经皮枢椎椎弓根螺钉内固定的影像学研究

目的根据枢椎椎弓根影像学测量数据探讨实施经皮穿刺枢椎椎弓根螺钉内固定的可行性与安全性。方法测量40名正常成人中立位寰枢椎二维CT水平位及矢状位断层图像上枢椎椎弓根螺钉经皮置人的标准角度及置钉角度的安全范围，皮肤穿刺点与水平位上颈后中线距离和矢状位上枢椎基底前缘顶点皮肤投影点的标准距离及其安全范围等影像学参数。结果（1）水平位枢椎椎弓根螺钉置钉的标准角度为42．34±2．95度．其安全范围为13．68±2．17度；（2）矢状位上椎弓根螺钉置钉的标准角度为27．94±3．98度，安全范围为19．39±2．19度；（3）水平位上皮肤穿刺点与颈后中线标准距离为57．39±7．47mm．安全范围为19．46±3．48mm；（4）矢状位上皮肤穿刺点与枢椎基底前缘顶点皮肤投影点的标准距离为36．50±4．62mm．其安全范围为37．35±4．96mm。结论枢椎椎弓根螺钉经皮置人的标准角度及距离个体差异较大，但在水平面和矢状面上均有一定的安全范围．该手术在充分考虑个体差异情况下具有一定安全性和可操作性。

Radiographic study of percutaneous transpedicular lag screw internal fixation

Objectives To study the feasibility and safety of the placement of percutaneous transpedicular lag screw internal fixation by the radiographic measurement data of pedicle of axis. Methods The horizontal and sagittal section of two-dimensional CT of axis pedicle in neutral position were performed in 40 cases with normal morphology of atlases and axes, the regular angle and safe angle for the placement of screw into the axis pedicle, the regular and safe distance of the point on the skin for puncture to the central line of the posterior of neck ,and the regular and safe distance of the puncture point on the skin to the projection point of the front vertex of the basal of axes were evaluated radiologically. Results （1）On the horizontal imagine of CT, the regular angle for the screw projection to the axis pedicle was 42.34±2.95 degree, and the safe angle was 13.68±2.17 degree; （2） the regular distance of the point on the skin for puncture to the central line of the posterior of the neck was56.66±8.94 mm and the safe distance was 19.08±2.65 mm on the horizontal scans; （3）on the saglttal imagine of CT, the regular angle for the screw projection was 27.94±3.98 degree, the safe angle was 19.39±2.19 degree; （4） the regular distance of the puncture point on the skin to the projection point of the front vertex of the basal of axis was 36.50±4.62 mm and the safe distance was 37.35±4.96 mm. on the sagittal scans. Conclusion Great variances axe found in the regular angle and the distance of puncture point on the skin,but there are enough safe range of the angle and the distance for the screw projection on the of horizontal and sagittal imagine. So percutaneous transpedicular lag screw internal fixation has enough safty and possibility when we notice the variances of the pedicle of axis among humans.