According to Arthritis Australia, arthritis is the major cause of disability and chronic pain in Australia today. The most common form of arthritis is osteoarthritis (OA). This results from the breakdown of cartilage (a smooth, cushioning substance) on the end of bones where they meet to form a joint, making the normally smooth surface rough or uneven. Although the frequency of symptoms and severity of OA can vary among people, OA of the knee may lead to stiffness and pain around the knee joint, clicking, locking, unsteadiness, muscle weakness and pain when walking or standing.
Other possible causes of pain and loss of function in the knee include:
For some people affected by OA of the knee, replacement surgery (also known as a knee arthroplasty) may offer an improvement in their quality of life through reduced pain and increased mobility.
If you suffer from severe arthritis of the knee that remains painful despite medication, exercise, rest and supports to assist your mobility, you may benefit from a total knee replacement. The main indication for knee replacement is unrelieved pain — if you are adequately mobile and your pain is manageable, you probably do not need a knee replacement.
Your suitability for knee replacement surgery will be assessed based on your medical history and physical and X-ray examinations.
A knee replacement operation will usually take between one and 2 hours. After evaluation by an anaesthetist, you will be given either a general anaesthetic (which will cause you to fall asleep for the operation) or a spinal anaesthetic (where you remain awake but are anaesthetised from the waist down).
A knee reconstruction involves surgery to replace your knee joint with a prosthesis—an artificial knee joint. Mostly, these prostheses are made of plastic and metal, and consist of 3 main components:
The metal shafts of the femoral and tibial components are inserted to replace the end of the femur (thigh bone) and the top of the tibia (shin bone). On the end of the metal shafts is a polyethylene (plastic) coating which acts as replacement cartilage.
More than 90 per cent of knee replacements will last for more than 10 years, depending on your level of activity and weight. The heavier and more active you are, the more quickly they will wear out. Knee replacements can be replaced if they wear out, although revision surgery is generally more difficult than the initial replacement.
Most people spend about 5 to 7 days in hospital, depending on their progress and rehabilitation. Your surgeon may provide you with a programme designed to prevent blood clots in the legs — a complication which can happen after knee replacement surgery. Some warning signs include:
Although infection of the knee joint can occur, this is quite rare.
It is important to plan ahead for your recovery from knee replacement surgery. Here are some tips to help make your home accessible after surgery and to promote a fast recovery.
Physiotherapists can help greatly with rehabilitation, while occupational therapists are helpful in making sure your home is safe and advising on any modifications or appliances that may be needed.
The decision to have knee replacement surgery should be discussed with family members who may be responsible for assisting you following the operation.
Knee replacement can be a successful option for many people experiencing pain related to arthritis of the knee: more than 90 per cent of people who have a total knee replacement improve their ability to perform everyday tasks and have reduced levels of knee pain.
Last Reviewed: 10 April 2009