Total knee replacement is a surgical procedure in which the arthritic or damaged knee joint is removed and replaced with an artificial knee joint called a prosthesis. The artificial joint is designed to move just like a healthy human joint. Performed since the 1960s, total knee replacements now result in virtually pain-free living for over 90% of patients, enabling them to return to normal functioning and enjoy favorite activities once again.

The actual surgical procedure, lasts about 1 hour and is usually done under spinal anesthesia. Much of the operation involves preparing the joint for the new knee: before the area is ready for the prosthesis, diseased bone must be removed; existing connective tissues are realigned; leg bones damaged by arthritis may also need to be realigned.

The prosthesis comprises several parts that are made of metal alloy, to replace diseased bone, and of high-density plastic, to replace diseased cartilage. One part is attached to the end of the femur where diseased bone has been removed, and another is anchored to the shinbone. The replacement may also include another small component—a circular piece of plastic that attaches to the kneecap to replace cartilage or diseased bone. Cement may or may not be used to hold the prosthesis in place.

Unicompartmental Knee Replacement—an Alternative for Some Patients

For patients who have arthritis only on one side (compartment) of the knee, there is an alternative to total knee replacement: unicompartmental knee replacement, also known as partial knee resurfacing (PKR). This procedure restores only the side of the knee that is damaged without disturbing the knee’s healthy tissue.

A PKR implant is much smaller than a total knee implant and involves less invasive surgery. The PKR incision is much smaller than with traditional total knee replacement. The orthopaedic surgeon removes a small amount of bone in the affected knee compartment and the implant is fitted to the bone surface. The incision is closed with small, self-dissolving sutures that are hidden underneath the skin.

For appropriate patients—those whose x-rays show arthritis in one knee compartment only and who have not responded to conservative treatment—this less invasive approach to knee replacement offers the potential advantages of:

• quicker recovery
• shorter hospital stay
• less post-operative pain
• no physical therapy—a few gentle exercises and progressive walking is the only rehabilitation needed

Your sureon at the Knee Care Institute will advise you if you are a candidate for PKR. If so, you can look forward to the same excellent results as patients who undergo total knee replacement—with less invasive surgery.

Osteotomy—Buying Time Before Knee Replacement

There are several types of osteotomy—a surgical procedure that is intended to help relieve pain, delay the progression of osteoarthritis, and delay the need for knee replacement.

Most often, osteoarthritis affects the inside (medial) compartment of the knee, leading to a bow leg deformity. This condition places more pressure on the medial joint surfaces, which, in turn, leads to more pain and faster degeneration. The outside (lateral) compartment is sometimes affected, producing a knock-knee deformity, with similar debilitating results.

High Tibial Osteotomy (HTO) is a procedure in which bow leg deformity is corrected by cutting the tibia and moving it to a corrected angle. This realignment of the lower extremity shifts the weight-bearing force into the healthier lateral compartment. As a result, pressure and pain are reduced, and the need for knee replacement may be delayed by as much as 5 to 7 years.

Proximal Tibial Osteotomy (PTO) is a procedure in which bow leg deformity is corrected by removing a wedge of bone from the lateral side of the upper tibia. This realigns the angle of the extremity and shifts the weight-bearing force into the healthier lateral compartment.

PTO generally results in a significant reduction in pain and, once the bone heals, there are no restrictions to activity level; however, it is not always successful. Like HTO, PTO may delay the progression of the degeneration of the medial compartment, but total knee replacement may be needed in 5 to 7 years.

Distal Femoral Osteotomy (DFO) treats arthritis of the lateral compartment, correcting a knee that angles outward.

If your surgeon believes that you may benefit from osteotomy, he will explain the appropriate procedure in more detail. Keep in mind that osteotomy is not a cure for osteoarthritis, but is an important option for relieving pain and delaying the progression of the condition for a number of years.

Preparing for Total Knee Replacement Surgery

Preparing for knee replacement surgery begins weeks before the actual surgery date. Dr. Kolisek will provide you with specific instructions that may include the following:

• Begin exercising as prescribed by Dr. Kolisek—it is important to be in the best possible overall health to help ensure the best possible surgical experience. Increasing upper body strength is of special importance because of the need to use a walker or crutches after knee replacement.
• Have a general physical examination—patients who are considering total knee replacement should check with their primary care physician to assess overall health. (Dr. Kolisek’s staff will assess TKR-specific health requirements.)
• Have a dental examination—although infections after joint replacement are not common, an infection can occur if bacteria enter the bloodstream. Therefore, dental procedures such as extractions and periodontal work should be completed before knee replacement surgery.
• Stop taking certain medications—Dr. Kolisek can advise you which over-the-counter and prescription medications, as well as which natural/herbal supplements, should not be taken before surgery.
• Stop smoking—a good idea at any time, but particularly before major surgery in order to help reduce the risk of post-operative lung problems.
• Lose weight—in patients who are obese, losing weight will help reduce the stress on the new knee.
• Arrange pre-op visit—Dr. Kolisek’s staff will arrange this important opportunity for you to meet with healthcare professionals at the hospital to discuss your personal hospital care plan, including anesthesia, preventing complications, pain control, diet.
• Have routine laboratory tests—Dr. Kolisek’s staff will arrange any tests that may be prescribed to confirm that you are fit for surgery, such as blood tests, urine tests, an EKG or cardiogram, and chest X-ray.
• Evaluate post-surgical needs for at-home care—every patient who undergoes total knee replacement will need help at home for the first few weeks, including assistance with dressing, getting meals, and transportation. Be sure to enlist your family, friends, and neighbors to help with your recovery care.
• Conduct a post-surgical home safety evaluation—make your home post-op patient-friendly by reducing safety risks, such as throw-rugs and extension cords, and enhancing access to everyday items