Types of Fracture

Fractures of the talus are relatively uncommon injuries and are normally caused by major forces. The usual site of a fracture is across the waist and this is caused by forced hyper-dorsiflexion of the ankle. The commonest cause for this is a road crash in which the car driver’s foot is forced backwards in a head-on collision. Injuries can also occur in a fall from a height.

Fractures of the neck of the talus are classified as:

• Type I – undisplaced (Fig 1)
• Type II – displaced (Fig 2)
• Type III displaced with dislocation (Fig 3)

Undisplaced fractures are easily missed and displaced fractures may be thought to be undisplaced and so CT is valuable in the assessment of these injuries. As they are high velocity injuries, they may be associated with life-threatening injuries of the head and trunk and may be overlooked.

The major complication of these injuries is avascular necrosis of the proximal part of the bone.

Osteochondral fractures of the talar dome are discussed under ankle injuries.

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