🦶 Charcot Foot Syndrome (CFS) is one of the most devastating complications affecting patients with diabetes and peripheral neuropathy.
📖 About
- Neuropathic joint → loss of sensation, so damage may go unnoticed.
- Progressive bone and joint deformity → destructive arthritis 🦴.
- Associated with a mean reduction in life expectancy of ~14 years ⏳.
⚠️ Causes (any sensory neuropathy)
- Diabetic neuropathy (most common) 🍬
- Tabes dorsalis (syphilis)
- Syringomyelia (upper limbs)
- Alcoholic neuropathy 🍷
- Cerebral palsy with sensory loss
- Leprosy 🦠
- Congenital insensitivity to pain
⚙️ Aetiology
- Neurotraumatic theory: Repetitive trauma + loss of pain/proprioception → bony destruction.
- Neurovascular theory: Autonomic hyperaemia → osteopenia + trauma → joint collapse.
- Intrinsic muscle imbalance → eccentric loading → microfractures, laxity, deformity.
🔎 Clinical Features
- Numbness, redness, swelling (pain only in ~50%).
- Injuries, fractures, deformity 🦴.
- Peripheral neuropathy (fails 10 g monofilament test).
- Assess arterial perfusion: pulses (palpation/Doppler) 💓.
🧪 Investigations
If acute Charcot arthropathy is suspected → arrange weight-bearing X-ray.
If X-ray is normal but suspicion remains → MRI 🖥️.
- Bloods: FBC, U&E, LFT, urate, glucose, HbA1c, CRP (raised CRP → ?osteomyelitis).
- Blood cultures if infection suspected.
- Infrared dermal thermography: >2.0°C difference vs contralateral side 🌡️.
- Plain weight-bearing radiographs.
- MRI: stress fractures, fragmentation, subluxation/dislocation, osteopenia, osteolysis.
- Indium-111 leukocyte scan for osteomyelitis if unclear.
🔍 Differential Diagnosis
- Osteomyelitis 🦠
- Acute gout 🦶🔥
- DVT 🩸
- Deep abscess
- Inflammatory arthritis
🖼️ Imaging
🩺 Management
- Urgent referral: Within 1 working day → multidisciplinary foot service (NICE NG19).
- Immediate: Non-weight-bearing + immobilisation (total contact cast) until resolution.
- Step-down: Gradual partial weight bearing as advised.
- Moderate deformity: Custom footwear + offloading orthotics 👟.
- Severe deformity: CROW boot; consider surgical referral 🛠️.
- Psychological support + physiotherapy for strengthening 💪.
- 3-monthly reviews to monitor for reactivation 🔄.
💡 Exam Tip: In suspected acute Charcot foot, the key is urgent referral + non-weight-bearing.
Confusing it with cellulitis or osteomyelitis is a classic exam trap ⚡.
📚 References