Relationship Between Vertebral Bone Mineral Density and Strength

The relationship between bone mineral density and bone strength has been investigated as a ubiquitous property of bone. This study utilized 22 isolated vertebral body preparations which had their volumetric bone mineral density quantified and their compressive mechanics measured. Cadaveric baboon ninth thoracic vertebral body samples were investigated which ranged in age from 1 to 30 years and included both sexes. Isolated ninth thoracic vertebrae (T9) were subjected to compressive loading to document their compressive mechanical properties (yield load, stiffness, yield strength, and elastic modulus) and ashed to determine their volumetric bone mineral density. Maturation, sex, and species differences were observed for the stiffness, yield load, and vBMD. The vertebral body strength followed a direct relationship with vBMD regardless of sex, age, or species. This relationship (Strength = 35.3*vBMD – 1.46) demonstrates the association (r = 0.817) between vertebral bone material property and structure. These data support the biomechanical modeling of vertebral bone which is nonspecific for age and sex.