Charcot-Marie-Tooth Disease

Overview

  • Commonest inherited peripheral neuropathy
  • Leading cause of paediatric cavovarus foot
  • Weak tibialis anterior and peroneus brevis against stronger peroneus longus and tibialis posterior
  • Result is a plantarflexed first ray, hindfoot varus and claw toes
  • Every cavus foot, especially unilateral, needs neurological examination and consideration of spine MRI
  • Soft tissue release, tendon transfer and osteotomy, with arthrodesis for rigid deformity

Paediatric Cavus Foot Deformities from Orthofracs on Vimeo.

Presentation from Victorian Tasmanian Orthopaedic Training Program

Aetiology

  • Commonest inherited neuropathy and commonest neurological cause of paediatric cavovarus
  • CMT1A is a PMP22 duplication on chromosome 17, autosomal dominant, with slow conduction
  • CMT2 is axonal with preserved velocities
  • X-linked forms involve connexin 32

Pathology

Charcot-Marie-Tooth Disease, onion bulb formation in a nerve biopsy from hereditary motor and sensory neuropathy
Onion bulb formation in a nerve biopsy from hereditary motor and sensory neuropathy. Image by Jensflorian, Wikimedia Commons, CC BY-SA 3.0.
  • Weak tibialis anterior is overpowered by peroneus longus, plantarflexing the first ray
  • Weak peroneus brevis is overpowered by tibialis posterior, causing hindfoot varus
  • Intrinsic weakness causes toe clawing and a high arch
  • Forefoot-driven varus is flexible initially, then becomes fixed

Clinical Features

  • Peek-a-boo heel sign
  • Lateral foot pain, ankle sprains and callosities under first and fifth metatarsal heads
  • Steppage gait, absent reflexes and calf and hand wasting

Investigations

Charcot-Marie-Tooth Disease, cavus foot in charcot-marie-tooth disease
Cavus foot in Charcot-Marie-Tooth disease. Image by Benefros at English Wikipedia, Wikimedia Commons, CC BY-SA 3.0.
  • Coleman block test, hindfoot correction indicates flexible forefoot-driven varus
  • Spine MRI if asymmetric or rapidly progressive
  • Lateral radiograph shows increased calcaneal pitch and Meary angle

Management

  • Bracing does not prevent progression
  • Plantar fascia release and first metatarsal dorsiflexion osteotomy
  • Peroneus longus to brevis transfer
  • Tibialis posterior transfer through the interosseous membrane for foot drop
  • Jones procedure for the clawed hallux
  • Dwyer lateralising calcaneal osteotomy for fixed hindfoot varus
  • Triple arthrodesis is salvage for rigid deformity in the mature foot

Prognosis

  • Recurrence is common as the neuropathy progresses
  • Joint-sparing reconstruction with tendon balancing gives the best long-term results

Reviewed by Professor Phong Tran, Head of Orthopaedic Surgery, Western Health. Last updated 10 October 2026.