Anatomic and radiographic study of the rib head associated with spinal canal and vertebral body in adult

English Keywords:Rib head  Thoracic vertebrae  Anatomy  Video assisted thoracoscopic surgery,（VATS） Rodiology

English Abstract:

  【Abstract】　Objective：To investigate the anatomic and radiographic relationship between rib head and spinal canal or vertebral body in normal adult.Method：Ten normal adult cadavers（anatomic group，A） underwent thoracic CT scan.The rib head with respect to the spinal canal and vertebral body，and the ratio of vertebral body covered by rib head（defined by ratio of distance from bilateral anterior rib head to anterior wall of spine canal on the distance from anterior part of vertebra body to anterior wall of spine canal），and the orientation angle when placing anterior screw were measured.CT scan on 30 healthy adults（radiographic group，Ｂ）　was performed.The above-mentioned parameters were measured and compared with group A.Result：The ratio of vertebral body covered by rib head decreased significantly from T4 to T12.The rib head was sited more anteriorly with respect to the more cephalad vertebral body，while more posteriorly with respect to the more caudal vertebral body.The anterior maximum safe angle increased significantly from T4（27°）　to T12（38.3°）　and the posterior safe angle decreased significantly from T4（23°）　to T12（-9°），however no significant difference between anatomical group and the radiographic group was noted.Conclusion：Preoperative CT scan can show the relationship between the rib head and vertebral body，which may guide screw placing under VATS.Removal of rib head when placing screws in upper thoracic vertebra and removal of anterior part of rib head in lower thoracic vertebra can promise accuracy of instrumentation.