talar neck fracture
Talar neck fractures extend through the thinnest cross-sectional portion of the talus, just proximal to the talar head. They represent one of the most common types of talus fracture (~30-50%), along with chip and avulsion fractures of the talus (~40-49%). These fractures are commonly associated with subtalar dislocation and/or posterior body fractures .
Mechanism of injury
These fractures usually result from hyperdorsiflexion.
- Canale view (15 degree internal rotation with 15 degree, tube angle (similar tube angle to an AP foot)) demonstrates the fracture well
Hawkins classification :
- type I: non displaced fracture
- type II: displaced fracture with subluxation or dislocation of the subtalar joint and a normal ankle joint
- type III: displaced fracture with body of talus dislocated from both subtalar and ankle joint
Canale and Kelly described a rare type IV category which in addition to features described for type III there is dislocation or subluxation of the head of the talus at the talonavicular joint.
- type I fractures: short leg cast or boot & no weight bearing
- type II-IV fractures: open reduction - internal fixation (ORIF)
- hardware complications
- backing out
- hardware or peri-hardware fracture
- tendon entrapment or injury
- risk of avascular necrosis (AVN) increases with increasing classification type
- type I fractures have 0%–15% risk
- type II fractures have 20%–50% risk
- type III fractures approach 100% risk
- type IV fractures have 100% risk
History and etymology
The classification of talar neck fractures was described by Dr Leland G Hawkins in 1970 .