Patellar dislocation, which generally tends to occur laterally, is a major traumatic event for the knee joint with damage to the ligamentous structures that stabilize and maintain the patella in the center of the femoral trochlea during joint movements and to which cartilage damage can be associated articulate up to small osteochondral detachments both femoral and patellar. Patellar dislocation is an event that most commonly affects young women who practice sports, aged between 14 and 17, while it is rare in individuals over 25 years of age. While in the acute phase the clinical picture is diagnostic, radiological imaging allows us to highlight and quantify the damage to the patellofemoral ligaments and the possible involvement of the articular cartilage. Treatment is generally conservative and rehabilitative, but in cases of recurrent episodes resulting from a framework of joint instability, surgery is necessary. The different imaging techniques allow us to have a panoramic view of the lower limb and the knee joint, with the possibility of assessing the presence and the severity of malformative aspects of the articular surfaces of the femoral trochlea and of the patella, beyond with malformative frameworks that affect muscle, tendon and ligament structures.