Patellar dislocation

Alternative names:

dislocation of the knee cap; injury - knee - patellar; injury - patella; knee cap dislocation; knee injury - patellar

Definition:

A dislocation (subluxation) of the knee cap which usually occurs to the outside of the leg (laterally).

Causes, incidence, and risk factors:

Dislocation usually occurs as a result of sudden direction changes while running and the knee is under stress or it may occur as a direct result of injury. During this maneuver the knee cap may slip sideways and around to the outside of the knee. The first episode (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 immediate disability. However, the remain just as damaging to the patellar/femoral joint.