Study On Computer Aided Design Of Ni-Ti Shape Memory Alloy Stemless Femoral Prosthesis

[Objective]The method for designing Ni-Ti shape memory alloy stemless f emoral prosthesis by computer aided design technique was researched.To evalu ate the biomechanical features of Ni-Ti shape memory alloy stemless femoral p rosthesis.Proposed a new design ideas for the non-stem hip prosthesis's desig n.[Methods]Using CT(computer tomography) scanning photographs of adult femur to build three-dimensional model of the femur by CAD(computer aided design) Software.Based on the the structure of Femoral model,shape memory alloy stemless hip prosthesis was designed.Biomechanical analysis of artificial hip prosthesis was made by finite element analysis(FEA).Three-dimensional finite element model were created for the normal femur,Ni-Ti shape memory alloy stemless hip prosthesis and traditional stemmed hip prosthesis.Under static loads and walking loads,the Von Mises stress distributions of each model were analyed and compared.[Results]Under static loads and walking loads,The stress distribution of shape memory alloy stemless hip prosthesis is not obviously different from normal femur. Stemless femoral prosthesis's proximal femoral stress close to that of normal femoral model but significantly higher than traditional stemmed hip prosthesis.Von Mises stress of Memory alloy claws is distributed evenly,and the Max is only 13.23Mpa,there are no stress concentration.[Conclusion](1) Ni-Ti shape memory alloy stemless hip prosthesis has great biomechanical properties may reduce the stress-shieding effect of the proximal femur.(2)The fixed way that use memory alloy claws can made prosthesis fixed firmly and reduce stress concentration.(3)Using CAD technologies to design hip prosthesis has many advantages such as high efficiency,predictable effect and design optimization.