Jefferson fracture: burst fracture of C1 with lateral mass displacement

A Jefferson fracture is an unstable burst fracture of the atlas (C1) characterized by bilateral disruption of the anterior and posterior arches and outward displacement of the lateral masses on open-mouth odontoid radiographs.

• Teaching/educational content describing the classic radiographic findings and mechanism of Jefferson fractures on LearningRadiology.
• Key imaging hallmark: bilateral offset of C1 lateral masses relative to C2 on open-mouth odontoid view; transverse ligament integrity determines stability.

RadPigeon summaries are original and for information only. They are not clinical advice.