人工髋关节置换手术，作为治疗髋关节骨折等疾病的一种有效的治疗方法，在国内外已得到了广泛的应用，人工关节柄的形状与股骨腔吻合的程度，是直接影响人工关节长期稳定性，活动度及髋关节生物力学性能的重要因素。本文介绍了一个计算机辅助人工髋关节设计关系。它能从烯疏和间隔不均匀的CT图象重构髋关节的三维图象。本文介绍一个计算机辅助人工髋关节设计系统，它能从稀疏和间隔不均匀的CT图象重构髋关节的三维图象，然后根据它设计出人工关节。设计出的关节柄的形状与患者股骨腔比较吻合，主要几何尺寸与患者股骨一致，该系统还能显示截取了关节头后股骨，模拟股骨和人工关节装配的情况，为制定手术方案提供直观的观察工具。

he artificial prosthesis is widely used today as a measurer of curing hip prosthesis diseases. Its long-lasting functionability is affected heavily by the fitness between the femoral stems and the patient's marrow. However,the off-shelf femoral stems are available only in limited number of models. It usually does not fit individual patient well. There fore, the use of patient-fit artificial prosthesis is recommended. In this article a computer aided system for designing patient-fit intramedullary femoral stems is developed based upon the volume visualization technique. After the 3-D image of the femur is generated,the design of the femoral stem is carried out interactively. The system also simulates the cutted bone and the assembly of the femoral joint with the bone. It gives the doctor a good perspective of the operation before it is really done.Another advantage of the system is that less number of CT-images are needed in 3-D image reconstruction. The CT images are usually taken at relatively large interval,say about 2.0mm. Reducing this distance further is harmful to the health of patients. However,such distance is too large for reconstructing the 3-D image, since the dimension of the voxels must be compatible with it. It leads to a low-resolution image. Therefore,in this system a new interpolating algorithm is developed. The distribution of gray density in the new layers inserted into two given CT layers can be calculated directly from the distribution of gray density on the two known CT layers. With this new interpolating algorithm, the system is suitable for clinic purpose.