Imaging of the Cervical Spine > Fractures > Jefferson Fracture

Jefferson Fracture

Description: compression fracture of the bony ring of vertebra C1, characterized by lateral masses splitting and transverse ligament tear.

Mechanism: axial blow to the vertex of the head (e.g. diving injury).

Radiographic features: the key radiographic view is the AP open mouth, which shows displacement of the lateral masses of vertebrae C1 beyond the margins of the body of vertebra C2. A lateral displacement of >2 mm or unilateral displacement may be indicative of a C1 fracture. CT is required to define the extent of fracture and to detect fragments in the spinal canal.

Stability: unstable

In the above odontoid view, the lateral displacement of C1 indicates a Jefferson fracture.