Shape optimal design of the stem of a cemented hip prosthesis to minimize stress concentration in the cement layer.

Abstract

An optimal shape of the metal stem of a cemented total hip prosthesis minimizing stress concentration in the cement layer was searched for. A gradient projection method of numerical optimization and a finite element method of stress analysis were employed. A two-dimensional model of the femoral part of a total hip prosthesis was derived equivalent to a simplified three-dimensional axisymmetric model. The result of the stress analysis of the two-dimensional model compared favorably with that of the three-dimensional axisymmetric model. Using this two-dimensional model, an optimal shape of the stem, minimizing stress concentration in the cement layer, was obtained by a gradient projection method and the shape was checked again by the three-dimensional finite element analysis. The resulting optimal shape of the stem profile was in good agreement with conventional ones, except in the proximal region where a significant amount of stress reduction in the cement layer was achieved by tapering the stem to the limit that the stem still could withstand the increased stem stress.

Cite this paper

@article{Yoon1989ShapeOD, title={Shape optimal design of the stem of a cemented hip prosthesis to minimize stress concentration in the cement layer.}, author={Y S Yoon and Gwang Hoon Jang and Yunki Kim}, journal={Journal of biomechanics}, year={1989}, volume={22 11-12}, pages={1279-84} }