T9 or Ninth Thoracic Vertebra, Lateral View

Description

Seen in lateral profile, the ninth thoracic vertebra (T9) presents its vertebral body anteriorly, with the pedicle and lamina forming the vertebral arch posterior to it and enclosing the vertebral foramen. A long, inferiorly sloping spinous process projects posteriorly, while the transverse process extends laterally and carries the transverse costal facet, shown as a smaller articular surface than in upper thoracic levels. Blue-highlighted articular cartilage marks the superior and inferior zygapophyseal facets on the articular processes, positioned posterolaterally to the vertebral body and oriented to favor thoracic rotation while limiting flexion and extension. Rib articulations matter here. T9 is a useful landmark at the thoracolumbar junction for teaching how rib-bearing vertebrae transition toward lumbar morphology, including the changing size and prominence of costal facets and the gradual shift in facet joint orientation. That transverse process facet corresponds to the tubercle of the ninth rib in the costotransverse joint, a relationship surgeons and radiologists reference when localizing thoracic levels for procedures such as thoracic epidural placement, paravertebral blocks, or operative planning around the posterior elements. Degenerative facet arthropathy and osteophyte formation at this level can narrow the intervertebral foramen and contribute to thoracic radicular pain patterns that are easily confused with visceral causes. Use this illustration in gross anatomy and musculoskeletal courses to contrast typical thoracic vertebrae with cervical and lumbar patterns, and in spine surgery or anesthesia materials to anchor level identification by posterior bony landmarks and rib articulation points. It also suits textbooks and CME modules discussing thoracic spondylosis, costovertebral joint mechanics, and approach corridors that respect the transverse process and facet complex. Anatomical accuracy verified by SciePro's Medical Advisory Board.