Structural Behavior Analysis of a Bone-Scaffold System According to the Elastic Modulus of Bone Cement and Pore Size in the Proximal Femur

Bone scaffolds are porous artificial structures that replace damaged bone tissue and promote bone regeneration. In clinical settings, bone cement is used to provide initial fixation stability between the bone scaffold and surrounding bone tissue. To analyze the performance of bone scaffolds more accurately, the cement mantle should be considered. This study considers the cement mantle between the bone scaffold and surrounding bone tissue and the structural behavior according to variations in the elastic modulus of the cement mantle and the pore size of the bone scaffold. The results showed that the cement mantle energy ratio increased with increasing pore size, particularly in the femoral head and intertrochanteric region. In the femoral head with a pore size of 1.50 mm, increasing the cement mantle elastic modulus from 7 to 24 GPa reduced the mean strain energy within the bone scaffold from 3.79 μJ to 2.51 μJ, corresponding to a decrease of approximately 33.8%. These findings suggest that as cement mantle stiffness increases, external loads may not be sufficiently transferred to the bone scaffold interior, and the proportion of the load borne by the cement mantle may increase. In the femoral neck, the cement mantle energy ratio also increased with increasing pore size; however, the magnitude of this change was more limited than that in the other regions of interest. These findings highlight the mechanical importance of the cement mantle and suggest that both cement stiffness and scaffold pore size should be jointly considered to ensure appropriate load sharing for bone regeneration.