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Unicompartmental Knee Replacement


  • Unicompartmental knee replacement (UKR) is also called unicompartmental arthoplasty. This surgery removes a part of the knee joint that is damaged by osteoarthritis, avascular necrosis, or osteonecrosis. Osteoarthritis is a condition where the joint surface of your knee wears out, causing problems with the cartilage in your knee. Cartilage is the hard tissue at the end of long bones that cushions the bone and decreases friction. Avascular necrosis or osteonecrosis is a condition that occurs when blood flow to certain bones of the body is decreased. The decrease in blood flow causes bones to weaken, leading to breakdown of the joint. These conditions can cause pain, and make it harder for you to move your knee.
    Picture of a normal knee
  • The knee is made up of three compartments (sections). The middle and lateral sections are formed where the femur bone meets the tibia bone. The third section is where the patella (kneecap) makes contact with the femur. During UKR, surgery is only done on the damaged section of your knee. This section of your knee is replaced with a prosthesis (man-made implant). The implant may be made of plastic, ceramic, or metal. Having UKR may make movements such as walking, sitting, or standing easier, and may decrease your knee pain.


Take your medicine as directed:

Call your primary healthcare provider if you think your medicine is not helping or if you have side effects. Tell him 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.

  • Non-steroidal anti-inflammatory medicine: This family of medicine is also called NSAIDs. Nonsteroidal anti-inflammatory medicine may help decrease pain and inflammation (swelling). NSAIDs may also be used to decrease a high body temperature (fever). This medicine can be bought with or without a doctor's order. This medicine can cause stomach bleeding or kidney problems in certain people. Always read the medicine label and follow the directions on it before using this medicine.
  • Pain medicine: You may be given medicine to take away or decrease pain. Your caregiver will tell you how much to take and how often to take it. Do not wait until the pain is too bad before taking your medicine. The medicine may not work as well at controlling your pain if you wait too long to take it. Tell caregivers if the medicine does not decrease your pain, or if your pain comes back too soon.
  • Antibiotics: This medicine is given to prevent or treat an infection. When there is an implant in your knee, you are at a higher risk of getting infections. Your caregiver may tell you to take antibiotic medicine before you have dental work done, and before having other procedures, such as a colonoscopy. You may need to do this for three or more years after surgery.
  • Blood thinners: Blood thinners are medicines that help prevent blood clots from forming. Clots can cause strokes, heart attacks, and death. Blood thinners make it more likely for you to bleed or bruise. If you are taking a blood thinner:
    • 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 on your teeth. This can keep your skin and gums from bleeding. If you shave, use an electric shaver. Do not play contact sports, such as football.
    • Be aware of what medicines you take. Many medicines cannot be used when taking medicine to thin your blood. Tell your dentist and other caregivers that you take blood-thinning medicine. Wear or carry medical alert information that says you are taking this medicine.
    • Take this medicine exactly as your caregiver tells you. Tell your caregiver right away if you forget to take the medicine, or if you take too much. You may need to have regular blood tests while on this medicine. Your caregiver uses these tests to decide how much medicine is right for you.
    • Talk to your caregiver about your diet. This medicine works best when you eat about the same amount of vitamin K every day. Vitamin K is found in green leafy vegetables and other foods, such as cooked peas and kiwifruit.

Ask for information about where and when to go for follow-up visits:

For continuing care, treatments, or home services, ask for more information.

  • Ask your caregiver when to return to have your wound checked, and the drain, stitches, or staples removed. You may also need to have an x-ray to check on your knee implant, and you may need to have blood collected for tests.

What to do to help your wound heal:

  • Do not drink alcohol. Alcohol is found in adult drinks such as beer, wine and whiskey. Alcohol can damage your brain, heart, and liver. Drinking alcohol can also make you more likely to get an infection after your surgery. Talk to your caregiver if you drink alcohol, and ask for information on how to stop.
  • Eat healthy foods. Eat a variety of healthy foods to give you more energy and help your wound heal faster. Some healthy foods are fruits, vegetables, whole-grain breads, low-fat dairy products, beans, lean meat and fish. Being overweight or obese may make it take longer for your to heal. Eating the right foods may also help you lose weight. Talk to your caregiver about the right diet plan for you.
  • Watch your blood sugar levels. Having a high blood sugar level can make your would take longer to heal. Keep your blood sugar levels in the range that your caregiver tells you they should be. Ask your caregiver for help and information about managing your blood sugar levels.
  • Stop smoking. Smoking harms the heart, lungs, and the blood. You are more likely to have a heart attack, lung disease, and cancer if you smoke. Smoking can also delay wound healing. You will help yourself and those around you by not smoking. Ask your caregiver for more information on how to stop smoking if you are having trouble quitting.
  • Talk to your caregiver about taking vitamins. Vitamin C and E, and minerals such as zinc may help wounds heal faster. These supplements can help repair tissues during wound healing. They can also help your body fight off infections.

Using ice:

Ice causes blood vessels to constrict (get small) which helps decrease swelling, pain, and redness. Put crushed ice in a plastic bag and cover it with a towel. Place it on your knee for 15 to 20 minutes every hour as long as you need it. Do not sleep on the ice pack because you can get frostbite.


Your exercise plan may include stretching your leg muscles and making the muscles stronger. At first you may need to use crutches, or a cane or walker. Walking aids can help you get around, and decrease your chances of falling. Use your crutches, cane, or walker correctly. Ask your caregiver for more information about how to choose and use crutches, a cane, or a walker. As your knee heals caregivers may suggest that you increase how far you walk each day. After this you may be asked to climb stairs. You may need to use wedges in your shoes when you walk. Your caregiver may also suggest that you ride a bicycle.

Compression stockings:

Your caregiver may tell you to wear compression stockings. These are tight elastic stockings that put pressure on your legs. The pressure is strongest in the toe and decreases as it goes toward your thigh. Wearing pressure stockings helps push blood back up to the heart and keeps clots from forming. Ask your caregiver for more information on using compression stockings.


  • There is still drainage coming from your knee incision for four or more days after surgery.
  • You have a fever (high body temperature).
  • You are not able to do the exercises that you have been told to do.
  • You have trouble stretching your leg and moving or bending your knee.
  • Your knee incision begins to drain fluid again after it has stopped.
  • Your skin is itchy, swollen, or has a rash.
  • You have questions or concerns about your knee surgery, healing, or medicine.


  • You are unable to walk or move your legs, or have knee stiffness while moving your leg.
  • You fell and injured your knee.
  • You have fainted (passed out).
  • Your leg feels warm, tender, and painful. It may look swollen and red.
  • You have chest pain or trouble breathing that is getting worse over time.
  • You suddenly feel lightheaded and have trouble breathing.
  • You have new and sudden chest pain. You may have more pain when you take deep breaths or cough. You may cough up blood.

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.

Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.