Elemental and morphological identification of third-body particulate and calcium stearate inclusions in polyethylene components

Third-body particulate such as human bone chips, hydroxyapatite, and bone c ement are considered contributing factors in accelerated wear in total join t replacement. Particulate wear debris is now considered the major contribu ting factor in aseptic loosening of total joint replacements. The ability t o distinguish between different third-body particulate is necessary to bett er understand wear mechanisms when conducting implant retrieval analysis. T he objective of this investigation is to demonstrate that backscattered ele ctron imaging with correlated energy dispersive S-ray analysis can accurate ly identify third-body particulate in retrieved polyethylene components. It is important that this technique can also distinguish between third-body p articulate and normal inclusions in the polyethylene such as calcium steara te, based on the distinct morphology and elemental composition of each mate rial. Therefore, the ability to distinguish third-body particulate from cal cium stearate inclusions is essential in gaining a better understanding of the contributing factors associated with coating separation and accelerated wear observed in clinically retrieved polyethylene components. (C) 2000 Jo hn Wiley & Sons, Inc.