Knee replacement surgery is a procedure to repair a knee damaged by severe osteoarthritis which cannot be controlled by other forms of treatment, according to Johns Hopkins Medicine. The damaged part of the joint is replaced by a metal or plastic artificial joint to relieve knee pain.
Osteoarthritis is a chronic condition wherein the joint cartilage breaks down, making movements such as walking, climbing or bending down painful. The unstable joint may also cause swelling of the knee. With the artificial joint in place and continuous physical therapy to help restore muscle strength, patients may once again enjoy regular activities, reports WebMD.