Foot and Ankle Manifestations of Charcot-Marie-Tooth Disease

Abstract

The term Charcot-Marie-Tooth disease represents a spectrum of neurological dysfunction more recently described as hereditary motor-sensory neuropathies. An abnormality of myelination is thought to be responsible for the clinical manifestations. While histological findings have been well described, the exact biochemical basis for this disorder remains unknown. Over one half of patients with Charcot-Marie-Tooth disease manifest foot and ankle problems, including pain, weakness, deformity, and, rarely, paresthesias. Characteristic patterns of neuromuscular weakness have been identified. Bilateral pes cavovarus is the most common pathologic foot deformity seen. The specific components include hindfoot varus, anterior or forefoot cavus, and, often, clawtoes. The etiology of this abnormal foot posture usually results from tibialis posterior overpowering peroneus brevis coupled with peroneus longus overpowering tibialis anterior. Multiple treatment options have been described. Rationale for specific tendon transfers, soft tissue release, osteotomies, and arthrodesis is discussed. Results of surgical intervention are difficult to interpret and compare because of the wide spectrum of both neurological dysfunction and described operative procedures. In the presence of flexible deformity, early soft tissue release and tendon transfers may help prevent or delay more extensive bony procedures. The clinical results of triple arthrodesis in the Charcot-Marie-Tooth disease patient appear to deteriorate with time. Genetic transmission, progression of the neurological dysfunction, flexibility of the deformity, distribution of muscular weakness, and anticipated foot demands vary a great deal within this patient population. Treatment decisions, therefore, must be individualized and based upon a clear history, careful examination, and well-defined patient goals.