""Astragalus" is an archaic term for the talus. The term "aviator's astragalus" was coined by Henry Graeme Anderson (1882-1925) 3 in 1919 due to his observations of injury patterns secondary to crashing planes 1-3. After the birth and growth of aviation in the early 20th century, crashing planes at sub-lethal speeds was a fairly common occurrence. This term is now obsolete because people don't routinely crash planes at non-lethal velocities."
"Fractures included under this name include compression talar neck, talar body fractures, posterior talar process fractures, or fracture-dislocation injuries. More specifically, the term can be used to describe an aviator's fracture, a coronal-plane fracture of the neck of the talus resulting from forced dorsiflexion of the ankle."