Congenital transverse deficiency of the tibia and fibula: a report of two cases

We report two similar, but unrelated, patients with congenital bilateral pa rtial deficiencies of the tibia and fibula associated with intact feet. In both patients, the tibia and fibula were absent on initial radiographs, whi le the femur and the tarsal bones were well developed and there was bilater al teratologic dislocation of the hips. Ultrasound and magnetic resonance i maging (MRI) studies suggested the presence of cartilaginous remnants of th e tibia and fibula. There were multidirectional instabilities in the knees and ankles. The clinical and radiological features of these cases are disti nct from those of congenital longitudinal deficiency of the tibia, in which the fibula is always preserved, and from longitudinal deficiency of the fi bula, in which the tibia is present and the foot is usually involved. We su ggest that the bilateral partial deficiencies of the tibia and fibula assoc iated with the intact foot and teratologic dislocation of the hips is a sin gle-entity disorder, possibly categorized as an intercalary transverse defi ciency of the lower limb.