What hip replacement materials exist? What are the different material options for hip replacement and their pros and cons?
Hip Materials. Engineers are always trying new materials in hope of making hips last longer. Sadly most of the new materials have not worked as well for the majority of patients. Ceramics break and squeak, metal on metal has caused some problems for patients with metal reactions, leaving metal on plastic (the old fashioned way) as the best answer for most patients. The plastics are newer and may last longer.
This . This is a very complicated question and could be the topic of an extensive ongoing research. Presently, hip replacements are either metal-on-poly or metal-on-metal. Poly refers to polyethylene, a plastic like synthetic material commonly used to like the socket of the hip joint. The ball part, also called the proximal femur, is typical metallic, and is usually made of an amalgam of cobalt and chromium. If the socket is metallic as well, this would be called a metal-on-metal prosthesis. There are numerous advantages and disadvantages to each. Metal-on-metal is valued for its presumed durability, but many have cited concerns about the metal ion wear particles that are created through normal use and get into the bloodstream and are excreted by the kidneys. Metal-on-poly produces polyethylene wear particles, which are larger in size and less numerous. These do not get into blood circulation. They do however trigger cells in the immune system to release inflammatory mediators that can lead to loosening of the implants, which can cause the joint to fail. Ceramic implants are also available. These are made of glasslike substances that are very hard and do not produce much wear at all. However, they are prone to catastrophic failure by cracking, and as a result are not commonly used in this country.