The anatomy of the foot is complex.
The foot can be broadly divided into three main parts:
Fig. 1: Right foot radiographs demonstrating the broad anatomical divisions of the foot into the hindfoot, midfoot and forefoot.
Requires AP and lateral weight bearing radiographs.
Fig. 2: Weight bearing AP radiograph of the left foot demonstrating normal hindfoot alignment. The mid-talar line intersects the first metatarsal and the mid-calcaneal line intersects the fourth metatarsal. The talocalcaneal angle is normal.
Fig. 3: Weight bearing AP radiograph of the right foot demonstrating a reduced talocalcaneal angle, in keeping with varus deformity of the hindfoot. The mid-talar and mid-calcaneal lines are not intersecting the first metatarsal or fourth metatarsal respectively.
Fig. 4: Weight bearing radiograph of the right foot. There is hindfoot valgus, the mid-talar line and mid-calcaneal lines no longer intersect the first and fourth metatarsals respectively. The talocalcaneal angle is subsequently widened. Of note, this is a patient with congenital vertical talus.
Fig. 6: Lateral radiograph of the right ankle demonstrating how to measure the talocalcaneal angle.
Fig. 7: Lateral radiograph of the right foot demonstrating an increased tibiocalcaneal angle (>90 degrees) due to the foot being held in fixed equinus.