Type IV congenital deficiency of the tibia.

Type IV congenital deficiency of the tibia is associated with two major problems: the equinovarus position of the foot with the talus incarcerated in the distal tibiofibular mortise and the limb length inequality due to the shortened dysmorphic tibia. The purpose of this study was to formulate guidelines for the management of this rare but complex condition. Eleven patients treated for type IV congenital deficiency of the tibia between 1963 and 2000 were evaluated. The treatment consisted of a Boyd or Syme amputation of the foot in seven patients, ankle reconstruction surgery in three patients, and heel cord lengthening for correction of the equinovarus deformity of the foot in one patient. Even though seven patients treated by Boyd or Syme amputation were community ambulators with a prosthesis, parents and patients preferred ankle reconstruction. All three patients treated by ankle reconstruction surgery presented with a stable ankle, a plantigrade foot, and independent ambulation. Reconstruction of the ankle mortise should be the treatment of choice for type IV congenital deficiency of the tibia.