Knee replacement surgery (pokanga turi) involves removing damaged parts of your knee and replacing them with new parts made of metal and plastic.
On this page, you can find the following information:
- What is knee replacement surgery?
- What are the alternatives to knee replacement surgery?
- When is a knee replacement considered?
- Is a knee replacement right for me?
- Preparing for knee replacement surgery
- Recovering from knee replacement surgery
- How can I be involved in my surgery?
Key points
- Knee joint replacement surgery is carried out if pain from severe arthritis or another injury to your knee stops you from doing your day-to-day activities.
- It is only offered when other treatments such as physiotherapy haven’t worked.
- People who actively participate in their care before and after surgery are likely to have a better recovery.
- There are many things you can do to take part in your care, starting from before your operation, during your stay in hospital and when you get home after discharge.
- You can improve the outcome of your surgery by getting yourself as fit and healthy as possible beforehand. This may include stopping smoking, exercising, eating a balanced diet and limiting or avoiding alcohol.
What is knee replacement surgery?
Knee replacement surgery replaces the damaged parts of your knee with new parts. For example, in some surgeries metal parts replace the ends of your femur (thigh bone) and your tibia (shin bone), and a plastic part separates the two metal pieces. However, there are variations to this, such as replacing only one part or half a joint.
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What are the alternatives to knee replacement surgery?
Knee surgery is usually only offered if other treatments have not worked for you. These other options include regular exercise, losing weight, physiotherapy or occupational therapy, and pain relief medicines.
Read more about the alternatives to knee replacement surgery.
When is a knee replacement considered?
Knee replacement surgery is usually recommended if you have severe arthritis or a knee injury that causes disabling pain and other treatments, such as physiotherapy haven't helped reduce pain or improve mobility. The most common reason a knee needs replacing is osteoarthritis of the knee joint.
You may be offered knee replacement surgery if:
- you have severe pain, swelling and stiffness in your knee joint and your mobility is reduced
- your knee pain is so severe that it interferes with your quality of life and sleep
- everyday tasks, such as shopping or getting out of the bath, are difficult or impossible
- you're feeling depressed because of the pain and lack of mobility
- you can't work or have a normal social life.
You'll also need to be well enough to cope with both a major operation and the rehabilitation afterwards.
Is a knee replacement right for me?
To decide whether a knee replacement is right for you, talk with your doctor about the risks and benefits of the surgery. Also, find out what you can do if you choose not to have surgery. The following summary is a guide.
What are the benefits of having knee surgery?
The aim of knee surgery is to relieve pain and decrease stiffness or deformity, and therefore help to improve your independence and quality of life. More than 90% (9 of every 10) of knee replacement surgeries last beyond 10 years. Patients who have knee replacement surgery experience less pain and greater mobility in their knee after the procedure.
Are there any risks to having knee surgery?
As with all surgeries, complications sometimes occur with knee replacement surgery. Smoking, obesity or some illnesses may increase your chance of complications.
Complications include the possibility of blood clots or deep venous thrombosis (DVT) of the veins in your legs or pelvis, bleeding, infection, joint stiffness, or loosening and wear of the knee replacement. Though uncommon, when these occur they may delay or limit your full recovery.
Also, for some people, the pain may not change much.
Preparing for knee replacement surgery
The better prepared you are for surgery, physically and emotionally, the quicker you will recover from it. Recovery from surgery is not the same for every person. Some people recover faster than others depending upon their age, health status, personal motivation and response to rehabilitation. The following video gives a good explanation about how to prepare for surgery and what to expect during and after the operation.
The videos below provide advice on how you can prepare for your operation and what you can do before and after surgery to help your recovery. It also includes information on what you can expect during your stay in hospital. The full video is 25 minutes long and has been split into 15 chapters which can be viewed as separate videos. The first video of the series is below.
(Ministry of Health, NZ, 2015)
To see the rest of these videos, visit Your guide to knee replacement on the Ministry of Health YouTube channel.
Recovering from knee replacement surgery
Many district health boards (DHBs) have introduced a new way of caring for people who need a hip or knee joint replacement. This is called ERAS –Enhanced Recovery After Surgery. The ERAS pathway of care starts when you and your doctor decide that you need surgery and continues through to your rehabilitation at home or in the community. The approach covers a number of evidence-based interventions that aim to ensure you:
- are in the best possible condition for surgery
- have the best possible management during and after your surgery
- participate in the best possible rehabilitation after surgery.
You are encouraged to be a partner in your own care. The sooner you get out of bed and begin to walk, eat and drink after your operation, the quicker and more comfortable your recovery will be. You return home earlier to your normal life, work and play. All going well, you are likely to return home after 2 to 4 nights in hospital. Read more about ERAS.
How can I be involved in my surgery?
Research has shown that people who actively participate in their own care before and after surgery are likely to have a better recovery. There are many things you can do to take part in your care, starting from before your operation, during your stay in hospital and when you get home after discharge. Your ERAS booklet will give you more details but here is a summary of what to expect and the sorts of things you can do.
Knee surgery | What to expect and things you can do |
Before your surgery | Things you can do
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While in hospital | What to expect
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Discharge | What to expect
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Hip and knee surgery
(Dr Mike Evans, Reframe Labs, 2013)
Learn more
Knee replacement – a guide for patients ERAS and Canterbury DHB, NZ, 2020
Joint replacement surgery – a patient's guide Family Doctor, NZ
Reviewed by
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Dr Bronwyn Lennox Thompson is a senior lecturer & Academic Coordinator, Postgraduate Programmes Pain & Pain Management, Orthopaedic Surgery & Musculoskeletal Medicine, University of Otago Christchurch. Her main interest areas include resilience, daily coping choices, and knowledge translation from research to clinic. |