A fracture dislocation is a severe injury in which both a fracture and dislocation occur simultaneously. It is a combination of a broken bone and a joint that is forced out of position. A loose piece of bone may remain jammed between the ends of the dislocated bones and may have to be removed surgically before the dislocation can be reduced. Immobilization must be longer than in a simple dislocation to permit healing of the fracture, and chances for permanent stiffness or disability are greater than in uncomplicated dislocation or fracture. Dislocations or fractures can occur due to a sudden impact from a blow, fall, or other trauma. Dislocations are serious injuries that occur when one of the bones that make up a joint is forced out of position, and this means the joint can no longer move. Dislocations often occur in the shoulders, elbows, fingers, hips, knees, and ankles, and they are usually caused by a traumatic event such as a fall, car accident, or sports injury.