You’ve probably heard the old saying, “If it’s not broke, don’t fix it.” But what if it’s half-broke? For example, damage to the knee joint from arthritis may only affect a portion of the joint. Is it really necessary to replace the entire joint?
Some doctors don’t think so. New materials and techniques now make it possible to replace one side of the knee joint. This is called a unicompartmental knee arthroplasty (UKA). It can be done on either the inner half or outer half of the joint. Doctors try to preserve as much of the natural knee joint as possible. They also want the knee replacement parts to survive 10 years or more.
New research shows that using a UKA in the “right” patient has excellent results. The 10-year survival rate of the implant is 94 percent. Only a small number of knees must be revised with a second surgery during the first 10 years.
Which patients are best selected for this method of treatment? The best choice includes those with damage in one compartment only. Cartilage on the other side must be in good shape. A total knee replacement is advised when there is a great loss of cartilage on both sides of the knee. Cartilage must also be healthy in the patellofemoral joint. This is where the kneecap (patella) meets the upper leg bone (femur).
It isn’t always necessary to have a complete knee joint replacement. Treatment is possible for joint damage on one side only. The results are favorable for most patients. A simple revision can be made years later to replace the liner of the implant if it becomes worn.