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Knee Dislocation


What is a knee dislocation?

A knee dislocation happens when an injury forces your thigh bone out of alignment with your shin bone. It may occur with other injuries. It can also cause torn ligaments in your knee or nerve damage.

What can cause a knee dislocation?

  • A car or motorcycle accident
  • Being hit by a car while walking or biking
  • A sports injury
  • A fall from a high height, such as from a ladder
  • Stepping in a hole, or stepping off a curb or stair

What are the signs and symptoms of a knee dislocation?

  • Pain and swelling in your leg and knee
  • Numbness or weakness in your lower leg
  • A lower leg that looks pale or feels cold
  • Not being able to move or stand on your leg
  • A change in the shape of your knee

How is a knee dislocation diagnosed?

Your healthcare provider will examine your knee and any other wounds. Tell him how your injury happened. He may ask you to move your leg and foot, or flex your toes. Tell him if you have other health conditions. Tell him if you take medicines, such as blood thinners. You may need the following tests:

  • X-rays are pictures of your knee. They are used to see if your knee is dislocated and if you have other injuries.
  • An arteriogram is an x-ray test in which dye is injected into your blood vessels. The pictures will show if blood is flowing normally through your leg. Tell the healthcare provider if you have ever had an allergic reaction to contrast dye.
  • An ultrasound uses sound waves to show pictures of your knee on a monitor. The pictures are used to look for damage to blood vessels or nerves.
  • An MRI scan uses powerful magnets and a computer to take pictures of your knee. You may be given dye to help the pictures show up 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 CT scan is also called a CAT scan. An x-ray machine uses a computer to take pictures of your knee. You may be given dye before the pictures are taken to help healthcare providers see the pictures better. Tell your healthcare provider if you have ever had an allergic reaction to contrast dye.

How is a knee dislocation treated?

The goal of treatment is to repair your knee dislocation and other injuries. The type of treatment depends on your injuries, your age, and your activity level and lifestyle. You may need the following:

  • Pain medicine may include acetaminophen, NSAIDs, and prescription pain medicine. These are given to decrease swelling and pain.
  • Reduction is a procedure to move your leg bones back into place. This is done by moving your knee and leg in different positions until your bones line up properly. You will be given medicine to help you relax before your healthcare provider reduces your knee. Reduction is sometimes done during surgery. After reduction, you will have another x-ray.
  • Fasciotomy is a procedure to make a long incision in your leg. This is done to relieve the pressure caused by swelling or bleeding.
  • Surgery may be done to repair damaged nerves, ligaments, and blood vessels. It may also be done to move your leg bones back into place. Your healthcare provider may perform surgery right away after your knee dislocation. He may decide to wait until other injuries are treated to perform surgery.

What are the risks of a knee dislocation?

You could have tissue damage or an infection if you have an open wound. You may have nerve damage. This can make it hard for you to lift or move your foot. You may have small pieces of bone or cartilage in your knee. You could have heavy bleeding caused by damage to the blood vessels in your leg. Your leg may need to be amputated above the knee. You could have a blood clot in your leg or lungs. This may become life-threatening. You may have long-term pain or arthritis in your knee. You may need more surgery in the future. Even after treatment, there is a higher risk that you might dislocate your knee again.

How can I manage my symptoms?

It may take weeks or months for your knee to heal and for you to return to your previous activity level.

  • Care for your wound as directed. 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.
  • Immobilize your knee for up to 6 weeks or as directed. Your healthcare provider may put on a cast or splint. You may need to wear a leg brace to stabilize your knee. A leg brace can be adjusted to increase your range of motion as your knee heals.
  • Use crutches if your healthcare provider tells you not to put weight on your injured knee. Your healthcare provider will show you how to use crutches. You may need crutches for 4 to 6 weeks.
  • Physical therapy teaches you exercises to strengthen your leg, increase balance, and decrease pain. Physical therapy may also help prevent another knee injury.

When should I contact my healthcare provider?

  • You have leg pain that does not go away after you take pain medicine.
  • Your knee is red or swollen, or your wound is leaking pus.
  • Your stitches come apart.
  • You have questions or concerns about your condition or care.

When should I seek immediate care?

  • Blood soaks through your bandage.
  • You have severe pain and swelling in your lower leg.
  • Your lower leg looks pale.
  • You feel lightheaded, short of breath, and have chest pain.
  • You cough up blood.
  • Your leg feels warm, tender, and painful. It may look swollen and red.

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 caregivers 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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