Costal Facets of the Vertebrae

Description

Shown are two stacked thoracic vertebrae from an adult male spine, separated by an intervertebral disc and aligned along the vertebral bodies anteriorly with the vertebral arches and spinous processes posteriorly. Along the lateral margins of each vertebral body, the superior and inferior costal demifacets (foveae costales superiores et inferiores) are identified as paired, blue-highlighted articular surfaces that face laterally to receive the head of a rib. Posterolaterally, the superior and inferior articular processes form the zygapophysial joints, while the pedicles and laminae bridge the body to the posterior elements. Costal facets matter because they define the rib-bearing character of the thoracic spine and constrain motion in a way the cervical and lumbar regions do not, coupling spinal rotation with rib movement during respiration. Subtle variation in demifacet size, orientation, or marginal osteophytes can alter costovertebral joint congruence and contribute to focal thoracic pain or limited chest wall excursion, a pattern clinicians often see with degenerative costovertebral arthropathy or after rib fractures. Clear separation of the costal demifacets from the zygapophyseal facets prevents common teaching errors when correlating anatomy to CT or MRI. Use this illustration for thoracic spine modules in gross anatomy and osteology courses, for radiology teaching files that compare osseous landmarks on axial CT, and for spine or thoracic surgery texts discussing costovertebral joint anatomy in posterior approaches. It also suits patient-facing education on why thoracic discs and facet joints behave differently from the lumbar region. Anatomical accuracy verified by SciePro's Medical Advisory Board.