Instruments Used in Total Knee Replacement

Knee replacement surgery is one of the largest and most complex surgeries that can be performed by an orthopedic surgeon. Although it has become almost commonplace, it is still a serious and major surgery that involves the cutting and removal of large sections of bone, the implantation of a prosthetic device, and long and painful rehabilitation. Despite the drawbacks of the surgery, it is reported that over 95 percent of those who undergo the operation experience significant pain reduction and an increase in quality of life.

The Surgery: Stage 1

• In the first stage of the operation, the surgeon will use general anesthetic to put the patient to sleep, and monitors will be used throughout the operation to make sure all the vitals of the patient are stable. Once the patient is properly draped and prepared, the surgeon will use a scalpel to open an incision anywhere from 4 to 8 inches long, depending on the type of knee replacement being done and the needs of the surgeon. Once the incision has been made, tools called retractors are used to hold open the cut and keep the skin and soft tissues away from the surgical site. During this stage a bovie pencil is used to cauterize any blood vessels that are bleeding. Once the knee joint is exposed and the retractors set up, the next stage begins.

Stage 2

• At this point the surgeon examines the joint and will use a rongeur to rasp away bone spurs that will not be removed during the surgery itself. Next, the surgeon employs a set of "jigs" or bone cutting instruments, which will be used to cut the patellar bones, the tibia, and the femoral joints of the knee and remove them from the body of the patient. The bovie pencil is used to keep bleeding to a minimum. The prosthetic is placed into the hollow knee joint and marks are made where holes are to be drilled.

Stage 3

• A bone saw is employed to shape the ends of the exposed bones to better fit the prosthetic. Once a proper fit is made, a drill is used to drill into the remaining bone, where screws will then be applied to secure the prosthetic to the living bone. A thick layer of cement is applied to the exposed bone, and the prosthetic is fit into the joint. A mallet and metal pins are then hammered through the prosthetic and into the upper and lower leg bones of the patient, securing it with both pins and cement.

Stage 4

• The surgeon then begins the tedious process of reattaching the tendons and ligaments, and closing the layers of muscle and tissue that have been realigned to the new knee. Various types of sutures are used for this process. Most of them will remain in the patient until they are either absorbed, or are permanent sutures. The final outer layer of skin and tissue is usually closed with staples. These are removed around 12 to 14 days after the surgery.

Misconceptions

• A misconception about knee replacement surgery is that because it has become more common, and usually does not take more than a couple of hours at most, it is a simple procedure and not dangerous. This could not be further from the truth. The shock to the body is significant, as large sections of bone are being cut and removed, and the rough handling that is a necessity when dealing with joint replacement causes damage to the surrounding tissues. Bleeding can become profuse, and blood transfusions during this surgery are common. Infection is a real possibility as well, and there is always a small chance that the results of the surgery will be less than ideal. In a vast majority of cases, however, knee replacement surgery is safe and significantly improves the patients quality of life.