Classification Description Notes
Type 1 Oblique fracture through the odontoid tip Stable
Type 2 Fracture through the base of the dens Unstable. Higher risk of nonunion with comminuted fracture, age > 50 or more than 5mm displacement
Type 3 Fracture through the body of C2 Will heal with immobilization, but may have residual spinal stenosis



Dreizin, D., et al. (2014). “Multidetector CT of blunt cervical spine trauma in adults.” Radiographics 34(7): 1842-1865.

Anderson LD, D’Alonzo RT. Fractures of the odontoid process of the axis. J Bone Joint Surg Am 1974;56(8):1663–1674.