Displacement of the bones of a joint .
It disrupts the ligaments , muscles , and capsule (encasing membrane) holding the joint in place. The joint, painful and tender, appears misshapen and swollen, with discoloration of the overlying skin. The patient cannot use the joint and often feels a grating or grinding sensation on trying to move it. The bones must be returned to their normal position (reduction) and the joint kept immobile until healed. Recurrent and congenital dislocations usually require surgical reconstruction.