The knee is divided into three main compartments, the medial or inside part of the knee, the lateral or outside part, and the patellofemoral or front of the knee between the kneecap and thighbone. While all three works together to move the largest joint in the body, sometimes osteoarthritis can cause joint damage resulting in pain and reduced range of motion. People with osteoarthritis that is confined to one section of the knee may be candidates to undergo a procedure called minimally invasive partial knee replacement, also known as unicompartmental knee replacement.
This type of operation is typically recommended only when other non-surgical treatments, such as activity modification, strengthening exercises, medications, cortisone injections, or use of a cane while walking, have not been effective in providing relief for arthritis symptoms. Patients who are most likely to experience positive outcomes from the surgery tend to be over the age of 55, not obese, relatively sedentary, and have ligaments that are intact.
In partial knee replacement, only the damaged compartment is replaced with a metal and plastic implant while the healthy cartilage and bone in the rest of the knee is left in place. Prior to the procedure, the doctor examines the knee, tries to identify the location of the pain, and tests the knee for range of motion and ligament quality. Imaging tests, such as X-rays or magnetic resonance imaging, may be done to see the pattern of arthritis or better assess the cartilage.
In a minimally invasive partial knee replacement procedure, an incision of about three to three-and-a-half inches is made to allow for insertion of the knee replacement. This results in minimal damage to surrounding muscles and tendons around the knee. The short length of the incision and less-invasive nature of the procedure causes less discomfort, swelling and blood loss for patients, as well as abbreviated hospitalization and rehabilitation compared to conventional surgery that requires a larger incision and is more invasive to soft tissues or bone. Patients also are able to return to work earlier.
During the operation, the surgeon checks all three compartments of the knee for cartilage damage and to make sure the ligaments are intact. The affected cartilage is then removed and the ends of the femur and tibia are capped with metal coverings that are held in place to the bone with cement. A plastic insert is placed between the two metal parts to ensure a smooth gliding surface.
Patients can start to put weight on their knee immediately after surgery. They usually can walk without a cane several weeks after surgery, but may need physical therapy for a few months. Most types of exercise are allowed after surgery, including walking, swimming, and biking. However, patients should avoid high-impact activities such as jogging. Patients typically recovery quickly and experience less pain than they did before surgery. For more information about minimally invasive partial knee replacement, please visit our website at WestBocaMedCtr.com or call 866-904-9262 for a free referral to an orthopedic surgeon near you.