The talar body is the posterior and largest segment of the talus, comprising the trochlea (superior articular surface for the ankle mortise), the medial and lateral facets of the posterior subtalar joint, and the posterior talar process with its medial and lateral tubercles. The posterior talar body is covered by articular cartilage on three surfaces and has no direct muscular attachments, its blood supply entering from the sinus tarsi anteriorly.
Talar body fractures are rare but severe high-energy injuries distinct from talar neck fractures. Because all blood supply enters anteriorly through the sinus tarsi and the tarsal canal, talar body fractures that disrupt the blood vessels produce AVN of the entire body. The posterior talar process (os trigonum zone) is a common site of posterior ankle impingement in ballet dancers. The medial and lateral talar processes are avulsed in specific ankle sprain mechanisms: the lateral process ('snowboarder fracture') from forced dorsiflexion and inversion.
Crush or high-energy axial load fracturing the talar body disrupts its entire blood supply, producing near-universal avascular necrosis of the entire talus requiring prolonged non-weight-bearing, total talar replacement, or eventually tibiocalcaneal fusion.
Forced dorsiflexion and inversion during snowboarding avulses or impacts the lateral talar process, producing an injury clinically indistinguishable from a lateral ankle sprain but visible on CT; missed diagnosis leads to non-union causing chronic posterolateral ankle pain.
