The morbid anatomy of congenital deficiency of the tibia and its relevance to treatment.

Two specimens obtained from a 5-month-old boy with bilateral type 1a congenital tibial deficiency were dissected to describe their morbid anatomy. Examination revealed a rigid equinovarus deformity, absence of a tibial remnant, an abnormal saddle-shaped talus, and several tarsal coalitions. Observation of the arterial pattern during surgery supported the previously reported finding that persistence of an immature arterial structure is inherent in this condition. Knowledge of potential structural anomalies is essential during the planning of an amputation or of a knee or an ankle reconstruction. Anatomic abnormalities may affect the design of soft-tissue flaps in an amputation and plantigrade positioning and foot biomechanics in reconstructive procedures.