3D Models Related Images

The Axis

Surgical Correlation


The axis is distinguished by the odontoid process (dens). On the front of the dens is an articular facet that forms a joint with the facet on the back of the anterior arch of the atlas. The dens is grooved at the base of its posterior surface where the transverse ligament of the atlas passes. The oval superior articular facets articulate with the inferior facets of the atlas. The superior facets are anterior to the inferior facets. The pedicles and laminae are thicker than on the other cervical vertebra and the lamina fuse behind to form a large spinous process. The transverse foramina are directed superolaterally, thus permitting the lateral deviation of the vertebral arteries as they pass up to the more widely separated transverse foramina in the atlas. The inferior articular facets face downward and forward. E, Anterior view. F, Lateral view. G, Superior view. H, Inferior view. (Images courtesy of AL Rhoton, Jr.)