| Classification | Description | Notes |
| Type 1 | Comminuted, impacted | |
| Type 2 | Extension of skull fracture | |
| Type 3 | Avulsion of alar ligament | unstable |
References
Dreizin, D., et al. (2014). “Multidetector CT of blunt cervical spine trauma in adults.” Radiographics 34(7): 1842-1865.
Anderson, P. A. and P. X. Montesano (1988). “Morphology and treatment of occipital condyle fractures.” Spine 13(7): 731-736.