Talar Fracture Flashcards
Mechanism of injury
High-energy trauma such as fall from a height or RTCs.
Ankle is fored into dorsiflexion leading to talus pressing against tibial plafond and fracturing
Pathophysiology
Most talar fractures occur through the talar neck.
It can however also occur through the body, lateral process or posterior process.
The talus is reliant on extraosseous arterial supply which is highly susceptible to interupption.
This means that there is a high risk of avascular necrosis
Clinical features
Hx of high-impact trauma with immediate pain and swelling around ankle.
Inability to dorsiflex or plantarflex their ankle.
Examination findings
Clear deformity if the talus is dislocated
Swelling
Check if it is an open or closed fracture and see if the overlying skin is threatened (white, non-blanching and tethered)
Also assess distal neurovascular status
Dx
Ankle fractures
Pilon fractures
Ix
Plain X-ray both AP and lateral
Lateral films should be taken in dorsiflexion and plantarflexion in attempt to differentiate between types of fracture (Type I and Type II)
CT imaging should be done in complex injuries for pre-op planning.
Classification system used
Hawkins classification
Explain Hawkins classification
Aids in both management planning and can determine risk of avascular necrosis
Classifications in Hawkins
Type I - Undisplaced (0-15% risk of AVN)
Type II - Subtalar dislocation (20-50%)
Type III - Subtalar and tibiotalar dislocation (90-100%)
Type IV - Subtalar, tibiotalar and talonavicular dislocation (100%)
What is management dependent on?
Hawkins classification
How should all undisplaced fractures be managed?
Conservatively in a non-weight bearing orthosis
How should all displaced fractures be managed?
Require immediate reduction in the ED and then surgical repair
Management of type I fractures
Conservatively in a plaster with non-weight bearing crutches for approx 3 months.
Assessment should be done for evidence of union and avascular necrosis in fracture clinic as follow up.
Management of Type II to IV fractures
Initially with attempted closed reduction in the ED.
Once reduced put a cast on and repeat X-ray + neurovascular assessment.
Definitive surgical fixation is required.
Post-op patients will require and extended period of non-weight bearing.
Complications
Avascular necrosis
OA secondary to avascular necrosis or malunion.
Arthrodesis might be considered if severe OA
What is Hawkins sign?
Sunchondral lucency of the talar dome that is visible 6-8 weeks following injury on AP view.
This is indicative of sufficient vascularity of the talus and therefore suggest low risk of AVN.
