Total knee replacement surgery
Knee-joint replacement is surgery to replace all or part of the knee joint with a man-made, or artificial joint. The artificial joint is called prosthesis.
Your new knee joint
Damaged cartilage and bone are removed from the knee joint. Man-made pieces are then placed in the knee.
Up to three surfaces of the knee joint may be replaced. They are the:
- Lower end of the thighbone. This bone is called the femur. The replacement part is usually made of metal.
- Upper end of the shinbone, the large bone in your lower leg. This bone is called the tibia. This replacement part is usually made of metal and a strong plastic liner.
- Underside or backside of your kneecap. Your kneecap is called the patella. This replacement part is usually made from a strong plastic.
Some orthopedic surgeons use other materials. Some of these are metal on metal, ceramic on ceramic, or ceramic on plastic.
What happens during surgery?
You will not feel any pain during surgery because you will receive anesthesia, medicine that blocks pain. You will have one or a combination of the 2 types of anesthesia:
- General anesthesia: This means you will be unconscious and unable to feel pain.
- Regional (spinal or epidural) anesthesia: Medicine is put into your back to make you numb below your waist. You will also receive medicine to make you sleepy if you have this type of anesthesia.
After you receive anesthesia, your surgeon will make an incision (cut) over your knee to open it up. This cut is often 3 to 5 inches long. Then your surgeon will:
- Move your kneecap out of the way, then cut the ends of your thighbone and shinbone (lower leg bone) to fit the replacement part.
- Cut the underside of your kneecap to prepare it for the pieces that will be attached there.
- Fasten the 2 parts of your new knee joint to your bones. One part will be attached to the end of your thighbone and the other part will be attached to your shinbone.
- Attach both parts to the underside of your kneecap.
- Apply a special bone cement (usually) to hold these parts together.
- Repair your muscles and tendons around the new joint and close your surgical cut.
This surgery usually takes about 2 hours. You will stay in the hospital for 1 to 3 days. Some people need a short stay in a rehabilitation center after they leave the hospital and before they go home.
What is minimally invasive knee replacement?
Some surgeons are using a newer surgery technique called "minimally invasive" knee replacement. This type of surgery uses a slightly smaller surgical cut or incision.
The surgeon will use special instruments to work through the small cut. In minimally invasive surgery, your surgeon will still:
- Cut and remove bone and cartilage.
- Move some muscles and other tissues, but less than in open (traditional) surgery. Fewer muscles around the knee may need to be cut or detached.
- Use the same implants as in open surgery, or use newer ones.
These newer surgery techniques are rapidly changing. The hope is that they will allow for a quicker, less painful recovery from knee-replacement surgery.
Talk with your surgeon about the benefits and risks of these newer techniques, and whether your surgeon has experience doing them.