Total Knee Replacement - A Common Need as We Age
One of the normal results of living a long active life is that our joints begin to wear out as we age. Our joints begin to wear out and various forms of arthritis make joints painful and less functional the longer we live and the hip and knee are the primary joints that cause trouble. Inevitably in many people, particularly those 60 or older, pain and immobility become so disabling that surgery is chosen as the treatment of choice.
Who Should Have Surgery and Why
As in almost all medical conditions surgery is the last resort, not because it is unsuccessful, but because it is more invasive than exercise, diet and medications. Over 250,000 patients a year will have a total knee joint replaced so it is common to require this surgical procedure. The table at the right shows criteria for the operation.
The surgery replaces the cartilage and ligaments that are no longer effective in creating a smooth and effective movement between the upper leg bone (femur), ligaments and muscles with the lower leg bone (tibia), tendons and muscles. Generally a whole new union of the upper and lower leg is created using existing ligaments and muscles, but replacing cartilage with plastic and tips of the bones with metal device (prosthesis). If this sounds like big surgery, it is, and one needs to know that going in. In time after surgery, the “new knee” joint functions much as it does before arthritis wore the cartilage out and caused the tibia and femur to grind against each other in a very painful way.
What to Expect
The most important aspect of a total joint operation is to be informed about all aspects of the surgery. When faced with the prospect of surgery one’s general physician tends to refer you to an orthopedic surgeon who, with you, ultimately determines if surgery is indicated. A question that needs to be answered is who should perform the surgery?
A while back, Dartmouth Medical School scientists did a study to discover who chooses the hospital and doctor when surgery is elective. It turns out that 31% of patients said their doctor made the choice, 22% said they alone made the choice, 42% said it was a team effort – the patient and doctor, and 5% said others like family made the choice. The reason that this question is important is that it is widely known that results do differ by surgeon and by hospital for the identical operation. Thus, if one wishes to have the very best possible outcome it follows that one would choose the surgeon and hospital where the results are the best. In other words get some data rather than relying solely on what your physician advises or what others have done for the identical operation.
Once surgical treatment is decided, some physical therapy before the surgery is often begun in anticipation of it being continued postoperatively and having familiarity with the types of exercises that will be needed to ensure optimal convalescence. Surgery is generally performed the day of admission (patient goes directly to surgery, then to recovery and then to a hospital bed for several days.) Anesthesia today is usually performed with an epidural that is continued into the postoperative period to give analgesia immediately after surgery. Usually sedation during the operation is such that patients are not awake during the procedure, but if an epidural is used patients usually are not given general anesthesia. Thus nausea and vomiting and pain are not as prevalent in the first day or two after surgery. Once the epidural is discontinued, oral and sometimes injections are used with pain killers.
An important aspect of the operative period is prophylaxis against the formation of leg veins clotting. This is accomplished with a variety of exercises, sometimes mechanical devices and stockings and medications. It is important to prevent clots from forming in the deep veins of the legs that could flow up to the heart and lungs.
The most amazing aspects of the recuperation is the insistence of everyone on exercise, walking and other normal activities to be resumed even on the first postoperative day. This is not only good for the legs, but reminds everyone of the original purpose of the surgery: to enhance movement and lifestyle. However, don’t be fooled, the surgery takes time to recover from.
Long Term Result
Resumption of almost all normal activities is expected over about 4 months, and only jogging, contact sports and some very strenuous sports on the knee are advised against. Walking, climbing steps, and all those things that had become almost impossible are regained after the surgery. There is no doubt that total knee replacement has worked wonders for the majority of the millions of patients who have had this procedure since it was introduced in 1968.
Symptoms & Criteria for Total Knee Replacement
- Severe knee pain that limits normal, everyday activities
- Moderate knee pain at rest or night
- Chronic swelling and inflammation
- Deformities of the legs (bowing in or out at the knee)
- Knee stiffness severely limiting normal motion
- Failed medical therapy (unable to function while on medication)
- Failed non-medicine therapy (physical therapy, other)