Charcot-Marie-Tooth

Question 1

What is Charcot-Marie-Tooth disease?

Answer 1

A hereditary motor sensory neuropathy (HMSN) that has two forms resulting in muscles weakness and sensory changes; most common inherited neurological disease 1:2500

Question 2

What muscles are weakened by Charcot-Marie-Tooth?

Answer 2

1) Peroneus brevis
2) tibialis anterior
3) Intrinsic muscles of hands and feet

Question 3

What is the genetic etiology of CMT (Charcot-Marie-Tooth)?

Answer 3

Mutation on Ch 17 that codes for Peripheral myelin protein 22 (PMP 22)

Question 4

What are the common orthopedic manifestations of Charcot-Marie-Tooth disease?

Answer 4

1) Pes cavus
2) hammer toes
3) hip dysplasia
4) scoliosis

Question 5

What is the typical foot deformity a/w Charcot-Marie-Tooth?

Answer 5

Rigid cavovarus foot; will have weakness with dorsiflexion (tibialis ant.) and foot eversion (peroneus brevis)

Question 6

What is the initial deformity seen with Charcot-Marie-Tooth?

Answer 6

Plantarflexed 1st ray; then will see the cavus (strong peroeus longus, weak tibalis anterior) and varus (strong tibialis posterior, weak peroneus brevis)

Question 7

What shoe orthotic would be indicated in conservative management of the cavovarus foot a/w Charcot-Marie-Tooth?

Answer 7

Post for the lateral forefoot and lateral heel; must be flexible deformity; can also use AFOs for foot drop

Question 8

What is the surgical management for Charcot-Marie-Tooth?

Answer 8

Regardless if flexible soft tissue deformities that are symptomatic:

1) Posterior tibialis transfer to the dorsum of foot
2) Peroneus longus transfer to peroneus brevis

If rigid hindfoot:

3) all the above
4) dorsiflexion 1st MT osteotomy
5) Calcaneal valgus producing osteotomy

If severe deformity or symptoms:
6) triple arthrodesis

Question 9

What toe deformity is a/w Charcot-Marie-Tooth and how are they treated?

Answer 9

Claw toes (weak intrinsics with overpull of toe extensors); treat with Jones procedure (transfer toe extensor through MT neck)