An integrated CAD/CAM/robotic milling method for custom cementless femoral prostheses.
Aseptic loosening is the primary cause of cementless femoral prosthesis failure and is related to the primary stability of the cementless femoral prosthesis in the femoral cavity. The primary stability affects both the osseointegration and the long-term stability of cementless femoral prostheses. A custom cementless femoral prosthesis can improve the fit and fill of the prosthesis in the femoral cavity and decrease the micromotion of the proximal prosthesis such that the primary stability of the custom prosthesis can be improved, and osseointegration of the proximal prosthesis is achieved. These results will help to achieve long-term stability in total hip arthroplasty (THA). In this paper, we introduce an integrated CAD/CAM/robotic method of milling custom cementless femoral prostheses. The 3D reconstruction model uses femoral CT images and 3D design software to design a CAD model of the custom prosthesis. After the transformation matrices between two units of the robotic system are calibrated, consistency between the CAM software and the robotic system can be achieved, and errors in the robotic milling can be limited. According to the CAD model of the custom prosthesis, the positions of the robotic tool points are produced by the CAM software of the CNC machine. The normal vector of the three adjacent robotic tool point positions determines the pose of the robotic tool point. In conclusion, the fit rate of custom pig femur stems in the femoral cavities was 90.84%. After custom femoral prostheses were inserted into the femoral cavities, the maximum gaps between the prostheses and the cavities measured less than 1 mm at the diaphysis and 1.3 mm at the metaphysis.
['Wen-ming|Xi|X|', 'Ai-min|Wang|W|', 'Qi|Wu|W|', 'Chang-hua|Liu|L|', 'Jian-fei|Zhu|Z|', 'Fang-fang|Xia|X|']
D000818:Animals D019644:Arthroplasty, Replacement, Hip D000069343:Bone-Implant Interface D002138:Calibration D017076:Computer-Aided Design D029721:Drosophila Proteins D005269:Femur D006622:Hip Prosthesis D021621:Imaging, Three-Dimensional D008954:Models, Biological D057285:Precision Medicine D011474:Prosthesis Design D012371:Robotics D013552:Swine D014057:Tomography, X-Ray Computed
CAD/CAM/robotic Custom Cementless femoral prosthesis Integration method