Relationships between structure, density and strength of human trabecular bone.

The article deals with the examination of the relationships between density, structure parameters and strength of human trabecular bone. The tests were carried out on the samples taken from osteoporotic and coxarthrotic human femoral heads. The samples cylindrical in shape had the diameters of 10 mm and the height of 8.5 mm. During the tests with microCT scanner the parameters of a sample structure were measured. Bone mineral density (BMD) was measured as well. The samples were subjected to compression in order to assess the ultimate compression strength sigma(c). The relationships between two-element combinations (BMD and one of the structure parameters) and the compression strength of the samples have been studied. The consistency of the results for multiple regression and response surface regression was estimated based on the correlation coefficient R. For the examined pairs of parameters, the value R increased in the range of 7-30% in comparison with the case where for the strength description only BMD was used. Additionally, the authors' own models of two-variable regression was calculated. The comparison of the results obtained for all models of regression based on the coefficient E proved the consistency of these results.