Fretting-corrosion behavior in hip implant modular junctions: The influence of friction energy and pH variation
By Dmitry Royhman and Megha Patel and Maria J. Runa and Markus A. Wimmer and Joshua J. Jacobs and Nadim J. Hallab and Mathew T. Mathew
Published in Journal of the Mechanical Behavior of Biomedical Materials
2016
Abstract
AbstractBackground Recently, there has been increasing concern in the orthopedic community over the use of hip implant modular devices due to an increasing number of reports of early failure, failure that has been attributed to fretting-corrosion at modular interfaces. Much is still unknown about the electrochemical and mechanical degradation mechanisms associated with the use of such devices. Purpose Accordingly, the purpose of our study was to develop a methodology for testing the fretting-corrosion behavior of modular junctions. Methods A fretting-corrosion apparatus was used to simulate the fretting-corrosion conditions of a CoCrMo hip implant head on a Ti6Al4V hip implant stem. The device features two perpendicularly-loaded CoCrMo pins that articulated against a Ti6Al4V rod. A sinusoidal fretting motion was applied to the rod at various displacement amplitudes (25, 50, 100, 150 and 200 ?m) at a constant load of 200 N. Bovine calf serum at two different pH levels (3.0 and 7.6) was used to simulate the fluid environment around the joint. Experiments were conducted in two modes of electrochemical control