Talar Fracture

Abstract

The talus is a hindfoot bone that articulates with the calcaneus, tibia, fibula, and navicular. The blood supply is from the posterior tibial artery (artery of tarsal canal and deltoid branch of posterior tibial artery), anterior tibial artery, and perforating peroneal artery via the artery of the tarsal sinus. Talar neck fractures account for around 50% of all talus fractures. The Hawkins classification is used to help predict the chance of avascular necrosis after fracture of the talar neck. Hawkins I is a nondisplaced fracture and has a 0–13% AVN risk. Hawkins II is a talar neck fracture with subtalar dislocation (20–50% AVN risk). Hawkins III is a subtalar and tibiotalar dislocation (20–100% AVN risk). Hawkins IV is a subtalar, tibiotalar, and talonavicular dislocation (70–100% AVN risk). Talus neck fractures are usually managed with ORIF. A Hawkins sign is a subchondral lucency that appears on X-ray at 6–8 weeks suggestive of intact vascularity. Other fractures of the talus that occur are talar body, lateral process, posterior process, talar head, and osteochondritis dissecans lesions of the talar dome. A Canale view is the optimal view of the talar neck.

What is the mechanism of a talar neck fracture?	Forced dorsiflexion with axial load
What does the lateral process of the talus articulate with?	Posterior facet of calcaneus and lateral malleolus of fibula
What Hawkins classification has the highest risk of AVN?	Hawkins IV
What is a Canale view?	Optimal view of talar neck. Maximum equinus, 15° pronation, and X-ray 75° cephalad from horizontal
What should be done with an extruded talus?	Clean, reduce, and ORIF
What is a Hawkins sign ?	Subchondral lucency seen on mortise X-ray at 6–8 weeks representing intact vascularity and resorption of subchondral bone
What does a varus talar malunion lead to?	Decreased subtalar eversion and weightbearing on the lateral border of foot