On occasion, this type of dislocation can occur with minimal injury in the elderly, and because X-rays may not easily show a posterior dislocation, the diagnosis is often missed should the patient present for evaluation of shoulder pain and/or decreased range of motion of the shoulder joint.
A patellar dislocation occurs when your patella (kneecap) is forced out of place. It can be caused by a fall or a direct blow to your knee. It can also happen if your knee twists or rotates. It is most likely to happen during physical activity, such as sports, military training, or dance.
Perilunate dislocations and perilunate fracture dislocations are potentially devastating closed wrist injuries that are often missed on initial imaging. These injuries involve dislocation of the carpus relative to the lunate which remains in normal alignment with the distal radius.