Total Knee Replacement

Total Knee Replacement

I had a patient in the office today that was being seen for a general medical problem. I noticed the classic knee replacement surgical scar on his left leg, and asked him how he liked his new knee. His glowing report of loving the formerly cantankerous knee became the subject of this article.

There are over 600,000 knee replacements operations each year in the United States. This is a remarkable number since the first knee replacement only took place in 1968. Prior to that treatment was basically symptomatic only, and so often it was not sufficient to restore function. The majority of knee replacements succeed well, though about one in ten does not achieve maximally desire results. There are the potential complications of general anesthesia, blood clots of the legs during and after surgery which can go to the lungs with catastrophic results, and the occurrence of post-operative infection which can be very difficult to resolve in the new joint. The good news is that theses complications rarely occur because orthopedists and anesthesiologists take specific steps to prevent them.

My patient had a typical history of a knee joint which was failing him. He had worked for thirty-five years in a job which required him to be on his feet on hard concrete floors. He had done a lot of lifting, using his knees because his overall body stature was small. Being a male in his forties was a risk factor, as well as the fact that members of his family all seemed to develop arthritic knees at a relatively young age. He had been referred to an orthopedist due to the severe pain in his left knee which was becoming more and more disabling. Even on a plain x-ray, the orthopedist noted the classic bone-on-bone findings, along with bone spurs, in his knee. There was no joint space where the cushioning cartilages should have been. In osteoarthritis, the cartilages begin to thin, degenerate, and wear out. Bone spurs occur where bone rubs bone. When it occurs in the knee, the person has a lot of trouble with weight-bearing and walking on the knee. It may even hurt in certain positions of rest and wake the person at night. Bending the knee becomes an increasingly excruciating task depending on how great the cartilage loss is. If the patient had developed osteoarthritis after a specific knee injury, the orthopedist may have ordered an MRI scan to look for specific areas of cartilage damage for which other surgical treatments might be done. But with the diffuse absence of cartilage, it was apparent the patient would need a total knee replacement. One thing the patient had going for him was his weight of one-hundred and forty pounds. Knee replacements don’t do as well when the patient weighs over two-hundred pounds.

So our patient was scheduled for surgery and entered the hospital for his final pre-operative evaluation. After clearance, he was taken to the OR and given general anesthetic. An incision was made over his bent knee, and the joint was exposed. The end of his femur was removed shaved down to good bone, and a shiny new metal plate was attached. The upper tibia was then removed and formed in a similar way, and a metal plate was attached, with a hard plastic washer over it to act as cartilage. The back of his knee cap was shaved and a shiny metal knee cap surface was applied.

When he woke up, he says he had a morphine pump by which he could give himself in small regular quantities of pain medicine. He says he gave himself a squeeze of morphine, got up with assistance, and walked. That, no doubt, took a lot of gumption, but he says it hurt a lot less than he expected. He began physical therapy in the hospital, and continued it for several weeks after he was discharged.

The result now is that he says his knee never hurts. Sometimes he even forgets he had a knee replacement, or which knee it was. He is very happy with the outcome of the surgery. So, if you are troubled daily by a knee that is limiting your normal activities, talk to your doctor about knee replacement. He can perform a complete history and physical examination to determine if you are physically able to tolerate the surgery, and discuss these findings with your orthopedist. You may wish to postpone your surgery until your weight can be reduced to a more ideal number. Make up your mind that this procedure is not going to be a quick fix, but will require endurance and determination to successfully complete the many weeks of post-operative physical therapy. Work with your family or with a social worker to arrange the physical assistance you will need in your home as you recuperate. Most of all continue to visualize a time when you will be free of the knee pain which so negatively impacts your life now.

John Drew Laurusonis
Doctors Medical Center