What Is a Total Knee Replacement?

Knee replacement surgery is one of the largest and most complex surgeries an orthopedic surgeon can perform. It involves the removal of bone and the placement of a prosthesis in the joint. While it can be a frightening prospect to undergo such a large operation, the benefits usually far outweigh the risks. Educating yourself about the surgery can often help alleviate some of the anxiety you might feel.

Function

• The function of a knee replacement surgery is to remove diseased and injured bone and tissue, and replace it with man-made materials that will mimic the replaced joint. In cases where total knee replacement is done, the patient has often suffered for some time from extreme pain due to bone grating on bone, as all the protective cartilage has worn away. By replacing this degenerating material with a prosthesis, the body has functional joint that moves smoothly and without pain.

Significance

• In most cases of knee replacement surgery, the patient's quality of life has suffered to the point where everyday activities such as walking or getting up and down from a seated position are problematic. Sports activities or other movements that involve the knee are out of the question. When this kind of patient receives a new knee, it usually is a huge improvement.

  Once you have rehabilitated the knee after surgery, normal activities can be resumed, and although sports that require twisting, jumping, or running are not possible, just the ability to function on a day-to-day basis is wonderful for most patients.

The Surgery

• In a standard knee replacement operation, a six- to eight-inch incision is made over the knee midline, the knee joint is exposed and the lower part of the upper leg bone (femur) and the upper part of the lower leg bone (tibia) as well as the kneecap (patella) are removed. A prosthetic is then placed into the joint and secured with pins, screws and cement. Tendons and ligaments are reattached, and the surgery site is closed. Rehab begins the same day the patient wakens, and within six months to a year the patient is back to a normal, and in most cases vastly improved, lifestyle.

Types

• There are three types of knee replacement surgeries. The most common is standard knee replacement, which was described in the previous section. A type that is becoming more prevalent is minimally invasive knee replacement, where a smaller incision, from four to six inches, is used and arthroscopic cameras and other tools assist the doctor in the surgery. A less common is unicompartmental knee replacement surgery. This surgery is only available for patients who only have one section of the knee that is damaged and needs to be replaced. In this surgery, only that section is removed and replaced; the rest of the knee is left alone.

Misconceptions

• A common misconception about knee replacement surgery is that the knee will be as good as new once the patient has been fully rehabbed. Although in most cases the knee will be much better than it was before the operation, there is no replacement for the human body. Even the best technology can only reproduce a part of what was there originally. The new knee will not withstand the same abuse, and can and will wear out, so it is important to take care of your new joint to make it last as long as possible.