Definition

During knee replacement surgery a diseased or injured knee is removed insert an artificial joint is inserted.

Total Knee Replacement

nucleus factsheet image

© 2008 Nucleus Medical Art, Inc.

Parts of the Body Involved

Knee

Reasons for Procedure

Knee replacement is done when pain and stiffness limit normal activities. Before the surgery other measures, such as rest, medications, or physical therapy will be tried. The procedure is most often performed to:

Risk Factors for Complications During the Procedure

  • Pre-existing medical condition
  • Obesity
  • Urinary tract infection or dental or gum disease (each will increase the risk of bacteria entering the bloodstream and infecting the joint)
  • Diabetes
  • Taking steroid medication

What to Expect

Prior to Procedure

Your doctor will likely do the following:

  • Physical exam
  • X-rays of joint
  • Blood tests
  • Possibly, MRI scan —a test that uses magnetic waves to make pictures of the inside of the body

In the time leading up to your procedure:

  • If you are overweight, lose some weight to decrease the amount of stress on your new joint.
  • Patients often need blood during surgery. Consider donating your own blood before the procedure.
  • Make home modifications to help make recovery easier:
    • Install safety bars, a raised toilet seat with arms, a shower bench and shower hose, and handrails on stairways and steps.
    • Remove throw rugs and extension cords.
    • Purchase a stable, firm-backed arm chair and a footstool.
    • Consider creating a temporary living space on one floor, since climbing up and down stairs will be difficult at first.
  • Review your regular medications with the surgeon and follow instructions if asked to discontinue some drugs.
  • Arrange for a ride to and from the hospital and medical appointments.
  • Arrange for help at home after returning from the hospital.
  • The night before, eat a light meal and do not eat or drink anything after midnight the night before unless told otherwise by your doctor.

During Procedure

IV fluids, blood, anesthesia, and possibly sedation will be administered.

Anesthesia

You and your doctor will discuss the use of general , spinal , or epidural anesthesia.

Description of the Procedure

The surgeon makes an incision and removes damaged cartilage and bone. The remaining bone is prepared to receive the new plastic and metal joint. The artificial joint is placed in proper position and cemented within the bone. The incision is closed with stitches or staples and a drain is left in to allow extra fluid to flow out. A splint holds the knee in proper position.

Blood and fluid loss from this surgery are often significant, and may require blood transfusions. You will be given IV antibiotics just prior to the start of surgery and possibly during the procedure. Antibiotics are generally discontinued within 24 hours of surgery.

After Procedure

A urinary catheter will be placed. A splint or brace will be placed on your knee.

How Long Will It Take?

The surgery takes about two hours.

Will It Hurt?

Anesthesia prevents pain during surgery. You may experience pain during recovery but you will receive pain medication to relieve this discomfort.

Possible Complications

  • Infection
  • Blood clots in a leg or pelvic vein that may travel to the lungs
  • Excessive swelling or bleeding
  • Injury to nearby nerves or blood vessels
  • Anesthesia-related problems

Average Hospital Stay

The procedure typically requires a 3-6 day stay in the hospital.

Postoperative Care

  • Move your foot and ankle to increase venous blood flow back to your heart.
  • Your leg may be placed in a continuous passive motion (CPM) machine that slowly moves your knee, restoring function, decreasing swelling, and improving circulation.
  • You may be given special support hose to wear that may help prevent blood clots from forming in your legs.
  • You may need to wear a brace or splint; you will be taught to use a walker, crutches, or other support device until your leg is healed enough to support your weight.
  • A physical therapist will help you perform specific knee exercises, usually starting the day after surgery. You'll be taught safe and painless ways to stand, sit, lie, walk, and otherwise move the knee and support your weight.
  • You will gradually progress to walking and then to climbing stairs.
  • Keep the incision area clean and dry, and place a dressing over the incision to protect it from irritation.
  • Stitches or staples will be removed in a few weeks.
  • You may be sent home with blood-thinning medications; be careful to take these medications exactly as prescribed.
  • Do not take over-the-counter remedies without your surgeon's approval.

Outcome

Within six weeks, you should be able to resume normal light activities and driving. You may feel a soft clicking in the joint when walking or bending. By following the recommended activity and rehabilitation program, you can speed your recovery and protect future joint function.

Maintain a healthy weight, and refrain from jogging and other high-impact sports, which can increase wear on the joint, cause it to loosen, and increase pain.

You'll need antibiotics before dental procedures to decrease the risk of bacteria entering the bloodstream and traveling to the prosthesis.

Call Your Doctor If Any of the Following Occurs

  • Signs of infection, including fever and chills
  • Redness, swelling, increasing pain, excessive bleeding, or discharge from the incision site
  • Cough, shortness of breath, chest pain, or severe nausea or vomiting
  • Your leg, foot, or toes appear chalky white, blue, or black
  • Numbness or tingling in your leg, foot, or toes
  • Pain, burning, urgency, frequency of urination, or persistent bleeding in the urine
  • Pain and/or swelling in your feet, calves, or legs, or sudden shortness of breath or chest pain