FIFTEEN PERCENT OF cervical spine fractures involve the odontoid proce
ss. Most odontoid fractures can be classified as Types I through III a
ccording to the scheme developed by Anderson and D'Alonzo. We report a
case of a vertically oriented fracture through the odontoid process t
hat does not fit into any of these categories. Only two such cases hav
e been described in the literature. Our patient is an 18-year-old man
who sustained an axial loading injury to his cervical spine. Plain lat
eral cervical tomography and computed tomography were performed to cha
racterize the fracture and to evaluate the instability. The patient wa
s placed in a rigid orthosis for 12 weeks, and at 6-month follow-up, h
e had full range of motion and showed no evidence of abnormal movement
, as revealed by flexion-extension studies. This case demonstrates the
shortcomings of the current classification system for odontoid fractu
res and the value of plain tomography and computed tomography in evalu
ating odontoid fractures.