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 Surgery
During knee joint replacement surgery, damaged cartilage and bone are removed from the knee joint. Man-made (artificial) pieces, called prostheses, are then placed in the knee. These pieces may be placed in up to three surfaces in the knee joint:
- Lower end of the thigh bone, which is called the femur. The replacement part is usually made of metal.
- Upper end of the shin bone, which is the large bone in your lower leg. This bone is called the tibia. The replacement part is usually made from metal and a strong plastic.
- Back side of your kneecap. Your kneecap is called the patella. The replacement part is usually made from a strong plastic.
Learn more about what to expect.
Is a Knee Replacement Right for Me?
The most common reason to have a knee joint replaced is to relieve severe arthritis pain, such as osteoarthritis, rheumatoid and post-traumatic. Your doctor may recommend partial or total knee joint replacement if you experience the following signs:
- Daily pain
- Pain severe enough to restrict work, recreation and ordinary activities of daily living
- Significant stiffness in the knee
- Significant instability (constant giving way) of the knee
- Significant deformity (knock-knees or bow-legs) that hinders normal function of the knee
- Damage from arthritic conditions, such as osteoarthritis, rheumatoid arthritis or post-traumatic arthritis
- Failure of non-surgical treatment
Before considering whether a knee replacement is the right choice for you, your doctor will conduct a full examination of your knee, testing for strength, stability and range of motion as well as a comprehensive review of your current health status.