Knee replacement surgery

In a total or partial knee replacement, artificial parts replace the lower end of the thigh bone (femur) and upper end of shin bone (tibia). Some patients may need replacement of the back of the knee cap (patella).

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Would I benefit from knee replacement surgery?

People with severe arthritis usually benefit from knee replacement surgery but there are other reasons why you might need it. In the long term surgery stops most, if not all pain in your knee but you may still have some pain when twisting or kneeling.

Most patients need a total knee replacement but you may only need one part or one side of your knee joint replaced. It’s known as a partial, or unicompartmental knee replacement.

Your surgeon will discuss the most suitable option for you.

The majority of people who have surgery will eventually feel free from pain and knee arthritis disability. You will feel more independent but may find it difficult to do everything you were once able to do to start with.

What happens during knee replacement surgery?

You will have an anaesthetic for your operation. The most common is a spinal anaesthetic but some people may need a general anaesthetic.

The surgeon will make a cut (incision) on the front of your knee and remove any excess arthritic bone. This helps to make a smooth base for your new implant.

When satisfied with the position of the implant the surgeon will close the wound with metal clips (skin staples) or stitches. They may use a drain which allows any collection of blood or fluid to drain out.

You may experience numbness over the outside of your knee.

What are the risks of surgery?

SAs with all operations, there are risks involved. There’s a low risk of serious complications, estimated to be less than one in 100 people.

Your surgeon will answer any questions you have and discuss the risks with you before your surgery to make sure you fully understand them.

These risks include:

Blood clots

Also known as Deep Vein Thrombosis (DVT). Blood clots can form in the veins, usually your leg, after surgery. Because you’ll be moving less than normal after your operation, you’re at a higher risk of developing DVT.

You may need to take medication to reduce this risk.

More information about DVT

Watch this video about how to prevent DVT.

Learn more about DVT including symptoms and how to treat it.


This is usually minor which your surgeon stops during the operation.


Your knee will feel painful after the operation but we’ll give you painkillers and the pain will reduce overtime.

Implant wear and loosening

With modern operating techniques and implants, we expect your new knee to last more than 15 years. In some cases the implants may wear or loosen and may need further surgery for infection or instability.

Known as revision surgery, the surgeon will remove your original joint implant and replace it with a new one.


To minimise the risk of infection we use ultra clean air theatres. Our surgical team take special precautions including gowning and draping but some infections can still happen. If the wound becomes red or hot, it may be a sign of infection. If you develop any of these symptoms please contact the orthopaedic ward on 01736 758812 or call your GP.

Nerve damage

In rare cases, surgery can cause damage to the nerves around the knee joint including injury, stretching or cutting.

Preparing for your operation

Before your operation you must attend a pre-admission clinic to assess your health and fitness. You’ll also get information about your operation and what you need to bring with you for your stay in hospital. This includes:

  • crutches.
  • operation booklet.
  • loose night and day wear.

We’ll give you the relevant equipment before your admission to hospital.

You’ll also need to attend our joint school. It’s an educational session that will help you prepare for your surgery and learn more about what to expect.

It’s also important to plan your discharge from the hospital before surgery to prevent any delays in getting home.

Enhanced recovery after surgery

The rapid recovery programme helps you prepare for your surgery, recover more quickly and let you get back to normal life and activities as soon as possible.

Watch this introductory video which explains what to expect from the rapid recovery programme for joint replacement.

Watch the following videos which will help you prepare for your surgery:

Watch this video on getting fit for your operation and managing your lifestyle.

Learn how to do knee exercises to help your recovery.

Find out how to make preparations at home before your surgery.

During your stay in hospital

Where do I need to go for my surgery?

Your operation letter will tell you what time to arrive and where to go for your surgery.

Your operation

Your knee replacement surgery usually takes around 1 to 2 hours under a spinal and light sedation. After the operation, you’ll wake up in the recovery area before being moved to the orthopaedic ward.

Find out more about your stay in hospital for a knee replacement operation.

What happens after my operation?

You’ll be encouraged to move around as soon as possible on the day of your operation to prevent DVT and maximise your recovery.

We will encourage you to wash and dress almost straight after surgery and do this independently where possible.

You will need to have an X-ray and a blood test before you go home.

A physiotherapist will ensure you can walk, climb stairs (where appropriate) and do your exercises independently.

An occupational therapist will discuss your home circumstances with you to ensure you can manage and have enough support in place.

How long will I stay in hospital?

It’s likely you can leave hospital 1 to 2 days after your surgery if there are no complications and you’re fit enough to go home.
More information about what happens after your operation please watch the following videos:

Watch this video about what happens during your stay in hospital

Watch this video about exercising after your operation.

Leaving hospital after your operation

You’ll need to use crutches to help you walk for around 6 weeks after your operation and follow the advice from our clinical team.

You’ll see your consultant or a member of their team 6 to 12 weeks after your surgery. You will normally have an X-ray which we’ll review at this appointment. If the consultant is happy with your X-ray, you will not usually need any further follow up.

You will not need to see a physiotherapist or occupational therapist after you leave hospital. If you need more support, we will assess this based on your individual needs.

Who can I call for advice about my knee replacement surgery?

For concerns about your knee replacement and signs of infection after your operation

St Joseph’s Ward
St Michael’s Hospital
01736 758812

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