What type of fracture is a Jefferson fracture?

A Jefferson fracture refers specifically to a type of fracture that occurs at the first cervical vertebra, known as C1 or the atlas. This injury is characterized by a comminuted fracture, which means the bone is broken into several pieces. Jefferson fractures typically result from axial loading, such as a diving injury, where there is a significant force applied vertically down onto the skull, causing the ring of the atlas to split.

Understanding the anatomy involved is crucial; C1 is the vertebra that supports the skull and allows for nodding movements of the head. A comminuted fracture of this area can have serious implications because it risks damaging the spinal cord and can lead to instability in the cervical spine.

The other options describe different types of fractures that occur in different locations or mechanisms of injury, which do not align with the defining characteristics of a Jefferson fracture.