Definition of Unicompartmental knee arthroplasty:

Unicompartmental knee arthroplasty (UKA) is surgery to replace either the inside (medial) or outside (lateral) compartments of the knee.

Because only part of the damaged knee is replaced, it is often called a partial knee replacement.

See also: Total knee replacement

Description:

You may receive either general anesthesia (asleep, no pain) or local anesthesia (awake but no pain). The surgeon will make a small cut about 3 inches long over the knee that is damaged.

The damaged bone is removed and replaced with an implant (prosthetic) made of plastic and metal. The thigh and shin bone may be slightly shaped to fit the implant. Once the implant is in the proper place, it is secured with bone cement, and the wound is closed with stitches.

The operation takes about 1 - 1 1/2 hours.

UKA has gone under significant changes since first performed in the 1970s. Today, the procedure offers many benefits over total knee replacement, including:

• Smaller surgical cut. The cut used in UKA is about 2 - 3 times smaller than the one required for total knee replacement. A smaller cut means less blood loss, less tissue damage, and a faster recovery.
• Better range of motion after surgery.
• Shorter hospital stay.
• Cheaper procedure. UKA costs about half that of total knee replacement.
• If needed, the implant can be easily converted to a total knee replacement.

Pain relief is the same for both procedures.

Indications:

Certain diseases and conditions can affect knee function. The most common reason for UKA is arthritis.

This procedure may be considered in patients with the following conditions:

• Avascular and aseptic necrosis
• Knee deformity
• Osteoarthritis of the knee
• Refractory osteomalacia

Patients age 60 and up who are not physically active and who have no history of inflammatory arthritis are good candidates for this procedure. UKA is not recommended for patients who:

• Are obese
• Engage in heavy work or sports
• Have significant ligament problems