Atlantooccipital Joint

articulatio atlantooccipitalis

The atlantooccipital joint allows the nodding yes movement of the head on the atlas, providing approximately 15 degrees of flexion and extension at the craniocervical junction. The occipital condyles rest in the superior atlas facets, stabilised by the anterior and posterior atlantooccipital membranes and the joint capsule. Craniocervical instability at this level from ligamentous disruption is a serious condition associated with high cervical cord injury risk.

Region: Neck

Clinical Relevance

Clinical Notes

Occipital condyle fractures from high-energy trauma are increasingly detected on CT scans of the craniocervical junction and are classified by Anderson and Montesano into three types. Craniocervical dissociation from ligamentous disruption is a highly lethal injury that can be missed on initial lateral cervical radiographs but is identified on CT by the basion-dens and powers ratio measurements. Greater occipital nerve irritation from atlantooccipital joint dysfunction is a cause of cervicogenic headache.

Pathology

Common Injuries & Conditions

Occipital Condyle Fracture

High-energy craniocervical junction fracture detected on CT, managed with rigid collar for stable fractures and halo or surgical stabilisation for ligamentous disruption.