Knee cap dislocation

Injury	Disease	Nutrition	Poison

Symptoms	Surgery	Test	Special Topic

Arthroscopy

Patellar dislocation

Knee arthroscopy - series

Knee cap dislocation

Definition:

A dislocated knee cap is when the triangular bone covering the knee (patella) moves or slides out of place. The displacement usually occurs toward the outside of the leg. See dislocation.

Alternative Names:
Dislocation - knee cap; Patellar dislocation or instability
Considerations:

text continues below

The doctor will conduct a physical examination, which could provide a visual confirmation of the dislocated knee cap. In addition, touching the knee cap during the examination would confirm that it moves abnormally.

A knee X-ray may be performed, confirming dislocation.

Causes:

Dislocated knee caps most often occur in women with certain anatomic features of the knee, which predispose them to this condition.

It is usually a result of sudden direction changes while running. This puts the knee under stress. Dislocation may also occur as a direct result of injury. When it is dislocated, the knee cap may slip sideways and around to the outside of the knee.

The first episode or first several episodes are accompanied by pain and inability to walk. If the condition causing dislocation is left uncorrected, repeat dislocations tend to cause less pain and less immediate disability. However, they remain just as damaging to the patellar/femoral joint.