Objective To study the effects of porous prothesis with radial gradient and homogenized structures on stress transmission in the tibia by using finite element method.Methods Based on the reverse engineering technology,the tibial model was constructed,and the bionic trabecular bone structure prosthesis with gradient change of pore edge diameter and the homogeneous bionic trabecular bone structure prosthesis were designed.The Vicon dynamic capture platform was used to obtain the human gait and the axial force of the tibia-femoral joint during flexion,which was imported into ANSYS Workbench as a boundary condition for mechanical performance analysis.Results In the case of proximal defect,the von Mises stress of the bone for prosthesis with radial gradient structure was increased by 3.68 MPa,and that in the case of distal defect was increased by 7.34 MPa.Compared with the homogenized prosthesis,the von Mises stress of the proximal and distal defects was decreased by 171 MPa and 190.4 MPa,respectively.Conclusions The stress of the radial gradient structure prosthesis diffuses from the outside to the middle high porosity area along the prosthesis,which can effectively transfer the tibial plateau load,reduce stress concentration of the prosthesis,improve bone stress and prolong service life of the prosthesis.This study provides a theoretical reference for clinical prosthesis replacement.

Objective To study the effects of porous prothesis with radial gradient and homogenized structures on stress transmission in the tibia by using finite element method.Methods Based on the reverse engineering technology,the tibial model was constructed,and the bionic trabecular bone structure prosthesis with gradient change of pore edge diameter and the homogeneous bionic trabecular bone structure prosthesis were designed.The Vicon dynamic capture platform was used to obtain the human gait and the axial force of the tibia-femoral joint during flexion,which was imported into ANSYS Workbench as a boundary condition for mechanical performance analysis.Results In the case of proximal defect,the von Mises stress of the bone for prosthesis with radial gradient structure was increased by 3.68 MPa,and that in the case of distal defect was increased by 7.34 MPa.Compared with the homogenized prosthesis,the von Mises stress of the proximal and distal defects was decreased by 171 MPa and 190.4 MPa,respectively.Conclusions The stress of the radial gradient structure prosthesis diffuses from the outside to the middle high porosity area along the prosthesis,which can effectively transfer the tibial plateau load,reduce stress concentration of the prosthesis,improve bone stress and prolong service life of the prosthesis.This study provides a theoretical reference for clinical prosthesis replacement.