Superior Articular Facet Of The Teh Human Axis, Superior View

Description

Axis (C2) anatomy is centered on the superior articular facets, paired surfaces on the superior aspect of the vertebral arch that sit posterolateral to the dens and frame the superior opening of the vertebral foramen. From this superior perspective, each facet is seen flanking the midline, with the laminae converging posteriorly into the bifid spinous process that projects inferiorly and posteriorly. Laterally, the superior articular regions blend into the pedicles and transverse processes, defining the boundaries of the spinal canal at the C2 level. Bone contours are crisp. Facet orientation at C2 matters because it defines the inferior half of the atlantoaxial zygapophysial articulation, a frequent pain generator in cervicogenic headache and a key restraint in rotational stability of the upper cervical spine. The same bony geography guides posterior instrumentation, where pars interarticularis or pedicle screw trajectories must respect the nearby vertebral artery in the transverse foramen and the medial margin of the spinal canal, and it also frames fracture patterns such as traumatic spondylolisthesis of the axis (Hangman fracture) involving the pars region. A superior, fixed viewpoint makes the joint surfaces, posterior elements, and canal margins easier to relate to each other than an oblique lateral-only look, which can hide the true breadth of the facet and the bifid split of the spinous process. Use this illustration in gross anatomy and musculoskeletal anatomy teaching to distinguish C2 from other cervical vertebrae, and in spine surgery or interventional pain publications to orient atlantoaxial joint injections, medial branch targets, and C1-C2 fusion planning. It also supports radiology teaching when correlating CT axial or reformatted images of the cervical spine with the superior articular facets and posterior arch morphology. Anatomical accuracy verified by SciePro's Medical Advisory Board.