寰椎椎弓根螺钉进钉点与枢椎椎弓根内壁水平间距关系的研究

Studying the relationship on the horizontal distance from atlas pedicle screw entry point to medial border of axis pedicle

目的:建立以枢椎椎弓根内壁为解剖标志的寰椎椎弓根螺钉进钉点定位技术。方法:选择100例(男女各50例)正常成人寰枢椎CT片。在CT横断面扫描上分别应用Tan等的进钉方法(方法一)和马向阳等的进钉方法(方法二)模拟出寰椎椎弓根螺钉进钉通道,建立以枢椎椎弓根内壁为解剖标志的寰椎椎弓根螺钉进钉点定位技术,临床应用该定位技术进行后路寰枢椎椎弓根螺钉固定治疗寰枢椎不稳。结果:寰椎椎弓根进钉点与枢椎椎弓根内壁的水平间距在方法一男性为(6.0±0.8)mm,女性为(5.5±0.8)mm;方法二男性为(9.4±1.1)mm,女性为(8.2±1.3)mm。4例患者应用枢椎椎弓根内壁作为解剖标志行寰椎椎弓根螺钉内固定,术中无脊髓和椎动脉损伤等并发症,术后影像学显示螺钉位置均良好。结论:枢椎椎弓根内壁可作为寰椎椎弓根螺钉进钉点的解剖标志。该解剖标志较以往的解剖标志恒定明确,结合术前CT扫描能较准确指导螺钉进钉。

Objective：To establish a technique of marking the position of atlas pedicle screw entry point with the medial border of axis pedicle as an anatomical landmark. Methods： 100 atlantoaxial CT films of normal adults （including 50 males and 50 females） were selected randomly to measure the horizontal distance from atlas pedicle screw entry point to medial border of axis pedicle by Tan＇s method （method a）and Ma Xiangyang＇s method （method b）. The reliability of using the horizontal distance for marking the positioning of atlas pedicle screw entry point through clinical application was evaluated. Results：In method a, the horizontal distance was（6.0 ± 0.8） mm in male,and（5.5 ± 0.8） mm in female. In method b,it was（9.4 ± 1.1） mm in male,and（8.2 ± 1.3） mm in female. 8 atlas pedicle screws were placed exactly in 4 patients, and no neural or vascular injury was observed. The postoperative radiographs verified all of atlas screws with a good position. Conclusion：The medial border of axis pediele could be as a convenient anatomic landmark to determine the position of atlas pedicle screw entry point,and the landmark is more invariant and clear comparing with the previous anatomical ones.