摘要
目的探讨术前CT三维重建经枢椎椎弓根螺钉内固定钉道轨迹的方法及其临床意义。方法用GE LightSpeed 16 Pro螺旋CT对15具枢椎完整成人干燥标本进行扫描,扫描完成后内插重建为层厚0．6 mm、层距0．3 mm,在ADW4．2软件上采用容积再现(volume rendering,VR)及多平面重建(multiple planar reformatting,MPR)技术重建和分析图像。在图像工作站中模拟不同方法(方法A：进钉点为下关节突根部的中垂线,出至上关节突与齿突交界处；方法B：进钉点为下关节突背侧的头内1/4处,平行于狭部轴线至上关节突下缘)和不同直径的经枢椎椎弓根钉固定,观察虚拟螺钉在骨性通道中的通行情况,并将钉道参数结果应用于干燥枢椎标本的实际椎弓根内固定。结果螺钉的轨迹可以从多方位、多角度以及任意轴面上得到动态观察,2具3侧标本的横突孔内侧壁和上关节突下方骨壁菲薄,明显不适于行椎弓根内固定。方法A与B两种钉道轨迹参数比较,二者的钉道长度相近(P＞0．05),方法A的上倾角度和内倾角度大于方法B(P＜0．05,0．01),方法A的骨性通道中可容纳虚拟螺钉的直径明显小于方法B(P＜0．05)。结论本研究可以模拟经枢椎椎弓根钉固定的不同进钉点、螺钉的不同直径和不同安全角度,并动态观察螺钉的轨迹是否完全在骨性结构内通行,在临床治疗和科研中有较大的应用价值。
Objective To discuss the technique and value of preoperative reformatting with three-dimensional computed tomography technique for C2 pedicle screw track. Methods GE Light Speed 16 Pro spinal CT scans of 15 adult dry vertebrae were loaded into an imaging station （software ADW4.2 ）. Two methods of C2 pedicle screw techniques were analyzed through virtual screw trajectory by VR （volume rendering） and MPR （multiple planar reformatting） techniques, in method A, screw entry point was the intersection between the media-vertical and the cranial line of C2 inferior facet joint, in method B , the screw track was from the cranial and medial quadrant of the dorsal part of C2 inferior facet joint. Results The screw track could be observed dynamically from any plane. Two vertebrae were observed with smaller height in isthmus and the medial edge of the transverse foramen since no space was available for the screw. The screw trajectories data were compared between method A and method B, which showed that the angles towards the cephalad （in sagittal plane ） and midline （in transverse plane） were bigger in method A than in method B （ P 〈 0.05, 0.01 ） , but the safe screw diameter was smaller in method A than in method B （P 〈 0.05 ） , and there was no difference of the screw length between the two methods（P 〈 0.05 ）. Conclusion In this research, the individual C2 pedicle screw entry points, screw diameter and security screw angle can be simulated, and the screw track can be observed dynamically to make sure if it transits the bone structure completely. Preoperative three-dimensional computed tomography reformatting for pedicle screw track is of great value in clinical and basic researches.
出处
《中华创伤杂志》
CAS
CSCD
北大核心
2006年第8期613-616,共4页
Chinese Journal of Trauma
