Axis Bone's Inferior Articular Facet, Inferior View

Description

Axis (C2) is presented from an inferior perspective with emphasis on the inferior articular facet and the adjacent pars interarticularis, the bony bridge between the superior and inferior articular processes at the junction of the pedicle and lamina. The inferior articular facet lies posterolateral to the vertebral body and faces inferiorly to meet the superior articular facet of C3, forming the C2 to C3 zygapophyseal joint. Medial to the facet, the vertebral foramen and laminar margins frame the posterior elements, while the transverse processes extend laterally from the vertebral arch. Orientation is unambiguous. This view matters when teaching or planning around C2 posterior element injuries and fixation, because the pars interarticularis is the common fracture line in traumatic spondylolisthesis of the axis (Hangman fracture) and directly relates to the geometry of the inferior articular process. By holding the viewpoint under the vertebra, the illustration clarifies the articular surface contour and its relationship to the pars and neural arch, a relationship that can be harder to communicate using only lateral radiographs or axial CT slices. The facet’s inferior slope also helps explain how extension and axial loading can translate forces across the C2 to C3 joint in high-energy trauma. Use this illustration in gross anatomy and osteology labs to teach cervical zygapophyseal joint orientation, in spine surgery atlases when discussing posterior C2 instrumentation trajectories near the pars, and in radiology teaching files to correlate fracture patterns seen on CT with the underlying bony landmarks. It also supports patient-education graphics for cervical facet arthropathy and post-traumatic instability at the C2 to C3 level. Anatomical accuracy verified by SciePro's Medical Advisory Board.