寰椎椎弓根螺钉进钉点与寰椎椎弓根内壁水平间距的关系

Relationship of atlas pedicle screw entry point and horizontal distance from it to medial border of atlas pedicle

目的建立以寰椎椎弓根内壁为引导的寰椎椎弓根螺钉进钉定位技术。方法随机选择50例(男女各25例)寰椎解剖正常的成人寰椎CT片,在CT横断面扫描上分别应用改良后的Tan等的进钉方法(方法一)和改良后的马向阳等的进钉方法(方法二)模拟出寰椎后路椎弓根螺钉进钉通道,建立以寰椎椎弓根内壁为引导的寰椎后路椎弓根螺钉进钉点定位技术,并应用该定位技术治疗5例上颈椎的疾患。结果寰椎后路椎弓根螺钉进钉点与寰椎椎弓根内壁的水平间距在方法一男性为(4.8±0.6)mm,女性为(3.9±0.6)mm;方法二男性为(6.6±0.7)mm,女性为(5.2±0.6)mm。5例患者应用寰椎椎弓根内壁为引导行后路寰椎椎弓根螺钉内固定,术中未发生脊髓和椎动脉损伤等并发症,术后影像学检查显示螺钉位置均良好。结论寰椎椎弓根内壁可作为术中判定寰椎椎弓根螺钉进钉点的解剖学参照,术前CT扫描模拟定位有助于术中指导螺钉进钉。

Objective To establish a technique of marking the position of atlas pedicle screw entry point guided by the medial border of atlas pedicle. Methods The horizontal distance from atlas pedicle screw entry point to medial border of atlas pedicle of 50 atlas CT films of normal adults （25 males and 25 females） was measured by modified Tan＇s method（method A） and modified 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 The horizontal distance measured by method A was（4.8±0.6） mm in male and （3. 9±0. 6） mm in female, which by method B was （ 6.6 ± 0. 7） mm in male and （5.2 ± 0. 6 ） mm in female. Ten atlas pedicle screws were placed exactly in 5 patients and no neural or vascular injury was observed. The postoperative radiographs verified all of atlas screws with a good positioru Conclusion The medial border of atlas pedicle could be as a convenient anatomic landmark to determine the position of atlas pedicle screw entry point.