Torsional tests of long bones with computerized equipment.

An experimental method using a computerized torsion machine to study the mechanics of entire diaphyseal bones is described. Besides controlling continuous torsion to ultimate fracture of the bone, the computer is able to use non-linearity of the torque-twist curve as a criterion for reversal of the direction of torsion and to control repeated loadings and unloadings with a graduated increase of deformation until final fracture. It permits determination of a small residual deformation, and several other parameters characterizing the load-deformation curve. The linearity of the equipment is shown to be good and precision is high, with a method error of 2.3% when determining stiffness. Repeated loadings and unloadings of entire dog femora revealed a minor residual deformation before ultimate fracture.

[1]  P. Netz,et al.  Material reaction of diaphyseal bone under torsion. An experimental study on dogs. , 1980, Acta orthopaedica Scandinavica.

[2]  W C Hayes,et al.  Compact bone fatigue damage: a microscopic examination. , 1977, Clinical orthopaedics and related research.

[3]  N. Dalén,et al.  Experimental measurement of maximum torque capacity of long bones. , 1976, Acta orthopaedica Scandinavica.

[4]  P. Netz,et al.  Non-linear properties of diaphyseal bone. An experimental study on dogs. , 1979, Acta orthopaedica Scandinavica.

[5]  M M Panjabi,et al.  Mechanical properties of bone as a function of rate of deformation. , 1973, The Journal of bone and joint surgery. American volume.

[6]  A. Burstein,et al.  A standard test for laboratory animal bone. , 1971, Journal of biomechanics.

[7]  H G Vogel,et al.  Influence of maturation and aging on mechanical and biochemical parameters of rat bone. , 1979, Gerontology.

[8]  P. Netz,et al.  Ultimate failure of diaphyseal bone. An experimental study on dogs. , 1980, Acta orthopaedica Scandinavica.

[9]  A. Burstein,et al.  The Mechanical Properties of Cortical Bone , 1974 .

[10]  K G Heiple,et al.  Bone strength. The effect of screw holes. , 1972, The Journal of bone and joint surgery. American volume.

[11]  A Chamay,et al.  Mechanical and morphological aspects of experimental overload and fatigue in bone. , 1970, Journal of biomechanics.

[12]  P. Paavolainen.  Studies on mechanical strength of bone. I. Torsional strength of normal rabbit tibio-fibular bone. , 1978, Acta orthopaedica Scandinavica.

[13]  J. Currey,et al.  The Mechanical Properties of Bone , 1970, Clinical orthopaedics and related research.

[14]  F. Sigurdsson,et al.  Recovery of diaphyseal bone strength after rigid internal plate fixation. An experimental study in the rabbit. , 1980, Acta orthopaedica Scandinavica.

[15]  A. Ekeland,et al.  Mechanical properties of fractured and intact rat femora evaluated by bending, torsional and tensile tests. , 1981, Acta orthopaedica Scandinavica.

[16]  C. Dent.  BIOCHEMISTRY AND PHYSIOLOGY OF BONE , 1956 .

[17]  D M Robertson,et al.  Fracture toughness, critical crack length and plastic zone size in bone. , 1978, Journal of biomechanics.

[18]  C. Hirsch,et al.  Factors affecting the determination of the physical properties of femoral cortical bone. , 1966, Acta orthopaedica Scandinavica.