Knee Replacement Surgery
If you have medical conditions then you may be invited to attend a pre-assessment clinic by one of our specialist nurses or if you have a complex medical history then you will be also seen by a consultant anaesthetist. Routine blood tests, tracing of the chest (ECG) and an MRSA swab will be performed to ensure you are safe to be admitted to hospital.
If you have any source of infection then you need to contact us at your earliest convenience. For example any cuts or grazes near the knee or a dental / urinary / chest infection. Your surgery may well need to be postponed for your safety. If you have had any injections into your knee performed too then we will have to postpone due to increased risk of infection.
Some medication for the heart / tablets to thin the blood / tablets to control rheumatoid arthritis will need to be stopped and can be discussed with our pre-assessment team.
Seeing a physiotherapist prior to surgery will improve your recovery after surgery.
Follow instructions to stop eating and drinking before surgery. Usually 6 hours before you should not eat or drink.
We perform pre-operative checks according to the World Health Organisation to ensure that we operate on the correct site.
Most people have a spinal anaesthetic where a needle is inserted into your back and you do not feel anything from the waist down. This is accompanied by medication to make you relax and you will not remember anything from the surgery if you wish. Due to medical reasons you may need a general anaesthetic or if the spinal injection does not work.
A cut is made along the front of your knee allowing a good view of the knee joint. The damaged surfaces of the bone are carefully removed and a new knee will be cemented onto the ends of your femur and tibia with a plastic liner between them. The knee cap may also be replaced with a plastic ‘button’.
To reduce swelling and improve your recovery a mixture of anti-inflammatory, local anaesthetic and drugs to reduce bleeding will be injected around your new knee. A further dose of a chemical called tranexamic acid is given to help reduce the risk of bleeding. This is part of an enhanced recovery programme.
The knee is meticulously stitched up and a layer of ‘superglue’ placed over the skin to reduce the risk of bleeding and infection. All stitches used are dissolvable so no painful removal of stitches needed.
You will need to recover from the anaesthetic and the feeling will gradually return to your legs. Strong painkillers are given to help reduce the discomfort.
You will be encouraged to get up and walk as soon as you feel able. This is one of the many ways we reduce the risk of clots, along with injections of medication into your tummy, stockings on your legs (if well fitting) and pumps on your feet and calf.
You will be seen by physiotherapy staff that will ensure you are safe walking with crutches or a frame. You will also get an information sheet with activities to perform to ensure a quicker recovery to function.
People should expect to go home in 2 days.
Risks of Knee Replacement Surgery
A knee replacement is a major undertaking for your body. The overall rate of complication is 1 in 20 but most are minor and can be managed successfully. The risk of death is very low and has actually halved over the past few years to a chance of 0.2% within the first 45 days of surgery (this time is the highest risk).
Infection of the wound – this may be treated with antibiotics but deeper infection will require further surgery and may need to remove the knee implants. 1-2%.
Haematoma – swelling in the knee cased by bleeding.
Ligament, artery or nerve damage – rare.
DVT or PE (Blood clots) – They can happen in anyone who has had surgery to their legs and are relatively immobile. The risk is reduced by medication taken to thin the blood up to 14 days after surgery.
Arthrofibrosis – A build up of scar tissue in certain individuals after major surgery. There may be overlap with chronic regional pain syndrome.
Numbness – It is common to have numbness on the outer side of your knee scar.
Fracture – can occur when dealing with patients with soft bone or after replacing the knee cap.