Charcot-Marie-Tooth (CMT), also called hereditary motor and sensory neuropathy (HMSN) or peroneal muscular atrophy (PMA), is a common hereditary peripheral neuropathy. The disease affects an estimated 1 in 2,500 individuals and has profound manifestations in the foot and ankle.


The foot is a delicate balance of stability and motion and is driven by coupled motor forces across the foot and ankle to allow form and function. The tibialis anterior is force coupled with the peroneus longus, and the posterior tibialis is coupled with the peroneus brevis. Uneven loss of motor strength in these paired muscle groups disrupts the balance of forces in the forefoot and ankle, resulting in progressive deformity.

Denervation of the tibialis anterior and peroneus brevis results in an imbalance of forces across the foot. The weaker tibialis anterior is overpowered by a stronger peroneus longus. The result is plantarflexion of the first ray and eversion of the foot, disrupting the normal tripod for the foot. As the deformity progresses, a stronger posterior tibialis overpowers a weaker peroneus brevis and the hindfoot is driven into varus. The deformity is initially flexible but will eventually become fixed if left untreated. Claw deformity results from intrinsic muscle weakness and recruitment of lesser toe extensors to compensate for weak ankle dorsiflexors.


Presentation typically occurs in adolescence with complaints of symmetric weakness and atrophy of the lower legs and hands. Patient or family members may complain of difficulty running, clumsiness with frequent trips or falls or numerous ankle sprains. The foot and ankle may have a varied extent of involvement, with potential deformities that include foot drop, lesser toes deformity and cavus arch. Involvement of the hands often occurs later in the disease course, and includes complaints of weakness or loss of fine motor control. Muscle cramps or neuropathic pain are rare presenting symptoms. Additionally, patients may report a family history of diagnosed disease or similar complaints.


Non-surgical Treatment
Supportive therapy is the mainstay for treatment of CMT. Care requires a multimodal approach, involving neurologist, genetic counselors, physical and occupational therapists, in addition to treating orthopeadic surgeon.

The goals of therapy are to maintain strength while minimizing pain and sensory disturbances, in order to preserve maximal function and independence for activities of daily living. Physical therapy focuses on heel cord stretching for ambulation and AFO’s. Crutches or wheelchairs may be required. Occupational therapy may also be utilized to assist the patient with adaptive equipment.

Surgical Treatment
Indications for surgical intervention are dictated by the degree of deformity and impairment. Flexible forefoot deformities may be addressed with soft tissue reconstruction, potentially combining plantar fascia release, tendon transfers and Achilles tendon lengthening. As the deformity becomes more rigid, valgus producing calcaneal osteotomy may be required for hindfoot varus with dorsiflexion osteotomy of a plantarflexed first ray. In the setting of arthritic changes, fusions may be indicated. Lesser toe deformity may also need to be addressed. Treatment for each patient must be individualized.

Written by Donald Covell, MD, Reviewed by Thomas Dowd, MD, Last reviewed June 2015