A Total Knee Replacement, also known as Knee Arthroplasty, is a procedure that is undertaken to relieve pain and restore function of knee joints which are severely worn out due to arthritis.
What is a Total Knee Replacement?
During the procedure, damaged cartilage and bone are cut away, and are replaced with a Prosthesis (artificial joint). The Prosthesis is made from metal and high-grade plastic.
There is a broad range of knee replacement prostheses which can be chosen. The type which your doctor chooses will be dependent on several factors, including the size and shape of your knee, your age, your overall health, and your activity level.
The decision to undergo a Total Knee Replacement is a joint one between you, your family, GP and the Orthopaedic Surgeon. Those who benefit from a Knee replacement have one of the following symptoms:
- Severe pain or stiffness in the Knee that limits day to day activities like walking, climbing stairs, and getting into and out of vehicles.
- Knee deformity: bow leg or knock knee
- Severe Knee pain at rest or disturbing sleep
- Failure to improve with other treatments like pain killers/anti-inflammatory tablets, cortisone injections or physiotherapy
It should be noted that there are no restrictions for a Total Knee Replacement in terms of weight or age. In general, patients who undergo this procedure are aged between 50 and 80 years old, although the procedure can be performed on people of all ages.
A Total Knee Replacement is usually done under a general anaesthetic (which puts you to sleep) or a regional anaesthetic (which numbs you from the waist down).
Your knee will usually be put in a bent position for the procedure so that all surfaces of the joint are exposed. The surgeon will begin by making an incision of around 10-15cm, allowing the kneecap to be moved aside and the damaged joint surfaces to be cut away. After testing the components for proper function, the parts of the new knee are fitted. The incision is then closed. A Total Knee Replacement usually takes about 1-2 hours depending on the type of procedure.
After the procedure, you will be taken to a recovery room for a few hours, before being moved to a hospital room where you will stay for one to two days. You will be given painkillers such as opioids or non-steroidal anti-inflammatory drugs (NSAIDs).
You are encouraged to start moving your foot and ankle as soon as possible, to increase blood flow through the leg muscles and reduce the risk of blood clots. Your activity level will gradually be increased, and a physiotherapist will demonstrate how to exercise your new knee, increasing its range of motion and building up the strength of the muscles around it. You will be given an exercise programme for the weeks following the procedure, as well as instructions on wound care and diet.
It is important to have realistic expectations and understand what a knee replacement can and can not do. While most patients will have excellent relief of pain and stiffness, a Knee replacement will not allow you to do more than what you could do before the onset of arthritis. The activities one may be able to do after a successful Knee Replacement would include unlimited walking, swimming, hiking, biking, dancing, Golf, and light Badminton or Tennis. High impact activities are not advisable.
Following surgery, it is important to work with the Physiotherapy team diligently to build the core strength of the muscles around the knee and improve the range of motion. A Knee replacement is only as good as how much effort one is willing to put in. It is also important to understand that it may take up to a year to achieve significant improvement in symptoms and function.
Knee replacement is a very successful operation. However, like any other procedures, there are risks associated with a Knee Replacement that you must be aware of and accept prior to knee replacement. The risks include Infection, Clots (Deep Vein Thrombosis, Embolus, Stiffness, Persistent pain, incomplete relief of symptoms following surgery, Vessel or Nerve damage, re-operation/revision, medical, anaesthetic and mortality risks. Every effort is taken to minimise these risks. This will include giving antibiotics before and after surgery, Injection/Tablet and use of surgical stockings to reduce the risk of clots and thorough pre and post-operative assessment and care.