Although not as common as total knee replacement, partial (or “unicompartmental”) knee replacement is a viable alternative to full knee replacement in about 10 percent of patients.

The design of partial knee-replacement components has undergone rapid improvement in recent years, as has the sophistication of the instruments used to implant them. One of the most attractive features of the procedure, for most patients, is the fact that it generally requires a smaller, less invasive incision. Recovery is also much quicker than with total knee replacement.

In a partial knee procedure, only one of the knee joint’s three “compartments” is replaced. The three compartments are the medial (inner), the lateral (outer), and the patellofemoral (kneecap). If the damage is confined to either the medial or lateral compartment, it may be possible to replace only that compartment.

If two or more compartments are damaged, partial knee replacement may not be your best option. The procedure may also be less appropriate for a young, active person because the implant may not be able to withstand the extremes of stress associated with high-impact activities. However, recent studies do suggest that a partial knee procedure can be appropriate for a younger patient who agrees to refrain from high&*45;impact activities.

Partial knee replacement is best suited to an older, slim person with a relatively sedentary lifestyle. Fewer than 10 out of 100 patients with arthritic knees are good candidates for the partial knee procedure.

As noted above, partial knee replacement can be accomplished through a relatively small incision (approximately 3 to 4 inches in length) that does not impinge on the main muscle controlling the knee (the quadriceps muscle). Therefore, in most cases, rehabilitation is faster, hospitalization is shorter, and the return to normal activities is more rapid than after a total knee replacement.

However, partial knee replacement should not be taken lightly, since it carries all of the same risks as total knee replacement. These risks, as well as whether you are a good candidate for the procedure, should be thoroughly discussed with your fellowship-trained orthopedic surgeon at Plaza Medical Center.

Frequently Asked Questions

“How does partial knee replacement differ from the total knee procedure?”

Partial knee replacement is an option for patients who have some knee-joint surfaces that are still healthy. In partial knee-replacement surgery, the surgeon leaves the healthy portion untouched, removing only the diseased portion prior to placing the implant. The initial incision, therefore, is usually smaller in size than the one required for total knee replacement. The typical recovery time is also shorter - only about three to five weeks compared to six to ten weeks. Only about 10 percent of patients meet the strict requirements to undergo partial knee replacement. Our surgeons have performed the procedure for more than 10 years.

“What are the benefits of the partial knee procedure vs. standard total knee replacement?”

Clinical results to date suggest that patients who undergo partial knee replacement are likely to experience a shorter hospital stay (24 to 48 hours), faster rehabilitation and a smaller incision scar. Patients may also enjoy increased range-of-motion in the knee that has been repaired. A successful partial knee replacement may delay or even prevent more extensive knee-replacement surgery later on. In addition, it may be used as a stepping stone to total knee replacement in younger patients.

“How do I know if I am a candidate for partial knee replacement?”

The ideal candidate is someone with osteoarthritis that is confined to just one compartment of the knee. The procedure is not performed on a patient suffering from rheumatoid arthritis. One of our fellowship-trained surgeons can determine if you are a candidate for this less invasive procedure.

Go to top