Knee transplant surgery, which is also known as artificial knee replacement surgery or knee arthroplasty, is a common surgical procedure that replaces an arthritic knee joint with an artificial joint or prosthesis. Two major types of knee transplant surgery are common. One involves a cemented knee prosthesis, or artificial knee joint, and the other typically uses an uncemented prosthesis.
Knee transplant surgery prevents the bones in the joint from rubbing together and causing pain in the knee. The artificial knee provides a new surface in the joint, one that can move smoothly without causing pain. That helps people return to their previous activity level with pain-free movement.
The artificial knee joint may be cemented into place with an epoxy that attaches the metal prosthesis directly to the bone during the knee surgery. An uncemented prosthesis is created with a layer of fine-mesh holes on its surface. After surgery, the patient's bone will grow into the mesh of the knee prosthesis and become naturally attached inside the joint.
The surgeon's decision to use one type of knee surgery over the other is based on the patient's age and lifestyle, and the current condition of the arthritic knee. Sometimes a combination of the two types of surgery is performed. The kneecap, or patellar portion of the artificial knee, is usually the part cemented into place in such a surgery.
The prosthesis, or artificial knee joint, consists of three parts. The bottom part, or tibial component, replaces the top surface of the tibia, or lower leg bone. The top of the artificial joint is the femoral component; it is made of metal and replaces the bottom surface of the femur, or upper leg bone. The patellar component — the artificial kneecap — replaces the patella surface, which glides in the groove on the bottom surface of the femur.
Knee transplant surgery may involve a total knee replacement or a partial knee replacement. The decision about which knee surgery is chosen depends on the diagnosed condition of the three compartments of the knee. If just one or two of those knee compartments are severely arthritic and painful, then partial knee replacement may be an option. An orthopedic surgeon can replace just one compartment of the knee using unicompartmental arthroplasty. Partial knee replacement allows the surgeon to avoid removing ligaments from the knee, which is necessary with most total knee replacements.
Another option in knee transplant surgery allows the surgeon to use a muscle-sparing approach, in which there is no cutting of muscle during the surgery. This provides a faster recovery for the patient, with a quicker return of function in the post-operative knee. Patients who need knee transplant surgery should discuss with their doctors the different types of knee replacement available, and learn about the different options for knee prosthetics and knee replacement.