A Jefferson fracture consists of a fracture of the C1 ring. This results from an axial loading injury to the head with compression force to C1 (typically from diving). The fracture consists of unilateral or bilateral fractures of the anterior and posterior arches of C1. This is an unstable injury. Other burst type fractures are possible in the spine. These also result from axial loading injuries (compression) and result in severe comminution of a vertebral body. Posterior element displacement into the spinal canal is common.

A	Lateral view of the cervical spine. The patient is severely osteopenic. Nevertheless, there is irregularity of the neural arches at the C1 level.
B	Axial CT. This demonstrates the fracture of the anterior arch of C1.
C	Axial CT. The image shows the fracture of the posterior arch of C1.
D	Axial CT. This image depicts the severe fracture of the anterior arch of C1.

Links to online textbooks:

• Wheeless' Orthopedics: discussion of Jefferson fractures

Links to online cases:

• University of Hawaii
• Emedicine.com
• University of Iowa

References:

• Guiot B, Fessler RG: Complex atlantoaxial fractures J Neurosurg. 1999 Oct;91(2 Suppl):139-43.           [See related articles]
• Kesterson L, Benzel E, Orrison W, Coleman J: Evaluation and treatment of atlas burst fractures (Jefferson fractures) J Neurosurg. 1991 Aug;75(2):213-20.           [See related articles]