Knee Replacement surgeon . Knee pain is a common problem among adults. It may be due to an injury, joint problems or osteoarthritis. When persistent knee pain prevents you from enjoying your favorite activities – and other treatments don’t help – it may be time to consider knee replacement. The knee is the largest joint in the body. It is commonly known as the "hinge" joint, because it allows the knee to flex and extend, similar to the hinge on a door. The knee also has the ability to rotate and glide. The knee joint is composed of the tibia (shin bone), the femur (thigh bone) and the patella (kneecap). Each bone is covered with a layer of cartilage that cushions, protects and keeps the bones from rubbing together. Ligaments (bands of tissues) connect the femur and tibia, while muscles and tendons stabilize the knee and enable it to move. The patella helps protect the knee joint and anchors the tendons while allowing movement. If the cartilage becomes damaged, your bones rub together causing friction, pain and eventually, deterioration of the bone surfaces. Your doctor may try medications or even minor surgery to treat the problem. When treatment does not help, your doctor may suggest partial or total knee replacement. Knee Replacement surgeon .