Towards the optimal design of an uncemented acetabular component using genetic algorithms

Abstract

Aseptic loosening of the acetabular component (hemispherical socket of the pelvic bone) has been mainly attributed to bone resorption and excessive generation of wear particle debris. The aim of this study was to determine optimal design parameters for the acetabular component that would minimize bone resorption and volumetric wear. Three-dimensional finite element models of intact and implanted pelvises were developed using data from computed tomography scans. A multi-objective optimization problem was formulated and solved using a genetic algorithm. A combination of suitable implant material and corresponding set of optimal thicknesses of the component was obtained from the Pareto-optimal front of solutions. The ultra-high-molecular-weight polyethylene (UHMWPE) component generated considerably greater volumetric wear but lower bone density loss compared to carbon-fibre reinforced polyetheretherketone (CFR-PEEK) and ceramic. CFR-PEEK was located in the range between ceramic and UHMWPE. Although ceramic appeared to be a viable alternative to cobalt–chromium–molybdenum alloy, CFR-PEEK seems to be the most promising alternative material.

Keywords:

• acetabular component
• bone remodelling
• wear
• multi-objective optimization
• genetic algorithm

Acknowledgements

The authors wish to thank Department of Biotechnology, New Delhi, for supporting this study. The authors are also thankful to Mr Kaushik Mukherjee, Ms Debatri Ghosh and Mr Souptick Chanda for their help and suggestions.