Score: Hawkins classification
Use: Talar neck fractures
Type I
Displacement: undisplaced
Risk of avascular necrosis: < 10%
Type II
Displacement: displaced with subtalar subluxation or dislocation
Risk of avascular necrosis: > 40%
Type III
Displacement: displaced with subtalar and ankle dislocation
Risk of avascular necrosis: > 90%
Type IV
Displacement: type III + variants (e.g. dislocation of talonavicular joint)
Risk of avascular necrosis: 100%Reference
Classification and Diagnosis in Orthopaedic Trauma. Editors: Rahij Anwar, Kenneth W. R. Tuson, Shah Alam Khan. Cambridge University Press, 2008