total knee replacement

What is it?
An artificial joint designed to replace a damaged or worn-out knee.

Why am I having it?
This procedure is performed for a painful worn knee joint, where symptoms have failed to respond to non-operative treatments such as pain-killers and physiotherapy.

What is the artificial knee made of?
The ends of the bones that form the knee (tibia and femur) are resurfaced with specially designed prostheses made of cobalt-chrome. In addition a polyethylene (high density plastic) bearing fits on the tibial component and articulates with the femoral component. See picture.

What will actually happen?
Firstly you will undergo “pre-assessment”. These are routine pre-operative investigations including blood tests, blood pressure measurement and x-rays. The hospital will contact you regarding this. You will usually be admitted on the day of surgery and be starved for 6 hours prior to the operation (you may be allowed water up to 2 hours before). The anaesthetist will talk to you about the anaesthetic which may involve a spinal and/or general anaesthesia. During surgery an incision will be made down the middle of the knee which will be covered by a dressing. There will often be a drainage tube which will be removed the following day.

How long will I be in need to stay in bed?
If the operation is in the morning the physiotherapists will endeavour to get you up and starting to mobilise the same day. Otherwise you will be up and walking the following day.

How long will I be in hospital?
Most patients will be able to leave at 3 or 4 days.

What else happens after the operation?
You will usually be able to your full weight through the leg straight away. The physiotherapists will help you and give you crutches or a frame if need be.  They will ensure that you can mobilise adequately and get up and down stairs before you are discharged. Therapy will also continue for several sessions as an out-patient. There will usually be clips in the skin that will need to be removed about 12 days following the operation.

How long will I need off work?
This is variable and depends really on the nature of your work. As a general rule, you will be uninsured to drive for four to six weeks following the operation. Most people would probably require a similar time off work. However, working from home would be possible after a couple of weeks.
What are the risks of the operation?
All surgery carries an element of risk. knee replacement surgery is a very successful pain-relieving and function-restoring operation. The main risks and methods employed by Mr Waters in order to avoid them are:
These are main risks and the methods employed by Mr Waters in order to avoid them.
• Infection
Joint replacement surgeons are fanatical about avoiding this, as an artificial joint cannot fight off infection.You will be given antibiotics at the same time as the anaesthetic and your skin will be coated with a special antiseptic solution prior to surgery. A special ultra clean operating theatre is used for all joint replacement procedures.
If, despite all this, there is any suspicion of infection (i.e an inflamed wound) you will be given further antibiotics. Very rarely you may need to return to the operating theatre for the wound to be cleaned. Deep infection of the joint is very uncommon and may require its removal.
• Venous thromboembolism (DVT, pulmonary embolism)
Clots may occur in the veins of the leg following surgery. In most cases this does not cause any problem and a clot travelling to the lung is extremely rare (less than 1/1000)
You will be given special stockings to wear and we may give you special foot-pumps to keep the blood in the veins moving. At present the guidelines suggest that you receive blood-thinning injections for 4 weeks following hip replacement surgery.
• Nerve injury
There may be some numbness on one side of the scar. The size of the affected area tends to reduce over time
Persistent discomfort
In some patients there is a different persistent discomfort despite the severe original pain being relieved. This may take a couple of years to settle.
You will be have very active physiotherapy to regain your range of movement following surgery. Despite this, in a few cases there can be some persistent stiffness. This usually responds to intensive physiotherapy but occasional requires a little manipulation under anaesthetic to break down scar tissue that may have formed.

Any more questions?
Please contact us if you have any other questions about this or any other procedure.