Superior Articular Facet Of The Axis, Anatomy

Description

Axis (C2) anatomy is centered on the superior articular facet and the stout pedicle that bridges the vertebral body (centrum) to the posterior arch. The superior articular process rises from the junction of the pedicle and lamina, with its smooth facet positioned posterolateral to the dens and oriented to receive the inferior articular facet of the atlas (C1) at the lateral atlantoaxial joint. Medial to the facet, the vertebral canal is bounded by the pedicle anteriorly and the lamina posteriorly, while laterally the pedicle transitions toward the transverse process and the foramen transversarium for the vertebral artery. Bony contours are the point. Clinical relevance is strongest at the C2 pars interarticularis and pedicle, where hangman’s fracture (traumatic spondylolisthesis of the axis) classically propagates through the neural arch near the superior articular facets, risking C2–C3 instability even when the spinal cord is initially spared by canal widening. The fixed perspective emphasizes the relationship between the superior facet, pedicle, and posterior arch, a relationship surgeons reference when planning C2 pedicle screws, pars screws, or translaminar fixation while respecting the vertebral artery laterally and the spinal canal medially. Joint surface orientation is also a teaching anchor for understanding atlantoaxial rotation and the mechanics of C1–C2 arthropathy. Use this illustration in gross anatomy and spine surgery teaching files when explaining the C2 superior articular facet, pedicle, and posterior arch landmarks, or in radiology and orthopedic texts correlating CT bony windows with operative corridors for posterior cervical fixation. It also suits patient-facing materials on C2 fractures when you need accurate bony geometry without soft-tissue distraction. Anatomical accuracy verified by SciePro's Medical Advisory Board.