| Description |
More than 285,000 total hip replacement (THR) surgeries are performed in the United States each year. Most prosthetic hip joints consist of a cobalt-chromium (CoCr) femoral head that articulates with a polyethylene acetabular component lubricated with synovial fluid. The statistical survivorship of these metal-on-polyethylene prosthetic hip joints declines significantly after 10 to 15 years of use, primarily as a result of polyethylene wear and wear debris incited disease. The current engineering paradigm to increase the longevity of prosthetic hip joints is to manufacture ultra-smooth articulating surfaces. In contrast, this work shows that adding a patterned microtexture to the ultra-smooth CoCr femoral head reduces friction when articulating with the polyethylene acetabular liner. The microtexture increases the load-carrying capacity and the thickness of the joint lubricant film, which reduces contact between the articulating surfaces. As a result, friction and wear is reduced. A lubrication model is used to design the geometry of the patterned microtexture, and we experimentally demonstrate reduced friction for the microtextured compared to conventional smooth surrogate prosthetic hip joints. |
