Health Topic

Knee Replacement

Knee replacement surgery (or knee arthroplasty) provides artificial knees in place of your damaged knees to restore function and relieve pain.

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Also called: Knee arthroplasty

Important: This page is general information, not medical advice. It does not recommend or prescribe any treatment. Always consult your doctor or pharmacist before starting, stopping or changing any medicine.

About Knee Replacement

Knee replacement surgery is a surgery to replace parts of your knee joint with new, artificial parts. You may need a knee replacement if you have knee damage that causes severe pain and difficulty doing daily activities, such as walking and climbing stairs. It is usually done when other treatments for knee pain haven't helped enough. The goal of a knee replacement is to relieve pain and help you move better.

People of all ages may have knee replacement surgery. But it is more common in older people. The decision whether to have surgery is based on your overall health and how much your knee bothers you.

Knee replacement surgery treats conditions that cause the cartilage of the knee joint to wear away. These include:

  • Knee osteoarthritis. This is the most common reason for knee replacement surgery. It usually develops over time after an injury or with aging.
  • Knee damage from other types of arthritis.
  • Problems from knee joints that aren't formed correctly.

During the surgery, a surgeon removes damaged cartilage and some bone from the surfaces of your knee joint. Cartilage is tissue that covers your bones where they meet. Healthy cartilage is smooth and helps the bones glide over each other when you move. When cartilage becomes rough and wears away, the bones rub against each other, causing pain.

After removing the damaged knee cartilage and bone, the surgeon attaches the artificial parts to your bones. The artificial parts are made of metal and plastic. They will give your knee new, smooth surfaces.

Knee replacement surgery may replace all the damaged parts of your knee (total knee replacement) or just part of your knee (partial knee replacement). In a total knee replacement, the surgeon replaces 3 surfaces:

  • The end of the shinbone
  • The end of the thighbone
  • The back of the kneecap

Some people go home the same day they have surgery. Other people will stay in the hospital a few days. To help prevent blood clots, you'll most likely take blood thinners and wear special socks or coverings on your legs for a short time after surgery.

The success of your surgery depends a lot on what you do at home to help yourself recover. A physical therapist will teach you exercises to make your knee stronger and help it bend. It is important to do these exercises regularly. You may need to use a cane or walker for several weeks after the surgery. It will probably also be several weeks before you can drive. Your doctor will tell you when you can start driving again.

Most people who follow their recovery instructions can get back to nearly all of their normal daily activities within 3 to 6 weeks after surgery.

After recovering from surgery, most people can move better with less pain than before surgery. But having an artificial knee is not the same as having a normal, healthy knee.

You need to protect your new knee by:

  • Staying at a healthy weight.
  • Getting regular physical activity.
  • Not doing any high-impact activities, such as jogging, running, and jumping. Instead, you can try low-impact activities that are good for your knee, such as walking, biking, and swimming

The chance of having problems after knee replacement surgery is low. But there are risks after any surgery. Possible problems after knee replacement surgery include:

  • Infection
  • Blood clots
  • Heart attack
  • Stroke
  • Nerve damage
  • Scarring that limits how far you can bend your knee

Your age, general health, and how active you are can all affect your risk of having a problem after knee replacement surgery.

A knee replacement doesn't last forever. After 15 to 20 years, the artificial knee parts may become loose or worn. If that happens, you may need another surgery on the same knee.

If you're thinking about having knee replacement surgery, talk to your doctor about the risks and benefits. Together you can decide if a knee replacement is right for you.

It sits within Bones, Joints and Muscles and Surgery and Rehabilitation.

The lead U.S. institute for this subject is the National Institute of Arthritis and Musculoskeletal and Skin Diseases.

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Research on Knee Replacement

3,001 studies areregistered for this condition on ClinicalTrials.gov, the U.S. National Library of Medicine's public registry. A selection is below — the links go straight to the registry entry, not to a summary of ours.

What a registered study does and does not mean. Registration means a study exists and has been declared publicly. It says nothing about whether the treatment being tested works, is safe, or is available to you. Many studies find no benefit — that is what research is for. Never seek out an experimental treatment on the strength of a registry entry alone.

Research currently under way

Research already completed

Study data from ClinicalTrials.gov, a service of the U.S. National Library of Medicine. Retrieved 2026-07-30. Registry entries are supplied by study sponsors and investigators; ClinicalTrials.gov does not verify their scientific validity. PocketsInfo is not affiliated with, and not endorsed by, the NLM or the NIH.

Where to read more

Rather than paraphrase, we point you to the primary sources. Every link below is to a government health agency, a national institute or a recognised medical body — grouped by what you are trying to find out.

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Medical subject headings

Clinicians and researchers index this subject under Arthroplasty, Replacement, Knee. These are the terms to use when searching medical literature.

This page is built from the MedlinePlus health topic record for Knee Replacement, a service of the U.S. National Library of Medicine (NLM), National Institutes of Health. Information is from MedlinePlus.gov. PocketsInfo is not affiliated with, and is not endorsed by, the NLM or the NIH. Retrieved 30 July 2026.