Knee arthroplasty, commonly known as knee replacement surgery, is a medical procedure that involves removing damaged cartilage and bone from the knee joint and replacing it with artificial components. This surgery is typically recommended for individuals suffering from severe knee pain or disability due to conditions like osteoarthritis or rheumatoid arthritis. The procedure can be performed as a total knee replacement, where both sides of the knee joint are replaced, or as a partial knee replacement, which targets only the damaged area. Recovery usually involves physical therapy to restore movement and strength, helping patients return to their daily activities.