T12 vertebra

Last reviewed 01/2018

The twelfth thoracic vertebra is an atypical thoracic vertebrae in that:

  • body has a single, oval costal facet sited more posteroinferiorly to those above, at the lateral junction of pedicle with body
  • inferior articular process:
    • articulating surface is convex
    • plane of surface still predominantly lies anteriorly, but is tilted more laterally
  • transverse process is replaced by:
    • lateral tubercle projecting posteroinferiorly; equivalent to transverse process of superior vertebrae
    • superior tubercle projecting posterosuperiorly; equivalent to mamillary process of lumbar vertebrae
    • inferior tubercle projecting posteroinferiorly; equivalent to accessory process of lumbar vertebrae