Superior Articular Process Of The Lumbar Vertebra, Anatomy

Description

Lumbar vertebrae present a stout superior articular process rising from the junction of the pedicle and lamina, capped by the superior articular facet that faces posteromedially toward the matching inferior facet of the vertebra above. From an oblique posterior perspective, the process sits medial to the transverse process and lateral to the base of the spinous process, with the lamina forming its posterior buttress. The pars interarticularis lies inferior to the facet, bridging toward the inferior articular process and completing the posterior elements around the vertebral foramen. Facet anatomy matters in the low back because the zygapophyseal joint is a frequent generator of axial pain, and degenerative hypertrophy of the superior articular process can narrow the lateral recess or contribute to foraminal stenosis at levels such as L4 to L5 and L5 to S1. Orientation is the story here, lumbar facets are more sagittally aligned than thoracic facets, limiting rotation while permitting flexion and extension, and that relationship becomes easy to teach when the articular surface, the pars, and the adjacent lamina are all visible in one frame. Small bony details, including the contour of the articular cartilage bearing surface and the sharp transition to cortical bone, support accurate labeling for anatomy and radiology correlation. Use this illustration for spine modules in gross anatomy, orthopedics, and physical therapy curricula, or as a figure in publications covering facet arthropathy, medial branch blocks, radiofrequency ablation targets, and decompression planning near the superior articular process. It also fits surgical orientation guides discussing lumbar facet joint access and the pars interarticularis as a landmark in spondylolysis. Anatomical accuracy verified by SciePro's Medical Advisory Board.