Learn All About Kneecap Dislocation

16 January, 2020
Kneecap dislocation frequently occurs as a result of a sudden change of direction of your leg when you touch the ground. Learn more about it in this article.

Kneecap dislocation occurs when the knee bone is forced out of place. It can occur due to a fall, a direct blow to the knee or after turning or twisting it.

Often, kneecap dislocation occurs toward the outside of the leg. It’s more likely to occur during athletic activity.

The causes of kneecap dislocation

A person with knee pain.

Kneecap dislocation frequently occurs as a result of a sudden change of direction of the leg when it touches the ground. However, it can also occur when there’s a direct injury to the knee. It’s almost always due to something that predisposes the person to it.

When you dislocate your patella, or kneecap, the joint becomes unstable and you can fall. Also, you’ll feel intense pain and you won’t be able to bend your knee. Often, people can even see their patellas out of place and notice that their knees look deformed. However, if patellar or kneecap dislocation occurs due to direct trauma, it can even break the articular capsule.

Factors that increase the risk of kneecap dislocation

Some factors can increase the risk of suffering from kneecap dislocation. Among them, being overweight or tall or having previously suffered from another patellar dislocation or another knee injury all play a role.

Also, you must take into account the physical characteristics that increase the risk of suffering a dislocated kneecap, such as:

  • Patella Alta: Having an overly high patella.
  • Knock knees: Having X-shaped legs increases the angle between the quadriceps and the patellar tendon, favoring the displacement of the patella.
  • Lateralized patellar tendon insertion
  • Medial patellofemoral ligament rupture: This ligament connects the patella to the femur on the inside. It prevents the patella from popping out when the knee is extended, which is when dislocation occurs in most cases.

Discover: Recovery after a Knee Transplant

Diagnosis and symptoms

To diagnose patellar or kneecap dislocation, the doctor will touch the patella and bend the knee, moving it in different directions. By using X-rays, magnetic resonance imaging (MRI), or computed tomography (CT), they may see images of the dislocated kneecap and other knee injuries.

When you suffer a dislocated kneecap, the following symptoms usually appear:

  • First, swelling and a deformed knee.
  • Second, the inability to bend your knee or bear weight on your leg.
  • Third, patella displacement towards the outside of the knee.
  • Sensitivity and pain.
  • Also, patellar hypermobility.
  • Finally, cartilage injuries, which may increase the risk of developing osteoarthritis.

This article may also interest youKnee Dislocation Causes and Treatment

How to relieve the symptoms

A person applying ice on their knee to relieve pain.

To relieve the symptoms caused by a dislocated kneecap, experts recommend:

  • Take nonsteroidal anti-inflammatory drugs. The use of these drugs helps reduce inflammation and pain. Nevertheless, you have to remember to always take them according to the schedule indicated by your doctor.
  • Apply ice. Ice helps reduce inflammation and pain and prevents damage to the tissue. Place it on your knee according to your specialist’s instructions.


In some cases, patellar or kneecap dislocation can’t be prevented, especially if physical factors make you susceptible to suffering from it. However, exercise by using appropriate techniques and try to keep your knees strong and flexible.

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  • Segura, F., Soler Heredia, A., Fernández, R., & Gascó Gómez, J. (2001). Luxación congénita de rótula. Revista Española de Cirugía Osteoarticular.