OSF Medical Group

Total Knee Replacement

The doctors at OSF Medical Group understand that the decision to have knee replacement surgery can be hard. Many times, patients have tried to find relief in other ways with no success. Total knee replacement can help ease the pain and allows patients to return to an active, healthy lifestyle.

Arthritis is the most common reason patients decide to have knee replacement surgery. People usually have problems with walking, climbing stairs, and trying to sit down or stand up.


The knee joint is made up of four bones: the femur (the thigh bone), the tibia (the shin bone), the fibula (the calf bone) and the patella (the knee cap). A smooth substance called articular cartilage protects the bones and enables them to move easily. The menisci are C-shaped wedges between the femur and tibia that act as "shock absorbers" to cushion the joint. The rest of the knee is covered by a thin lining called the synovial membrane. This membrane releases a fluid that lubricates the cartilage, reducing friction.

About the Procedure

During a total knee replacement, the knee is not actually taken out and replaced. Rather, the ends of the femur and tibia are reshaped and then capped with an implant called a prosthesis. The process is similar to having a crown put on your tooth. A plastic spacer is attached to the prosthesis that creates a smooth cushioning effect much like the original cartilage.

What to Expect

Knee replacement surgery takes just over one hour. This time does not include operating room set-up and time in the post-anesthesia care unit (often referred to as “recovery”).

Patients can expect to stay at the hospital for two to three days; however, some may leave earlier. Before you leave, you must meet certain goals. You will learn more about these goals before you have the surgery. Keeping your new joint moving will help your recovery process. You will be instructed by the orthopedic care team to avoid specific positions that could put stress on your new joint.


Your recovery largely depends on how committed you are to your exercises and physical rehabilitation. Recovery can be as little as four weeks or as long as six weeks or more.

The physical demands required for your job, as well as your own progress, will determine when you can return to work. Typically, people plan on taking a one month leave of absence from work. Some people who have jobs where they are seated most of the time may be able to return sooner. Your surgeon will tell you when you can return to work.