Knee replacement

A knee replacement is when a surgeon replaces your knee joint with a new knee joint that is artificial (man-made). A knee replacement is sometimes called a knee arthroplasty.

Knee replacements may be:

• total — this is when the whole joint is replaced
• partial — this is when only part of your joint is replaced

A knee replacement may be recommended when medicines and other treatments have not helped with your symptoms. The most common reason for a knee replacement is osteoarthritis. Osteoarthritis is a joint condition that causes pain, stiffness or reduced movement.

Knee replacements are usually the last option to treat chronic (long-lasting) and severe knee pain. A knee replacement can help:

• reduce your knee pain
• improve movement in your knee

If you have a knee replacement, you may need another operation in later life. This is because knee replacements will wear out over time. How long a knee replacement lasts is different for everyone and depends on factors such as your:

• weight
• level of activity
• age when you have the procedure 

During a knee replacement, the surgeon will replace your damaged joint with an artificial joint.

To replace your knee joint, the surgeon will remove the damaged bone and cartilage (cushioning between the bones). The surgeon will then insert an artificial joint. This is usually held in place with a special bone cement. 

If you have a total knee replacement, the surgeon will remove bone and cartilage from both sides of your knee joint. If you have a partial knee replacement, only the damaged part of the knee joint is replaced.

You will have a general anaesthetic (medicine that puts you to sleep) while having a knee replacement.

Your doctor will tell you what you need to do to prepare for a knee replacement. 
You will be asked to fast (not to eat) before your surgery. You may also need to stop taking certain types of medicine.

Your doctor may recommend you see a physiotherapist for strengthening exercises before your surgery.

Read more about preparing for surgery.

Most people leave hospital 2 to 4 days after a knee replacement. How quickly you leave hospital depends on many factors, such as:

• your age
• your general health and fitness
• whether you have a partial knee replacement or a total knee replacement 

You may be given pain-relief medicines and anti-inflammatory medicines to take after you leave hospital. Your doctor will talk with you about how long to take these medicines for.

You may also need a cane, crutches or walking frame for a few weeks after surgery. 
You will be given an exercise program to strengthen the muscles around your knee. While you are recovering, you should avoid activities that involve jumping or twisting. Your surgeon will talk with you about what activities you can do while you are recovering.

Most people make a full recovery from a knee replacement after about one year.

Knee replacement surgery is generally very safe and effective. However, complications can include:

• infection of the wound
• problems with the new joint
• ongoing pain
• injury to your nerves or blood vessels during surgery

After surgery, you should watch for any signs of a deep vein thrombosis (blood clot), such as:

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

If you experience any signs of a deep vein thrombosis after a knee replacement, go straight to the nearest hospital emergency department.

You can help lower your chance of developing a deep vein thrombosis by:

• following your doctor’s instructions about specific exercises after surgery
• taking anticoagulant medicines (blood thinners), if prescribed

Alternatives to knee replacement surgery depend on what is causing your knee pain.
Some treatments to try before having a knee replacement may include:

• low-impact exercise such as swimming, walking or cycling 
• losing weight if you're overweight — this can reduce the strain on your knee
• physiotherapy to help strengthen the muscles around your knee
• wearing special footwear or insoles in your shoes 
• pain-relief medicines or anti-inflammatory medicines — talk to your doctor or pharmacist about what medicine is right for you
• a corticosteroid injection — this can help with knee pain and stiffness
• an arthroscopy — this is a procedure that can help treat some knee conditions 

Knee replacement surgery is usually only considered if other treatments have not helped with your symptoms. Talk with your doctor about the benefits and risks of delaying surgery in your situation. 

Arthritis Australia has more information on:

• what to expect from joint replacement surgery
• physical activity if you have arthritis (Opens in new tab) 
• medical management of arthritis (Opens in new tab) 

Languages other than English

Talk with your doctor about the benefits and risks of getting a medical implant. Use the Therapeutic Goods Administration's guide (Opens in new tab) on what to ask. The guide is available in multiple languages.