Talar neck fracture - Hawkin's classification:
Type I: nondisplaced talar neck fracture, risk of AVN 0%–15%
Type II: displaced fractures with dislocation or subluxation of the subtalar joint, risk of AVN 20%–50%
Type III: displaced fractures with dislocation or subluxation of ankle and subtalar joints, risk of AVN 100%.
Type IV: displaced fractures with dislocation or subluxation of the subtalar, tibiotalar, and talonavicular joints, risk of AVN 100%
