What mechanism commonly causes a burst fracture of the cervical spine?

• A. Hyperflexion causing posterior tension
• B. Lateral bending
• C. Rotation
• D. Axial loading causing ring fracture with retropulsion of fragments into canal

Answer: (D)

Burst fractures come from a high-energy axial (vertical) compressive load that drives the vertebral body to fail as a ring. The body fractures into multiple pieces, and some of those bone fragments are forced backward into the spinal canal (retropulsion). That posteriorly displaced material can compress the spinal cord or nerve roots, which is the hallmark of a burst injury in the cervical spine.

Other mechanisms produce different injury patterns—for example, flexion injuries tend to stress the anterior column with posterior tension, lateral bending causes side-to-side loading and possible facet injury, and rotation produces rotational instability or facet fractures. But the defining feature of a cervical burst fracture is axial loading with ring failure and retropulsion into the canal.