Patellar Dislocation: What you ‘knee’d to know

Patellar Dislocation (also known as kneecap dislocation) occurs when a twisting injury to the knee causes the kneecap (the triangle-shaped bone covering the knee) to move or slide out of place. This usually occurs in Basketball, Soccer or Football when an athlete makes a plant, then changes direction suddenly, or performs a cutting motion which leaves the foot firmly planted whiled the body twists around the knee. When the patella is dislocated, it can slip sideways and around to the outside of the knee.

Symptoms of Patellar Dislocation include:

  • Severe pain and inability to walk
  • Stiffness, tenderness and swelling around the knee
  • Pain in the knee that increases with activity
  • Instability or collapsing of the knee
  • Creaking or cracking sounds during movement
  • Kneecap physically slips to the outside of the knee


A physical examination by a doctor or orthopedic surgeon is needed to determine proper diagnosis. This may include walking around or being asked to straighten and bend the knee. The doctor may also feel the area around the kneecap and take measurements to determine if the bones are out of alignment or if the thigh muscles are weak. An X-ray of the patella may be required to rule out underlying conditions, such as fracture. An MRI may also be needed to determine if the injury has caused damage to ligaments or cartilage in the knee.


Once patellar dislocation is confirmed, the kneecap will be physically pushed back into place. If the kneecap is only partially dislocated, and the doctor has confirmed that there’s no fracture or damage to the knee’s cartilage the knee may be placed an immobilizing brace for several weeks. Following a period of immobilization, physical therapy is recommended to build muscle strength and improve range of motion in the knee.

If the patella remains unstable and recurrent dislocations occur, arthroscopic or other surgery may be recommended to stabilize the patella. This may involve repairing the soft tissue or realigning the patella. Dislocation often damages the underside of the kneecap and the end of the thighbone, which can lead to additional pain and arthritis. Arthroscopic surgery can also correct this condition.

Dislocations that continue to occur and are left untreated, can cause damage to the knee joint.


It’s impossible to prevent all kneecap dislocations, but there are steps you can take to reduce the likelihood that the injury will occur or reoccur.

  • Proper technique when exercising or playing sports
  • Proper warm up before exercise or playing sports
  • Proper quad strengthening, core strengthening, and proper body mechanics
  • Starting slowly and gradually increasing the speed of movements required in your sport

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