A warm, swollen, red foot in a person with diabetes and peripheral neuropathy is one of the most consequential findings in lower limb medicine — and one of the most frequently missed. Active Charcot neuro-osteoarthropathy (CNO) is a progressive inflammatory process affecting the bones and joints of the neuropathic foot. Left unrecognized, it can produce fracture, dislocation, deformity, ulceration, infection and, in some cases, amputation.
Why Charcot Foot Is So Often Missed
The clinical picture is deceptively bland. Because protective sensation is impaired, the foot is often only mildly painful or entirely painless, and the warmth and swelling resemble cellulitis, gout, deep vein thrombosis or osteomyelitis. The consequences are measurable. In a systematic review published in The Journal of Foot and Ankle Surgery, Korst and colleagues (2022) pooled data across seven studies and found that 53.2% of Charcot cases experienced a diagnostic delay, with an average interval from symptom onset to correct diagnosis of 86.9 days — nearly three months during which an unprotected foot keeps being loaded.
The condition also clusters in a recognizable population. A multicentre study of 774 patients across eight diabetic foot clinics in six countries, reported by Jude and colleagues in the Journal of Diabetes Research (2025), found a mean age at diagnosis of 54.5 years and a median diabetes duration of 15 years. Neuropathy was present in 91.7%, retinopathy in 60.2% and nephropathy in 45.2%. Patients with type 1 diabetes were diagnosed considerably younger (46.9 versus 57.9 years). Charcot foot is, in short, a disease of long-standing diabetes with established microvascular disease.
What the 2023 IWGDF Guideline Recommends for Diagnosis
In 2023 the International Working Group on the Diabetic Foot published its first dedicated guideline on active CNO, developed by Wukich and colleagues using GRADE methodology and a systematic review. Its diagnostic recommendations are notable for how low they set the threshold of suspicion. The guideline states as a best practice that active CNO should always be considered in a person with diabetes, neuropathy and intact skin who presents with increased temperature, oedema and/or redness compared with the opposite foot. It suggests infrared thermometry, using a standardised technique, to quantify the temperature difference between the affected site and the matching point on the contralateral limb.
Imaging follows a defined sequence. Plain X-rays of the foot and ankle should be obtained, ideally bilaterally and weight-bearing. Critically, normal radiographs do not exclude the diagnosis: the guideline strongly recommends magnetic resonance imaging when X-rays appear normal, since MRI can demonstrate bone marrow oedema and early stress injury before any radiographic change is visible. Where MRI is unavailable or contraindicated, scintigraphy, CT or SPECT-CT may be considered. Inflammatory markers are explicitly not recommended — the guideline suggests against relying on CRP, ESR or white blood cell count.
Separating Charcot from osteomyelitis remains one of the hardest calls in practice. A case series by Pham and colleagues in Wounds (2023) illustrates the stakes: three neuropathic patients with bone fragmentation initially concerning for osteomyelitis were maintained as Charcot diagnoses and treated with immobilisation and offloading alone, with resolution of the fragmentation without antibiotics.
Offloading: Immobilise First, Confirm Second
The most consequential treatment recommendation concerns timing. The guideline strongly recommends initiating knee-high immobilisation and offloading while further diagnostic studies are being performed, rather than waiting for confirmation.
For the device itself, the guideline strongly recommends a non-removable knee-high device to promote remission and prevent progression of deformity. A total contact cast is the suggested first choice, with a knee-high walker rendered non-removable as a second choice, and a removable knee-high device worn at all times as a third option where non-removable casting is contraindicated or not tolerated. Below-ankle devices — surgical shoes, postoperative sandals, custom moulded shoes, slipper casts — are advised against, as they neither immobilise the affected bones and joints nor offload them sufficiently. On monitoring, serial skin temperature measurement, clinical oedema and imaging should be considered together when judging remission; resolution of swelling alone is not a sufficient signal to stop treatment.
Drug Therapy and Long-Term Footwear
The guideline is direct about drug treatment: alendronate, pamidronate, zoledronate, calcitonin and parathyroid hormone are not to be used for active CNO, and denosumab is also suggested against. Evaluating the need for vitamin D and calcium supplementation is advised. After remission, footwear and orthoses should accommodate and support the shape of the foot, with additional measures to optimise plantar pressure where deformity or instability is present.
Risk persists once deformity and infection coexist. Berli and colleagues, in BMC Musculoskeletal Disorders (2017), reported that among 40 patients with both Charcot neuroarthropathy and osteomyelitis in the same foot, the overall amputation rate was 52%, and osteomyelitis within the active Charcot region was associated with a higher amputation level and longer antibiotic and immobilisation courses.
Clinical Summary
The evidence converges on a few practical points. Any unilateral warm, swollen foot in a neuropathic patient with diabetes should be treated as Charcot until proven otherwise.
Normal X-rays do not rule it out, and MRI is the recommended next step. Immobilisation in a non-removable knee-high device should begin at the point of suspicion rather than confirmation, because the documented delay — roughly three months in more than half of cases — occurs while the foot is still being walked on. Bisphosphonates and related agents have no established role in active disease, and remission is a composite judgement based on temperature, swelling and imaging together.
References
- 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/Metabolism Research and Reviews. 2024;40(3):e3646. doi:10.1002/dmrr.3646
- Korst GS, Ratliff HT, Torian J, Jimoh RO, Jupiter DC. Delayed Diagnosis of Charcot Foot: A Systematic Review. The Journal of Foot and Ankle Surgery. 2022;61(5):1109–1113. doi:10.1053/j.jfas.2022.01.008
- Jude EB, Siafarikas C, Rastogi A, et al. Demographic and Clinical Characteristics of Patients With Charcot Neuro-Osteoarthropathy in People With Diabetes Mellitus in Six Countries: A Multicenter Observational Study From 1996 to 2022. Journal of Diabetes Research. 2025;2025:4275741. doi:10.1155/jdr/4275741
- Pham HT, Sanders E, Mendeszoon ER, Tseng W. Charcot neuroarthropathy versus osteomyelitis: a case series. Wounds. 2023;35(6):E203–E208. doi:10.25270/wnds/22063
- Berli M, Vlachopoulos L, Leupi S, Böni T, Baltin C. Treatment of Charcot Neuroarthropathy and osteomyelitis of the same foot: a retrospective cohort study. BMC Musculoskeletal Disorders. 2017;18(1):460. doi:10.1186/s12891-017-1818-4
- Schweitzer M, Rockhill S. Conservative Management of Charcot Neuroarthropathy. Clinics in Podiatric Medicine and Surgery. 2022;39(4):585–594. doi:10.1016/j.cpm.2022.05.005
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