Ebraheim N A, Xu R, Darwich M, Yeasting R A
Department of Orthopaedic Surgery, Medical College of Ohio, Toledo, USA.
Spine (Phila Pa 1976). 1997 Oct 15;22(20):2338-41. doi: 10.1097/00007632-199710150-00003.
The authors analyzed anatomic parameters between the lumbar pedicles and the dural sac as well as the spinal nerve roots.
To determine quantitatively the anatomic relations between the lumbar pedicle and adjacent dural sac and nerve roots.
Posterior transpedicular screw fixation is the most commonly used method of instrumentation for stabilization of the unstable lumbar spine. A thorough knowledge of the unique anatomy of the lumbar pedicle and adjacent neural structures may avoid or minimize neurologic complications with pedicular screw placement.
Fifteen adult cadavers were obtained to evaluate quantitatively the anatomic relations of the lumbar pedicle to the adjacent neural structures. After removal of the laminas and facets, the lumbar pedicles, dural sac, and nerve roots were exposed. Direct measurements were taken from the pedicle to the dural sac medially, to the nerve roots superiorly and inferiorly, and between the pedicles. Also, the superoinferior diameter of the nerve root and the frontal angle of the nerve root were measured. Symmetric structures were measured bilaterally.
No consistent changes from L1 to L5 were found in all parameters. The mean distances from the lumbar pedicle to the dural sac medially and to the adjacent nerve roots superiorly and inferiorly for all levels were 1.5 mm, 5.3 mm, and 1.5 mm, respectively. The mean interpedicular distance ranged from 23.2 to 24.4 mm. The mean superoinferior diameter of the nerve root ranged from 3.8 to 4.6 mm. The mean nerve root angle ranged from 33.7 degrees to 39.2 degrees.
On the basis of this study, improper placement of the pedicle screw medially or caudally in the lumbar spine should be avoided.
作者分析了腰椎椎弓根与硬膜囊以及脊神经根之间的解剖学参数。
定量确定腰椎椎弓根与相邻硬膜囊及神经根之间的解剖关系。
后路经椎弓根螺钉固定是治疗不稳定腰椎最常用的器械固定方法。深入了解腰椎椎弓根及相邻神经结构的独特解剖学知识，可避免或减少椎弓根螺钉置入时的神经并发症。
获取15具成年尸体，定量评估腰椎椎弓根与相邻神经结构的解剖关系。去除椎板和关节突后，暴露腰椎椎弓根、硬膜囊和神经根。直接测量从椎弓根到内侧硬膜囊、到上方和下方神经根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。
所有参数从L1到L5均未发现一致的变化。各节段从腰椎椎弓根到内侧硬膜囊以及到上方和下方相邻神经根的平均距离分别为1.5毫米、5.3毫米和1.5毫米。平均椎弓根间距在23.2至24.4毫米之间。神经根的平均上下径在3.8至4.6毫米之间。神经根的平均角度在33.7度至39.2度之间。
基于本研究，应避免在腰椎内将椎弓根螺钉向内侧或尾侧不当置入。
