Charcot neuro-osteoarthropathy (CNO) is an inflammatory, destructive condition of the bones and joints of the foot and ankle that occurs in people with diabetes and peripheral neuropathy. Without early recognition, bones fracture and joints collapse, producing deformity that predisposes to ulceration, infection, and amputation. Lifetime incidence is generally cited at roughly 0.4% to 1.3% of people with diabetes, rising to about 13% among high-risk clinic attendees, and relapse rates of 12% to 33% have been reported (Gooday et al., 2023). The 2023 International Working Group on the Diabetic Foot (IWGDF) guideline and its supporting systematic review provide the most current synthesis of how active CNO should be diagnosed and treated.
Recognising Active Charcot: Clinical Signs and Imaging
The IWGDF guideline (Wukich et al., 2023) advises considering active CNO in any person with diabetes and neuropathy who has intact skin and a foot that is warmer, swollen, or red compared with the other foot. Because the presentation can resemble infection, gout, or deep vein thrombosis, the condition is easily missed. The accompanying systematic review (Raspovic et al., 2023) identified 14 observational studies on diagnosis and described a paucity of high-quality data, so many recommendations carry low certainty of evidence.
Standardised infrared skin thermometry is suggested as an adjunct, comparing the hottest point on the affected foot with the same site on the other limb. Weight-bearing radiographs, ideally of both feet, are recommended first. When radiographs are normal but CNO is suspected, magnetic resonance imaging (MRI) receives a strong recommendation with moderate-certainty evidence, because it can detect bone marrow oedema and microfractures before structural change appears. The guideline specifically advises against using blood tests such as C-reactive protein, erythrocyte sedimentation rate, or white cell count to diagnose or exclude CNO.
Immobilisation and Offloading: Start Early, Use Non-Removable Devices
The central treatment principle is prompt, knee-high immobilisation and offloading, which the IWGDF gives a strong recommendation to begin as soon as active CNO is considered, even while the diagnosis is being confirmed (Wukich et al., 2023). The total contact cast is the preferred option; a non-removable knee-high walker is second choice, and a removable knee-high device worn at all times is reserved for situations in which a non-removable device is contraindicated or not tolerated. Below-ankle devices are not recommended for active CNO. Assistive devices such as crutches or a wheelchair are suggested to reduce weight-bearing on the affected limb.
Observational data from the feasibility trial by Gooday et al. (2023) in the Journal of Foot and Ankle Research are consistent with this approach. Among 30 participants with confirmed CNO across five English clinics, non-removable devices were associated with faster remission (hazard ratio 0.285, 95% CI 0.107 to 0.758). This was an exploratory finding from a study not powered to test effectiveness, but it aligns with the guideline.
Defining Remission and Monitoring Activity
Deciding when to return a person to ordinary footwear is difficult. Reported remission times differ between health systems, with UK estimates of 9 to 12 months compared with 3 to 5 months in some US studies (Gooday et al., 2023, protocol background). The IWGDF recommends against relying on soft tissue oedema alone and suggests combining skin temperature, oedema, and imaging to judge remission. Serial temperature measurement of both limbs is suggested for monitoring.
The CADOM feasibility study examined whether serial MRI could shorten immobilisation. Of 43 randomised participants, 13 were later found to have an alternative diagnosis. Of the 30 with CNO, 19 (63%) reached remission. Mean time to remission was longer in the MRI arm than in the standard-care arm (292 versus 235 days in the published abstract), but the difference was not statistically significant (HR 0.405, 95% CI 0.140 to 1.172, p = 0.096). MRI completion was 84% and no safety incidents occurred. The authors concluded that a definitive randomised trial is feasible and warranted.
Medications, Surgery, and Preventing Reactivation
Pharmacological bone-targeted therapy has not shown benefit. The IWGDF gives a strong recommendation, based on moderate-certainty evidence, against bisphosphonates (alendronate, pamidronate, zoledronate), calcitonin, parathyroid hormone, and methylprednisolone for treating active CNO, and conditionally recommends against denosumab. Vitamin D and calcium status should be evaluated during fracture healing. Surgery may be considered for instability, high-risk deformity, or pain not controlled by casting or a knee-high device.
Once in remission, the risk of reactivation remains. The guideline strongly recommends footwear or orthoses that accommodate foot shape, and custom below-knee devices when deformity or instability is present. Notably, the systematic review found no studies on prevention of reactivation that met inclusion criteria, so these recommendations rest on expert consensus and indirect evidence (Raspovic et al., 2023).
Key Takeaways
Active CNO should be suspected in a neuropathic, warm, swollen foot with intact skin. Radiographs come first, with MRI when radiographs are normal. Knee-high, preferably non-removable, offloading should begin immediately rather than waiting for confirmation. Bone-active drugs are not recommended, remission should be judged by temperature, oedema, and imaging together, and protective footwear is advised after remission. Much of the underlying evidence is observational and of low certainty, which is why ongoing trials of monitoring strategies are important.
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. 2023.
- Raspovic KM, Schaper NC, Gooday C, et al. Diagnosis and treatment of active Charcot neuro-osteoarthropathy in persons with diabetes mellitus: a systematic review. Diabetes/Metabolism Research and Reviews. 2023.
- Gooday C, Game F, Woodburn J, Poland F, Sims E, Dhatariya K, Shepstone L, Barton G, Hardeman W. A randomised feasibility study of serial magnetic resonance imaging to reduce treatment times in Charcot neuroarthropathy in people with diabetes (CADOM). Journal of Foot and Ankle Research. 2023;16:2.
- Gooday C, Game F, Woodburn J, et al. CADOM: a randomised feasibility study of serial magnetic resonance imaging to reduce treatment times in Charcot neuroarthropathy in people with diabetes: a protocol (ISRCTN74101606). 2019.
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