Perrichon Armelle, Reynard Bruno, Gremillard Laurent, Chevalier Jérôme, Farizon Frédéric, Geringer Jean
Ecole Nationale Supérieure des Mines de Saint-Etienne, CIS-EMSE, SAINBIOSE, INSERM U1059, F-42023 Saint-Etienne, France; Université de Lyon, F-69000 Lyon, France.
Laboratoire de Géologie de Lyon, Université de Lyon, Ecole Normale Supérieure de Lyon, Université Claude Bernard Lyon 1, CNRS, 46 Allée d'Italie, 69364 Lyon Cedex 07, France.
J Mech Behav Biomed Mater. 2017 Jan;65:600-608. doi: 10.1016/j.jmbbm.2016.09.019. Epub 2016 Sep 19.
Ceramics are materials of choice for hip joint implants because of their excellent biocompatibility and mechanical properties. Wear of the bearing couple (femoral head and cup) remains one of the main concerns of hip implants. Although ceramics are known for their good tribological properties, shocks due to micro-separation, friction and hydrothermal ageing in physiological environment remain the three main sources of wear. It has been recently suggested that shock effects dominate but the three degradation mechanisms were so far simulated separately. We developed a procedure that combines sequences of shocks, hydrothermal ageing in an autoclave and friction on hip-walking simulator to investigate their combined effects on Zirconia Toughened Alumina (ZTA) implants. Our results confirm that shocks can be considered as the key phenomenon causing wear, and that their effect is independent of friction and hydrothermal degradation. The analysis of retrieved femoral heads reveals wear features comparable to the ones created experimentally by shocks. Standards (ASTM or ISO) could be improved by including shock tests, which are more relevant than wear tests currently performed on hip simulators at least for Ceramic-on- Ceramic couplings.
由于具有出色的生物相容性和机械性能，陶瓷是髋关节植入物的首选材料。承重副（股骨头和髋臼杯）的磨损仍然是髋关节植入物的主要问题之一。尽管陶瓷以其良好的摩擦学性能而闻名，但在生理环境中，微分离、摩擦和热液老化引起的冲击仍然是磨损的三个主要来源。最近有人提出冲击效应占主导地位，但到目前为止，这三种降解机制是分别模拟的。我们开发了一种程序，该程序结合了冲击序列、高压釜中的热液老化以及髋关节步行模拟器上的摩擦，以研究它们对氧化锆增韧氧化铝（ZTA）植入物的综合影响。我们的结果证实，冲击可被视为导致磨损的关键现象，并且其影响与摩擦和热液降解无关。对回收的股骨头的分析揭示了与冲击实验产生的磨损特征相当的磨损特征。通过纳入冲击试验，标准（ASTM或ISO）可以得到改进，至少对于陶瓷对陶瓷耦合而言，冲击试验比目前在髋关节模拟器上进行的磨损试验更具相关性。
