Knee Replacement

A surgical procedure to remove a diseased or injured knee joint and insert an artificial joint, called a prosthesis.

Parts of the Body Involved

Knee

Reasons for Procedure

Knee replacement becomes an option for treating a damaged knee when pain and stiffness limit normal activities and are not relieved by other measures, such as rest, medications, or physical therapy. The procedure is most often performed to:
  • Alleviate knee pain and disability due to osteoarthritis, rheumatoid arthritis, or severe knee injury
  • Correct a knee deformity (knee bows in or out)

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)

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 excess pounds 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, possibly sedation

Anesthesia - General, spinal, or epidural

Description of the Procedure - The surgeon makes an incision and removes damaged cartilage and bone. The remaining bone is prepared to receive the prosthesis and the new plastic and metal joint is placed and cemented in position. 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 during surgery, and for several days after.

After Procedure - Urinary catheter, splint or brace

How Long Will It Take? 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 vein or traveling to the lungs
  • Excessive swelling or bleeding
  • Injury to nearby nerves or blood vessels
  • Anesthesia-related problems
  • Reaction to the metal prosthesis
Average Hospital Stay: 3-6 days

Postoperative Care:
  • Move your foot and ankle to increase blood flow.
  • Your leg may be placed in a continuous passive motion (CPM) machine that slowly moves your leg, 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 may 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 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'll probably be sent home with oral antibiotics; take all of the pills prescribed
  • You may be sent home with blood-tinning medications
  • Do not take over-the-counter remedies without your surgeon's approval

Outcome

Within 6 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, but 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