There are two major types of artificial hip replacements: a cemented prosthesis and an uncemented prosthesis. Both are widely used. The choice is usually made by the surgeon based on your age, your lifestyle, and the surgeon's experience.

Each prosthesis is made up of two parts:

• The acetabular shell (socket portion) replaces the acetabulum. The acetabular component is made of a metal shell with a medical grade plastic or metal inner socket liner that acts like a bearing.

• The femoral component (stem portion) replaces the femoral head. The femoral component is made of metal. The femoral head that attaches to the stem may be a separate part. It is made either of metal or ceramic, although metal is more common.

A cemented prosthesis is held in place by a type of epoxy cement that attaches the metal to the bone.

An uncemented prosthesis has a fine mesh of holes on the surface that allows tissue to grow into the mesh and attach the prosthesis.