Knee Replacement Surgery

What is knee replacement surgery?

The knee is a large joint that joins your thigh bone (femur) with your shin bone (tibia). The kneecap (patella) and the smaller bone in your lower leg (fibula) are also part of this joint. Tendons connect your leg muscles to the knee bones so that the joint can move. Ligaments connect the bones of the joint to one another and give the knee stability. The cartilage and fluid-filled sacs in the joint help the knee move smoothly.

The most common cause for knee replacement is severe pain, often from arthritis. The surgery is done to remove a painful, broken, or diseased knee joint and replace it with an artificial knee joint. The artificial knee is usually a combination of metal and plastic parts, but can also be ceramic.

How is knee replacement surgery done?

Before the procedure:

• Your healthcare provider will ask you to sign a consent form for knee replacement surgery. The consent form will state the reason you are having the procedure, what happens during the procedure, and what you may expect afterward.
• There is risk with every treatment or procedure. Talk to your healthcare provider for complete information about whether any of these risks apply to you:
  • Anesthesia problems
  • Infection
  • Blood clots
  • Bleeding
• Tell your healthcare provider if you have any food, medicine, or other allergies such as latex.
• Tell your healthcare provider if you are taking any medicines, including nonprescription drugs, herbal remedies, or illegal drugs.
• You will have a small tube (IV catheter) inserted into a vein in your hand or arm. This will allow for medicine to be given directly into your blood and to give you fluids, if needed.

During the procedure:

• A cardiac (heart) monitor may be used to keep track of your heart rate and rhythm.
• Your blood oxygen level will be monitored by a sensor that is attached to your finger or earlobe.
• You will be given a sedative through your IV to help you to relax.
• You will be given medicines to prevent pain during your surgery. These may include:
  • Regional anesthesia, which numbs a large area of your body
  • General anesthesia, which relaxes your muscles and puts you into a deep sleep. It also keeps you from remembering the operation. While you are asleep, you will have a tube in your throat to help you breath and to make sure you are getting enough oxygen. The tube may be removed before you wake up after the surgery.
• You may have a small tube (catheter) placed into your bladder to drain and measure urine.
• The surgeon will replace the knee by:
  • Making a cut in the skin and tissues over your knee to see the bones
  • Moving the tendons and kneecap to the side
  • Cutting and removing the damaged cartilage and lower femur and upper tibia
  • If necessary, removing the damaged surface of the kneecap
  • Placing an artificial (metal and plastic) surface on the bones of the joint
  • Placing a plastic piece in between the artificial bone surfaces to help the joint move smoothly
  • Placing the kneecap, leg bones, and tendons back in the proper position
• The skin and tissues will be closed with stitches or staples.
• Temporary tubes may be left in place to drain blood and fluid.

After the procedure:

• You will be checked often by nursing staff.
• There will be a dressing on your knee. The dressing will be checked and changed by your provider or the nursing staff as needed.
• Your leg may be moved regularly with a machine to help muscle and bones heal. This is called continuous passive motion or CPM.
• Your provider may prescribe medicine to:
  • Treat pain
  • Treat or prevent an infection
  • Treat or prevent blood clots
• Your provider may recommend other types of therapy to help relieve pain, other symptoms, or side effects of treatment.
• If a drain has been left in the wound, it will be checked and emptied regularly.

What can I do to help?

• You will need to tell your healthcare team if you have new or worsening:
  • Pain that is not controlled with your medicines
  • Redness, swelling, pain, warmth, or drainage from your surgical wound
  • Fever, chills, or muscle aches
  • Swelling in your leg, ankle, or foot on the side of your knee replacement
  • Coldness or change in color of the skin of your leg, ankle, or foot on the side of your knee replacement
  • Warmth, redness, or pain in your leg
  • If you are taking medicine to prevent blood clots, unusual or unexpected bleeding
• Ask questions about any medicine, treatment, or information that you do not understand.

How long will I be in the hospital?

How long you stay in the hospital depends on many things, such as your general health, why you are in the hospital, and the treatment you need. The average amount of time to stay in the hospital after a knee replacement is 3 to 5 days. Talk with your provider about how long your stay may be.

You may need to go to a rehab facility to continue your knee replacement rehab program before going home.