Material selection in the design of the femoral component of cemented total hip replacement

The finite element stress analysis technique can be used to optimise both design and materials selection in many load-bearing components. Three-dimensional finite element models for a femur implanted with a cemented prosthesis were constructed with a representative physiological loading condition. The effect of prosthesis Young’s modulus and cement Young’s modulus on stresses in the prosthesis stem and cement layer was studied. A range of materials was considered for the stem and cement, enabling the derivation of two equations predicting the maximum principal stress in either material when any combination of materials is used. The materials selection criterion is proposed based on fatigue strength.