This is a synovial pivot joint. There are 2 laterally located facet joints where the inferior facets of the atlas are almost planar and the superior articular processes of the axis are also only gently curved to allow sliding within the joint capsules during rotation. There is a small amount of curvature to make the articulation convex on convex. There is a small amount of caudal head movement with rotation and rostral motion with return to neutral. The transverse atlantal ligament is necessary for maintenance of joint integrity.
Motion is primarily around a vertical axis.
These are atypical synovial joints and assist in limiting lateral bending and flexion of the cervical spine. The WB often stimulate posterolateral osteophyte formation then encroaches in the intervertebral foramna and spinal Nn. Plane synovial joints between the articular facets of adjacent vertebrae. C7-T3 represent a transitional region where all ranges are diminished. It runs from the sacrum to C2.