The knee cap is a tiny bone on a tendon, the knee is more complex, it is the whole joint with three bones and mucles, ligament and tendon, and there can be a lot of soft tissue damage.
"A dislocated knee occurs when the position of the thighbone relative to the shinbone becomes disrupted at the knee joint. It can happen through trauma to your leg, like from falls, sports injuries, and car accidents.
A dislocated knee is different than a
dislocated kneecap. That occurs when the kneecap bone slips out of place. It can happen when a sudden change of direction or blow occurs while your foot is planted on the ground.
A dislocated knee is a
rare but serious injury. Dislocation can damage several important ligaments, blood vessels, and nerves. The health and integrity of the joint and leg may be at risk."