Correlation between bone histomorphometry and bone strength

Abstract

Context: The structural and mechanical characteristics of bone have been extensively studied to understand the functional adaptations associated with the properties of biological material. While measures of apparent density used as an estimate of mechanical properties do not account for the structural organization of the trabecular bone, thus rendering this scalar measure inadequate for predicting the material properties. Structurally bone can be divided into macro- and micro-structure. Whereas macrostructure can be understood in terms of its mass, shape, and density of the bone, microstructure is related to bony trabecular meshwork. Thus, the evaluation of bone microstructure plays an important role in defining material properties of bone including the bone strength. Aim: This study uses histomorphometric parameters and compares the same with compression strength of cancellous bone. Materials and Methods: Static histomorphometric parameters such as trabecular number, trabecular thickness, trabecular separation, and bone volume were calculated using 40 cubical specimens obtained from femoral heads of patients who underwent hip replacement procedures. These cubes were subjected to uniaxial compression test and yield point at failure calculated and results compared with histomorphometric indices. Discussion and Conclusions: We found the best correlation between bone volume microstructural parameter and uniaxial compression strength. The order of significance was bone volume (Spearman correlation 0.9652) > trabecular number (Spearman correlation 0.7646) > trabecular separation (Spearman correlation 0.7541) > trabecular thickness (Spearman correlation 0.6726). We concluded that microstructural parameters are valid predictors of bone strength and hence, noninvasive in vivo imaging modalities need to be developed which use these parameters to assess the risk of fracture.