Knee replacement surgery

An operation to replace parts of the knee with artificial implants.

About knee replacement surgery

Knee replacement surgery is an operation to replace worn-out, diseased or damaged parts of the knee joint with artificial parts. The procedure is also known as arthroplasty.

The most common reason for a knee replacement is pain and loss of movement caused by osteoarthritis.

In your knee joint, the ends of your thigh and shin bones are covered in hard cartilage. This lets the bones move smoothly against each other.

The cartilage in your knees can be damaged by injury and worn away by arthritis. This makes moving your knee stiff and painful.

You may need a knee replacement if non-surgical options, such as physiotherapy or steroid injections, haven’t helped.

Different types of knee replacement surgery

There are two main types of knee replacement surgery – total and partial. Your orthopaedic surgeon will recommend what type of treatment is right for you.

How knee replacement surgery is carried out

A knee replacement is usually carried out under spinal anaesthetic. This means you’ll be awake during the operation but the anaesthetic blocks feeling from your waist down.

It can also be done under general anaesthetic, which means you’ll be asleep.

Your surgeon will make a cut down the front of your knee so they can access your knee joint. They will remove the damaged ends of your shin and thigh bone.

The ends of the bones will be shaped and measured precisely so that the artificial knee joint can be fitted. The back of your kneecap may also be replaced if needed.

Your surgeon will then close your wound with stitches. It will be dressed and bandaged tightly to reduce swelling. Knee replacement surgery usually takes up to two hours.

After knee replacement surgery

After a knee replacement, you’ll need to stay in hospital for up to five days.

You’ll be given painkillers to help relieve any pain. There will be a tube attached to your knee to help drain any fluid that builds up around your knee.

You will be encouraged to start walking around on crutches usually within 24 hours. Our physiotherapy team will teach you exercises to help strengthen your knee.

You will need some help when you get home. It’s a good idea to arrange for a family member or friend to stay with you for the first few days.

It can take between six and 12 weeks to recover from surgery but everyone is different. Your consultant will let you know when you can go back to everyday activities like work, driving and sport.

“I had a great experience at the Cromwell Hospital; the staff were amazing, and is another level of professionalism compared to other hospitals I’ve stayed in.”

Lorne, Bupa Cromwell patient

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Published: 14 January 2020 | Review: 14 January 2023

Disclaimer: This information is published by Cromwell Hospital and is based on reputable sources of medical evidence and experience from over 30 years of treating patients. It has been peer reviewed by Cromwell Hospital doctors. The content is intended for general information only and does not replace the need for personal advice from a qualified health professional. If you have any feedback on the content of this patient information document please email info@cromwellhospital.com or telephone 020 7460 5901.