CT三维定点坐标法对寰枢椎椎弓根的解剖学测量

目的设计一种定点参照测量法在螺旋CT三维重建下测量寰枢椎椎弓根。方法56例18岁～75岁（平均40．3岁）正常成人寰枢关节．螺旋CT扫描并重建，模拟寰枢椎弓根钉植入，3D重建后应用自行设计的定点测量法测量寰枢椎双侧椎弓根各主要解剖数值：椎弓根高度、宽度、进钉点距后正中矢状面距离、椎根弓内斜角及上斜角；应用SPSS12．0软件对人正常状态下寰枢椎椎弓根各测量数据进行分析。结果正常寰枢椎椎弓根各测量数据双侧差异均无统计学意义，取双侧平均值。正常寰枢关节寰椎椎弓高度（4．51±0．69）mm，上斜角7．00°±1．04°，内斜角13．93°±2．11°，椎弓根宽度（5．70±0．80）mm，长度（28．75±1．57）mm，进钉点距后正中矢状面距离（20．17±1．83）mm；枢椎椎弓根高度（720±1．11）mm，上斜角25．00°±3．20°，内斜角24．49°±3．70°，椎弓根宽度（5．40±0．85）mm，长度（28．10±1.21）mm，进钉点距后正中矢状面距离（19.44±1．32）mm．结论自行设计的定点参照测量法在CT三维重建下测量上颈椎椎弓根准确可靠，为临床上颈椎疾患诊治和手术设计、风险评估提供了一种新的影像解剖学测量方法。

Fixed-point Coordinate Method to Measure Pedicles of Atlas and Axis by Helical Computer Tomography and Three-dimensional Reconstruction

Objective To design a fixed-point coordinate method to measure pedicles of atlas and axis by helical computer tomography and three-dimensionalreconstruction. Methods Fifty six normal atlantoaxial joints in adults from eighteen to seventy five （averaged forty point three）, scanned by the way ofhelical computer tomography and three-dimensional reconstruction, to simulate the screws way of pedicle of atlas and axis, measuring the both sides pedicles of atlas and axis： Height, width, length of pedicles, inside oblique angles, upslope angles of pedicles, distance from screw point of the pedicles to the median sagittal plane. To analyze the Anatomic measurements of pedicles of atlas and axis in the normal atlantoaxial joints by SPSS 12.0. Results The difference was not statistically significant, with which the two sides anatomic measurements of pedicles of atlas and axis in the normal atlantoaxial joints, got the averaged measurements of both sides. In normal atlantoaxial joints, the measurements of atlas are： Height ofpedicles is （4.51 ±0.69） mm, width ofpedicles is （5.70 ± 0.80） mm, length ofpedicles is （28.75 ± 1.57） mm, inside oblique angles ofpedicles is 13.93°±2.11° , upslope angles ofpedicles is 7.00°± 1. 04° , distance from screw point of the pedicles to the median sagittal plane is （20.17 ±1.83） mm; the measurements of axis are： Height of pedicles is （7.20 ± 1.11 ） mm, width of pedicles is （5.40 ± 0.85 ） mm, length of pedicles is （28.10 ＋ 1.20） ram, inside oblique angles of pedicles is 24.49°±3.70° , upslope angles ofpedicles is 25.00°± 3.20° , distance from screw point of the pedicles to the median sagittal plane is （ 19.44 ± 1.32） mm. Conclusions It is reliable and exact to measure atlantoaxial joints by the fixed-point coordinate method by helical computer tomography and three-dimensional reconstruction, which provides a new image anatomy evidence to design surgical way and to do risk assessment before operation of atlantoaxial joints.