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Knee replacement

5-minute read

Key facts

  • A knee replacement is when doctors remove your damaged knee joint and put in a new knee joint.
  • Knee replacements are usually a last option for severe knee pain.
  • Knee replacements may be total (the whole joint is replaced) or partial (part of your joint is replaced).

What is a knee replacement?

A knee replacement is when doctors remove your damaged knee joint and put in a new knee joint. The new joint is artificial, or man-made.

A knee replacement is an operation that is done in hospital. A knee replacement is also called a knee arthroplasty.

A knee replacement can help:

  • reduce knee pain
  • you to be more active
  • improve your flexibility
  • you to move more freely

They can help when medicines and other treatments have not been helpful in managing pain. Knee replacements may be total (the whole joint is replaced) or partial (part of your joint is replaced).

When is a knee replacement needed?

Knee replacements are usually thought to be a last option to treat severe knee pain that does not go away.

The most common reason for a knee replacement is osteoarthritis. This condition can lead to ongoing pain. Some people also find their joints are very stiff. Osteoarthritis can impact your quality of life.

Knee replacement can also be done if someone has a disability. This can happen after other things have been tried to help reduce pain.

Most people who have a knee replacement are over 60 years of age. If you have a knee replacement when you're under 50 years, you may need another operation in later life.

How do I prepare for a knee replacement?

Your doctor will tell you what you need to do to prepare for surgery. You will be asked to fast (not to eat) before your surgery.

You may also need to stop taking certain types of medicine. You can read more about what you need to do in healthdirect's preparing for surgery article.

What happens during a knee replacement?

In a total knee replacement, the surgeon removes bone from the outside of your knee joint. The surgeon also removes any damaged cartilage. Cartilage is the tissue at the ends of bones that cushions the joints.

The removed bone and cartilage are replaced with an artificial joint. This man-made joint is made of metal and plastic.

In a partial knee replacement, only the damaged part of the knee joint is replaced. The healthy parts are left alone.

Recovering from a knee replacement

Most people leave hospital 1-4 days after a knee replacement surgery. How quickly you get back to normal depends on many factors, such as your age, general health and fitness.

You will probably need a cane, crutches or walking frame in the first few weeks. You will also be given an exercise and physiotherapy program. This will help you recover.

Most people's strength and flexibility slowly recovers over about 12 months. Doing the exercises given to you makes the recovery quicker.

Possible complications of knee replacement surgery

Knee replacement surgery is generally thought to be safe and effective. However, complications can include:

  • infections
  • blood clots in the leg veins
  • problems with the new joint
  • continued pain
  • injury to your nerves or blood vessels during surgery

After surgery, you need to watch for any signs of a blood clot, such as:

  • if your calf becomes red, swollen or painful
  • if you become short of breath or have chest pain

If these happen, go straight to the hospital emergency department. These could be signs of a blood clot in your leg or your lungs.

Should I have a knee replacement?

To help you decide whether to have a knee replacement, you can ask your surgeon questions such as:

  • What can I do instead of surgery?
  • What are the possible problems and how likely are they?
  • What can I expect during the recovery period?
  • How much improvement is normal after surgery?
  • Would a new knee last all my life?

ASK YOUR DOCTOR — Preparing for an appointment? Use the Question Builder for general tips on what to ask your GP or specialist.

Are there any alternatives to a knee replacement?

Alternatives to surgery depend on what's wrong with your knee joint.

If you have arthritis, other options to try before knee replacement may include:

Resources and support

You should talk to your health professional about the pros and cons of getting a medical implant. Use the Therapeutic Goods Administration's guide on what to ask. The guide is in English and other languages. These include Arabic, Croatian, Farsi, Greek, Italian, Korean, Mandarin, Spanish, Turkish and Vietnamese.

To find out more about different types of knee replacements, visit healthdirect's pages on:

Learn what you need to do to prepare for surgery.

If you want to know more about knee replacements, you can call the healthdirect helpline on 1800 022 222 (known as NURSE-ON-CALL in Victoria). A registered nurse is available to speak with 24 hours a day, 7 days a week.

Learn more here about the development and quality assurance of healthdirect content.

Last reviewed: August 2023

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