微创经皮下颈椎椎弓根置钉的三维解剖学研究

目的　探讨颈椎椎弓根进钉参数与棘突的三维关系，为经皮椎弓根螺钉内固定及器械的设计提供参考。 方法　20例健康成人颈椎CT重建模型导入UG imageware 13.2，以70%、80%、90%边界深度为研究基础，测量椎弓根通道进钉螺钉半径、外偏角、通道长度(L)、通道与矢状面、水平面的角度；进钉轴与冠状面的交点与椎弓根的角度。B、C点到参考平面、棘突的距离。 结果　（1）C3~7椎弓根通道内切圆半径在2.79~3.89 mm之间。（2）通道长度、外偏角随着边界深度的增加而增大。（3）C3~7的Ac最大值出现在70%边界深度。（4）B点到正中矢状面、冠状面的距离都随着边界深度增加而增大。（5）B点、C点棘突末端的距离随着边界深度增加而增大。 结论　颈椎椎弓根螺钉进钉参数与棘突的三维关系，为经皮微创椎弓根螺钉固定器械设计提供依据。

Morphometric measurement of the cervical spine for minimally invasive pedicle screw fixation using reverse engineering and three-dimensional reconstruction

Objective　To study the entry point of cervical pedicle screw insertion and its three-dimensional relationship of the spinous process, and to provide anatomical basis for percutaneous cervical pedicle screw fixation and the design of the aiming device.　Methods　3D models were imported into UG13.2 imageware for measurement. We took the 70%、80% and 90% as our research foundation, and several measurements were conducted, including the biggest inscribed circle radius(R), the lateral angle(Ap) and the length of pedicle insertion channel(L).The intersection between entry axis and coronal plane was defined as point C. Besides, point E and point F respectively represented medial and lateral midpoints of the pedicle. The angel between line CE and line CF was calculated(Ac). The distance from the entry point(B) and point C to each reference plane; BD and CD represented to the distances from point B and point C to the end of the spinous process, respectively.　Results　(1) The inscribed circle radius from C3 to C7 ranged from 2.79 mm to 3.89 mm.(2)The PSC length increased with the increase of borderline depths. (3)The bigger the borderline depths, the larger the insertion angle. (4) The maximum of Ac from both C3 to C7 appeared at 70% borderline depth.(5)The distance from point B and point C to sagittal plane and spinous process increased with the increase of borderline depth.　Conclusion　The three-dimensional relationship of the cervical pedicle and its relationship of spinous process in 70%,80%, and 90% boundary depths in this study have been analyzed, which can provide the anatomical basis for percutaneous cervical pedicle screw placement and its locating device design.