Definition of Knee Arthroplasty

Knee arthroplasty, also known as knee replacement surgery, is one of the largest and most complex operations an orthopedic doctor can perform. It involves a large incision down to the bone, the cutting and removal of large sections of living bone, the removal of the entire knee joint, and the placing of a prosthetic into the joint.

Function

• The function of a knee arthroplasty is to replace the human knee joint with a manmade prosthetic knee. The reasons for this can vary. In most cases, this is the solution to end stage osteoarthritis, where the cartilage that surrounds and protects the knee joint has worn away and bone is painfully scraping on bone. In some cases, it is necessitated by trauma to the knee, where the joint is destroyed and the only option for a functional joint is a replacement.

Types

• There are three types of knee arthroplasty. The first is the most common - standard knee replacement surgery. A 6 to 10 inch incision is made midline over the knee, the joint exposed, the bones cut and removed, the prosthetic placed and secured, and the tissues secured and incision closed. The second type is minimally invasive total knee replacement. The surgeon does the same procedure, but makes a smaller cut, and used more arthroscopic type tools to guide him in the areas which are not open to eyesight. The final type is partial knee replacement. The incision is made in the side of the knee and only the part of the knee that is diseased or injured is replaced.

The Surgery

• In all of the different types of knee replacement surgeries, the goal is the same. The removal of defective, diseased, or damaged bone and the replacement of that bone with man-made materials that will then mimic the use and function of a normal knee. The surgery can take as little as 1 1/2 hours to 3 hours or more, depending upon the needs of the patient and the surgeon.

Benefits

• The benefits of knee arthroplasty far outweigh the risks. In most cases where knee replacement is needed, the patient has been suffering for an extended period of time from the pain of end-stage osteoarthritis or severe injury. Daily activities have become problematic, and the patient's quality of life has lessened. When the damaged joint is replaced, the patient can suddenly use their leg again, and oftentimes did not even realize the extent of their pre-operative pain until after the replacement.

Misconceptions

• A common misconception about knee replacement surgery is that the new knee will be just as good, if not better, than the old one. While this is certainly true in terms of pain relief, it cannot be further from the truth as far as function. No man made material can compete with the wonders of the natural human body. A prosthetic knee cannot endure sports other than walking, biking, swimming, or other low impact exercises. A replaced knee must be cared for and maintained with good diet, weight loss, physical therapy, and exercise. And it will wear out. Take care of the replaced knee, as most people can only have two knee replacements in their lifetime.