Surgical Anatomy of the Thoracic Pedicle

PURPOSE: To evaluate the surgical anatomy of the thoracic spine to determine if pedicle screw placement can be safely performed.

METHODS: 231 thoracic pedicles from human cadaveric vertebrae were examined. Pedicle heights and widths were measured. Angles of the pedicles to the vertebral bodies in sagittal and coronal planes were measured.

RESULTS: Pedicle height increased significantly at caudal levels, P<0.001. Pedicle width varied significantly, P<0.05. Medial angulations of the pedicles in the coronal plane demonstrated marked variations, but angulation of the pedicles in the sagittal plane was less variable.

CONCLUSIONS: The rate limiting factor to screw placement is pedicle width. Screw placements in T1-T2 and T7-T12 are usually reasonable options. Safe pedicle screw placement in T3-T6 should be evaluated on an individual case-by-case basis.