Luo Y - A clinical cohort comprising of 961 women (316 hip fractures and 645 controls) was used to examine the relationships of periosteal expansion and bone loss quantitatively and their combined impact on bone stiffness, strength, and fracture risk. The investigation results exhibited that compared with the other stiffness components, femoral-neck width had more robust relation with femoral bending stiffness, whereas bone mineral density had stronger association with axial/shearing stiffness, strength, and fracture risk index compared with with bending stiffness; and the relation between femoral bending stiffness and age was unimportant. The correlation of axial/shearing stiffness, strength, and fracture risk index with age were notable. Fracture risk index had the most robust relationship with actual fracture status, followed by strength and axial/shearing stiffness. The weakest association was femoral bending stiffness. Hence, to maintain femoral bending stiffness among old women, periosteal expansion could be sufficient, however it might not aid in preserving strength and decreasing hip fracture risk.