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Patellar Fracture


What is a patellar fracture?

A patellar fracture is a break in your kneecap.

What are the types of patellar fractures?

  • Nondisplaced fractures are broken pieces of bone that stay in line.
  • Displaced fractures are broken pieces of bone that move out of line.
  • Open fractures involve a break in the skin that covers the kneecap.
  • Closed fractures do not involve a break in the skin.

What causes a patellar fracture?

  • Direct trauma such as a car accident or a sports injury can cause a patellar fracture. A direct blow to your knee or a hard fall on your knee are also examples of direct trauma.
  • Indirect trauma can cause a patellar fracture. A strong contraction (tightening) of the thigh muscles when the knee is bent is an example of indirect trauma. This contraction pulls the tendon connected to the kneecap, which breaks the kneecap.

What increases my risk for a patellar fracture?

If you had total knee replacement surgery, you are more likely to have a patellar fracture. This is because your knee is less stable after knee replacement surgery. Osteoporosis (brittle bones) or arthritis also increases your risk.

What are the signs and symptoms of a patellar fracture?

  • You have pain when your knee is touched or when you move your leg.
  • You have swelling and bruising around your knee.
  • You are able to straighten your leg but you cannot bend it.
  • You cannot stand up or put weight on your injured leg.

How is a patellar fracture diagnosed?

Your healthcare provider will ask you about the injury and examine you. He may check if the bone pieces are in their correct places by feeling your knee. You may need any of the following tests:

  • An x-ray is a picture of your knee to see what kind of fracture you have. More than one picture may be taken. Healthcare providers may also x-ray your other leg.
  • A CT scan or an MRI is a type of x-ray that is taken of your knee. You may be given a dye before the pictures are taken to help healthcare providers see your knee better. Tell the healthcare provider if you have ever had an allergic reaction to contrast dye. Do not enter the MRI room with anything metal. Metal can cause serious injury. Tell the healthcare provider if you have any metal in or on your body.
  • A bone scan is a test to look at your patellar fracture and check for infection. You will get a radioactive liquid, called a tracer, through a vein in your arm. The tracer collects in your bones and pictures are taken.

How is a patellar fracture treated?

  • A brace, cast, or splint may be needed. These are supportive devices that stop the kneecap from moving and help it heal. They often extend from the groin to the ankle. You may also need to use crutches to help you move around while your knee heals.
  • Medicines can help decrease pain or help fight or prevent an infection. You may also need a Td vaccine. This vaccine is a booster shot used to help prevent diphtheria and tetanus. You may need the Td vaccine if you have an open patellar fracture.
  • Surgery:
    • Irrigation and debridement is a procedure to clean and remove objects, dirt, or dead tissue from the fracture area.
    • Open reduction and internal fixation surgery may be needed. Healthcare providers make a large incision over your kneecap. The broken pieces of bone and ligaments are moved back to their correct places. Bone pieces and ligaments may be secured using wires, pins, screws, or bands.
    • Closed reduction surgery may be needed. Healthcare providers move the broken pieces of bone and ligaments back to their correct places without a large incision. External fixation may be used to hold your kneecap in place, and then later removed.
    • Patellectomy is surgery to remove part or all of your kneecap.
  • Physical therapy may be needed. A physical therapist teaches you exercises to help improve movement and strength, and to decrease pain.

What can I do to help my patellar fracture heal?

  • Elevate your knee above the level of your heart as often as you can. This will help decrease swelling and pain. Prop your knee on pillows or blankets to keep it elevated comfortably.
  • 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.
    Ice and Elevation

When should I contact my healthcare provider?

  • You have a fever.
  • Your wound is red, swollen, and feels warm.
  • You have pus coming from your wound.
  • Your knee pain is getting worse, even after treatment.
  • You have questions or concerns about your condition or care.

When should I seek immediate care?

  • Your cast or splint breaks or gets damaged.
  • Your foot or toes are swollen, cold, numb, or they turn white or blue.
  • Blood soaks through your bandage.
  • Your leg feels warm, tender, and painful. It may look swollen and red.
  • You feel lightheaded, short of breath, and have chest pain.
  • You cough up blood.

Care Agreement

You have the right to help plan your care. Learn about your health condition and how it may be treated. Discuss treatment options with your healthcare providers to decide what care you want to receive. You always have the right to refuse treatment. 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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Further information

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