Acknowledgments

References

Comments on this article Comments (0)

Open Peer Review

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Open Peer Review

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Reviewer Reports

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Sonographic features and acquisition protocols for Charcot neuro-osteoarthropathy in diabetes: a scoping review protocol

Abstract

Background

Methods

Discussion

Keywords

Introduction

Aim and objectives

Review question

Protocol

Design, reporting standards and registration

Amendments

Eligibility criteria

Information sources and search strategy

Selection of sources of evidence

Data charting process

Data items and coding assumptions

Charting domains and prioritisation

Synthesis of results

Consultation exercise

Ethics and dissemination

Conclusions/Discussion

Data availability

Underlying data

Extended data

Reporting guidelines

Acknowledgments

References

Comments on this article Comments (0)

Open Peer Review

Comments on this article Comments (0)

Open Peer Review

Reviewer Status

Reviewer Reports

Comments on this article

Competing Interests Policy

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Are you a HRB-funded researcher?

Thank you!