Os Odontoideum: Rare Cervical Lesion

We report the case of a 22-year-old Marine who presented to the emergency department, after a martial arts exercise, with transient weakness and numbness in all extremities. Computed tomography cervical spine radiographs revealed os odontoideum. Lateral flexion-extension radiographs identified atlanto-axillary instability. This abnormality is rare and can be career ending for military members who do not undergo surgical fusion.