Oshina Masahito, Horii Chiaki, Hirai Shima, Matsubayashi Yoshitaka, Taniguchi Yuki, Hayashi Naoto, Tanaka Sakae, Oshima Yasushi
Departments of Orthopedic Surgery.
Computational Diagnostic Radiology and Preventive Medicine, The University of Tokyo Hospital, Tokyo, Japan.
Clin Spine Surg. 2018 Aug;31(7):E357-E362. doi: 10.1097/BSD.0000000000000663.
Anatomic study using computed tomographic scans.
The purpose of this paper was to determine the trajectory of pedicle screw insertions, in regard to posterior bony landmarks encountered during standard posterior exposure of the spine between the seventh cervical (C7) and the fifth thoracic (T5) vertebrae, when lateral fluoroscopic and radiographic guidance may be obstructed by the scapula and shoulders.
Only a few studies have evaluated the intraoperative sagittal trajectory of pedicle screw insertion.
We assessed 64 participants of a health screening program using whole-spine computed tomographic scans. On the basis of 5 previously reported methods, we designed 3 freehand trajectories: lamina surface method (angle between the superior vertebral endplate and the surface of the lamina), spinous process method (angle between the superior vertebral endplate and a line connecting the tips of the index spinous process and the one cephalad to it), and facet tilt method (angle between the superior endplate and the superior facet tilt). We calculated each of the angles for the C7-T5 vertebrae and determined the most reliable method using coefficients of variation (CV) and intraobserver and interobserver reliability.
The lamina surface method had the smallest CVs for C7 and T1, and the mean angles were larger than 90 degrees (range, 94.7-102.4 degrees). The spinous process method had the smallest CVs between T2 and T5, and the mean angles were <90 degrees (range, 85.0-87.0 degrees). The intraobserver and interobserver reliabilities were good or excellent for both methods.
The ideal sagittal trajectories for pedicle screw insertion are nearly orthogonal to the lamina surface or the line connecting the spinous processes, but were different for each of the vertebrae. The lamina surface method was the most reliable for C7 and T1, whereas the spinous process method was most reliable between T2 and T5.
Level III.
使用计算机断层扫描进行解剖学研究。
本文旨在确定在第七颈椎（C7）至第五胸椎（T5）椎体之间进行标准脊柱后路暴露时，当侧位透视和放射成像引导可能被肩胛骨和肩部遮挡时，椎弓根螺钉置入的轨迹。
仅有少数研究评估了椎弓根螺钉置入术中矢状面轨迹。
我们使用全脊柱计算机断层扫描评估了64名健康筛查项目参与者。基于先前报道的5种方法，我们设计了3种徒手轨迹：椎板表面法（上位椎体终板与椎板表面之间的角度）、棘突法（上位椎体终板与连接食指棘突尖端及其上方一个棘突尖端的直线之间的角度）和关节突倾斜法（上位终板与上位关节突倾斜之间的角度）。我们计算了C7 - T5椎体的每个角度，并使用变异系数（CV）以及观察者内和观察者间可靠性确定了最可靠的方法。
椎板表面法在C7和T1的CV最小，平均角度大于90度（范围为94.7 - 102.4度）。棘突法在T2至T5之间的CV最小，平均角度小于90度（范围为85.0 - 87.0度）。两种方法的观察者内和观察者间可靠性均良好或优秀。
椎弓根螺钉置入的理想矢状面轨迹几乎与椎板表面或连接棘突的直线正交，但每个椎体有所不同。椎板表面法对C7和T1最可靠，而棘突法在T2至T5之间最可靠。
三级。
