Evaluation of phase stability in zirconia femoral heads from different manufacturers after in vitro testing or in vivo retrieval.
Yttria-stabilized zirconia femoral heads from 3 different manufacturers were tested in vitro with respect to their phase stability and compared with retrieved zirconia heads. The monoclinic content on the surface of unused heads was analyzed by confocal Raman spectroscopy after exposure for increasing times to moist atmosphere. The increase in monoclinic content was then plotted as a function of geometric location on the head surface of the head and compared with that measured at similar locations after in vivo exposure. Profiles of residual stress associated to polymorphic transformation were also measured from the collected Raman spectra. A striking finding was that, in some samples, polymorphic transformation occurred since the very early stage of the environmental exposure even if those samples belonged to new-generation products.
Fukatsu
Kyoju
K
Research Institute for Nanoscience, Kyoto Institute of Technology, Sakyo-ku, Kyoto, Japan.
Pezzotti
Giuseppe
G
Hayaishi
Yasuhisa
Y
Sugano
Nobuhiko
N
D019644:Arthroplasty, Replacement, Hip; D001672:Biocompatible Materials; D019544:Equipment Failure Analysis; D006622:Hip Prosthesis; D006801:Humans; D066298:In Vitro Techniques; D011474:Prosthesis Design; D011475:Prosthesis Failure; D013059:Spectrum Analysis, Raman; D015040:Zirconium
D001672:Biocompatible Materials; D015040:Zirconium; C028541:zirconium oxide