The kneecap is a flat, triangular-shaped bone that protects the knee joint and helps muscles move your leg more efficiently. A healthy kneecap glides up and down a groove at the end of the thigh bone.
There is a fold inside the kneecap called the plica that can get pinched when the kneecap is gliding up and down, and the membrane that surrounds the joint is called the synovial membrane. Its main function is to produce fluid that helps lubricate and nourish the knee joint. In these procedures, the surgeon removes the damaged tissue using a small incision for the arthroscope to view the damaged area and another small incision for the insertion of the surgical instruments.
Cartilage removal may also involve scraping the bone to help heal the injured area.