Unstable Kneecap

Unstable Kneecap
Unstable Kneecap

Overview Of Unstable Kneecap

An unstable kneecap occurs when the triangle-shaped bone covering the knee (patella) shifts out of place. It is also known as kneecap dislocation.

The dislocation mostly occurs toward the outside of the leg.


An unstable kneecap often occurs after a sudden change in direction when planting your foot putting your kneecap under stress.

This can occur when playing sports such as basketball. Direct trauma can also cause dislocation.

Symptoms Of Unstable Kneecap

Symptoms of unstable kneecap include:

  • A deformed kneecap
  • A bent knee
  • Knee pain and tenderness
  • Knee swelling
  • Shifted kneecap (to the outside of the knee)
  • “Sloppy” kneecap (hypermobile patella)

The first few times an unstable kneecap occurs, you will be in pain and be unable to walk.

Subsequent dislocations may not hurt as much but treatment is still necessary. Kneecap dislocations damage your knee joint and can lead to cartilage injuries.

The risk of developing osteoarthritis at a younger age also increases.

Treatment Of Unstable Kneecap

You can straighten out or stabilize (splint) your knee and get medical attention.

Your health care provider may order an x-ray or an MRI to check for a broken bone or cartilage damage.

If there is no damage, your knee will be placed into an immobilizer or cast for about 3 weeks to prevent movement.

When the cast is removed, physical therapy can help build back muscle strength and improve the knee’s range of motion.

If there is damage to the bone and cartilage arthroscopic or open surgery will be needed to stabilize the kneecap.


Use proper techniques during exercise or sports and keep your knees strong and flexible.

Knee dislocation may not be preventable where physical factors make dislocation more likely.