顺行拉力螺钉固定髋臼后柱骨折进钉的解剖学参数研究

Anatomic parameters of antegrade lag screw placement in the postertor column of the acetabulum

目的 探讨顺行拉力螺钉固定髋臼后柱骨折的进钉参数,为进钉瞄准器的研制提供应用解剖学基础.方法 收集40例正常成人（男20例,女20例）骨盆的螺旋CT扫描数据,重建骨盆三维模型.经髂前上棘（A）和髂后上棘（B）的骨性最突出点的连线中点M做一平面（γ）垂直于AB,在髋臼后柱的γ截面上模拟置人虚拟圆柱体,该圆柱体从髂翼内侧的穿出点（O）即为拉力螺钉的入钉点.在弓状缘上取点D,使OD成为入钉点与弓状缘之间的最短距离,连结OD,G点为骶髂关节最前缘,连结DG.测量OD、DG的距离、置入拉力螺钉的长度、拉力螺钉与冠状面的夹角（α）及与矢状面的夹角（β）. 结果 OD距离平均为（13.62±2.19）mm,DG距离平均为（15.27±4.01） mm,能置入拉力螺钉的长度平均为（116.65±7.19） mm,α夹角平均为15.47°±4.01°,β夹角平均为6.65°±2.93°.男、女性在DG距离、β夹角、置入拉力螺钉的长度方面差异均有统计学意义（P＜0.05）,而在OD距离及α夹角方面差异均无统计学意义（P＞0.05）. 结论 根据髋臼后柱顺行拉力螺钉置钉的解剖学参数,术中置入合适长度的拉力螺钉是可行的,可作为研发进钉瞄准器的应用解剖学依据.

Objective To provide evidence of applied anatomy for development of a targeting device for antegrade lag screw fixation in the treatment of fractures of the acetabular posterior column. Methods Virtual three-dimensional pelvic models were reconstructed from computed tomography （CT） scans of the pelvis obtained from 40 adult subjects without any bony problem （20 males and 20 females）.The most prominent bony points on the anterior supetior iliac spine （ASIS） and posterior superior iliac spine （PSIS） were identified and respectively marked as A and B.Next,a plane （γ） that was perpendicular to the section AB was made to pass through the midpoint （M） of section AB.Virtual cylindrical implants were placed into the postetior column of the acetabulum.The projection point （O） of the antegrade lag screw on the inner table was thus defined.Next a line designated as OD was drawn perpendicularly from the point O to the linea terminalis at the point D.Another line,designated as DG,was drawn from the point D to the anterior border of the auricular surface （G）.The lengths of OD and DG were measured.The length of the screw,Angle α between the cylindrical and the coronal planes and Angle β between the cylindrical and the sagittal planes were also measured. Results The average lengths of OD and DG were 13.62 ± 2.19 mm and 15.27 ± 4.01 mm,respcctively.The average length of the lag screw was 116.65 ± 7.19 mm,Angle αwas 15.47 ° ± 4.01° and Angle β was 6.65 ° ± 2.93 °.There were significant differences between males and females in DG length,lag screw length,and Angle β （ P 〈 0.05）.Conclusions An adequate length of the antegrade lag screw can be placed in the posterior column of the acetabulum.This study also provides evidence of applied anatomy for development of a targeting device for antegrade lag screw fixation in the treatment of fractures of the acetabular posterior column.