Three Dimensional Reconstruction Of Femur And Study On Biomechanics Of The Artificial Hip Prosthesis

Individualized hip prosthesis can improve matching between femur and femoral prosthesis, which extends service life of prosthesis. And it can meet special cases. Most previous researches focus on precise femoral model with anatomic structure and biomechanics analysis for optimizing design of prosthesis. Accordingly, on the basis of image processing technique and computer aided design technique, three dimensional (3D) digital model of femur was reconstructed from spiral CT data. Biomechanical analysis of artificial hip prosthesis was made by nonlinear finite element method (FEM). As a complication, infection is disastrous and unexpected for the total hip arthroplasty (THA). So material surface modification was studied by ion implantation to investigate antibacterial activity, wear resistance, etc. According to the above-mentioned, 3D model and design criteria of its geometrical shape and materials were established, which would be helpful for design and fabrication of individualized hip prosthesis.Imageware, Unigraphics and Mimics software which enables precise DICOM data transfer between CT and PC, were employed for reconstruction process of digital 3D models, which were able to construct a 3D femoral model and to distinguish 3D structures between cortical bone and cancellous bone. The constructed models are highly precise, with average error of carved surface less than 0.5 mm. Femoral neck anteversion (FNA) of present model was measured by 3D CT method. Moreover, abnormal femur with complicated shape was reconstructed and its solid model was also fabricated by Rapid Prototype (RP).3D finite element model of acetabular and head prosthesis was created for stress analysis of ultra high molecular weight polyethylene (UHMWPE) liner by nonlinear FEM. The results showed that the stress of liner was much lower than the yield strength of UHMWPE in gait. Compared to swing phrase, the stress during stance phrase was higher and the majority of stressed occurred the posterior-lateral quadrant of the acetabular. The stress of liner decreased with increasing head diameter. The thickness of liner and head material had little effect on the stress.3D finite element model of head and neck prosthesis was created for analysis of the relative displacement and the contact stress between head and neck by nonlinear...