Question

Would a synthetic emerald potentially make a good articulating surface for artificial hip implants? Why or why not? 1)

Answer 1

Aluminum oxide or alumina has been used since 197 as a bulk material in the manufacture of components of the prosthesis and is the inert ceramic most commonly used for surgical implants. It is found in nature as corundum in emery, topaz, amethyst, and emerald. However, it is from the more abundant ores such as bauxite and cryolite and from clays that the material is commercially extracted and purified.

The alumina is used as an articulating surface in hip and knee joints. The ability to be polished to a high surface finish makes it an ideal candidate for this wear application, where alumina operates against materials such as ultrahigh molecular weight polyethylene and alumina itself.

1. Surely the synthetic emerald potentially makes a good articulating surface for artificial implants because due to its ability to be polished to a high surface finish and its excellent wear resistance, this is often used for wear surfaces in joint replacement prosthesis. This application includes femoral heads for hip replacements.

In hip replacements, the alumina femoral head is used in conjunction with a metallic femoral stem and an acetabular cup made from ultra-high-molecular-weight polyethylene or alumina itself for the opposing articulating surfaces.

The success rates depend upon:

a)The frictional and wear behavior of the materials

b)The reliability of the anchorage of the components in their bony environment

Advantages:

-The main advantage is, it not only eliminates the polyethylene from the device system but its extremely low coefficient of friction and potential for far superior wear resistance are very advantageous.

-The usual biologic event is a fibrocytic reaction with very few macrophages and no giant cells.

-Unless there is metallic debris or a very large amount of ceramic debris generated by abnormal contact, or following a long period of component loosening.

-The rate of implant survivorship is satisfactory.