Charcot neuro-osteoarthropathy (CNO) is a destructive inflammatory condition of the bones and joints of the foot and ankle in people with diabetes and neuropathy. Left unrecognized, it can progress to fracture, collapse, deformity, and ulceration, which in turn raise the risk of amputation. Despite its seriousness, the evidence guiding diagnosis, immobilization, and the decision to return to normal footwear remains surprisingly limited.
What the Evidence Base Looks Like
A 2023 systematic review prepared for the International Working Group on the Diabetic Foot (IWGDF) and published in Diabetes/Metabolism Research and Reviews examined 37 studies of active CNO in people with diabetes and intact skin. Fourteen addressed diagnosis, 18 addressed treatment (offloading, medical therapy, and surgery), and five addressed how to identify remission. No studies met criteria for preventing reactivation. The reviewers concluded that high-quality evidence is scarce across diagnosis, treatment, and prognosis.
This matters because CNO is often confused with infection, gout, or deep vein thrombosis. A warm, swollen, red foot in a person with neuropathy should prompt consideration of CNO, even when pain is minimal or absent.
Offloading and Immobilization
Total contact casting and weight bearing
Immobilization in a non-removable, knee-high device, most often a total contact cast, is the cornerstone of treatment for active CNO. Whether the patient must remain strictly non-weight bearing is less certain. A 2024 systematic review by Prem and colleagues in SAGE Open Medicine compared weight-bearing and non-weight-bearing casting. Only five studies, all retrospective or uncontrolled, met inclusion criteria, covering roughly 148 patients. Mean time to resolution ranged from 9.2 to 18.5 weeks, though individual cases ranged from 4 to 32 weeks. Complication rates varied widely, from 7.3% to 78%, with the highest figures including minor problems such as skin irritation. None of the studies directly compared weight-bearing with non-weight-bearing casting, and risk of bias was judged moderate to serious.
The authors found that weight bearing within a cast did not appear to impair healing in early active CNO, but they stated that evidence for strict non-weight-bearing practice is limited and called for randomized comparisons.
How long is long enough?
Gooday and colleagues, in their 2020 protocol in Pilot and Feasibility Studies, noted that treatment typically lasts from about six months to more than a year, with UK studies reporting roughly 9 to 12 months to remission. Reported relapse rates range from 12% to 33%, although inconsistent definitions of remission and relapse make these figures difficult to interpret. Most supporting studies were small retrospective series of 9 to 55 participants.
Monitoring Remission: Temperature, Radiographs, and MRI
Remission is conventionally judged by a small skin temperature difference between the two feet, together with radiographic stability. The CADOM investigators argue that these markers may over- or underestimate true disease activity, and that magnetic resonance imaging (MRI), which can detect bone marrow edema, might guide earlier or more accurate decisions about when to leave the cast.
To test this idea, Gooday et al. published a multicentre randomized feasibility study in the Journal of Foot and Ankle Research in 2023. Forty-three participants were randomized to standard care (temperature monitoring and X-rays) or standard care plus serial non-contrast MRI at 3, 6, 9, and 12 months. Thirty had a confirmed diagnosis and were analyzed; 19 reached remission. Mean time in a cast or offloading device was 235 days with standard care and 292 days with MRI monitoring, a difference that was not statistically significant. No safety events were linked to MRI, and 94% of study visits were completed. The study was not powered to test effectiveness, but the authors concluded that a definitive trial is feasible. Notably, these results do not show that MRI shortens treatment; they show only that the question can be properly studied.
Key Takeaways
Active CNO remains a diagnosis that depends on clinical suspicion: a warm, swollen neuropathic foot warrants prompt evaluation and immobilization. Non-removable knee-high offloading is the accepted foundation of care, but the optimal degree of weight bearing, treatment duration, and criteria for remission rest on low-certainty evidence. Temperature and radiographs remain standard tools for monitoring, while MRI is a promising but unproven adjunct. Rigorous randomized trials are still needed to refine these decisions.
References
- IWGDF working group. Diagnosis and treatment of active Charcot neuro-osteoarthropathy in persons with diabetes mellitus: a systematic review (IWGDF). Diabetes/Metabolism Research and Reviews. 2023.
- Prem R, Vignaraja V, Lewis T, Budair B. Weight bearing versus non-weight bearing total contact cast in the management of active Charcot foot: a systematic review. SAGE Open Medicine. 2024;12.
- 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, Poland F, Sims E, Dhatariya K, Shepstone L, Hardeman W. CADOM: a protocol. Pilot and Feasibility Studies. 2020;6:85.
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