What is a Jefferson fracture?

A Jefferson fracture specifically refers to a fracture of the C1 vertebra, also known as the atlas, caused by an axial load to the head. This type of injury typically occurs from a vertical impact, such as a fall from a height or a diving accident, where the force is transmitted directly down through the skull to the cervical spine.

The mechanism behind this injury creates fractures that can present as disruptions of the ring-like structure of the atlas, often manifesting as bilateral fractures of the anterior and posterior arches. The critical nature of this injury lies in the potential for spinal cord injury and the instability it can cause, which distinguishes it from other cervical spine injuries.

In contrast, a C2 fracture of the pars articularis refers to a Hangman's fracture, which involves a different mechanism and location. Moreover, while some cervical spine injuries can be stable, a Jefferson fracture is considered unstable due to the axial load forces involved. A fracture involving the body of the odontoid pertains to a different structure (the Dens), which is involved in another type of injury and not specific to the Jefferson fracture.