What is a dislocated knee?

A knee dislocation occurs when the tibia and fibula (bones of the lower leg) are moved in relation to the femur (thigh bone). The bones are held together with ligaments (strong connective bands of tissue). When the knee dislocates, the ligament tears.

In order to avoid the loss of a leg, it is important to treat a knee dislocation right away.

Common related conditions
Knee Fracture Anterior Cruciate Ligament (ACL) Injury Lateral Collateral Ligament (LCL) Injury Medial Collateral Ligament (MCL) Injury Posterior Cruciate Ligament (PCL) Injury

Causes of a dislocated knee

Knee dislocations are rare and typically occur in the following situations:

  • Car collisions
  • High speed injuries, such as from downhill skiing
  • After a major fall

Risk factors for a dislocated knee

  • Participating in sports where falls are common — participating in sports such as basketball, football, wrestling and gymnastics put you at a higher risk for a knee dislocation.
  • Car collisions — people who do not wear seat belts are at a higher risk for a knee dislocation.
  • Genetics — people who have bone with lose ligaments are at higher risk for suffering from a knee dislocation.
  • Susceptibility to falls — if you are susceptible to falls, you are more likely to suffer from a knee dislocation.

Symptoms of a knee dislocation

Intense pain is an immediate symptom of a dislocated patella (knee). Your knee is also likely to be swollen, and the kneecap will look displaced. You may be unable to walk or move the knee after dislocating the knee.

Knee dislocations in some people will pop back in place on their own but will still be painful and swollen.

Diagnosis of a dislocated knee

If you suspect you have dislocated your knee, visit Mercy Health ER right away. A knee dislocation can be diagnosed in a physical exam. While waiting to see the doctor, immobilize and ice the knee joint.

The provider will order an x-ray, an ultrasound, check the pulses and examine the nerves to confirm the diagnosis.

Treatments for a dislocated knee

Knee dislocations must be treated by a doctor right away. Treatments for a knee dislocation include:

  • Relocation — your orthopedic physician will manipulate the lower leg back into place; it is important relocation occur right away to repair damage to nerves, blood vessels, ligaments and other tissues in the knee.
  • Surgery — if there is an arterial injury, a vascular surgeon must repair the vessel to maintain blood flow to the leg.
  • Reconstruction surgery — reconstruction surgery in the knee may be required if there are other tears or sprains in the tissues to help you regain function in the knee.

Recovery from a dislocated knee

Your physician will encourage you to do physical therapy or rehabilitation to strengthen the tissues surrounding the knee.

He or she may also put you in a splint or brace to immobilize the joint after surgery as well as prescribe crutches to keep you off the injured knee.

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