数字技术在椎弓根通道设计中的应用

Application of digitalized technique in design of pedicle channel

目的探讨精确定位椎弓根通道的数字解剖学方法,为经椎弓根内固定提供安全、有效、标准化的理论参考依据。方法原始数据来源于1例健康成人腰骶部的CT连续断层扫描数据集,将CT连续断层扫描数据导入Mimics8.11软件,三维重建腰椎数字解剖模型,将任意节段椎骨数字模型导入Surface10.0,确定椎骨正交正中矢状面和水平面作为椎骨参考平面,确定椎弓根位置,获取椎弓根表面轮廓,根据任意预定方向定位通道位置,建立该方向椎弓根通道。通过定位定量分析确定通道内最大螺钉通道位置、半径大小、长度及最佳方向轴,确定通道及最大螺钉通道在椎板表面的定位区,并三维可视化显示。结果建立右侧椎弓根25°外偏角和0°头尾角及左侧椎弓根20°外偏角和0°头尾角方向通道及其最大螺钉通道,确定通道及其最大螺钉通道在椎板的定位区、进钉轴范围、最佳中心轴、最大螺钉通道半径大小及长度。结论应用现代影像技术和计算机辅助设计技术可以个体化三维精确定位定量设计椎弓根通道。

[Objectives] To research the cigitalized anatomical method of pedicle channel. To provide safe, effective and standard theoretical evidence for pediele screw fixation. [Methods] CT scan images of lumbar of a healthy adult were digitally analyzed by Mimics 8.11 software （Materialise） and established their three-dimensional （3D） models. These models were saved as .stl format, then import Surface 10.0 software to computer aided design .Firstly, the cross seetion plane were located in the vertebra middle sagittal and the transverse direction. Secondly, lumbar pedicle channel were projected to the plane along the vertical direction and obtained inner borderline of each direction project, respectively, meanwhile fitted the outer and inner circle of each inner borderline, as well as. Then recorded the radius of the outer and inner circle of each inner borderline and its center coordinate point, measured the channel length of inner circle of each inner borderline approaching podicle. [Results] The pedicle channel and the largest screw channel were reconstructed in the 25° angle of transverse plane and 0° angle of sagittal plane direction in left podicle. Also reconstructed podicle channel and the largest screw channel in the 20°angle of transverse plane and 0° angle of sagittal plane direction in right podicle. We confirmed the size of location area, the axis range of entrance, the best central axis, and the largest screw channel length and radius. [Conclusion] Modem imaging methods and computer-aided design.techniques can provide precise location and pinpoint three-dimensional design pedicle channel individually.