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Knee Dislocation

Knee Dislocation Overview

A knee dislocation occurs when the bones that form your knee are out of place.

The bones of your calf (the tibia and fibula) get moved compared to the bone of your thigh (femur). The bones of your knee are held together by strong bands of tissue, called ligaments. For a knee dislocation to happen, these bands have to tear.

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Knee Dislocation Causes

Knee dislocations are rare. They usually happen only after major trauma, including falls, car crashes, and other high-speed injuries.

  • If the knee is dislocated, it will look deformed. The usual straight line of your leg will be crooked.
  • Sometimes, knee dislocations relocate (go back into place) on their own. In this case, the knee will be very swollen and painful.

Knee Dislocation Symptoms

Specifically, there will be a large amount of pain in the knee. Sometimes, there will be no feeling below the knee. If the knee relocates, it will become swollen. You may not be able to feel a pulse (your heartbeat) in your foot.

When to Seek Medical Care

If you think you dislocated your knee, go to the nearest hospital's emergency department. Seek care for these reasons:

  • Extreme pain or swelling after a serious injury (such as a car crash)
  • An obvious deformity of your knee
  • Numbness in your foot
  • No pulses in your foot

Go to the hospital's emergency department for medical care for a dislocated knee.

Exams and Tests

Depending on how the knee looks, you can expect the doctor to check the injury in the following ways:

  • X-rays: X-rays will be taken to make sure there are no breaks in the bone.
  • Examination of pulses: Injury to the arteries in the knee is common with this injury. The doctor will make sure there are pulses in your foot (the place the artery in your knee runs to).
  • An arteriogram (x-ray of the artery): This x-ray may need to be done to make sure there are no injuries to the artery. Some medical centers may also use special ultrasound or Doppler (sound wave) machines to assess the blood flow in your arteries.
  • Examination of nerves: Nerves also run through your knee, so it is possible that they may have been damaged. The ability to feel touch and to move certain muscle groups are the main ways nerves are tested. Specifically, the ability to move your foot up and down and to turn your foot inside (inversion) and outside (eversion) are important muscle movements to check for. Any feeling of numbness is concerning for nerve injury.

Knee Dislocation Treatment Self-Care at Home

This injury should not be cared for at home. It is best to get medical care as soon as possible.

Placing ice on the injured area may help for some pain control and to decrease some of the swelling. But the most important treatment is to have a doctor assess the injury and relocate or put the knee back in place.

WebMD Medical Reference from eMedicineHealth

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