Computed tomographic findings after anterior dislocation of the hip

Anterior dislocation of the hip is a rare phenomenon, seen in only 5–10% of all hip dislocations. These dislocations can be divided into two types: superior or subspinous and inferior or obturator dislocations. Osteochondral impaction fractures of the femoral head are a known complication of anterior dislocation, but little has been reported on the types of acetabular and pelvic fractures associated with this dislocation. Five anterior dislocations were studied with radiographs and computed tomographic (CT) imaging, and the CT findings are described. Fractures were seen in the femoral head, acetabular roof, and medial wall, as well as in the anterior inferior iliac spine. The most severe injuries occurred after a superior dislocation, but the obturator dislocations demonstrated impaction fractures of the femoral head as well as an intra-articular bone fragment. CT of the acetabuli is recommended after reduction of these dislocations to identify these complications.