Patient Education: Knee Replacement

Understanding Knee Replacement

The knee is a complex, hinged joint. With support from cartilage, ligaments, and muscles, the two bones at the joint move over each other so you can straighten and bend your leg. A knee that becomes stiff and painful may be replaced with a knee prosthesis, which will allow you to walk without pain. 

In a healthy knee (shown below), the surfaces of the thigh and shin bones are smooth so they can glide easily over each other. Cartilage covers the bones evenly, allowing smooth movement. Protected by the kneecap and held in place by muscles and ligaments, the joint bends freely. 

A HEALTHY KNEE

In a problem knee (shown below), the surfaces of the bones may become rough, causing pain when they rub together. The cartilage may wear away, becoming rough and no longer allowing easy movement of the joint bones. Because of arthritis, the joint may be swollen and inflamed, resulting in stiffness and pain. 

A PROBLEM KNEE

Your damaged knee joint can be replaced with new, smoothly surfaced components (shown below). The lower knee component will replace the rough surface of the shin bone, while the upper knee component will replace the surface of the thigh bone. The kneecap component will cover the underside of your kneecap. 

A KNEE PROSTHESIS

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