Design And Performance Analysis Of Gradient Porous Femoral Shank

The femoral stem is one of the implants used in hip replacement surgery,which directly affects the therapeutic effect of the surgery.Currently,the femoral stems available on the market exhibit high stress shielding effects and a high probability of postoperative complications.This study aims to design and prepare a femoral stem product that has low stress shielding effects and meets the requirements for bone implants in the human body,and to analyze and study the biological and mechanical properties of a 3D printed gradient porous femoral stem.Based on medical CT images,the femur was visualized using Mimics software,and a three-dimensional editable model of the femur was reconstructed using reverse engineering software.Physiological parameters of the human femur were extracted,and combined with femoral stem design principles,a three-dimensional model of the femoral stem was established.Finite element simulation was performed on the femoral stem to analyze stress and displacement data and verify the reliability of the femoral stem designed in this study.The human hip joint motion posture was analyzed,and a simplified model of femoral stress was established.Finite element simulation analysis was performed on the femur model and the solid femoral stem implant model to observe the overall displacement changes of the femur before and after implantation and to test the stability of the femoral stem implant.The stress shielding effect of the solid femoral stem implant was analyzed,and the influence of the elastic modulus on the stress shielding effect was explored.A gradient porous structure was proposed as an optimization solution to reduce the stress shielding effect.A surface porous structure was constructed using a triply periodic minimal surface function,and different porous structures were compressed and simulated to select a suitable basic type of porous structure.Based on the requirements of the gradient porous structure,a gradient porous femoral stem model was constructed.Simulation was performed on the solid femoral stem and the gradient porous femoral stem to analyze their differences in stress shielding effect and compressive strength and verify the superior performance of the gradient porous femoral stem designed in this study.Experimental specimens of solid femoral stem and gradient porous femoral stem were prepared using 3D printing technology.Compression and strain measurement tests were designed according to industry standards,and displacement and strain data were analyzed to compare the differences in compressive strength between the gradient porous femoral stem and the solid femoral stem.A dynamic fatigue test was designed for the gradient porous femoral stem to test its fatigue performance and ensure that it has sufficient service life.Through the above research work,a method for effectively reducing the stress shielding effect of the femoral stem using a gradient porous structure has been proposed,which improves the effect of hip replacement surgery and provides ideas and technical support for other medical enterprises and hospitals to design related orthopedic implants.