Elastic trabecular bone

TABLE 47.4 Elastic Moduli of Trabecular Bone Material Measured by Different Experimental Methods... 

As stated earlier, this chapter has concentrated on the elastic and viscoelastic properties of compact cortical bone and the elastic properties of trabecular bone. At present there is considerable research activity on the fracture properties of the bone. Professor William Bonheld and his associates at Queen Mary and Westfield College, University of London and Professor Dwight Davy and his colleagues at Case Western Reserve University are among those who publish regularly in this area. Review of the literature is necessary in order to become acquainted with the state of bone fracture mechanics. 

Zysset, P. K., Edward Guo, X., Edward Hoffler, C., Moore, K. E. Goldstein, S. A. Elastic modulus and hardness of cortical and trabecular bone lamellae measured by nanoindentation in the human femur. Journal of Biomechanics 32, 1005-1012, doi 10.1016/s0021-9290(99)00111-6(1999). 

When trabecular bone is loaded in compression beyond its elastic range, unloaded, and reloaded, it displays loss of stiffness and development of permanent strains (Fig. 8.14). In particular, it reload with an initial modulus close to its intact Young s modulus but then quickly loses stiffness. The residual modulus is statistically similar to the perfect-damage modulus (a secant modulus from the origin to the point of unloading). In general, the reloading stress-strain curve... 

Van Rietbergen, B., Weinans, H, Huiskes, R., and Odgaard, A. (1995), A new method to determine trabecular bone elastic properties and loading using micromechanical finite element models, J. Biomech. 28(1) 69-81. 

Tissue Properties. The properties of human tissues when the body is considered a linear, passive mechanical system are summarized in Table 10.1 (von Gierke et al., 2002 Goldstein et al., 1993). The values shown for soft tissues are typical of muscle tissue, while those for bone depend on the structure of the specific bone. Cortical bone is the dominant constituent of the long bones (e.g., femiu, tibia), while trabecular bone, which is more elastic and energy absorbent, is the dominant constituent of the vertebrae. The shear viscosity and bulk elasticity of soft tissue are from a model for the response in vivo of a human thigh to the vibration of a small-diameter piston (von Gierke et al., 1952)... 

Compressive loading of human trabecular bone specimens loaded at low strain rates (< 1.0/sec) and taken from a range of anatomic sites. Originally reported dry densities have been converted to wet densities, t Ultrasound was used to measure the elastic properties, ft Specimens oriented along femoral neck axis. 

Augat P et al. (1998) Anisotropy of the elastic modulus of trabecular bone specimens from different anatomical locations, Medical Engineering Physics 20 124-131... 

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