High resolution finite element modeling of cemented bone-implant interface using X-ray microtomography

Abstract

The aim of the research was to investigate the cemented bone-implant interface behavior. To determine the degradation caused by mechanical loading both numerical and experimental approach have been used. The main problems (cement layer degradation and bone-cement interface debonding) during physiological loading conditions have been investigated using a custom hip simulator. The experimental setup was designed to allow cyclic loading of a sample of pelvic bone with implanted cemented acetabular component. The hip contact force of required direction and magnitude was applied to the implant using a spherical femoral component head. The most unfavorable activity (downstairs walking) was simulated in two million cycles with 4Hz frequency. The process of damage accumulation in cement fixation was monitored by repeated scanning using high resolution micro-focus X-ray Computed Tomography (microCT). Use of micro-focus source and large high resolution flat panel detector allows investigation of structural changes as well as development of full-scale micro-structural models. Three-dimensional high resolution finite element model was reconstructed from the microCT data. The FE model is suitable for prediction of bone-implant interface behaviour.