Your Health - Knee Replacement

Knee Replacement

(Knee Arthroplasty)

Definition

This is surgery involves removing a diseased or injured knee joint and replacing it with an artificial one.

Total Knee Replacement

Reasons for Procedure

This is done if you have pain and stiffness in the knee joint that limits activities. Before surgery, other measures are tried, such as:

Rest
Medications
Physical activity

Knee replacement surgery is most often done to:

Ease knee pain and disability due to arthritis, or previous severe knee injury
Correct a knee deformity (eg, knee bows in or out)

Possible Complications

Complications are rare but no procedure is completely free of risk. If you are planning to have a knee replacement, your doctor will review a list of possible complications, which may include:

Infection
Blood clots
Excessive swelling or bleeding
Injury to nearby nerves or blood vessels
Anesthesia-related problems

Some factors that may increase the risk of complications include:

Pre-existing medical conditions
Obesity
Current infection
Diabetes
Taking steroid medication

Be sure to discuss these risks with your doctor before the surgery.

What to Expect

Prior to Procedure

Your doctor will likely do the following:

Physical exam
Blood tests
X-ray —a test that uses radiation to take a picture of structures inside the body, especially bones
MRI scan —a test that uses magnetic waves to make pictures of structures inside the body

Leading up to your procedure:

If you are overweight, lose weight. This will help to decrease the amount of stress on your new joint.
Make home modifications to help make recovery easier:
- Install equipment to help keep you safe, such as:
  - Safety bars
  - Raised toilet seat with arms
  - Shower bench and shower hose
  - Handrails on stairways and steps
- Remove items that could cause falls. These might include throw rugs and extension cords.
- Make sure you have a firm-backed arm chair and a footstool.
- Stay on the first floor. Climbing stairs will be difficult at first.
Talk to your doctor about your medicines. You may be asked to stop taking some medicines up to one week before the procedure like:
- Anti-inflammatory drugs (eg, aspirin )
- Blood thinners like clopidogrel (Plavix) or warfarin (Coumadin)
If advised by your doctor, take antibiotics.
Arrange for a ride to and from the hospital. Also, arrange for help at home.
Eat a light meal the night before the surgery. Do not eat or drink anything after midnight.

Anesthesia

Different types of anesthesia can be used, including:

General anesthesia —blocks pain and keeps you asleep through the surgery; given through an IV in your hand or arm
Spinal or epidural anesthesia —numbs the area from the chest down to the legs; given as an injection into the back

Description of the Procedure

The doctor will make an cut in the skin. The damaged cartilage and bone will be removed. The remaining bone will be prepared to receive the new plastic and metal joint. The doctor will then place the artificial joint in the proper position. It will be cemented within the bone. The doctor will close the incision with staples. A drain will be left in to allow extra fluid to flow out.

Immediately After Procedure

You will be taken to the recovery room and monitored closely
A splint or brace will be placed to hold the knee in the right position

How Long Will It Take?

About 2 hours

How Much Will It Hurt?

You will have pain during recovery. Your doctor will give you pain medication.

Average Hospital Stay

This procedure is done in a hospital setting. The usual length of stay is 3-4 days. Your doctor may choose to keep you longer if complications arise.

Post-procedure Care

At the Hospital

While you are recovering at the hospital, you may need to:

Use a continuous passive motion machine, which is designed to:
- Slowly move your knee
- Restore function
- Decrease swelling
- Improve circulation
Move your foot and ankle to increase blood flow back to your heart.
Wear support stockings. These may help prevent blood clots from forming in your legs.
Work with a physical therapist. You may start the day after surgery. You will learn safe ways to move your knee and support your weight.
Wear a brace or splint. You will learn how to use a walker , crutches , or other support devices.
Take blood-thinning medications.

At Home

When you return home, do the following to help ensure a smooth recovery:

Be sure to follow your doctor's instructions .
Keep the incision area clean and dry. Place a clean dressing over it.
Slowly progress to walking and then to climbing stairs. Avoid jogging and other high-impact sports.
Get the staples removed in a few weeks.
Maintain a healthy weight after surgery.
Talk to your doctor before taking over-the-counter medications.
Take antibiotics before surgery or dental procedures. Antibiotics will decrease the risk of bacteria entering the bloodstream and traveling to the artificial knee.

Within six weeks, you should be able to go back to light activities and driving. You may feel a soft clicking in the joint when walking or bending. Continue to work with the physical therapist. Water-based exercises may help to improve joint pain, swelling around the knee, and range of motion.

Call Your Doctor

After you leave the hospital, contact 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
Pain that you can't control with the medications you've been given
Nausea and/or vomiting that you can't control with the medications you were given after surgery, or which persist for more than two days after discharge from the hospital
Cough, shortness of breath, or chest pain
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
Swelling, redness or pain in your legs, calves, or feet

In case of an emergency, call 911.

RESOURCES:

American Academy of Orthopaedic Surgeons
http://www.aaos.org/

American Orthopaedic Society for Sports Medicine
http://www.sportsmed.org/

CANADIAN RESOURCES:

Canadian Orthopaedic Association
http://www.coa-aco.org/

Canadian Orthopaedic Foundation
http://www.canorth.org/

References:

Total knee replacement. American Academy of Orthopaedic Surgeons website. Available at: http://orthoinfo.aaos.org/topic.cfm?topic=A00389 . Updated August 2007. Accessed December 22, 2008.

¹4/16/2009 DynaMed's Systematic Literature Surveillance http://www.ebscohost.com/dynamed/what.php : Harmer AR, Naylor JM, Crosbie J, Russell T. Land-based versus water-based rehabilitation following total knee replacement: a randomized, single-blind trial. Arthritis Rheum. 2009;61:184-191.

Last reviewed October 2009 by Robert E. Leach, MD and Brian P. Randall, MD

Please be aware that this information is provided to supplement the care provided by your physician. It is neither intended nor implied to be a substitute for professional medical advice. CALL YOUR HEALTHCARE PROVIDER IMMEDIATELY IF YOU THINK YOU MAY HAVE A MEDICAL EMERGENCY. Always seek the advice of your physician or other qualified health provider prior to starting any new treatment or with any questions you may have regarding a medical condition.