Superior Articular Process Of Axis, Posterior View

Description

Axis (C2) superior articular process appears in posterior view as a paired bony prominence projecting superolaterally from the vertebral arch, bearing the superior articular facet that will meet the inferior articular facet of the atlas (C1). The facets sit lateral to the base of the dens and medial to the transverse processes, with the laminae converging toward the midline spinous process inferiorly and posteriorly. From this fixed posterior perspective, the relationship between the superior articular facets, the pedicles, and the posterior margin of the vertebral foramen is apparent, helping orient the viewer to the atlantoaxial region without distraction from anterior elements. Atlantoaxial mechanics concentrate load across these facets, so small changes in facet congruity matter clinically. Degenerative cervical spondylosis and inflammatory arthropathy, including rheumatoid arthritis, can alter the superior articular facet surfaces and contribute to atlantoaxial instability, with risk to the upper cervical spinal cord at the C1 to C2 level. Surgical planning for C2 instrumentation also depends on recognizing how the superior articular process relates to the pedicle and lateral mass, since screw trajectories must respect the nearby vertebral artery course within the transverse foramen laterally. Landmarks are unforgiving. Use this illustration for teaching osteology and upper cervical joint anatomy in gross anatomy and orthopedic or neurosurgical spine modules, and for atlas figures discussing C1 to C2 facet arthrosis, atlantoaxial subluxation, or posterior C2 fixation concepts. It also fits radiology education when correlating bony landmarks with CT bone windows of the cervical spine. Anatomical accuracy verified by SciePro's Medical Advisory Board.