Time Dependent Changes of Insufficiency Fractures of the Sacrum von Prof. A. Stäbler | Feb 4, 1996 Stäbler A, Steiner W, Kohz P, Bartl R, Berger H, Reiser M. Time Dependent Changes of Insufficiency Fractures of the Sacrum: Intraosseous Vacuum Phenomenon as Early Sign Europ Radiol 1996; 6:655-657