Knee Replacement

What Is a Knee Replacement?

A knee replacement is a type of surgery in which parts of a damaged or diseased knee joint are removed and replaced with parts made of metal, plastic, or ceramic. Knee-replacement surgery is also known as knee arthroplasty.


The main symptoms of a knee that needs to be replaced are extreme pain and stiffness. When everyday activities like walking and climbing stairs become too difficult to do because of pain, your doctor may recommend knee-replacement surgery.

Causes and Risk Factors

Age is a major risk factor. The average age of a person having a knee replaced is 66.

The most common reason for a knee replacement is osteoarthritis. Osteoarthritis is a disease that damages the cartilage that helps joints move smoothly. When that cartilage breaks down, the bones in the joint begin to rub against each other. This can lead to pain and stiffness.

Treatment Options

Your doctor may suggest other options before recommending knee replacement. These include:

  • Using a cane or some other device to help with walking
  • Exercise to strengthen the knee joint
  • Medication to relieve pain

If other treatments don’t help, your doctor may take an X-ray of your knee or a tissue sample from inside your knee to decide if there is enough damage to recommend a knee replacement.