Wednesday, 22 May 2019

Knee joint surgery

A total knee joint replacement (also known as total knee arthroplasty) is an operation to remove a severely impaired knee joint and replace it with an artificial joint. The aim of the surgery is to relieve pain and restore function to the joint.
In a healthy knee, smooth cartilage covers the ends of the femur (thighbone) and the tibia (shinbone). The cartilage acts as a cushion between these weight-bearing surfaces and allows the bone ends to glide easily over one another, allowing for painless movement. Muscles and ligaments give side-to-side stability. A synovial membrane lines the joint and produces synovial fluid (a clear lubricating fluid) in order to lubricate the joint.
There are three main components of an artificial knee joint – the femoral component (to replace the end of the femur), the tibial component (to replace the end of the tibia) and the patellar component (to replace the back of the kneecap). In total knee joint replacement surgery, all of these components are used.
Components are designed so that metal always borders with plastic, which provides for smoother movement and results in less wear of the implant.

When a knee replacement is needed

Knee replacement surgery is usually necessary when the knee joint is worn or damaged to the extent that your mobility is reduced and you experience pain even while resting.
The most common reason for knee replacement surgery is osteoarthritis. Other conditions that cause knee damage include:
- rheumatoid arthritis
- haemophilia
- gout
- disorders that cause unusual bone growth (bone dysplasias)
- death of bone in the knee joint following blood supply problems (avascular necrosis)
- knee injury
- knee deformity with pain and loss of cartilage

Who is offered knee replacement surgery

A knee replacement is major surgery, so is normally only recommended if other treatments, such as physiotherapy or steroid injections, haven't helped reduce pain or improve mobility.

You may be offered knee replacement surgery if:

- you have severe pain, swelling and stiffness in your knee joint and your mobility is reduced.
- your knee pain is so severe that it interferes with your quality of life and sleep.
- everyday tasks, such as shopping or getting out of the bath, are difficult or impossible.
- you're feeling depressed because of the pain and lack of mobility
- you can't work or have a normal social life

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