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Wheeless' Textbook of Orthopaedics

Hawkins Classification of Talar Frx



- Type I Talar Fractures:
    - non displaced fractures of the talar neck without dislocation
    - AVN: 10%
    - important challenge w/ this injury is ensuring that anatomic reduction is obtained with no varus rotation;
    - treated closed, usually w/ short leg cast w/ foot in slight equinus;
         - leg is kept non-wt bearing for 4 wks, & then wt bearing is allowed in cast for another 8 wks or until healing is evident by x-ray (evidenced by trabeculations across fracture site);

- Type II Talar Fractures:
    - displaced fracture of the talar neck with subluxation or dislocation of the sub-talar joint (subtalar joint subluxation is usually dorsal) and the ankle remains aligned;
    - type II injuries are caused by the destruction of the talocalcaneal ligament;
         - it is difficult to perform closed reduction of the dorsal and supination deformity;
    - if closed reduction is possible then 8-12 weeks is necessary for healing (trabeculation across the fracture site);
    - ORIF is needed if there is more than 3-5 mm of dorsal displacement and any rotational deformity;
    - AVN: 30%

- Type III Talar Fractures:
    - displaced frx of talar neck w/ dislocation of body of talus from both subtalar joint and the ankle joint;
    - when body dislocates, it is usually found on posterior medial aspect  adjacent to the Achilles tendon;
    - in this location, there can be compression of neurovascular structures, & care must be taken when approaching by open means dislocated body of the talus;
    - talocalcaneal ligament is ruptured when there is dorsal displacement of the distal fragment;
          - after rupture of this ligament, it is difficult to control distal talar neck fracture by closed means;
    - requires ORIF:
          - retrograde K wires can be placed thru frx & out post-lateral aspect;
          - cannulated screws can be used thru the posterior-lateral aspect using the wires;
    - AVN: 90%

- Type IV:
    - subtalar, tibiotalar, and talonavicular joint subluxation or dislocation (see subtalar dislocation);
    - talar neck fracture w/ dislocation of the head fragment;
    - open type IV fractures are associated w/ high rate of infection (30%), despite aggressive debridement and infection;
    - salvage treatment:  
           - consider placement of methylmethacrylate spacer shaped like a talus;
           - there are documented cases of patients being pain free for several years with this method of treatment;



- Hawkins Sign:
    - appearance of decreased subchondral bone density in the dome of talus 6 to 8 weeks following injury indicates that there is sufficient vascular supply to bone to allow normal disuse osteopenia to occur;
    - resorption of subchondral bone is a consequence of disuse osteoporosis and suggests that the bone segment has adequate circulation, and that normal healing is occuring



Fractures of the neck of the talus. 

A new look at the hawkins classification for talar neck fractures: which features of injury and treatment are predictive of osteonecrosis?




Original Text by Clifford R. Wheeless, III, MD.

Last updated by Data Trace Staff on Monday, February 10, 2014 11:39 am