Hallux valgus and hallux flexus associated with cerebral palsy: analysis and treatment

Hallux valgus and hallux flexus associated with cerebral palsy foot deformity may be due to equinovalgus and/or metatarsus primus adductus or combinations of these. Occasionally the condition occurs in equinovarus feet. Hallux flexus or "dorsal bunion" is usually due to a weak extensor hallucis longus, overpull of the anterior tibial muscle on the first metatarsal and spasticity or contracture of the flexor hallucis longus or brevis. A weak peroneus longus muscle has not caused this deformity. The condition is usually predictable in the growing child if all factors related to gait, collagen stability and foot alignment are observed. Treatment includes soft-tissue and bone realignment. Release of the adductor hallucis, lateral collateral ligaments of the metatarsophalangeal joint, plication of the medial capsule and of the abductor hallucis and centralization of the extensor hallucis longus will realign the first ray. The flexor hallucis longus is transferred to athe extensor hallucis longus proximal to the metatarsophalangeal joint and the anterior tibial tendon is transferred to the second metatarsal. An osteotomy at the base of the first metatarsal and at the base of the proximal phalanx will realign the skeleton. Twenty-six great toes in 16 patients have been observed for two to 20 years. The correction has been maintained without arthrodesis of the metatarsophalangeal joint except where chondromalacia occurred. Once the pattern of deformity is evident, progression is unrelenting and treatment is indicated in order to prevent chondromalacia of the articular cartilage.