Geometric effect of stem on stress distribution and prosthesis failure

The geometry of the stem in a femoral prosthesis plays an important role in stress distribution and the rate of osteoporosis. Using the finite element method the geometrical effect of a femoral prosthesis on stress distribution in bone, cement and lateral edge of stem are obtained. Stress distribution in bone is a highly dependent on the curvature and length of the stem. Some models are considered for each factor. Using several models in implementing the load these effects are calculated. Results indicate that larger curvature and length causes uniform stress distribution in bone, and ultimately higher reliability.