[The anatomic and radiologic picture of the acetabulum (author's transl)]

The basic shape of the facies lunata shows at the inner margin of each of the three participating bones a dell into which the floor of the acetabulum progresses. These dells originate in nutritive vessels which enter the bone and claim this place. There always are groups of vessels and wide channels which may be visible on radiographs. The so far unexplained picture of a vascular canal in the roof of the acetabulum corresponds to the canal leading into the body of the ilium. Due to its position there is often restructuring leading to filling or covering of the canal. The entrance to this canal is shown as a gap in the arc of the acetabular cavity which would have to be added to that of the "tear figure" known so far. The closed arc, as always drawn, reults only when this entry has been filled up.