Soichiro Ota¹, Ken-ichi Muramatsu¹, Ikuto Takeuchi¹, Youichi Yanagawa^1,

A 75-year-old woman fell down after tripping over a step and suffered blunt face, neck and left shoulder injuries. On arrival, she had clear consciousness, tachycardia, tachypnea, posterior neck tenderness, left shoulder motion pain without motor or sensory disturbance at each extremity, and contused wounds at the forehead, nasion, upper lip, and left leg. Computed tomography (CT) showed congenital fusion of C3 and C4 (Klippel Feil syndrome) and separation of the dens body, which was initially diagnosed as acute dens fracture. Subsequent magnetic resonance imaging (MRI) showed dens body bruising and soft tissue injuries around the cervical spine. However, there was no sign of injury at the junction of the separated dens. She received a diagnosis of congenital os odontoideum without instability. She was treated with only a soft collar and pain killers and discharged on foot on day 10. To manage a patient with os odontoideum and blunt neck trauma, MRI is necessary to make a correct diagnosis, identify associated injuries and provide appropriate treatment.

os odontoideum, Klippel Feil syndrome, magnetic resonance image