Raphael S. F. Longobardi, MD, FAAOS Board Certified Orthopaedic Surgeon & Sports Medicine Specialist University Orthopaedic Center, PA 433 Hackensack Avenue, 2nd Floor Hackensack, NJ 07601 201-343-1717
The following information is designed to present an overview of a Total Knee Replacement. This applies particularly to those patients who have arthritis in their knee, or knees, which has progressed to the stage that the pain in the knee is making it difficult or impossible to carry out their activities of daily living or work activities. The primary reason to do this operation is to improve or substantially relieve your pain. Secondary reasons are to gain motion and correct deformity. I will try to answer the following questions which are most commonly asked:
1. When should the surgery be done or should I have it? The decision to have the surgery or not to have the surgery ultimately is your decision. As mentioned above, when your pain and dysfunction is severe enough to impact your work and activities of daily living, that is usually the time to consider a total knee replacement. I will make every effort, and this handout is one of those efforts, to be sure that you are informed of the nature of the operation and what to expect, both good and bad. If I have done my job in this area, you should be able to decide whether or not you would like to proceed with the surgery, delay your decision for a period of time or indefinitely, or not to have it at all.
2. What is done? Sometime prior to the surgery, most of you will be seen by an internal medicine specialist for a complete evaluation of your health prior to admission to the hospital to ensure that your general health is satisfactory to undergo the operation. This specialist will also follow you while you are in the hospital to check on your general medical condition and prescribe a blood thinner to help prevent blood clots. These things can also be done by your family physician if he or she is willing to come to the hospital and follow you after your surgery.
You will be admitted to the hospital usually on the day of surgery because Medicare and other insurance companies will not pay for admission on the day before surgery. Before the surgery, you will be seen by an anesthesiologist who will discuss the type of anesthetic. In most cases, this will either be a general, spinal, or an epidural anesthetic. The exact type depends on your medical conditions and your desires. An epidural can be used for anesthetic alone. If this is used, you do not have to go completely to sleep and the epidural can also be continued after the surgery to help control the post operation pain. I feel this is a very satisfactory and preferred anesthetic for patients, as long as there is no medical reason not to use it. At surgery, after you are given an anesthetic, an incision is made in the front of your knee and the articular surface is exposed. A series of small cuts are made to remove the arthritic surface. Not much bone is removed and only the rough, pitted arthritic surface is taken off. You have been furnished with some handouts with pictures illustrating this procedure, and they will help you to understand better what is done during surgery. This is done in a precise fashion so that a metal cap can fit snugly over the end of the thigh bone (femur), and a metal-backed, plastic component can be placed over the top of your shin bone (tibia). The back of the kneecap is also removed in the same fashion and replaced. You can think of it as being similar to recapping, re-surfacing or re-treading a tire.
These components are either bonded to the bone with an epoxy-type bone cement or a type of implant is used which has a porous backing on it and allows bone to grow into it, thereby securing the implant. The choice as to which is used is determined to some degree by your age, weight, bone quality, and other factors.
The surgery usually will take about two hours. You will be gone from your room six to eight hours, counting the time before the surgery, when you are being prepared, and the time in the recovery room afterwards. You can sit in a chair within a day or so after the surgery and will begin to walk with a walker or crutches one to four days after the surgery. Some tubes will be placed in your knee to drain the blood out, and these are usually removed about twenty-four hours after the surgery.
3. How long will I be in the hospital? The main goal of rehabilitation and physical therapy, while in the hospital and after discharge, is to regain motion and satisfactory strength in your knee. This includes the ability to straighten out the knee, which is in most cases, the most difficult aspect, as well as to regain the bend or flexion in the knee. A machine will be used to help you move your knee while you are in the hospital and can be rented and taken home after you are discharged. Most patients go home about three or four days after the surgery. Most do begin to bear full weight immediately after the surgery and will graduate from a walked or crutches to a cane after about three to four weeks. It takes at least three to six months to recover from the surgery and get your strength back.
4. How long will it take to get over it, and what can I expect? After two to three months, you can resume walking, golfing, and biking, if desired. You can swim within about two weeks after the surgery, and if there is a therapy pool at the therapy facility, this can be used for rehabilitation. I ask my patients not to run, jump, or participate in activities or sports which require that running or jumping be done. You can expect, in the absence of complication, a knee that hurts a lot less than it did and, hopefully, one that functions and moves better. It will not be “normal” and you will have some aches and pains, clicks and pops.
5. What are the complications? One of the most common complications which can occur is loss of motion. Some patients have severely limited motion before the surgery, but they should at least get back the motion that they had prior to the surgery, and hopefully, gain more. It can be difficult to get the knee to bend back more than 90 degrees (a right angle) after this surgery. Early rehabilitation and physical therapy in the hospital and in the first month is very important. If you do not regain motion beyond 90 degrees, you will have some trouble with stairs, getting in and out of chairs, church seats, and getting on your clothes, socks, stockings, and so forth.
What about other complications? Infection is a major but relatively rare (approximately 1-2%) complication. This is pus in the knee as a result of having had the surgery. It can happen in the hospital or after discharge. It can come from germs acquired in the hospital at the time of surgery or the immediate post operative period, or they can come from your own body soon after surgery or months or years later. If this occurs, another surgery or surgeries will be necessary to at least clean out the knee. The components often have to be removed and sometimes cannot be put back in. Some organisms which are relatively sensitive to antibiotics can be successfully treated and an attempt can be made to replace the components about six weeks post-removal. This stands about an 80% chance of being successful. If unsuccessful, either because the components cannot be replaced or because the infection again recurs, the knee then has to be fused, or made stiff and not move, keeping it in a straight position. The only consolation is that the pain in your knee would be substantially diminished after it was made stiff. This is a very serious complication and if it occurs in the worst form, it could lead to loss of limb and, possible, life.
It is important that you take prophylactic antibiotics if you have dental work done or surgery on your stomach, intestine, or gall bladder, or any sort of “…oscopy”. You can become ill with a high fever, so be sure to tell your doctor that you have had a total knee replacement. Loosening or failure of the components is another complication. This occurs fairly rarely at this time, but it was more common ten to fifteen years ago. If that does happen, the knee usually hurts enough to require another surgery to replace the loose component.
Wear of the plastic portion of the components does occur, and the rate of wear depends on many factors such as age, activity level, weight, and so forth. A severely worn plastic component will most often require revision or replacement as is required when the components become loose.
Blood clots (thrombosis) or inflammation of the blood vessels (phlebitis) can occur in either leg of the deep veins of the thigh and pelvis and require treatment with a blood thinner. If the clot gets loose and goes to your lung, it can be life-threatening. Everything possible will be done to prevent this complication. The internal medicine physician or your family physician will give you a blood thinner, and you will have alternating compression devices on both legs to help prevent blood clots. For more information on DVT (Deep Vein Thrombosis - click here)
Blood loss occurs enough to sometimes require a transfusion, or blood replacement. There is, as you probably know, a small chance of getting HIV/AIDS and/or hepatitis from a blood transfusion. We ask our patients prior to surgery for them to donate their own blood and/or have their families donate blood for them, if they have the right type. My staff will discuss this with you. We use a machine to recover some blood lost during and after the surgery and can give that back to you, reducing the need for transfusion. Nerve and blood vessel damage can occur, but in my experience, is quite rare. Severely deformed knees are more likely to have this type complication.
Some patients complain about the amount of pain after surgery. This is a major operation, and you should expect a good bit of pain in the immediate post operative period. You will either have an epidural or a patient-controlled anesthesia machine, which means that you can, by pressing a button, give yourself pain medicine through an intravenous line when you want it. After a few days, usually one to three, you will be switched off the patient-controlled anesthesia machine or the epidural will be removed and you will take pills for pain. The tolerance of pain is a highly individual phenomenon. Some patients have a little pain and suffer a lot, and others have a lot of pain and suffer very little. Some patients have told me “You did not tell me it was going to hurt this much.” It will, but for most, pain is controlled satisfactorily by one of the above methods.
6. How long will the knee replacement last? The life of the implant is difficult to predict with certainty. We can tell you what the results are in operations that were done 10 years ago, but techniques and implants have changed during that period of time. The life span of today’s implants are certainly expected to be longer than they were 10 – 15 years ago, and can range from 10- 20 years. Factors which have a negative impact on the life of the implant are: young age, excessive weight, inappropriate activity level such as work activities which require you to be on your feet constantly, running, jumping, and excessive walking. Patients over 65 with moderate to low demands and normal weight can probably reasonably expect the implant to last as long or nearly as long as they do. On the other end of the spectrum, a patient in his or her 40’s, overweight, with high demand and activity level can expect an earlier failure, possibly as early as 5 – 10 years after surgery.
We do everything we can to prevent all the above complications and to relieve pain. In spite of that, complications still occur in a small percentage of cases, and some patients experience more pain that they feel like they should have. The odds are, however, on the side of the patient not having any complications or undue pain and getting a good result.
The information contained in this patient education page is intended to help you and your families/ caretakers better understand a particular diagnosis and/or the treatment options available. If you have any questions after reading this, please don’t hesitate to contact Dr. Longobardi’s office at 201.343.1717 for a further explanation.
