Finite element analysis of biomechanical properties of bionic surface hip prosthesis / 中华骨科杂志

ABSTRACT

Objective:To compare the biomechanical properties of traditional surface hip prosthesis and bionic surface hip prosthesis.Methods:The Sawbone digital model (#3908, Left, Medium) was selected as the research object. Mimics 21.0 software was used to reconstruct the physical model of femur. Solidworks 16.0 software was used to build the model of prostheses, including the traditional and bionic (type 1-4) protheses and their assembly. The distances from the screw cross position to the top of pressure screw of type 1 to type 4 protheses were 20.22 mm, 30.12 mm, 32.17 mm and 37.76 mm, respectively. The mechanical distribution characteristics of the whole model were measured and the stress distribution cloud map was obtained.Results:The peak stresses at bone-stem junction of traditional prosthesis and type 1-4 hip prostheses were 32.18 MPa, 13.80 MPa, 15.01 MPa, 23.46 MPa and 34.51 MPa, respectively. With the fulcrums away from the top of the femur, the peak stresses at the fulcrums of type 1-4 hip protheses were 37.98 MPa, 48.60 MPa, 54.80 MPa, and 53.87 MPa, respectively. The maximum stress above femoral neck of traditional prosthesis and type 1-4 hip prostheses were 8.00 MPa, 7.80 MPa, 7.04 MPa, 7.03 MPa and 7.51 MPa, respectively. The maximum stresses under femoral neck was 15.38 MPa, 14.20 MPa, 11.11 MPa, 13.10 MPa and 12.18 MPa, respectively. The maximum stresses in the greater trochanter region of femur were 13.08 MPa, 11.61 MPa, 13.09 MPa, 11.02 MPa and 39.51 MPa, respectively.Conclusion:Compared with the traditional surface hip prosthesis, the type I bionic surface hip prosthesis is designed based on the lever balance reconstruction theory. With the bionic reconstruction of the tension trabeculae and compression trabeculae through reasonable screw placement angles and the inward movement of the fulcrum closer to the center of the femoral head, the new type prothesis make up for the design defects of the traditional surface hip prosthesis, optimize the stress distribution in the proximal femur, and improve the stability of the prosthesis after replacement, which help reduce the risk of femoral neck fracture and prosthesis loosening, and extend the service life of the prosthesis.