Knee replacement is a surgical procedure to replace parts of the knee joint that are damaged. It is most often done to treat arthritis, a common condition that causes stiffness and pain in the joints. Knee replacement is used only if other, less invasive treatments have not worked.
A knee replacement may be partial, involving only the damaged areas, or it may include the entire joint. During surgery, the cartilage, a smooth and tough piece of tissue that lines the ends of bones, is removed. The ends of the femur (thigh bone), tibia (lower leg bone), and, sometimes, patella (kneecap) are smoothed out and replaced with metal parts. The cartilage is then replaced with a plastic disc that the metal can glide across when moving. This removes any rough or grinding surfaces within the knee that may have been causing pain.
Surgery can be performed by a large incision along the knee or through tiny incisions with small tools and an arthroscope, a small lighted tube with a camera. The procedure takes one to two hours, and you will stay in the hospital for a few days following surgery as you heal and learn to use your new knee. Physical therapy can help you move correctly and prevent stiffness. Generally, you will be able to return to normal activity within a few weeks, but you may be asked to stop participating in high-impact activities, like football or running, which could injure your new knee.