Posterior dislocation following THA on radiograph

An AP radiograph of the right hip shows a dislocated right THA (images A and B). Image A shows that the metallic head (dashed arrow) is displaced cranially and laterally from the cup (arrow). The femur has been forced into a horizontal position. Image B is a cross table lateral examination, and the femur is held vertically. The head of the prosthesis (dashed arrow) is dislocated posteriorly and cranially in relation to the acetabula cup (arrow). Image C is an AP view obtained following reduction and shows the metallic head (dashed arrow) appropriately positioned in the acetabula cup (arrow).