Ankle and Foot Considerations

Abstract

In the evaluation of distal tibial deformities, one must consider the position of the talus, calcaneus, and foot relative to the tibia. The talus has a squared cross-sectional appearance in the frontal plane. The superior dome of the talus is parallel to the tibial plafond. There is normally no joint line convergence between the tibial plafond and the dome of the talus. This is different from the knee, where up to a 3° lack of parallelism between the femoral condyle line and the tibial plateau line (JLCA) is normal. The medial and lateral diaphyseal cortical lines intersect the talus laterally and medially, respectively, to the adjacent borders of the talus (► Fig. 18-1 a). This normal relationship is important to know when considering fusion of the ankle after distal tibial resection (► Fig. 18-1 b). The medial border of the talus will be medial to the medial cortex of the tibia. If the two are made collinear on the medial side, the heel will be laterally translated (►Fig. 18-1 b).