■機械金属部 廣崎憲一 中島明哉 舟田義則
■金沢工業大学 新谷一博
■金沢医科大学 兼氏歩


Custom-made Design of Artificial Hip Joint with Application of X-ray CT Image

Kenichi HIROSAKI, Akiya NAKASHIMA, Yoshinori FUNADA, Kazuhiro SHINTANI and Ayumi KANEUJI

In hip-replacing arthroplasty, an artificial hip joint stem should be tightly fitted into the proximal femoral canal for secure fixation of the prosthesis in the initial stage, and an effective conveyance of stress to the proximal femur. In this report, we propose a design method for custom-made stems that will provide each patient with a stem with high adaptability ― a stem that fills a higher ratio of the proximal femoral canal. According to this method, the shape of the proximal femoral canal is examined and the contour in the direction of stem insertion, which is projected based on the curve of femoral canal, is sampled to produce an optimized stem. Two images are obtained by the application of reverse engineering technology using 3D X-ray CT images and CAD system. Upon examination of prostheses fitted to patients, the filling ratios of stems in the femoral canals proved to be higher for the custom-made models produced by this method than for ready-made models.

Keywords:artificial hip joint, stem, custom-made, reverse engineering , X-ray CT image ,CAD