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Hawkins classification I–IV based on displacement/dislocation. AVN risk increases with stage: I <10%, II ~40%, III ~90%, IV >90%. Urgent reduction and fixation critical to preserve talar blood supply. Fixation: screws/plates, often dual incision approach. Hawkins sign (subchondral lucency) = revascularization on X-ray at 6–8 weeks.
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Talar neck fractures are serious injuries involving the neck of the talus and are associated with a high risk of complications, particularly avascular necrosis (AVN) of the talar body. Although relatively uncommon, these fractures are clinically significant because the talus plays a critical role in ankle and subtalar joint function.
The talus has a unique blood supply and is largely covered by articular cartilage, leaving limited areas for vascular penetration. Disruption of this vascular supply following talar neck fractures can lead to AVN and subsequent collapse of the talar dome.
The Hawkins classification system is widely used to categorize talar neck fractures and predict the risk of avascular necrosis. Early diagnosis and appropriate surgical management are essential to restore joint congruity and minimize long-term complications.
The talus is a unique bone in the foot that transmits body weight from the tibia to the foot. It articulates with multiple bones and forms important joints of the hindfoot.
Because approximately 60% of the talus is covered with articular cartilage, its blood supply is relatively limited and vulnerable to injury.
The blood supply of the talus is derived from branches of the posterior tibial, anterior tibial, and perforating peroneal arteries.
| Artery | Area Supplied |
|---|---|
| Posterior tibial artery | Major supply to talar body |
| Anterior tibial artery | Supplies talar neck and head |
| Perforating peroneal artery | Contributes to lateral supply |
Disruption of these vascular channels during talar neck fractures explains the high risk of avascular necrosis.
Talar neck fractures usually occur following high-energy trauma. The typical mechanism is forced dorsiflexion of the ankle, which drives the talar neck against the anterior tibial plafond.
The Hawkins classification categorizes talar neck fractures based on displacement and associated joint dislocations. The classification also correlates with the risk of avascular necrosis.
| Type | Description | Risk of AVN |
|---|---|---|
| Type I | Nondisplaced fracture | Low risk |
| Type II | Subtalar dislocation | Moderate risk |
| Type III | Subtalar and tibiotalar dislocation | High risk |
| Type IV | Subtalar, ankle, and talonavicular dislocation | Very high risk |
Because of the high-energy mechanism, associated injuries to the foot, ankle, or spine may also be present.
CT scanning is particularly helpful in evaluating fracture displacement and planning surgical treatment.
Management depends on fracture displacement and associated dislocations.
| Treatment | Indication |
|---|---|
| Immobilization | Nondisplaced fractures |
| Closed reduction | Dislocated fractures |
| ORIF | Displaced fractures |
The Hawkins sign is a radiographic sign that appears approximately 6–8 weeks after injury. It represents subchondral lucency in the talar dome due to bone resorption and indicates preserved blood supply.
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