Many patients exhibit arthritis in only one side of their knee. For certain patients a procedure called unicompartmental knee replacement can relieve pain and improve function without the need to replace the entire knee joint.

What are the Advantages?

There are a number of advantages to this procedure over the traditional total knee replacement.

Smaller Incision: Before the procedure, the entire knee is examined with an arthroscope through a very small incision. If the rest of the knee is relatively intact, a 3 inch incision is made. A traditional knee replacement requires an 8 inch incision.

Less Blood Loss: The minimally invasive nature of the procedure generally eliminates the need for a blood transfusion. Total knee replacement often requires transfusion or preoperative donation of blood.

Easier Rehabilitation: Since the incision is smaller and the knee cap is not turned upside down as it is during a full knee replacement, moving and bending the knee after the surgery is much easier.

Shorter Recovery: Most patients are driving a car and resuming their normal daily activities two weeks after the surgery. With a total knee replacement, recovery time can much longer and require more extensive physical therapy.

Less Bone Removed: Much less bone is removed than during a standard knee replacement and even less than other forms of unicompartmental knee replacement. If a total knee replacement is needed in the future, enough bone remains to perform the surgery without added difficulty.

Who Can Benefit From Unicompartmental Knee Replacement?

Persons 50 and older who show one or more of the following symptoms may benefit from this procedure:

• Pain while standing
• Pain while walking short distances
• Pain changing position, such as sitting to standing
• Persistent knee swelling
• Giving out or locking of the knee.
• Failure of the knee to respond to medical treatment

Knee X-rays, taken while standing, can indicate if the uni procedure may be appropriate. The X-ray must show complete loss of the joint cartilage in one of the two weight-bearing compartments, as demonstrated below.