Only a doctor can tell if you need a joint replaced. He or she will look at your joint with an x-ray machine or other machines. The doctor may put a small, lighted tube (arthroscope) into your joint to look for damage. A small sample of your tissue could also be tested.
After looking at your joint, the doctor may say that you should consider exercise, walking aids like braces or canes, physical therapy, or medicines and supplements. Medicines for arthritis include drugs that reduce inflammation. Depending on the type of arthritis, the doctor may prescribe corticosteroids or other drugs. However, all drugs may cause side effects, including bone loss.
If these treatments do not work, the doctor may suggest an operation called an osteotomy (aas-tee-AAHT-oh-me), where the surgeon "aligns" the joint. Here, the surgeon cuts the bone or bones around the joint to improve alignment. This may be simpler than replacing a joint, but it may take longer to recover. However, it is not commonly done today.
Joint replacement is often the answer if you have constant pain and can't move the joint well; for example, if you have trouble with things like walking, climbing stairs, and taking a bath.
Source By :niams.nih.gov
The femoral component is made of a metal stem with a metal ball on the end. Some prosthesis have a metal head on upper end attached to the metal stem. The acetabular component is a metal shell with a plastic inner liner that acts like a bearing. The type of plastic used is highly cross linked ultra high molecule weight Polyethylene which is wear resistant.