Macro-micro Integrated Structure Modeling Technique And Optimization Of Femoral Prosthesis

Artificial hip replacement surgery is the most effective way to solve the tumor,injury,inflammation and other diseases of the femur.However,the series of femoral prostheses with high elastic modulus currently used in surgery often do not completely match the patient’s specific femur characteristics,resulting in postoperative adverse reactions such as stress shielding.With the development of manufacturing technology,the impact of model complexity on manufacturing is being undermined.Porous structures are being considered for orthopedic implants due to their lower elastic modulus and mechanical properties.In this paper,a method for modeling the individualized parameters of macro-micro integrated structure based on femoral CT data and femoral force is proposed.The porous structure femoral prosthesis can effectively reduce the femoral stress shielding effect.The main research contents are as follows:(1)Because the serialized prosthesis cannot accurately match the femoral mechanical characteristics of the patient,the modeling process of the existing personalized prosthesis requires the use of multiple CAD software which resulting in complex processes and long design cycles.Based on the patient’s femur CT data,a modeling method of macro-micro integrated prosthesis was proposed in this paper.(2)Aiming at the problem that the high elastic modulus of the solid prosthesis is easy to cause postoperative adverse reactions such as femoral stress shielding,a parametric modeling method for porous structural prosthesis is designed.And an optimal design of the conformal matching of the porous structure part and the femoral prosthesis is realized.(3)The mechanical properties of different porous structures are different,and the adaptability to femoral load conditions is different.The mechanical properties of five typical porous structures are analyzed,and the parametric modeling of prosthesis with five different porous structures are realized.The effective mitigation of the stress occlusion effect on the femur was achieved through the biomechanical analysis experiments.(4)Aiming at the problem of the stress collection of the porous structure femoral prosthesis at the junction of the porous structure and the solid part,a method based on the stress of the porous structure to optimize the mechanical properties of the porous structure is proposed.Finally,the stress on the prosthesis is reduced to the fatigue limit of the titanium alloy.(5)Based on VS2015 and Openc Cascad modeling platform,a system of personalized Macro-micro integrated structure modeling software for personalized femoral prosthesis was developed,which realized the automatic design of macro-micro structure of femoral prosthesis.