Abstract

The term ‘bone strength’ is often used to explain why some children's bones fracture while others do not. Bone strength describes the general integrity of bone; a complex organ with multiple structural levels and an array of biomechanical properties. Key biomechanical properties of bone include stiffness, toughness, ductility and mechanical strength. When measured in bone tissue, these properties are known as the intrinsic biomechanical properties of bone, while the extrinsic biomechanical properties reflect the structural behaviour of a whole bone. The fine balance between various and often opposing intrinsic and extrinsic biomechanical properties of bone is crucial for fracture resistance. When clinically evaluating a child with a fracture, an understanding of basic bone biomechanics helps determine the likely mechanism of injury and whether underlying reduced fracture resistance exists.