Multi-elemental nanoparticle exposure after tantalum component failure in hip arthroplasty: In-depth analysis of a single case.

Porous tantalum components are widely used for complex acetabular reconstructions in revision hip arthroplasty. Multiple other metal alloys such as titanium-aluminum-vanadium or cobalt-chromium-molybdenum are principally used in artificial joint setups. We report a case of tantalum component failure being both cause and effect of a multiple metal exposure. Our aims were to assess and to characterize associated particle exposure and biological consequences. Metal level quantification revealed substantial in vivo exposure to particulate and dissociated tantalum, zirconium, chromium, cobalt, molybdenum, titanium, aluminum and vanadium in periprosthetic compartments. Aside from micron-sized particles, nanoparticles of a broad size range and elemental composition were obtained. Histological exams verified a spectrum of necrotic changes in the periprosthetic tissues. In the presented case tantalum release was accompanied by concomitance of particles originating from other utilized metals. We conclude that an overall in vivo exposure assessment is mandatory for realistic appraisal of metal toxicity and associated risks.