A workman falls from a height of 10 ft and lands on his feet. He complains of severe left foot pain and has diffuse swelling. You know that:
The most commonly fractured tarsal bone is the talus.
+Bohler's angle should normally be 20 degrees or less.
+An abnormal Bohler angle indicates a talus fracture.
+Avascular necrosis is a complication of a talar fracture.
+Lisfranc's fracture is treated with a weight-bearing cast.
Bohler's angle, normally 20–40 degrees, determines the presence of depression in calcaneal fractures. The calcaneus is the most frequently fractured tarsal bone. The mechanism of injury is usually compression. Associated injuries with a calcaneus fracture are injuries to the lumbar spine, pelvis, hip, and knee. Often, the only radiographic signs are the disruption of the trabecular pattern and an abnormal Bohler's angle (the angle formed by the axis of the subtalar joint and the superior surface of the tuberosity). Talar fractures are uncommon, although they are the second most common foot fracture. Because the blood supply to the talus is poor, avascular necrosis of the bone may result. Fracture/dislocations of the tarsal–metatarsal joint (Lisfranc's joint) are uncommon. A fracture through the base of the second metatarsal is almost pathognomonic of a disrupted joint. Separation between the base of the first and second metatarsals suggests separation or subluxation. Comparison views with the opposite foot are helpful. Treatment may require open reduction and internal fixation. (Some sources refer to Böehler's angle.)