Posterior atlantoaxial dislocation without associated fracture.

ABSTRACT

We report on a 38-year-old man with post-traumatic posterior displacement of the atlas with respect to the axis without any associated fracture or neurological deficit caused by the displacement. Radiographs, computed tomography (CT) and magnetic resonance imaging (MRI) revealed posterior displacement of the atlas with the odontoid peg lying anterior and to the right of the anterior arch of the atlas.