Lubricación in vitro en prótesis articulares

Understanding premature wear in joint replacements due to poor lubrication, which can result in high friction values, is a broad and intricate topic to address. In addition, if the lubricant is the synovial fluid, the lubrication mechanisms that occur are even more complex to unveil. This article reviews the current state of knowledge on synovial lubrication, as well as the rheological characteristics of the lubricating fluid. It is also made a mention of some experimental techniques and numerical methods with which the problem of lubrication has been studied. In some numerical simulations of lubrication in joint replacements the effect of the shear stress of the synovial fluid is not considered since it is assumed to have a Newtonian behavior; however, other research has shown that by assuming a non-Newtonian behavior the lubrication process is significantly affected. With all this, incorporating all the factors that can affect lubrication in joint replacements, in numerical simulations to date is a challenge. Through various investigations, new materials, designs and analysis techniques are sought to increase the useful life of implants in order to reduce revision surgeries.