寰椎椎弓根解剖和CT测量在椎弓根螺钉固定中的意义

Anatomic and CT scan measurement of the pedicle screw fixation on atlas

目的 :确定寰椎后路椎弓根钉的进钉点和验证螺钉在寰椎侧块中的位置。方法 :用 40副干燥寰枢椎标本测量进钉点的最佳位置和相关数据 ,临床应用该置钉技术 ,CT测量 6例术后病人钉在寰椎侧块中的位置和螺钉长度。结果 :寰椎椎弓根平均宽度为 7.78mm ,进钉点在寰椎椎弓根中线外缘 2 .2mm ,即枢椎下关节突中点的矢状线 ,CT测量螺钉均位于寰椎侧块内 ,螺钉长度为 2 8～ 3 0mm。结论 :寰椎椎弓根钉进钉点可用枢椎下关节突中点的矢状延长线来确定 ,螺钉长度 2 8～ 3 0mm。

Objective:To establish the placement technique of posterior pedicle screw on atlas and verify the accuracy for the technique. Methods: Forty pairs vertebra of atlas and axis were anatomic measured to the placement of pedicle screw on atlas, six cases of operation were observed them with CT scan. Results: The average width of the atlas pedicle was 7.78 mm and the entry point of the present technique was 2.2 mm lateral from the central vertical line through the central point of C_2 inferior articular process. On the CT imagings, all the screws were in the lateral masses and the length of the screw was 28～30 mm. Conclusion: The enter point of C_1 pedicle screw could be defined by the central point of C_2 inferior articular process, and the screw length was 28～30 mm.