Charcot Foot Syndrome (CFS)

Charcot Foot Syndrome (CFS) is one of the more devastating complications affecting patients with diabetes and peripheral neuropathy

About

• Neuropathic joint lacks any sensation and so patient may not recognise damage
• Progressive bone and joint deformity - a destructive arthritis
• Associated with a mean reduction in life expectancy of 14 years

Causes (any cause of a sensory neuropathy)

• Diabetic nephropathy or Tabes Dorsalis
• Syringomyelia in upper limbs
• Usually long standing diabetes.
• Alcoholic neuropathy
• Cerebral palsy and sensory loss
• Leprosy
• Congenital insensitivity to pain

Aetiology

• Neurotraumatic theory attributes bony destruction to the loss of pain sensation and proprioception combined with repetitive and mechanical trauma to the foot.
• Neurovascular theory suggests that joint destruction is secondary to an autonomically stimulated vascular reflex that causes hyperemia and periarticular osteopenia with contributory trauma. Intrinsic muscle imbalance with increased heel and plantar forces can produce eccentric loading of the foot, propagating microfractures, ligament laxity and progression to bony destruction

Clinical

• Numbness, redness, pain 50%, swelling
• Injuries and fractures and deformity
• Peripheral neuropathy (unable to detect 10g monofilament)
• Assess arterial perfusion: Pulses (palpation or Doppler)

Investigations

If acute Charcot arthropathy is suspected, arrange a weight bearing X-ray of the affected foot and ankle. Consider MRI if the X-ray is normal but Charcot arthropathy is still suspected.

• FBC, U&E, LFT, Urate, Glucose, Hba1C, CRP - elevated may suggest osteomyelitis
• Blood cultures may be indicated
• Infrared dermal thermography comparisons > 2.0 0C between contra-lateral corresponding locations using infrared dermal thermometer accurate to +0.10C
• Plain weight bearing radiographs
• MRI: swelling and stress fractures, Bony consolidation, fragmentation of subchondral bone, fractures, dislocation / subluxation, osteopenia, osteolysis)
• Indium-111 leukocyte scan or MRI for osteomyelitis

Differential

• Osteomyelitis, Acute gout
• DVT, Deep abscess
• Inflammatory arthritis

X ray showing joint destruction

Management

• To confirm the diagnosis of Charcot arthropathy, refer the person within 1 working day to the multidisciplinary foot service for triage within 1 further working day. Offer non-weight-bearing treatment until definitive treatment can be started by the multidisciplinary foot care service. NICE NG 19 (2015)
• Immobilisation (often with a total contact cast) until complete resolution of the active phase and diabetic/orthopaedic input. Exclude differentials above
• Gradual step down to partial weight bearing as required
  • Moderate deformity: Custom footwear + offloading orthotics
  • Severe Deformity + rearfoot or ankle Charcot: CROW + referral to orthopaedics for surgical review
  • Emotional support / Psychology input Physiotherapy referral for muscle strengthening.
  • 3 monthly reviews to monitor reactivation of Active CFS

References

• Active Charcot Foot Syndrome Guidelines
• Charcot Foot: The Diagnostic Dilemma
• The Charcot Foot in Diabetes