Effects of in vitro shocks and hydrothermal degradation on wear of ceramic hip joints: Towards better experimental simulation of in vivo ageing

摘要: In an ageing world population, increasing the lifetime of orthopedic devices is vital importance for reducing surgical risks patients and medical costs. Ceramic materials are gaining interest because their hardness chemical inertia with respect to metal prosthesis. Wear prosthetic couple (femoral head cup) one main rationales using ceramic hip implants, they induce much lower wear debris. The present study investigates combined effects shocks due microseparation hydrothermal on Zirconia Toughened Alumina (ZTA) bearings, which have been under strong development these past ten years. stripe patterns formed femoral heads tested a shock device. 3D profilometry used evaluate volume worn material released from that averages at 0.46mm 3 /year during simulation mimicking about 15 years ageing. This larger than formerly estimated walking simulators microseparation, effect we tentatively attribute force (9000 N) applied here where was not specified. experiment should allow refining head, hence simulate different patient conditions (weight, activity, accidents,...). Micro Raman spectroscopy reveals significant zirconia phase transformation within stripes. ZTA components show minor degradation in autoclave when compared changes induced by shocks. Finally, five clinically retrieved bearings characterized vivo comparison, also reveal track areas. association enhancement areas samples indicates shocks, rather Shock simulations therefore essential vitro experimentation aiming reproducing implants environment. On material's point view, it shown ceramics can exhibit beneficial stress, may limit stripes, without suffering