经S2椎弓根骶髂关节螺钉固定钉道参数的研究

目的 为经S2椎弓根水平骶髂关节螺钉固定提供解剖学依据并研究钉道参数的变异性相关因素。方法 用CT对100名健康成人骨盆进行扫描成像，测量经S2椎弓根骶髂关节螺钉固定的钉道直径、进针点至S2椎体前缘距离、进针点、进针方向；并记录受检者的性别、身高、体重；以上数据用SPSS13．0软件进行统计学处理。结果 S2椎弓根宽为16．6±3．8mmS2椎弓根高为12．8±4．5mm；螺钉进针点在髂后下棘前方24．7±3．5mm，坐骨切迹上方19．3±4．6mm；进针方向与冠状面夹角为14．5±2．40；进针方向与水平面夹角为8．9±1．90；进针点至S2椎体前缘距离为74．8±2．9mm除进针方向外，其余参数有较大的极差及四分位数间距。椎弓根宽度及钉道长度均与性别无关。泊松相关分析显示身高、体重与椎弓根宽度及钉道长度呈显著正相关，而进针角度与后两者无显著相关性。结论 经S2椎弓根骶髂关节螺钉固定钉道参数具有较大的变异性，不同个体、有显著不同：体重和身高是两个影响变异性重要的相关因素。

A Study of the Variability of the Parameters of Sacroiliac Joint Screw Path and Related Factors through S2 Pedicle

Objective： To provide the anatomic basis for sacroiliac screw fixation through S2 pedicle, and study the variability of the parameters. Method： 100 pelvic of the healthy adaults were scaned by spiral CT to measure the broad and height of the pediele of S2;the distance from the optimal entry point to contrary anterior cortex of S2. The distance from the optimal entry point to the posterior inferior iliac spine, to the greater sciatic notch. The direction of the centre axis of the pedicle of S2,the gender ,age ,height and weight were recorded at the same time. Results： The broad and height of the pediele of S2 was 16.6±3.8mm and 12.8±4.5mm,The distance from enty point to contrary anterior cortex of S2 vertebral body was74.8±2.9mm, The direction of screw was 14.5±2.4° to the coronal plane and 8.9±1.9° to the horizontal plane. The optimal entry point on posterolateral iliac ala for screw fixation was fund to exist 24.7±3.5mm anterior to posterior inferior iliac spine and 19.3±4.6mm superior to the greater sciatic notch. Bsides the direction of the centre axis, parameter of screw fixation showed a wide range value and quantity .No inter-gender difference existed between man and woman after effects of height and weight was removed.Both height and weight showed significant positive correlation with the screw path length and transverse diameter ofpedicle ,but no correlation with the direction of the centre axis. Conclusion： The parameters of the screw oath varied in different subjects.the height and weight are two important factors to influence the parameters.