Inferior Articular Surface of the Axis, Anterior View

Description

Oriented from the anterior aspect, the axis (C2 vertebra) is presented to emphasize its inferior articular surface, where the paired inferior articular facets lie posterolateral to the vertebral body and angle to meet the superior articular facets of C3. The vertebral body sits centrally and anteriorly, while the transverse processes project laterally and the base of the spinous process occupies the posterior midline, partly obscured by the inferior elements in this projection. Facet cartilage planes are rendered as flat, smooth surfaces against the surrounding cancellous texture of the bone. Clear joint geometry. Attention to the C2 to C3 zygapophyseal alignment matters when you are teaching cervical kinematics and when you are thinking about where pain generators sit in axial neck pain. The inferior articular facets of C2 form the superior half of the C2 to C3 facet joints, a common target for diagnostic medial branch blocks and radiofrequency ablation when the C3 medial branch and third occipital nerve distribution are implicated. Orientation also frames why malalignment after trauma or degenerative facet arthropathy can restrict rotation and extension even when the atlanto-axial joint remains intact. Use this image in gross anatomy lab materials and spine modules to contrast the inferior articular facets of the axis with the superior facets of C3 and to reinforce the difference between uncovertebral and zygapophyseal joints in the cervical region. It also supports orthopedic and neurosurgical teaching on posterior cervical approaches, facet joint injections, and preoperative planning where accurate facet orientation guides screw trajectory discussions. Anatomical accuracy verified by SciePro's Medical Advisory Board.