课题背景：延长人工关节的有效使用寿命是人工关节研究的目标和难题。骨吸收和无菌性松动是影响其使用寿命的主要因素。计算机辅助设计和制造在人工关节方面的应用是一个有价值和发展前途的方向。

应用要点：以CT二维图像为依据，进行三维反求，可获得精确的股骨内外轮廓三维实体模型；采用图像反求工程和正向CAD设计相结合的方法，设计出个体化股骨假体，可以有效减少和防止骨吸收和无菌性松动的发生。这对于其他人体器官的三维模型建立同样具有很好的借鉴作用。

相关链接：计算机辅助设计和制造个体化假体克服了其他假体的缺点，可有效地延长人工关节的使用寿命和使用质量，并可能解决人工关节的翻修问题。国内的研究尚处于起步阶段，个体化假体主要用于畸形和肿瘤患者的治疗。随着数字制造技术的发展，个体化假体的设计制造在21世纪将会越来越成为普遍和成熟的技术。

摘要
目的：基于CT图像的三维重建，探求个体化股骨假体计算机辅助设计在提高假体与病变骨骼匹配度中的作用。
方法: 实验于2005-09/2007-08在南通大学附属医院骨科实验室和南通大学机械工程学院机电CAD&CAM研究室完成。样本来源：CT扫描对象为健康男性志愿者1例，排除髋关节疾患，年龄30岁，身高175 cm，体质量65 kg。采用GE Speed Light 16排螺旋CT对股骨中上段进行层厚3 mm扫描，得到CT数据的二维图像，利用自主开发的数据格式转换软件将CT图像转换为bmp格式。对位图编辑预处理，用Mimics8.1软件进行矢量化处理，提取股骨内外轮廓。然后输入Mimics8.1和Rapidform2004三维反求工程软件中，生成股骨内外轮廓的特征曲线，重建股骨三维模型。将股骨髓腔的特征轮廓曲线dxf文件输入CAD建模软件Solidworks2004中，以此股骨髓腔轮廓为基础，完成个体化股骨假体的设计。
结果: 利用自主开发的数据格式转换软件，实现了CT图像信息的矢量转换。以CT二维图像为依据，进行三维反求，可获得精确的股骨内外轮廓三维实体模型。采用反求工程与正向CAD相结合,可设计出匹配良好的个体化股骨假体。
结论: 反求工程和CAD技术为个体化假体的研制提供了一个有效可行的途径，解决假体与病变骨骼的良好匹配，可防止假体松动，提高其长期稳定性。
关键词: 股骨；三维重建；计算机辅助设计；个体化假体；人工假体；假体松动；假体稳定性

朱建炜，刘璠，张烽，董启榕，许炜玮，白恩忠，黄希.基于CT三维重建个体化股骨假体计算机辅助设计：满足假体与病变骨骼的匹配度[J].中国组织工程研究与临床康复，2008，12(17):3233-3236 [www.zglckf.com/zglckf/ejournal/upfiles/08-17/17k-3233(ps).pdf]

Computer-assisted design of individualized femoral prosthesis according to three-dimensional reconstruction of CT images

Abstract

AIM:To study computer-assisted design for individualized femoral head prosthesis according to three-dimensional (3D) reconstruction of CT images for improving prosthesis and affected skeleton matching.
METHODS: The experiment was performed at the laboratory of Department of Orthopaedics, Affiliated Hospital of Nantong University and CAD&CAM laboratory of Mechanical Engineering College of Nantong University between September 2005 and August 2007. The CT scanning image of one healthy male 30-year-old volunteer, with no hip joint disease, 175 cm and 65 kg. His femur was scanned with GE Speed Light CT with 3.0 mm thick cross-section slices. CT 2D images were transmitted to a computer. The medical image format was translated from DICOM into bmp. Inner and external bone contours were drawn automatically or by hand and processed digitally, then these data were downloaded into 3D Mimics8.1, and Rapidform2004 software, and then the 3D femoral canal model was rendered. Femur canal contours curve was downloaded into the Solidworks2004 software in the form of dxf. Femoral prosthesis was designed on the base of femoral canal contours curve.
RESULTS: The CT image was transmitted in the form of vector by a set of self-made medical image processing software. The accurate 3D femoral internal/external outline model was obtained by CT 2D image and reserve technique. Suitable femoral prosthesis was designed by means of image reverse engineering and norientation CAD.
CONCLUSION: Reverse engineering and CAD provide an effective way to develop individualized prosthesis, improve the matching of prosthesis and affected skeleton, prevent prosthesis loosening and improve long-term stability.

Zhu JW, Liu F, Zhang F, Dong QR, Xu WW, Bai EZ, Huang X.Computer-assisted design of individualized femoral prosthesis according to three-dimensional reconstruction of CT images. Zhongguo Zuzhi Gongcheng Yanjiu yu Linchuang Kangfu 2008;12(17):3233-3236(China) [www.zglckf.com/zglckf/ejournal/upfiles/08-17/17k-3233(ps).pdf]