In the USA for example, more than a half a million Americans opt for this procedure every year. Is it necessary?
Many people have knee replacements (also called knee arthroplasty) because they have osteoarthritis. This condition occurs when the cartilage (tissue) that cushions the knee joint wears away. As a result, bone rubs against bone, which is quite painful. Other people may need a new knee because they have rheumatoid arthritis, a disease that causes painful chronic joint inflammation. Still others may have had an injury causing knee pain and limiting movement. Such conditions are known to cause gradual worsening of knee pain over time. It is however not always easy to know when knee replacement surgery is necessary. You and your doctor need to take several factors into account in deciding if (or when) joint replacement is right for you.