Different Types of Total Knee Replacement

The knee is the largest joint in the human body, and having it replaced is a complex and difficult process. It can cause huge shock to the body and significant bloodloss, and it contains the risks of blood clots and infection. Yet, despite the risks, knee replacement surgery has become relatively common and has a high success rate. In fact, for most patients who require a knee replacement, the surgery can improve the quality of life of the patient exponentially. Educating yourself on the procedure is one of the best ways to prepare for it.

Significance

• Total knee replacement surgery is when the surgeon cuts into the skin, exposing the knee joint, then uses tools to remove the diseased bone and replace it with a man-made prosthetic joint. No matter what type of knee replacement surgery you have, the goal is the same: removal of diseased and degenerating bone, and replacement with man-made materials. The idea is to restore more normal motion and allow the joint to flex without pain. In the cases of end-stage osteoarthritis, the patient usually has been suffering from bone-on-bone pain for some time, often years. The sudden correction of this painful disease is a wonderful surprise to many knee replacement patients.

Standard Knee Replacement

• The most common type of knee replacement surgery is the standard knee replacement. An incision is made from above the knee to a few inches below the knee, right down the middle of the leg. The incision is anywhere from six to 10 in. long. The joint is exposed, and the surgeon removes the top of the upper leg bone (tibia) and the bottom of the lower leg bone (femur), as well as the kneecap (patella). The remaining bone is shaped and then the prosthesis, which has been individually made for the patient using MRI imagery and X-rays, is cemented, pinned and hammered into place. The knee is put back together and the incision closed. Rehab begins within hours of waking.

Minimally Invasive Knee Replacement

• A newer method that is gaining popularity is minimally invasive knee replacement surgery. Not all patients will be qualify, as it depends on many factors that vary from patient to patient. But in the case of a minimally invasive knee replacement, the surgeon makes a smaller cut, usually four to six in., and uses cameras and smaller tools to do the same job as in a standard knee replacement. This operation usually takes a little more time, as the surgeon is having to do a big job in a small space, but the results are usually worth it: less damage to soft tissues, and a slightly shorter recovery time in most cases. The scar is smaller as well.

Partial Knee Replacement

• Partial knee replacement, or unicompartmental knee replacement surgery, is a rarer option that can be considered in cases where only one side or one section of the knee joint is damaged. In the case of injury, physical deformity, or the rare one-sided osteoarthritic condition where only one side of the knee is diseased, the doctor will make an incision on the side of the knee that is damaged, usually around a four in., then cut out the diseased portion and replace it with a special prosthetic that is made to replace only that one section. The process is the same, but on a smaller scale, and not all the knee joint bone is removed. This surgery does not have the same rate of success as the total knee, but it is an option for some patients.

Misconceptions

• A common misconception about total knee replacement surgery is that the knee will be "as good as new." This is not the case. No man-made product can equal the complexity of the human body. But in the cases where total knee replacement is needed, the patient will usually have been suffering for so long that the new knee feels "brand new." It is important to remember that the man-made joint can and will wear out. Heavy activity, hard labor, running, jumping and twisting will be activities of the past. Exercise is necessary, but should be limited to walking, biking, swimming and other low impact or non-impact activities. The better you care for your new knee, the longer it will last.