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.