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Knee Joint Replacement

Joint replacement surgery is a very successful operation, with a 90% success rate. It is recommended for patients who have moderately severe persistent pain which is not adequately relieved by an extended course of non-surgical management, and which interferes with activities of daily living (e.g. washing, dressing, lifestyle and sleep).

As a rule of thumb, if you have pain which:

  • Significantly limits your day-to-day function and quality of life
  • Disturbs your sleep on a regular basis
  • causes you pain even at rest
  • cannot be adequately managed with more conservative measures (such as those mentioned above),

then joint replacement may be a suitable treatment option for you.

When coming to a decision about whether joint replacement is the right decision for you, it is important to weigh up the risks against the benefits. If you feel the benefits of joint replacement (in terms of the improvements it will have on your pain and quality of life) outweigh the risks, then it may be the right choice for you.

What are the benefits?

  • Pain relief – 70% of people who have a knee replacement are pain free following surgery. 90 out of 100 people who have a knee replacement are very pleased with the results, but up to one in ten patients say it didn’t meet their expectations.
  • Increased walking tolerance – most people find that they can walk further than they could, with less pain, following knee replacement.
  • Improved sleep – pain at night generally reduces following knee replacement, thereby improving sleep.
  • Reduced dependency on pain killers

What are the Risks?

  • Ongoing pain or discomfort – 20% of people have ongoing discomfort following knee replacement, whilst 10% have ongoing pain.
  • Stiffness – some people find that they struggle to regain full bend at the knee following surgery, which can make it difficult to get up from a chair or climb stairs.
  • Inability to kneel – approximately 20-30% of people can’t kneel after knee replacement surgery due to sensitivity over the scar and general pain and discomfort associated with this activity.
  • Infection – around 2% of knee replacements become infected during the post-operative period, which may require further surgery to manage and control.
  • Blood clots – following any major surgery there is a risk of blood clots, which can be potentially fatal if they were to move to your heart, lungs or brain. Thankfully the risk of fatality following joint replacement surgery is low, and the orthopaedic team make sure that the risk of blood clot is minimised by giving you blood thinning medication and compression stockings following the surgery.
  • Blood loss – rarely you may require a blood transfusion due to blood loss during the surgery.
  • Loosening of the artificial joint due to wear and tear – your artificial joint may eventually wear out requiring further surgery. Overall, 90 out of 100 joint replacements last more than 10-years. Premature loosening may occur, needing revision surgery.


What does joint replacement involve?

  • The surgery is performed with a spinal anaesthetic (epidural), whilst you are sedated, so you don’t have the side-effects associated with a general anaesthetic to contend with.
  • You are generally in hospital for 3-5 days, and get sent home using 2 sticks after you have managed to progress your mobility to walk a decent distance and climb a flight of stairs (if necessary).
  • You have to wear compression stockings and take the blood thinning medication for 6-weeks following the operation.
  • You cannot drive for 6-weeks following the operation.
  • The first 3 months following the surgery can be quite hard work in terms of managing the post-operative pain while all the healing occurs, and getting your knee bending again, and the thigh muscle working again. You have to do regular exercises to help stretch out the scar at the front of your knee, and to strengthen the thigh muscle. It takes a little bit of hard work and determination sometimes to get things going again, but most people feel they are well on their way to recovery by 6-weeks, and have recovered pretty well by 3-months. You will continue to see improvements for the first 12-months following the surgery.

Further information about Knee replacements can be found in our patient information leaflet here.

Current Funding Restrictions for knee replacement

It is worth noting that the York CCG (Clinical Commissioning Group) will not fund knee replacement surgery if your BMI is above 30, nor if you are a current smoker. If this applies to you then you would need to:

  1. Give up smoking for a period of 8 weeks, OR wait for 6 months, before you can be referred to the orthopaedic surgeon for consideration of surgery.
  2. Bring your BMI down to 30 (or below) or lose 10% of your body weight (whichever is less), OR wait 12 months, before you can be referred to the orthopaedic surgeon for consideration of surgery. However, if your BMI remains above 35 you would still not be able to be referred for surgery until you had brought your BMI down below this upper threshold limit.

Where can I find further information to help me to make a decision about my ongoing treatment options?

The NHS  and Versus Arthritis have collaborated to create a “decision aid” document which you can use to help weigh up your options for managing your knee pain. You can find it here.