What is knee replacement surgery?
Knee replacement surgery involves replacing a damaged, worn or diseased knee with an artificial joint.
More than 70,000 knee replacements are carried out in England and Wales each year, and the number is rising. A replacement knee lasts over 20 years, especially if the new knee is cared for properly and not put under too much strain. Most patients who have a total knee replacement are usually 65-years-old.
There are two main types of surgery, depending on the condition of the knee:
- Total knee replacement – both sides (back and front) of the patient’s knee joint are replaced
- Partial (half) knee replacement – only one side (back or front) of the patient’s joint is replaced in a smaller operation with a shorter hospital stay and recovery period.
The most common reason for knee replacement surgery is decline in the cartilage and bone (osteoarthritis). Other reasons include:
- Long term condition causing pain, swelling and stiffness to the joints (rheumatoid arthritis)
- Inability to clot blood (haemophilia)
- Arthritis caused by acid crystal build up in the joints (gout)
- Knee injury.
A knee replacement is major surgery, so it is normally only recommended if other treatments, such as physiotherapy or steroid injections, haven't helped reduce pain or improved mobility.
Patient eligibility criteria:
If supported by your family doctor, your local NHS commissioning organisation will fund this treatment if the patient meets the top three bullet points, or the fourth bullet point:
- Conservative means, including medication, physiotherapy, walking aids, home adaptations, and general counselling, have failed to alleviate the patients pain and disability; and
- Severe pain unresponsive to pain relief medication and persistent loss of function affecting employment; and
Patient must accept and want surgery (most total knee replacements are carried out on people between the ages of 60 and 80). The patient will need to be well enough to cope with both a major operation and the rehabilitation afterwards; or
- The damage of the patient’s joint is so severe that delaying surgical correction would increase the difficulty of the procedure.
If a patient meets the criteria and is assessed as appropriate for surgery, but they have a BMI of 25 or more, they will be actively supported to engage with local weight management programmes to reduce their BMI to improve the likelihood of a successful hip replacement. A patient's BMI alone however will not be a reason to prevent surgery happening.
The clinician in charge of the care of the patient’s specific condition, usually a hospital doctor, can assist the application, if there is exceptional clinical need for the treatment to be funded. The patient’s clinician must evidence clinical exceptionality and must be supported by the patient’s local NHS commissioning organisation. See separate leaflet for more information on Individual Funding Requests (IFRs).
Advice and further guidance:
Knee replacement surgery is usually performed either under general anaesthetic (the patient is asleep throughout the procedure) or under spinal or epidural anaesthetic (the patient is awake but has no feeling from the waist down).
The worn ends of the bones in the patient’s knee joint are removed and replaced with metal and plastic parts (a prosthesis) which have been measured to fit. The patient may have either a total or a half-knee replacement. This will depend on how damaged the patients knee is. Total knee replacements are the most common.
- For more information, read the 'osteoarthritis of the knee decision aid' or search for ‘knee replacement’ at www.nhs.uk
- Choosing Wisely UK is part of a global initiative aimed at improving conversations between patients and their doctors and nurses.
Treatment policy for patients covered by NHS Birmingham and Solihull CCG