Knee Replacement: Partial (Unicompartmental)

Knee Joint

The knee is a hinge joint. The bones in the joint are the femur (thighbone), tibia (shinbone) and patella (kneecap). The bones in the joint are covered with cartilage, which is a lubricating and cushioning tissue that protects the bone ends during movement.

Osteoarthritis

Osteoarthritis, also called OA or degenerative joint disease, is the most common form of arthritis and is a wear and tear condition that can result from injury or overuse over time. Osteoarthritis causes painful bone-on-bone contact. There is no cure for osteoarthritis, but there are many nonsurgical treatments designed to reduce pain.

Total Knee Replacement

Sometimes conservative nonsurgical treatments are not enough to relieve knee pain and restore motion. It is at this point that you and your orthopaedic surgeon may discuss total knee replacement as a possible treatment option.

Total knee replacement typically involves resurfacing the damaged bone and cartilage in the knee joint with metal alloy and polyethylene (plastic) components. However, not every person is a candidate for total knee replacement.

Partial (Unicompartmental) Knee Replacement Surgery

Unlike total knee replacement involving removal of all the knee joint surfaces, a unicompartmental knee replacement replaces only one side of the knee joint. Knee osteoarthritis usually occurs first in the medial (inside) compartment as this side of the knee bears most of the weight. In knees that are otherwise healthy, a unicompartmental approach allows the outer compartment and all ligaments to remain intact. By retaining all of the undamaged parts, the joint may bend better and function more naturally.

Advantages

The potential advantages of a unicompartmental or partial knee replacement versus a total knee replacement include:

• A potentially shorter incision.
• Less bone and cartilage removed.
• Shorter hospital stay.
• Quicker return to activities. 

Complications

Potential complications during and after surgery include, but are not limited to, infection, blood clots, implant breakage, malalignment and premature wear. There are many things your surgeon may do to minimize complications. Please speak with your orthopaedic surgeon about potential complications.

Recovery

Recovery after a partial replacement typically takes approximately half as long as traditional total knee replacement. Most people should be able to drive after two weeks, garden after three to four weeks and golf after six to eight weeks. Your surgeon will tell you when you can return to these and other activities and will also tell you which activities to avoid.

To Find Out More

Read about some of the patients we've helped.