Structural Design And Mechanical Property Analysis Of Femoral Implant

The hip joint is an important connection that supports the movement of the lower limbs of the human body.With the aging of our country and the continuous promotion of national fitness,diseases related to the hip joint will follow.The current socially accepted treatment is hip replacement surgery,but the current replacement prosthesis has various problems.How to reduce the elastic modulus of the implanted prosthesis and effectively alleviate the stress shielding effect is the current research focus of the femoral implanted prosthesis design.Through the combination of spiral CT(Computed Tomography)scanning technology and medical software,the rapid establishment of the characteristic model of the femur is ensured,and the assignment of the heterogeneous material of the femur is realized.The rapid modeling of the prosthesis is realized by measuring the parameters of the in-cut section of the femoral model.Combining the actual bone tissue parameters,10 types of regular octahedral porous structure models were designed to make their porosity,equivalent elastic modulus and other parameters meet the implantation requirements.Complete the establishment of the spatial array and the finite element model,perform simulation analysis,and obtain the mapping relationship between the equivalent elastic modulus and the edge diameter.Using SLM(Selective Laser Melting)laser selective melting metal 3D printing(Three-dimensional Printing)technology to realize the formation of porous structure.Observing the surface morphology through SEM(Scanning Electron Microscope)electron microscope proves that the regular octahedral porous structure can be formed in a long-range order by using SLM technology.The real performance of the porous structure and the simulation results are verified by compression experiments.Within the design range and the equivalent elastic modulus change trend is consistent.The uniformity of the mechanical properties of the regular octahedron structure was obtained through the observation of the SEM fracture morphology and the compression test of the variable-angle structure.Considering the molding effect and mechanical properties,the optimal octahedral implantation parameters are 1.5mm unit cell,0.4mm edge diameter,equivalent elastic modulus of 2.18 GPa,compressive strength of 76.8MPa,and mechanical properties consistent with the implantation.Entry requirements.Based on the design of the implanted prosthesis and the selection of the implanted porous structure,the establishment of the finite element model for the replacement of the solid and partially porous femoral prosthesis was completed,and the simulation analysis was carried out for the two working conditions of standing and gait,focusing on the research of the replacement prosthesis.Stress concentration and stress shielding on the medial and lateral sides of the distal 1/3 of the femur.Through the simulation analysis of working conditions,the partial porous structure replacement prosthesis reduces the overall stress shielding effect on the distal femur by about 20% compared with the solid prosthesis,indicating that the porous structure replacement prosthesis can effectively improve the stress shielding phenomenon of the prosthesis on the femur.The focus of this article is on the appropriate porous structure design,complete the overall establishment of the femoral implant prosthesis,effectively alleviate the stress shielding effect under the premise of meeting the normal physiological activities of people,and provide new ideas for the design of hip prostheses,and provide new ideas for the clinical hip Joint replacement provides a certain theoretical basis.