Unicompartmental Knee Replacement

WHAT YOU SHOULD KNOW:

• 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.
  
  
• 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.

CARE AGREEMENT:

You have the right to help plan your care. To help with this plan, you must learn about your health condition and how it may be treated. You can then discuss treatment options with your caregivers. Work with them to decide what care may be used to treat you. You always have the right to refuse treatment.

RISKS:

• You may have an allergic reaction to the anesthesia and have trouble breathing. The nerves or tendons around your knee may be damaged during surgery. You may bleed more than expected, or get an infection. You may get blood clots in your legs or your lungs, or have problems with your heart. After surgery, your knee may be stiff and painful. Your legs may not be the same length. Your implant may loosen or move out of place. The implant may get worn out over time and need to be replaced. You may need more surgery. After having surgery, you may lose your balance and be more likely to fall for a time.
  
  
• If you do not have UKR, you will keep feeling pain with exercise and activity. Over time, your whole knee joint may be worn out. You may feel more pain, and need surgery at a later time. Ask your caregiver any questions that you have about your knee surgery, your medicine, and what to expect after surgery.

GETTING READY:

Before surgery:

• Ask someone to drive you home when you are ready to leave the hospital. Do not drive yourself home.
  
  
• Tell your caregiver if you know or think you might be pregnant.
  
  
• You may be given nonsteroidal anti-inflammatory medicine before your surgery. This medicine can help decrease your pain. This medicine can increase the risk of bleeding, stomach ulcers or kidney problems in some people.
  
  
• You may be given an antinausea medicine. This medicine may be given to calm your stomach and control vomiting (throwing up). Ask your caregiver whether you need to stop using any prescribed or over-the-counter medicine before your surgery.
  
  
• If you smoke cigarettes, you may be asked to stop smoking before your surgery.
  
  
• You may need to have imaging tests such as computed tomography (CT) scan or magnetic resonance imaging (MRI). You may also need an arthroscopy or x-rays of the knee and leg bones. Ask your caregiver for more information about the tests that you may need. Write down the date, time, and location for each test.

The night before surgery:

• If you have diabetes, ask your caregiver for special instructions about what you may eat and drink before your surgery. If you use medicine to treat diabetes, your caregiver may have special instructions about using it before surgery. You may need to check your blood sugar more often before and after having surgery.
  
  
• Ask caregivers about directions for eating and drinking.

The day of surgery:

• Write down the correct date, time, and location of your surgery.
  
  
• Bring your medicine bottles or a list of your medicines when you see your caregiver. Tell your caregiver if you are allergic to any medicine. Tell your caregiver if you use any herbs, food supplements, or over-the-counter medicine.
  
  
• What to bring: You may want to bring items such as a toothbrush and bathrobe.
  
  
• Caregivers may insert an intravenous tube (IV) into your vein. A vein in the arm is usually chosen. Through the IV tube, you may be given liquids and medicine.
  
  
• You or a close family member will be asked to sign a legal piece of paper (consent form). It gives your caregiver permission to do the procedure or surgery. It also explains the problems that may happen, and your choices. Be sure all your questions have been answered before you sign this form.

TREATMENT:

What will happen:

• You will put on a hospital gown and be taken on a stretcher to the operating room. Medicine will be given to decrease pain and allow you to sleep during your surgery. Your knee area will be cleaned and then covered with sheets. A tight band called a tourniquet may be put around your thigh. It is filled with air to stop blood from going to your knee during surgery.
  
  
• Your caregiver will do an incision (cut) into the front of your knee. The damaged bones and cartilage in the section of your knee will be removed using special tools. Pain medicine may be given as a shot into your knee while the damaged bones are being removed. The implant will be fitted to the bones and either cemented into place or fixed in place with screws. A drain (thin rubber tube) may be placed on your incision to drain blood and other fluids from the wound. The incision will be closed with stitches or staples and the tourniquet will be removed.

After your surgery: A bandage will cover your incision to keep the area clean, and help prevent infection. A caregiver will change the bandage and check your knee soon after your surgery. An x-ray may also be done. You will be taken to a room where you will stay until you are fully awake. Do not try to get out of bed until your caregiver says it is OK. 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.

Waiting room: This is a room where your family and friends can wait until you are ready for visitors. If your family leaves the hospital, ask them to leave a phone number where they can be reached.

CONTACT A CAREGIVER IF:

• You cannot make it to your surgery on time.
  
  
• You get sick (a cold or flu) or have a fever.
  
  
• You have an infection or wound near or on your knee.
  
  
• Your leg is swollen, painful or it feels warm to touch.

SEEK CARE IMMEDIATELY IF:

• You have new and sudden trouble moving your legs.
  
  

Copyright © 2008 Thomson Healthcare Inc. All rights reserved. Information is for End User's use only and may not be sold, redistributed or otherwise used for commercial purposes.

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.

Link to Page

Print Page

Email Page