2018-Sustainable Industrial Processing Summit
SIPS2018 Volume 4. Mamalis Intl. Symp. / Advanced Manufacturing
| Editors: | F. Kongoli, A. G. Mamalis, K. Hokamoto |
| Publisher: | Flogen Star OUTREACH |
| Publication Year: | 2018 |
| Pages: | 352 pages |
| ISBN: | 978-1-987820-88-1 |
| ISSN: | 2291-1227 (Metals and Materials Processing in a Clean Environment Series) |
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Perspective Ways for the Development of Endoprosthesis of Human Hip Implants
Sergiy Sheykin1; Athanasios G. Mamalis2; Raul S. Turmanidze3; S. Sohan4; I. Rostotskiy4; Dmitrii Vladimirovich Efrosinin5;1BAKUL INSTITUTE OF SUPERHARD MATERIALS, Kyiv, Ukraine; 2PC-NAE, DEMOKRITOS NATIONAL CENTER FOR SCIENTIFIC RESEARCH, Athens, Greece; 3GEORGIAN TECHNICAL UNIVERSITY, Tbilisi, Georgia; 4BAKUL INSTITUTE OF SUPERHARD MATERIALS, Kiev, Ukraine; 5BAKUL INSTITUTE FOR SUPERHARD MATERIALS, Kiev, Ukraine;
Type of Paper: Regular
Id Paper: 174
Topic: 48
Abstract:
Nowadays, the greatest spread in the practice of endoprosthesis replacement was obtained by a metal/UHMWPE (Ultra-high-molecular-weight polyethylene) friction pair. As a rule, in this case a CoCrMo alloy is used as the material of the metal component. However, from the point of view of biocompatibility, this alloy is not the best. Among the metals and alloys in this indicator, pure titanium is the best choice. Nevertheless, its usage as a component of the friction pair is hampered by the increased tendency to seize with structural materials (including the UHMWPE) and low mechanical characteristics.
To receive the needed level of operating specifications of friction pair, pure titanium/UHMWPE, the technology for modifying the surface layer of the spherical head by surface plastic deformation and subsequent thermal diffusion nitriding was elaborated. This technology made it possible to achieve an optimal combination of strength and adhesive inertness of the working surface of the titanium head [1]. The technology for shaping the working surface of a spherical head was developed, including preliminary precision and finishing. The technologists use tools used at the Institute of Superhard Materials. The technology made it possible to obtain a product conforming to the international standard ISO 7206-2-2013 (Ra <0.05 mm with deviation from non-circularity less than 0.006 mm). Comparative tests of nitrided pure titanium and CoCrMo alloy in pair with the surgeon performed on the ring-plane face friction machine in blood plasma (closest in composition to the synovial fluid of the natural joint) showed a clear advantage of nitrided pure titanium: friction in a pair of nitrided Grade 2 / surgical below by 25%, linear wear by 60%.
A promising alternative to the evolutionary development of the traditional endoprosthesis of the femoral head is also considered a fundamentally different technological solution— hybrid endoprosthesis of the femur head with a heart of metal and an outer layer of oxide ceramics [2]. This idea is implemented, for example, in the product with the commercial brand Oxinium™ (Smith & Nephew, Memphis, US).
The idea of a multilayer endoprosthesis of the femoral head was suggested by the authors in [3]. The outer part in the form of a spherical shell of artificial sapphire or ZrO<sub>2</sub>-ceramics has a cavity filled through a special heat-conducting technological layer in several layers by a metal core. In the metal core, there is a tapered hole for fixing the head. Due to the use of sapphire (it does not have harmful impurities in the interstitial space), such endoprosthesis is chemically inert, is electrically neutral, has an increased wettability of the surface, and has biological compatibility (activity). An additional advantage of this technical solution is the possibility of introducing a layer of polymer material that improves the damping properties of the endoprosthesis.
Keywords:
Ceramic; Materials; Mechanical; Metal; Optimization; Polymer; Processing; Technology;References:
[1] Increasing of functionality of c.p. titanium/UHMWPE tribo-pairs by thermodiffusion nitriding of titanium component / I.M. Pohrelyuk, S.E. Sheykin, S.M. Dub, A.G. Mamalis, I.Yu. Rostotskii, O.V. Tkachuk, S.M. Lavrys // Biotribology Volume 7, September 2016, Pages 38-45.[2] Pezzotti, G. Artificial hip joints: The biomaterials challenge / G. Pezzotti, K. Yamamoto / J. Mech. Behav. Biomed. Mat. 3 1 (2014) 3-20.
[3] Спосіб виготовлення головки ендопротеза кульшового суглобу: пат. 105064 U Україна МПК А61F2/32 (2006.1) / С.В. Сохань, Л.Ф. Головко, Н.О. Мельник-Кагляк, 201503079; заявл. 03.04.2015; опублік. 10.03.2016, Бюл. 5-3 с.