Incidence
- Most common tarsal fracture.
- 10% are bilateral.
- 10% are open fractures.
- Up to 80% associated with other injuries:
- Spine injuries.
- Femoral neck fractures.
- Lower limb long bone fractures.
Anatomy
Ossification
- Two Ossification Centres:
- Anterior Centre: Visible at birth.
- Posterior Centre: Last in the foot to ossify (around age 8 years).
Facets
- Posterior Facet (largest).
- Medial Facet.
- Anterior Facet (often continuous with medial facet).
Sinus Tarsi
- Separates medial and posterior facets.
Sustentaculum Tali
- Cortical medial process supporting the talus.
Mechanism of Injury
- Axial Compression:
- Fall from height.
- Road traffic accidents (RTA).
Classification
Essex-Lopresti
- Pre-CT Classification:
- Primary Fracture Line:
- Created by the talus’ lateral process driving into the crucial angle of Gissane.
- Intra-articular involvement of the posterior facet.
- Runs posteromedial to anterolateral from proximal to distal.
- Sustentaculum Tali: Always attached to the distal fragment (constant fragment for fixation).
- Secondary Fracture Line Determines Type:
- Joint Depression Type:
- Line runs from the primary fracture line to just posterior to the posterior facet.
- Tongue Type:
- Line runs from the primary fracture line to the posterior tuberosity.
- Problems:
- Does not indicate prognosis.
- Limited guidance for management (except tongue type).
Sanders Classification
- CT-Based Classification (coronal CT at the sustentaculum tali level).
- Grades based on the number of displaced fracture lines in the posterior facet:
- Grade 1: Undisplaced (regardless of fracture lines).
- Grade 2 (A, B, C): 1 fracture line causing 2 displaced fragments.
- Grade 3 (A, B, C): 2 fracture lines causing 3 displaced fragments.
- Grade 4: 3+ fracture lines with multiple fragments.
- Subclassification (A, B, C):
- A: Lateral position.
- B: Middle position.
- C: Near the sustentaculum.
- Prognostic Notes:
- Increasing grade indicates more severity and worse prognosis.
Evaluation
Initial Steps
- ATLS Protocol: Address high incidence of associated injuries.
- Screen for compartment syndrome (rare).
- Splint, ICE, and elevate foot.
- Ensure no skin compromise (especially in tongue-type fractures).
Imaging
- X-Ray Views:
- AP.
- Lateral.
- Axial.
- Harris View:
- Foot dorsiflexed, beam angled 45° cephalad.
- Broden View:
- Multiple X-rays showing posterior facet in different positions.
- Key Angles:
- Bohler’s Angle:
- Formed by the highest points of the:
- Anterior process.
- Posterior facet.
- Tuberosity.
- Normal range: 20-40 degrees.
- Crucial Angle of Gissane:
- Formed by cortical struts joining the posterior and anterior facets.
- Normal range: 120-140 degrees.
Back to top