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As with any operation, knee replacement surgery has risks as well as benefits. Most people who have a knee replacement do not have serious complications.

After having a knee replacement, contact your doctor if you get:


Anaesthetics are extremely safe, but carry a risk of minor (usually temporary) side effects such as sickness and confusion. There is also a slight risk of serious complications.

The risk of death in a healthy person having routine surgery is very small. Death occurs in around one in every 100,000 general anaesthetics given.

The risk is higher if you're older or have other health conditions, such as problems with your heart or lung.

Your anaesthetist and surgeon can answer questions you may have about your personal risks from anaesthetic or the surgery itself.

Other complications

Complications occur in about 1 in 20 cases, but most are minor and can be successfully treated. Possible complications include:

In some cases, the new knee joint may not be completely stable and further surgery may be needed to correct it.

How long will a replacement knee last?

Wear and tear through everyday use means your replacement knee might not last forever. Some people will need further surgery.

According to the National Joint Registry (NJR), around 1 in 20 patients who have a knee replacement will need further surgery after 12 years. However this depends on the type of replacement. Total knee replacements tend to last longer than partial knee replacements.

Find more information on how long knee implants last on the NJR website.