The talocalcaneal angle, also known as the kite angle, refers to the angle between lines drawn down the axis of the talus and calcaneus measured on a weight-bearing DP foot radiograph. This angle varies depending on the position of the calcaneus under the talus and the stiffness of the ligaments of the foot.
Measurement
The midtalar line should pass through (or just medial to) the base of the 1st metatarsal and the mid-calcaneal line should pass through the base of the 4th metatarsal.
Interpretation
Interpreting the talocalcaneal angle:
- hindfoot varus: <25°
- normal: 25-40°
- hindfoot valgus: >40°