Bending and Torsion Fractures in Long Bones (A Mechanical and Radiologic Assessment of Clinical Cases)

Article type: Research Article

Authors: Miyasaka, Yoshinori^; | Sakurai, Minoru | Yokobori, Jr., A. Toshimitsu | Kuroda, Sumio | Ohyama, Masamizu

Affiliations: Department of Orthopedic Surgery, Tohoku University School of Medicine | Department of Mechanical Engineering II, Tohoku University, Sendai | Department of Orthopedic Surgery, Sendai Municipal Hospital, Sendai

Note: [] Requests for reprints should be addressed to Assistant Professor Y. Miyasaka, Department of Orthopedic Surgery, Tohoku University School of Medicine, Seiryo-machi, Aoba-ku, Sendai 980, Japan.

Abstract: Long bone injuries in clinical cases are studied by comparison of roentgenograms with a rational mechanical analysis of the injuries. Fractures produced by torsional loads have a spiral shape with a smooth and even surface. Fractures induced by bending loads have uneven and rugged fracture surfaces perpendicular to the bone axis. Long bones are weak in torsion but strong in tensile stress produced by bending. This result corresponds to the clinical fact that a large direct external force is needed to produce a transverse fracture while a spiral fracture is produced by a relatively small torque.

Keywords: long bone injuries, transverse fracture, spiral fracture

DOI: 10.3233/BME-1991-1102

Journal: Bio-Medical Materials and Engineering, vol. 1, no. 1, pp. 3-10, 1991