The Björk-Shiley 70° Convexo-Concave Prosthesis Strut Fracture Problem - Ostermeyer, J; Horstkotte, D; Bennett, J; Huysmans, H; Lindblom, D; Olin, C; Orinius, E; Semb, G (The Thoracic and Cardiovascular Surgeon, 1987)