Cavus foot deformity in children.

A cavus deformity of the foot is easily recognizable, but appropriate neurologic assessment can help to determine the etiology. Cavovarus, the most frequent type of cavus foot, presents with an elevated medial longitudinal arch, first ray plantarflexion, and, if rigid, a fixed heel varus. Common causes include progressive motor sensory conditions, typically Charcot-Marie-Tooth disease, and nonprogressive conditions such as cerebral palsy and poliomyelitis. A calcaneocavus foot may be seen in poliomyelitis, spinal dysraphism, and peripheral neuropathy. Initially, the cavus deformity is flexible, but if left untreated, it becomes a fixed bony deformity. Physical examination should include the cavovarus block test, which assesses flexibility of the hindfoot deformity and can direct surgical treatment. Standing radiographs of the feet and spine, magnetic resonance imaging, and electrodiagnostic studies may be useful. Management goals are to obtain a plantigrade, mobile, pain-free, stable, motor-balanced foot. Surgical options include soft-tissue and plantar fascia releases for a flexible deformity, osteotomy for a fixed deformity, and tendon transfers to restore muscle balance. Triple arthrodesis has poor long-term results in patients with progressive deformity and sensory impairment.