Knee replacement surgery (arthroplasty) involves replacing a damaged, worn or diseased knee with an artificial joint.
It’s a routine operation for knee pain most commonly caused by arthritis.
Most people who have a total knee replacement are over 65.
For most people, a replacement knee will last for at least 15 to 20 years, especially if the new knee is cared for properly and not put under too much strain.
Types of Knee Replacement Surgery
There are two main types of surgery, depending on the condition of the knee:
- total knee replacement (TKR) – both sides of your knee joint are replaced
- partial (half) knee replacement (PKR) – only one side of your joint is replaced in a smaller operation with a shorter hospital stay and recovery period
Why is knee replacement surgery needed?
The most common reason for knee replacement surgery is osteoarthritis. Other conditions that cause knee damage include:
- rheumatoid arthritis
- knee injury
A knee replacement is normally only recommended if conservative treatments, such as physiotherapy or injections, haven’t helped reduce pain or improve mobility.
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 cannot work or have a normal social life
Can I have knee replacement surgery?
Adults of any age can be considered for a knee replacement, although it’s typically recommended for older people as young, physically active people are more likely to wear the joint out.
The earlier you have a knee replacement, the greater the chance you will eventually need further surgery. However, there is some evidence that replacing the knee joint before it becomes very stiff leads to a better outcome.
Most total knee replacements are carried out on people between the ages of 60 and 80. You will need to be well enough to cope with both a major operation and the rehabilitation afterwards. Read more about getting ready for knee replacement surgery and recovering from knee replacement surgery.
Are there any risks?
Knee replacement surgery is a common operation and most people do not experience complications. However, as with any operation, there are risks as well as benefits.
Surgical alternatives to knee replacement
There are alternative surgeries to knee replacement, but results are often not as good in the long term. These are described below.
1. Arthroscopic washout and debridement
An arthroscope (tiny telescope) is inserted through small incisions in the knee, also known as arthroscopy. The knee is washed out with saline and any bits of bone or cartilage are cleared away. It is not recommended if you have severe arthritis.
A keyhole operation in which small holes are made in the surface layer of bone with a small, sharp ‘pick’. This allows cells from the deeper, more blood-rich bone beneath to come to the surface and stimulate cartilage growth. It can be a good option if you have just a small area of damaged cartilage. However, the benefits are not well proven and the results are not as good as knee replacement for severe arthritis.