RELIABILITY OF MODERN CERAMIC HIP COMPONENTS

INTRODUCTIONCeramic hip components are known for their superior material properties and longevity. In comparison to other materials commonly used, ceramics have a very low friction coefficient and a high fracture load. However, even though in-vivo fractures of ceramic ball heads are a relatively rare occurrence compared to other reasons for revision, they are of concern to the surgeon using ceramic components. The goal of this work was to evaluate the most probable causes for fracture and to quantify the influence of the metal taper contamination and shell deformation, respectively.METHODSAn experimental set-up imitating the in-vivo loading situation was used to analyze different scenarios that may lead to the fracture of the ball heads, such as dynamic loading, edge loading and the metal taper contamination.58 ceramic ball heads made of pure alumina were loaded until fracture under various conditions. Parameters under investigation were the inclination of the insert, the loading velocity, and the contami...