Topology-Optimized Design of Microporous Filling Prosthesis

One of the main reasons for the loosening of the femoral stem prosthesis is that the femoral stem prosthesis is difficult to joint and grow in the femoral cavity. Thus, a new design method is proposed to reduce the risk of prosthesis loosening. Firstly, we use the image data of X-ray and CT to extract the characteristic parameters of the femoral cavity and design the prosthesis with the characteristic parameters. Secondly, the model is improved with topology-optimized design, to make it have better mechanical performance. Then, we use the microporous units to fill the deletion region of the optimized model, the prosthesis can be conformal and achieves good biological performance. Finally, the performance of the prosthesis is validated and evaluated by the finite element analysis (FEA).The design method has obvious effect on the quality reduction of prosthesis, its weight is 40% lower than that of the mainstream solid prosthesis. The effect of increasing the surface area also is obvious, which is 3.4 times of solid prosthesis. The mechanical performance is more excellent and meet the design requirements, whose stress shielding rate decreased by 10%. The prosthesis with the optimized filling design has the strength close to the solid prosthesis. But it is lighter in weight and have more surface area, its stress shielding rate is lower than solid prosthesis, which will help to improve the comfort of postoperative recovery and the joint and growth between prosthesis and femoral cavity. This method greatly reduces the risk of loosening of the prosthesis and improves the quality of life of patients.