FAQ’s about hips and knees

The purpose of this page is to answer some of the most frequently asked questions people often ask surgeons about treatments, surgery, and conditions.

  • General FAQs about joint replacement
  • FAQs about your knees
  • FAQs about your hips


Q: How long does a knee or hip replacement last?

It depends on the individual but latest data from the National Joint Registry says most joints will generally last up to 15 years.

Modern knee replacements can last for at least 20 year in around 80 per cent of patients, although if you have a half knee replacement  you have a 10 per cent chance of needing a repeat procedure after 10 years.

A lot will depend on how you look after it and how much strain you put on it.

Hip replacements secured with cement usually last 20 years or more, others  fused with other materials can last even longer.


Q: Am I too young for a joint replacement?

Obviously surgeons have to consider your age before performing  a joint replacement operation–  as if you have the operation done at a young age the likelihood is that it will have to be replaced at some point   For this reason most  people who have joint replacements operations are usually  aged over 60 ( CHECK).However age  alone should not be a bar  (see the National Institute of Clinical Excellence 2008 guidelines on osteoarthritis ). The NICE guidelines say that referral for joint replacement for people with osteoarthritis for example, should be considered for those “ who experience joint symptoms (pain, stiffness and reduced function) that have a substantial impact on their quality of life and are refractory to non-surgical treatment.” NICE also states that referral should be BEFORE there is a prolonged and established function limitation and severe pain.

If your symptoms are severe and affecting your quality of life, your surgeon may decide the risk of having a repeat operation in 20 years are outweighed by the benefits you would enjoy by regaining your mobility and being pain free.


Q: What are the possible complications of a knee replacement operation?

Most complications are minor and will depend on your overall health and age. Complications includes blood clots forming in the leg , although in most cases this can be prevented by wearing surgical stocking and/or taking tablets to thin the blood.. Other possible complications include deep wound infections which affect about 1 in 100 patients. The chances of developing an infection can be reduced by taking a course of antibiotics There  is also  a small risk of nerve or ligament damage during surgery, plus fracture of the bone surrounding the knee joint after a minor fall,  dislocation of the knee and collection of blood in a wound , causing a swelling.. Sometimes the knee joint may be unstable and further surgery may be needed.


Q:  How long does it take to recover from a knee operation?

ou will be left to rest for 24 hours after the operation (that’s unless you are on an enhanced recovery programme when you may be expected to get up and walk on the first day). After that you will be expected to start walking with frames and sticks. Physiotherapy will begin as soon as soon as possible and continue for several weeks. You can go home as soon as your wound starts to heal and this can be as soon as within 2-5 days .Within 7-10 days you will be expected to be able to walk up and down stairs and cover reasonable distances with the aid of a stick.   Within three to six weeks you should be able to resume normal activities and within six to 12 weeks you can expect to be back at work. Up and down stairs should be achieved before going home.


Q: How do I look after my knee after a knee replacement operation?

You’ll be given in-depth instruction on your after care, but it’s really important you practise the exercises you’ll be shown by a physiotherapist.  Generally in the first two years you’ll be told to try and restore your muscles to their previous strength and be on the look-out for any signs of problems, including infection, pain or stiffness.


Q: How long does it take to recover from a hip replacement?

Recovery time will vary according to your overall health, but is similar to a knee replacement operation (see above) and you can expect to be back at work within 6-12 weeks.


Q: Are metal on metal hip replacements safe?

This is currently an area of controversy as new research has confirmed metal on metal hip replacements have a higher failure rate. For up to date information on this go to the National Joint Registry.