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.

WHILE YOU ARE HERE:

Before your surgery:

• Informed consent: You have the right to understand your health condition in words that you know. You should be told what tests, treatments, or procedures may be done to treat your condition. Your doctor should also tell you about the risks and benefits of each treatment. You may be asked to sign a consent form that gives caregivers permission to do certain tests, treatments, or procedures. If you are unable to give your consent, someone who has permission can sign this form for you. A consent form is a legal piece of paper that tells exactly what will be done to you. Before giving your consent, make sure all your questions have been answered so that you understand what may happen.
  
  
• IV: An IV is a tube placed in your vein for giving medicine or liquids. This tube is capped or connected to tubing and liquid.
  
  
• Pre-op care: You may be given medicine right before your procedure or surgery. This medicine may make you feel relaxed and sleepy. You are taken on a stretcher to the room where your procedure or surgery will be done, and then you are moved to a table or bed.
  
  
• Anesthesia: Anesthesia is medicine to make you comfortable during surgery. Caregivers work with you to decide which anesthesia is best and whether you will be awake or completely asleep. Do not make important decisions for 24 hours after having anesthesia. Also, do not drive or use heavy equipment. An adult may need to drive you home and stay with you after you have had anesthesia.
  
  
• Foley catheter: A Foley catheter is a tube that is put into your bladder to drain your urine into a bag. The bladder is an organ where urine is kept. Keep the bag of urine well below your waist. Lifting the urine bag higher will make the urine flow back into your bladder, which can cause an infection. Avoid pulling on the catheter because this may cause pain and bleeding, and the catheter may come out. Do not allow the catheter tubing to kink because this will block the flow of urine.
  
  
• Vital signs: This includes taking your temperature, blood pressure, pulse (counting your heartbeat), and respirations (counting your breaths). To take your blood pressure, a cuff is put on your arm and tightened. The cuff is attached to a machine which gives your blood pressure reading. Caregivers may listen to your heart and lungs by using a stethoscope. Your vital signs are taken so caregivers can see how you are doing.

During your surgery: An incision (cut) is made into the front area of the damaged section of your knee. The damaged ends of your bones are removed using special tools. You may be given a shot of pain medicine into your knee during surgery. Caregivers will put the implant in place. Cement may be used to hold it in place, or it may be fixed in place with screws. A drain (thin rubber tube) may be placed in the area to drain blood and other fluids out of your knee. Your incision is closed with stitches or staples, and a bandage is placed over it.

After your surgery: The bandage may be changed soon after your surgery to check your wound. X-rays may be done to check the placement of your implant. You will be taken to a room where you can stay until you are fully awake. Do not try to get out of bed until your caregiver says it is OK.

• Cold therapy: The cold from ice placed on your knee causes blood vessels to constrict (get small), which helps decrease swelling, pain, and redness. Ice may be placed on your knee for 15 to 20 minutes every hour. Ice may also be used before you do knee exercises.
  
  
• Compression stockings: Your caregiver may ask you to wear compression stockings. These tight elastic stockings put pressure on your legs after surgery. Wearing pressure stockings helps blood flow through your blood vessels and helps prevent blood clots, also called deep vein thrombosis (DVT).
  
  
• Continuous passive motion machine: You may need to keep your leg in a continuous passive motion (CPM) machine. This machine slowly bends and straightens your leg for you as you lie in bed. You may need to use this machine for three or more hours each day, for ten days after surgery.
  
  
• Deep breathing and coughing: This breathing exercise helps to keep you from getting a lung infection after surgery. Deep breathing opens the tubes going to your lungs. Coughing helps to bring up sputum (mucus) from your lungs for you to spit out. You should deep breathe and cough every hour while you are awake even if you wake up during the night.
  
  
  • Hold a pillow tightly against your incision (cut) when you cough to help decrease the pain. Take a deep breath and hold the breath as long as you can. Then push the air out of your lungs with a deep, strong cough. Put any sputum that you have coughed up into a tissue. Take 10 deep breaths in a row every hour while awake. Remember to follow each deep breath with a cough.
    
    
  • You may be asked to use an incentive spirometer. This helps you take deeper breaths. Put the plastic piece into your mouth and take a very deep breath. Hold your breath as long as you can. Then let out your breath. Use your incentive spirometer 10 times in a row every hour while awake.
  
  
• Medicines:
  
  
  • Antibiotics: Antibiotics may be given to help treat or prevent an infection caused by germs called bacteria.
    
    
  • Anti-clotting medicines: This type of medicine is given to help prevent blood clots from forming in your legs. You may be given blood thinners before, during, and after your knee surgery. Medicine may also be given to help clots break apart. This type of medicine makes it easier for you to bleed and bruise. Use a soft toothbrush to help keep your gums from bleeding. If you shave, use an electric shaver.
    
    
  • Antinausea medicine: This medicine may be given to calm your stomach and control vomiting (throwing up). Pain medicine may upset your stomach and make you feel like vomiting. Because of this, pain medicine and anti-nausea medicine are often given at the same time.
    
    
  • Pain medicines: This medicine is given to decrease pain after surgery. Medicine may be given regularly, or may only be given if you ask caregivers for it. Tell caregivers if your pain does not decrease enough for you to feel better. Do not wait to ask for your pain medicine until the pain is very bad. The medicine may not work as well at controlling your pain if you wait too long to take it. You may have a PCA machine. With this machine, you will be able to press a button and give yourself pain medicine when you need it. Ask your caregiver for help getting out of bed if you feel tired or dizzy. If you take pain medicine before doing physical therapy, you may get through the therapy with less pain.
    
    
  • Non-steroidal anti-inflammatory medicine: This family of medicine is also called NSAIDs. It may help decrease pain and inflammation (swelling). This medicine can increase the risk of bleeding, stomach ulcers or kidney problems in some people. Tell caregivers if you have liver or kidney disease, or a history of bleeding in your stomach.
    
    
  • Muscle relaxers: This is medicine to help your muscles relax. When your muscles relax, you may move more easily and have less pain.
  
  
• Exercise: A physical therapist may help you exercise soon after surgery. Your exercise plan may include stretching your leg muscles and making the muscles stronger. At first you may need to use crutches, a cane, or a walker.

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.

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