The recognition and treatment of congenital flat foot in infancy.

Congenital flat foot is a rare condition. In a special clinic for foot deformities only one case was found in 121 patients (Osmond-Clarke 1956). Adequate correction depends on recognition of the deformity within a few weeks of birth, and any child presenting with a rigid, dorsiflexed and everted forefoot should be regarded as having congenital flat foot until careful clinical and radiological examinations have excluded the possibility. The rigid nature of the deformity distinguishes it from a simple postural talipes calcaneo-valgus, and even before the midtarsal bones have ossified careful antero-posterior and lateral radiographs taken with the foot at a right angle to the tibia will reveal the true nature of the complex deformity. This comprises : 1) dorso-lateral dislocation of the navicular bone on the talus ; 2) equinus and varus of the talus ; and 3) equinus of the calcaneus. In our view the heel deformity is a constant feature. It is often unnoticed, being masked by the soft tissues surrounding the heel and the much more obvious dorsiflexion and eversion of the fore part of the foot. Failure to recognise and correct this important component of the deformity is responsible for the frequency of relapse. Etiology-We believe that this condition is due to disparity of growth between the muscles and bones of the leg. It is seen in its most severe form in some cases of arthrogryposis when the muscles of the anterior compartment and the calf group fail to keep pace with the growth of the tibia. The flexor muscles of the toes and the tibialis posterior muscle are unaffected. The foot breaks in the midtarsal region, the talus occupies a vertical and varus position from lack of support of the sustentaculum tali and the navicular comes to lie above the head of the talus. There is no evidence of agenesis or lack of growth potential in the bones themselves and, if they are placed in the correct position without undue soft-tissue tension, they will grow normally.