Abstract: Personalized design for pedicle screw is an important part of the operation’s success in computer-aided spine orthopedic surgery. This design consists of two parts, the first part is making positioning planning for the screw, and the other part is to measure the parameters of the screw. As the traditional method has inaccurate positioning and the operation is not intuitive, a pedicle screw personalized computer-aided design method based on surface rendering algorithm and contour extraction is proposed. Firstly, the paper makes the positioning planning of the pedicle screw based on contour line extracted from spinal section. Secondly, it measures the parameters of the pedicle screw. Finally, it displays the experiment result of virtual surgery and completes the whole process of computer-aided design for personalized pedicle screws. The results of experiment show that this method can obtain the personalized pedicle screws which meet the requirement of the operation.

Key words: computer aided design, spinal surgery, affine transformation, contour extraction

摘要： 在计算机辅助脊椎的矫形手术过程中，椎弓根螺钉的个性化设计是手术成功的重要部分。这种设计包括两部分，一部分是对螺钉进行定位规划，另一部分是确定螺钉的参数。针对传统方法定位不准且操作不直观的问题，提出一种基于面绘制和轮廓线提取的个性化椎弓根螺钉计算机辅助设计方法。首先提取脊椎节的轮廓线，在轮廓线上实现对椎弓根螺钉的定位规划；然后根据定位规划的结果，测量椎弓根螺钉参数；最后显示虚拟手术的结果，完成个性化椎弓根螺钉辅助设计的整个过程。实验结果表明，该方法可以得到满足手术要求的个性化椎弓根螺钉。

关键词: 计算机辅助设计, 脊柱手术, 仿射变换, 轮廓线提取