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

BackgroundFemoral 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 (L-max), funding the indicator which effects L-max most.MethodsA 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 L-max.ResultsThe L-max, 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 L-max (P < 0.05). The cBMD has the strongest association with L-max in micro-structure (P < 0.05). In micro-chemical composition, crystal size has the strongest correlation with L-max (P < 0.05). Multiple linear regression analysis showed that elastic modulus was most strongly related to L-max (beta = 0.920, P = 0.000).ConclusionsCompared with other parameters, elastic modulus has the greatest influence on L-max. Evaluation of microscopic parameters on femoral neck cortical bone can clarify the effects of microscopic properties on L-max, providing a theoretical basis for the femoral neck OP and fragility fractures.