寰椎经后弓侧块螺钉固定通道的CT测量

CT measurement of the path of screw fixation in atlas via posterior arch and lateral mass

目的:提供国人寰椎CT测量的数据,探讨寰椎经后弓侧块行螺钉置钉的可行性。方法:采用50具寰椎骨标本,对经寰椎后弓侧块的螺钉固定通道进行多个切面的CT断层扫描并测量。结果:将寰椎后结节中点旁开18～20mm的矢状面与后弓下缘上方2mm处的水平面的交线在后弓后方的投影点确定为进钉点;进钉方向保持与冠状面垂直,在矢状面上钉尖向头侧倾斜约5°,是寰椎经后弓侧块螺钉固定较理想的置钉通道。结论:寰椎具备行经后弓侧块螺钉内固定的条件。

Objective:Normal anatomic properties of atlas were measured in radiology to evaluate the feasibility of screw fixation in atlas via posterior arch and lateral mass.Method:50 dry atlas of Chinese origin were measured with CT scanning aiming at the path of screw fixation.Result:The point of screw penetration was 18~20mm lateral to the midpoint of posterior tubercle and 2mm superior to the inferior edge of posterior arch.The screw direction chosen was parallel with sagittal plane and about 5° cephalad to the transverse plane.Conclusion: atlas has the condition of screw fixation via posterior arch and lateral mass.