Partial knee replacement

The knee joint is made up of three bones—the femur, the tibia and the patella, or kneecap. The femur contacts the tibia with two areas, called condyles—the medial condyle and the lateral condyle. The underside of the kneecap also contacts the femur and tibia as it glides along the groove in the femur. Any of these three areas of contact can fall victim to the wear-and-tear effects of arthritis, causing pain, heat, stiffness and swelling. Total knee replacement involves the replacement of all three surfaces with metal and plastic components. If arthritis is limited to either the lateral or medial compartment of the knee, partial knee replacement may be considered.

Partial knee replacement may be an option for those who have painful, debilitating arthritis limited to one area of the knee and who no longer get relief from conservative measures, such as physical therapy, medications or weight loss. Only your doctor can determine if you are a candidate for this procedure.

There are a number of advantages of partial knee replacement when compared with total knee replacement. Because a smaller area of the knee is affected, the implants are smaller, allowing surgeons to use smaller incisions. In addition, there is less trauma to the bone and surrounding tissue, resulting in less blood loss, less likelihood of transfusion, and a quicker recovery time when compared with total knee replacement.

Many people will be able to go home the day after the procedure. Because most of the knee joint is left intact after the operation, there is typically less pain than with total knee replacement. Patients will typically use a walker or cane for two weeks or so, can drive in two to three weeks, and golf, dance and bowl in four to six weeks. Keep in mind that these are just estimates, and that recovery and healing times vary with each person.

All knee replacements can wear out over time, including total knee replacements. How long a particular implant may last varies from patient to patient and depends on a number of factors, including the patient's weight, activity level and the accuracy of the implant's placement. Recent studies have shown that for appropriately selected patients, partial knee replacement can last 10 years or more.

Even though partial knee replacement is considered a minimally invasive procedure, it is still surgery, and as with any surgery there are risks you need to be aware of.

Possible complications include:

• Blood clots in your leg veins.
• Infection.
• Implant loosening.
• Fractures.
• Nerve or blood vessel damage.

Your surgeon and healthcare team will be taking great care to minimize the risk of these and other complications. Keep in mind that complications are relatively rare, but they need to be understood by you and your family. Your surgeon will be happy to answer any questions that you may have.