To begin the procedure, the surgeon makes an incision on the front of the knee to allow access to the joint. Several different approaches can be used to make the incision, usually based on the surgeon's training and preferences.
Once the knee joint is opened, a special positioning device, called a cutting guide, is placed on the ends of the femur, tibia, and sometimes the patella. These guides are used to ensure that the bone is cut in the proper alignment and angles. With the help of the cutting guide, the surgeon cuts several pieces of bone from the ends of the femur and the tibia. The artificial knee will replace these worn surfaces.
The femoral component, made of metal or occassionalyy ceramic; the tibial tray, made of metal); and the patella component, made polyethylene, are then placed on the cut bony ends. A plastic spacer is inserted between the femoral component and the tibial traay and locked to the tibial tray. If this plastic component should wear out and the rest of the artificial knee is sound, it can be replaced. Finally, the soft tissues are sewn back together, and staples are used to hold the skin incision together.