Key techniques for stress shielding effect of prosthesis implantation

Abstract

Stress shielding effect is the main factor which affects the reconstructive surgery effect of prosthesis. At present, the difference of constitutive relationship between 3D printed titanium alloy prosthesis implant and human bone leads to the stress shielding phenomenon in bone defect repairing surgery. To solve this problem, this paper establishes a porous structure model of prosthesis implantation conforming to the constitutive model of human bone through analysis on the mapping relationship between unit tissue structure and elastic modulus of model. And titanium alloy is printed with optimized print parameters for 3D printer to testify the experiment. The study finds that the elastic modulus of 3D printed titanium alloy could be reduced to 31.51 GPa when the linear energy density is 269.1 J/mm3; the porous structure with diamond structure and porosity of 70%-80% could be consistent with the modulus of human cortical bone and the corresponding relationship between them could be established. This paper builds the law of mapping relationship between unit tissue structure and modulus of human cortical bone, which accurately reflects the rule that the modulus of prosthesis implant increases with the increase of the size of 3D printing porous structure unit and decreases with the increase of porosity. It provides theoretical support for research of eliminating stress shielding phenomenon.