Bohler's angle is used in fracture of ?

Ans. is 'c' i.e., Calcaneum The Angle of Gissane, or "Critical Angle", is the angle formed by the downward and upward slopes of the calcaneal superior surface. On a lateral radiograph, an angle of Gissane of > 130deg suggests fracture of the posterior subtalar joint surface. Bohler's angle, or "Tuber Angle", is another normal anatomic landmark seen in lateral radiographs. It is formed by the intersection of (1) a line from the highest point of the posterior aicular facet to the highest point of the posterior tuberosity, and (2) a line from the former to the highest point on the anterior aicular facet. An angle < 20deg suggests a depression posterior facet and possible calcaneal fracture.