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Knee Replacement


What you need to know about knee replacement:

Knee replacement is surgery to replace all or part of your knee joint. It is also called knee arthroplasty. The knee joint is where your femur (thigh bone) and tibia (large lower leg bone or shin bone) meet. A small bone called the patella (kneecap) protects your knee joint.

How to prepare for knee replacement:

Your healthcare provider will talk to you about how to prepare for surgery. He may tell you not to eat or drink anything after midnight on the day of your surgery. He will tell you what medicines to take or not take on the day of your surgery. You may need x-rays, a CT scan, or an MRI to help your healthcare provider plan your surgery. Ask about any tests you may need.

What will happen during knee replacement:

  • You may be given general anesthesia to keep you asleep and free from pain during surgery. You may instead be given regional anesthesia to numb the surgery area. With regional anesthesia, you may still feel pressure or pushing during surgery. You may remain awake during the surgery or procedure, but you should not feel any pain in your knee. Your surgeon will make an incision over your knee joint. He will remove the damaged parts of your knee joint and replace them with a knee implant. The knee implant may be made of metal and plastic. He may secure it with medical cement.
  • Your surgeon will move the muscles and other tissues around your joint back into place. A drain may be placed to remove extra blood and fluid from the surgery area. Your healthcare provider will close your incision with stitches or staples. He may uses strips of medical tape and a bandage to cover your wound.

What will happen after knee replacement:

Do not get out of bed until your healthcare provider says it is okay. You will need physical therapy to help strengthen your knee and prevent stiffness. You may need to use a continuous passive motion (CPM) machine. This machine will slowly bend and straighten your knee for you as you lie in bed. Ask your healthcare provider how to use a CPM machine.

Risks of knee replacement:

You may bleed more than expected or get an infection. Nerves or blood vessels may be damaged during surgery. After surgery, your knee may be stiff or numb. You may continue to have knee pain. You may get a blood clot in your leg. This may become life-threatening. Your implant may get loose or move out of place. The implant may get worn out over time and need to be replaced.

Call 911 for any of the following:

  • You feel lightheaded, short of breath, and have chest pain.
  • You cough up blood.

Seek care immediately if:

  • Your leg feels warm, tender, and painful. It may look swollen and red.
  • You cannot walk or move your knee.
  • Blood soaks through your bandage.
  • Your incision comes apart.
  • Your incision is red, swollen, or draining pus.

Contact your healthcare provider if:

  • You have a fever or chills.
  • You have trouble moving or bending your knee.
  • You have increasing knee pain.
  • You have questions or concerns about your condition or care.


  • Prescription pain medicine may be given. Ask how to take this medicine safely.
  • NSAIDs , such as ibuprofen, help decrease swelling, pain, and fever. This medicine is available with or without a doctor's order. NSAIDs can cause stomach bleeding or kidney problems in certain people. If you take blood thinner medicine, always ask your healthcare provider if NSAIDs are safe for you. Always read the medicine label and follow directions.
  • Blood thinners help prevent blood clots. Examples of blood thinners include heparin and warfarin. Clots can cause strokes, heart attacks, and death. The following are general safety guidelines to follow while you are taking a blood thinner:
    • Watch for bleeding and bruising while you take blood thinners. Watch for bleeding from your gums or nose. Watch for blood in your urine and bowel movements. Use a soft washcloth on your skin, and a soft toothbrush to brush your teeth. This can keep your skin and gums from bleeding. If you shave, use an electric shaver. Do not play contact sports.
    • Tell your dentist and other healthcare providers that you take anticoagulants. Wear a bracelet or necklace that says you take this medicine.
    • Do not start or stop any medicines unless your healthcare provider tells you to. Many medicines cannot be used with blood thinners.
    • Tell your healthcare provider right away if you forget to take the medicine, or if you take too much.
    • Warfarin is a blood thinner that you may need to take. The following are things you should be aware of if you take warfarin.
      • Foods and medicines can affect the amount of warfarin in your blood. Do not make major changes to your diet while you take warfarin. Warfarin works best when you eat about the same amount of vitamin K every day. Vitamin K is found in green leafy vegetables and certain other foods. Ask for more information about what to eat when you are taking warfarin.
      • You will need to see your healthcare provider for follow-up visits when you are on warfarin. You will need regular blood tests. These tests are used to decide how much medicine you need.
  • Take your medicine as directed. Contact your healthcare provider if you think your medicine is not helping or if you have side effects. Tell him or her if you are allergic to any medicine. Keep a list of the medicines, vitamins, and herbs you take. Include the amounts, and when and why you take them. Bring the list or the pill bottles to follow-up visits. Carry your medicine list with you in case of an emergency.


Your healthcare provider will tell you when it is okay to drive and return to your normal activities. You may need to use a CPM machine to strengthen your leg muscles and prevent stiffness. Your healthcare provider may give you exercises to do, or you may need physical therapy. A physical therapist teaches you exercises to help improve movement and strength, and to decrease pain.

Care for your wound as directed:

Do not get your wound wet until your healthcare provider says it is okay. Carefully wash the wound with soap and water. Dry the area and put on new, clean bandages as directed. Change your bandages when they get wet or dirty. Do not put powders or lotions over your incision. If you have strips of medical tape over your incision, let them dry up and fall off on their own. If they do not fall off within 14 days, gently remove them. Check your wound every day for signs of infection, such as swelling, redness, or pus. If you have a drain, empty the drain as directed. You may need to write down how much you empty from your drain each time. Ask your healthcare provider for more information on drain care.


  • Apply ice on your knee for 15 to 20 minutes every hour or as directed. Use an ice pack, or put crushed ice in a plastic bag. Cover it with a towel. Ice helps prevent tissue damage and decreases swelling and pain.
  • Place a pillow or towel roll under your heel to help keep your knee straight. This will help decrease stiffness in your knee. Do not place a pillow under your knee. A pillow allows your knee to stay bent and can cause stiffness.
  • Wear pressure stockings as directed. The stockings are tight and put pressure on your legs. This improves blood flow and helps prevent clots.

  • Use a walker as directed. It will help decrease your risk for falls and take pressure off your knee.
  • Carry your ID card for your joint replacement at all times. All healthcare providers need to know about your joint replacement. You may need antibiotics before any procedure to prevent an infection of your new joint. The metal in your new joint may set off metal detectors. You will not be able to have an MRI with metal in your joint.

Prevent falls:

  • Remove all loose carpets and cords. These can cause you to trip and fall.
  • Use a shower bench or chair when you take a shower. Ask your healthcare provider where you can get one.
  • Use a chair with a firm cushion and back. The chair should also have arms that you can lean on when you get up. The seat cushion should be about 18 to 20 inches high. Keep a footstool nearby to elevate your knee as needed.
  • Use a toilet seat riser with arms if your toilet seat is low. Ask your healthcare provider where you can get one.
  • Know your limits. Do not do an activity until your healthcare provider says you are ready. Walk up stairs slowly.

Follow up with your healthcare provider as directed:

Write down your questions so you remember to ask them during your visits.

© 2016 Truven Health Analytics Inc. Information is for End User's use only and may not be sold, redistributed or otherwise used for commercial purposes. All illustrations and images included in CareNotes® are the copyrighted property of A.D.A.M., Inc. or Truven Health Analytics.

The above information is an educational aid only. It is not intended as medical advice for individual conditions or treatments. Talk to your doctor, nurse or pharmacist before following any medical regimen to see if it is safe and effective for you.