Unstable Charcot Neuropathic Foot When Orthotic Offloading Has Not Achieved Stability
This protocol applies to patients with unstable Charcot neuropathic osteoarthropathy (CNO) of the foot — including Sanders-Frykberg type IV or V involvement, or advanced bone destruction with joint instability — in whom conservative offloading management did not reach the expected clinical and radiographic endpoints.
Clinical scenario
In some patients with advanced CNO, foot destruction is more extensive and is combined with joint instability — and not rarely with concurrent diabetic foot ulcers and osteomyelitis. In these cases, conservative management alone is insufficient to achieve a stable, plantigrade foot.
When the prior treatment has not been enough
Offloading with a Sarmiento orthosis (dynamic or non-dynamic), or a special contact splint combined with wheelchair use, is the standard initial approach for unstable or advanced Charcot foot. This protocol is indicated when that line fails to achieve its targets: a sustained temperature difference of less than 2 °C between corresponding foot locations over 4–6 consecutive weeks, complete resolution of foot warmth, swelling, and erythema, and weight-bearing radiographs confirming the remodelling phase.
Next-step approach (partial overview)
For feet that have not responded to conservative management, the protocol involves a surgical reconstructive approach aimed at creating long-term structural stability. The complete regimen — including specific surgical options, selection criteria, and management of concurrent infection — is detailed in the full protocol.
Treatment goals
- Stable plantigrade foot
- Bony fusion evident on foot radiograph at 8–14 weeks
- Resolution of inflammatory changes on foot MRI
References
DOI: 10.1007/s40266-025-01234-0
- Patients suffering from unstable CNO of Sanders-Frykberg types I-III, stable Sanders-Frykberg type IV, V or more advanced CNO destructions are empirically treated by Sarmiento orthoses-dynamic or non-dynamic.
- In some cases, however there is more advanced destruction of the foot combined with joints instability and not so rarely with diabetic foot ulcers and osteomyelitis.
- More extensive reconstruction aims to create a stable, plantigrade foot through arthrodesis procedures.
- This approach is particularly valuable for severely unstable feet or those with recurrent ulceration after failed conservative or simpler surgical treatments.
- External fixators, particularly circular frames, such as the Ilizarov apparatus, provide solutions for complex cases requiring: (i) management of concurrent soft tissue problems or infection, (ii) gradual correction of severe deformities or (iii) supplementation of internal fixation.
- Pinzur et al. achieved 95.7% limb salvage with a protocol involving radical resection of bone, correction of deformity, external fixation and culture-specific antibiotic therapy.
- The transition to protected weight-bearing can be initiated when bony fusion is evident (8-14 weeks).
- Serial MRI monitoring every 3 months until resolution of inflammatory changes (average 8.3 months) helps determine appropriate immobilization duration.
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