This guide is prepared for our patients who will need knee replacement surgery. It is intended to give you an overview of the surgery, answer common questions and discuss important items that you will need to be familiar with before and after surgery.
The most common reason to replace a knee is arthritis resulting in pain, stiffness, deformity or instability which interferes with your lifestyle and is not controlled with simpler measures, such as medication, using a cane, or less extensive surgery such as arthroscopy. A normal knee joint has smooth cartilage surfaces which glide across one another with almost no friction. In an arthritic knee, the joint surfaces are rough and irregular, causing pain as the uneven surfaces grind across each other. In a knee replacement operation, the rough surfaces are replaced with smooth, gliding components and the deformities and stiffness are corrected.
Most commonly, the surgeon enters the knee through an incision centered over the front of the joint. The capsule of the knee is opened generally on the inside edge of the kneecap. The muscles and tendons are then pulled out of the way and the knee is bent to expose the arthritic bone ends. Two to three millimeters of bone are removed from the ends of both the tibia and the femur, which are shaped to accept the implants. The metal implants are anchored to the tibia and femur, using bone cement or a press fit technique. The technique of fixation depends on many factors, such as the strength and quality of your bone. A plastic implant is attached to the tibial implant to form a firm, stable, low friction articulation between metal and plastic. It is common to find considerable damage to the joint surface of the kneecap requiring it to be resurfaced as well. At surgery, great care is taken to restore the overall alignment of the knee and the position and function of the kneecap.