Effective mechanical parameters of bone tissue samples for the selection of individual osteoimplants

The results of the stress-strain state of model bone meso-volumes containing cancellous and cortical bone tissue together and micro-volumes of cortical and cancellous bone tissue separately under uniaxial compression are presented. Unconventional effective mechanical parameters, serving as a relative measure of the deformation response manifestation for the considered meso- or micro-volume of bone in three perpendicular directions, and the effective modulus of elasticity under axial compression are determined. It has been revealed that the micro- and meso-volumes of bone tissue with different structures and compositions may differ in the pattern of stress and strain distribution, but have similar elastic moduli, and vice versa. It has been shown that the micro- and meso-volumes of bone tissue samples with different structures and compositions, having the same distribution of stresses and strains, are characterized by the same values of the introduced effective mechanical parameters. It is proposed to use effective mechanical characteristics and longitudinal modulus of elasticity during the selection and development of individual osteoimplants. When installing an implant into the bone, it is suggested to coordinate the orthotropic axes of the implant and the replaced bone site to maintain a favorable mechanical state of the bone consistent with that before implant installation.