Intertrochanteric fractures: current concepts of an old subject.

The pre- or intraoperative classification of intertrochanteric fractures into stable and unstable is based on the status of the bone in the critical calcar femorale area and the obliquity of the fracture line. Modern management of unstable intertrochanteric fractures may include displacement at the fracture site, osteotomy, and fixation with a sliding screw system. These procedures produce postoperative films of an "unusual" appearance. The radiologist must understand the principles of classification and management to properly interpret the pre- and postoperative films.