[Foot deformities in longitudinal ectromelia of the lower limbs]

We have studied 204 feet in 181 children with congenital limb shortening. There were 17 short femurs in 11 children in whom it was impossible to lengthen the leg. Thirteen feet were abnormal. It was necessary to adapt the foot to fit the chosen prosthesis. In 34 children it was possible to correct the length of the short femur. In 21 the feet were normal. 13 had abnormal feet associated with fibular aplasia and deformities included equinovalgus, hind foot synostosis, and deficient rays. In 72 children with congenital hypoplasia or aplasia of the fibula, 76 feet were affected. The function of the foot depends on attaining a stable position beneath the tibia. In 34 children (35 feet), the feet were in a stable position. There were 22 ball and socket ankle joints. Before carrying out leg lengthening, operation was necessary on 9 feet, and a further 13 required operation after lengthening had been carried out. In 34 children (41 feet) there was fibular aplasia. The feet lay in equinovalgus and were often narrow. Only 5 did not have a degree of synostosis. Twenty-three feet in twenty two children were operated on with early soft tissue release, tendon transfer and tibiotalar arthrodesis. This is our treatment of choice. Twenty-seven children had tibial dysplasia which affected 37 feet. The feet lay in equinovarus and in 5 there was partial diplopodia. In the absence of a tibia (19 feet) disarticulation of the knee was carried out. In 12 there was proximal shortening of the tibia which in 9 cases was treated by tibiofibular union. It was possible to retain only 2 feet in a proper position in a lengthened leg. In 30 children (33 feet) both fibular and tibial hypoplasia was present. The feet functioned well. There were 22 ball and socket ankles, 28 narrow feet and numerous synostoses. In limbs with atypical dysplasia 7 abnormal feet were noted. If it is possible to preserve or lengthen the limb it is vital that the foot is retained in a stable position beneath the tibia in order that satisfactory function be obtained. If limb lengthening is impossible, the foot must be adapted to match the prosthesis.