What are the most common sites of avascular necrosis in the ankle?
The three areas in the ankle that are susceptible to avascular necrosis are the talar dome, the second or third metatarsal heads, and the lateral hallux sesamoid.
In the setting of a talar neck fracture, there is often compromise of the quite variable blood supply to the talar dome, which may result in avascular necrosis. This is problematic because it can lead to collapse of the talar dome and accelerated degeneration of the ankle joint.
Characteristic collapse of the second and third metatarsal heads, referred to as Freiberg’s infraction, is thought to be a result of avascular necrosis. This appearance is typically seen in the setting of chronic repetitive trauma.