Knee replacement, or knee arthroplasty, is a surgical procedure to replace the weight-bearing surfaces of the knee joint to relieve pain and disability. It is most commonly performed for osteoarthritis, and also for other knee diseases such as rheumatoid arthritis and psoriatic arthritis. In patients with severe deformity from advanced rheumatoid arthritis, trauma, or long-standing osteoarthritis, the surgery may be more complicated and carry higher risk. Osteoporosis does not typically cause knee pain, deformity, or inflammation and is not a reason to perform knee replacement.
Knee replacement surgery can be performed as a partial or a total knee replacement. In general, the surgery consists of replacing the diseased or damaged joint surfaces of the knee with metal and plastic components shaped to allow continued motion of the knee.
Joints are the tissues that connect bones together and allow them to move. Joints are made up of tissue, and these tissues move as a response to muscle movements.
These tissues undergo a lot of stress over the course of your life. While there is a fluid that prevents joints from experiencing too much friction (known as synovial fluid), every time your joints move they receive a small amount of damage.
Generally the joints regenerate as a response to this damage. But over time these joints can degenerate to the point where they are beyond normal repair. This causes the joints to experience inflammation, and this inflammation is known as degenerative knee joint disease.