A patella dislocation occurs when the kneecap moves out of its normal position, usually towards the outside of the knee. It can be caused by trauma or as a result of underlying anatomical factors. Symptoms include sudden pain and swelling, difficulty bending or straightening the knee, and visible deformity or instability in the knee joint. Treatment may involve reducing the dislocation with manual manipulation or surgery, immobilization with a brace or cast, and physical therapy to restore strength and stability. Prompt medical evaluation is important to prevent further damage to the knee joint.