The cavovarus foot deformity. Etiology and management.

The cavovarus foot is a complex deformity of the forefoot and hindfoot, frequently of neuropathologic etiology. A progressive spinal or peripheral neuromuscular disorder must be excluded by a thorough clinical evaluation. With the failure of nonoperative modalities, surgical options depend on patient age, etiology of the deformity, and the constellation and flexibility of the defects observed. If the hindfoot varus is flexible, correction of the cavus and forefoot pronation through extensive plantar release and metatarsal osteotomies is reliable. The underlying muscle imbalance must be addressed through tendon transfers to prevent further progression. In the young child, a rigid hindfoot varus will often be corrected by a radical plantar-medial release, but the more mature foot may require midtarsal osteotomy and calcaneal osteotomy or triple arthrodesis. The surgery is usually staged to provide correction of deformity and stabilization of the hindfoot prior to tendo Achilles lengthening or tendon transfer. Arthrodesis of a previously well-corrected foot is common due to progression of the neurologic deficit or failure to achieve muscular balance. The claw toe deformity also must be corrected by tendon transfer, osteotomy, and arthrodesis for reasons of both comfort and function.