Ebraheim N A, Jabaly G, Xu R, Yeasting R A
Department of Orthopaedic Surgery, Medical College of Ohio, Toledo, USA.
Spine (Phila Pa 1976). 1997 Jul 15;22(14):1553-6; discussion 1557. doi: 10.1097/00007632-199707150-00002.
This study analyzed anatomic parameters between the thoracic pedicles and the spinal nerve roots.
To quantitatively determine the anatomic relations of the thoracic pedicle to the adjacent neural structures.
Pedicular screw placement carries with it potential hazard to the surrounding neural structures, especially in the thoracic spine. No studies exist regarding the anatomic relations of the thoracic pedicle to the adjacent nerve roots.
Fifteen cadavers were obtained for study of the thoracic spine. All soft tissue was dissected off the thoracic spine. Laminectomy and total removal of the superior and inferior articular facets was then performed on C7-T1 through T12-L1 to expose the pedicles, nerve roots, and dura. Measurements were taken from the pedicle to the nerve root superiorly and inferiorly as well as between the pedicles. Also, the superoinferior diameter of the nerve root and the frontal angle of the nerve root were measured. Symmetrical structures were measured bilaterally.
The results showed that no epidural space could be found between the dural sac and the pedicle in all 15 cadavers. The average distances from the thoracic pedicle to the adjacent nerve roots superiorly or inferiorly at all levels ranged from 1.9 to 3.9 mm and from 1.7 to 2.8 mm, with a minimum of 1.3 mm, respectively. The interpedicular distance increased from T1 (13.8 mm) to T3, slightly decreased in T4-T5, then gradually increased to T12 (16.6 mm). The superoinferior diameter of the nerve root increased consistently from 2.9 mm at T1 to 4.6 mm at T11. The frontal nerve root angle decreased consistently from T1 (120.1 degrees) to T12 (57.1 degrees), except at T4-T5.
This study suggested that more care be taken into consideration in placing a transpedicular screw in the transverse plane than in placing a screw in the sagittal plane in the thoracic spine.
本研究分析了胸椎椎弓根与脊神经根之间的解剖学参数。
定量确定胸椎椎弓根与相邻神经结构的解剖关系。
椎弓根螺钉置入对周围神经结构存在潜在风险，尤其是在胸椎。目前尚无关于胸椎椎弓根与相邻神经根解剖关系的研究。
获取15具尸体用于胸椎研究。将所有软组织从胸椎上剥离。然后对C7-T1至T12-L1进行椎板切除术并完全切除上下关节突，以暴露椎弓根、神经根和硬脑膜。测量从椎弓根到神经根的上下距离以及椎弓根之间的距离。此外，还测量了神经根的上下径和神经根的额角。对双侧对称结构进行测量。
结果显示，在所有15具尸体中，硬脊膜囊与椎弓根之间均未发现硬膜外间隙。各节段胸椎椎弓根到相邻神经根的平均上下距离分别为1.9至3.9毫米和1.7至2.8毫米，最小值分别为1.3毫米。椎弓根间距从T1（13.8毫米）增加到T3，在T4-T5略有下降，然后逐渐增加到T12（16.6毫米）。神经根的上下径从T1的2.9毫米持续增加到T11的4.6毫米。神经根额角从T1（120.1度）持续下降到T12（57.1度），T4-T5除外。
本研究表明，在胸椎置入椎弓根螺钉时，在横平面上比在矢状平面上放置螺钉时应更加谨慎。
