<prompt> Flail chest is defined asFracture of 3 or more ribs at 2 or more placesFracture of 2 or more ribs at 2 or more placesFracture of 2 or more ribs at one placeFracture of multiple ribs at one place  <response>: Flail chest : Fracture of two or more consecutive ribs, with each rib having two or more fracture sites. Such segment is called flail segment. Ref : SRB;s 4thE pg:1196 