The role of microscopic properties on cortical bone strength of femoral neck.

BACKGROUND

Femoral neck fractures are serious consequence of osteoporosis (OP), numbers of people are working on the micro-mechanisms of femoral neck fractures. This study aims to investigate the role and weight of microscopic properties on femoral neck maximum load (Lmax), funding the indicator which effects Lmax most.

METHODS

A total of 115 patients were recruited from January 2018 to December 2020. Femoral neck samples were collected during the total hip replacement surgery. Femoral neck Lmax, micro-structure, micro-mechanical properties, micro-chemical composition were all measured and analyzed. Multiple linear regression analyses were performed to identify significant factors that affected the femoral neck Lmax.

RESULTS

The Lmax, cortical bone mineral density (cBMD), cortical bone thickness (Ct. Th), elastic modulus, hardness and collagen cross-linking ratio were all significantly decreased, whereas other parameters were significantly increased during the progression of OP (P < 0.05). In micro-mechanical properties, elastic modulus has the strongest correlation with Lmax (P < 0.05). The cBMD has the strongest association with Lmax in micro-structure (P < 0.05). In micro-chemical composition, crystal size has the strongest correlation with Lmax (P < 0.05). Multiple linear regression analysis showed that elastic modulus was most strongly related to Lmax (β = 0.920, P = 0.000).

CONCLUSIONS

Compared with other parameters, elastic modulus has the greatest influence on Lmax. Evaluation of microscopic parameters on femoral neck cortical bone can clarify the effects of microscopic properties on Lmax, providing a theoretical basis for the femoral neck OP and fragility fractures.