Ultrastructural characterization of soft tissues surrounding implanted hipprosthesis by complementary PIXE and TEM methods

We study soft tissues surrounding hip prostheses from three different patie nts. We evaluate the elemental composition of different fragments. The tiss ues are examined by means of two complementary methods in such analysis: Pa rticle Induced X-ray Emission (PIXE) and Scanning Transmission Electron Mic roscopy (STEM) coupled with X-ray microanalysis (Energy Dispersive X-ray, E DX). These methods allow to determine locally at 'macro' and 'micro' level the chemistry of soft tissues. The findings confirmed the presence of metal in soft tissue near the three different hips. The tissues' composition und ergoes important modifications with a systematic elevation of trace metal i n patients with failed implants. We observe a corrosion which causes the co ntinual release of particles into the tissues. Corrosion alters the shape s ize and chemical composition of wear particles embedded in soft tissue arou nd the failed hip. EDX analysis showed that the wear particles contained va rying quantities of titanium and aluminium. This phenomenon may be related with the variation of time of contact with soft tissues for each particle a nd Ti solubility. (C) 1999 Elsevier Science B.V. All rights reserved.