Can you clarify what knee cap dislocation really is?

Patella dislocation: During knee flexion, the knee cap or patella normally tracks in a groove in the distal femur called the trochlea. During a patellar dislocation, a traumatic event causes the patella to track outside of this groove while the knee flexes. This can injure some of the stabilizing structures surrounding the patella and can place a patient at risk fora future dislocation event.

Physically displaced: It is a condition in which the knee cap bone is pactually move out of the groove in the thigh bone(femur) it is often due to a trauma, canberra very painful, and needs tobe but back in place.You need to see a physician, probably an orthopedist. Small fratues can occur with this condition.