Tantalum as a buffer layer in diamond-like carbon coated artificial hip joints.
The acid resistance of tantalum coated and uncoated human hip joint prostheses was studied with commercial CrCoMo acetabular cups. The samples were exposed to 10% HCl solution and the quantities of dissolved Cr, Co, and Mo were measured with proton-induced X-ray emission (PIXE). The absolute quantities were obtained with the use of Cr and Se solution standards. Tantalum coatings (thicknesses 4-6 microm) were prepared in vacuum with magnetron sputtering. Tantalum coating decreased the corrosion rate by a factor of 10(6). As a spinoff from recent wear tests on artificial hip joints it was shown that tantalum has excellent mechanical properties as an intermediate layer of diamond-like carbon (DLC) coatings. When tantalum was tested together with DLC on three metal-on-metal hip joint pairs in a hip simulator, no observable defects occurred during 15 million walking cycles with a periodic 50-300-kg load (Paul curve).
Kiuru
Mirjami
M
Department of Physical Sciences, University of Helsinki, P. O. Box 64, FIN-00014, University of Helsinki, Finland. mirjami.kiuru@helsinki.fi
Alakoski
Esa
E
Tiainen
Veli-Matti
VM
Lappalainen
Reijo
R
Anttila
Asko
A
D000143:Acids; D001672:Biocompatible Materials; D001696:Biomechanical Phenomena; D002244:Carbon; D003343:Corrosion; D018130:Diamond; D019544:Equipment Failure Analysis; D006622:Hip Prosthesis; D006801:Humans; D066298:In Vitro Techniques; D008422:Materials Testing; D011474:Prosthesis Design; D012107:Research Design; D013499:Surface Properties; D013635:Tantalum
D000143:Acids; D001672:Biocompatible Materials; D013635:Tantalum; D002244:Carbon; D018130:Diamond