“Advancing bound and pore water as predictors of fracture risk”
The clinical gold-standard for assessing a patient’s fracture risk is the measurement of areal bone mineral density (aBMD). Although aBMD is better at predicting fractures than cholesterol levels are at predicting myocardial infarction, many individuals suffer low-energy, fragility fractures despite having normal to moderately low aBMD (osteopenia). This is one reason why the World Health Organization developed FRAX, an on-line tool that calculates the 10-year probability of experiencing a major osteoporotic fracture. To further advance the accurate prediction of fracture risk, research at the Vanderbilt Center for Bone Biology, in collaboration with the Department of Biomedical Engineering at Vanderbilt University, involves assessing the ability of matrix-sensitive techniques to provide potential predictors of fracture resistance. In several mechanical testing studies of human cortical bone, bound water (bw) and pore water (pw) measurements, as determined by proton nuclear magnetic resonance, helped explain the age-related decrease in material strength and fracture toughness, while a recent imaging study of cadaveric radii using ultra-short echo-time MRI found that the combination of bw and pw is as good as aBMD in predicting the material strength of the distal-third radius. Ongoing work using genetic mouse models and manipulations of cadaveric bone is beginning to revel potential determinants of bound water.
Dr. Nyman received an MS in Mechanical Engineering from the University of Tufts (1998) and Ph. D. in Biomedical Engineering from the University of California, Davis (2003). After a post-doctoral fellowship at the University of Texas at San Antonio (2003-2006), he joined the Vanderbilt Center for Biology and began working with animal models of disease, namely bone metastasis and neurofibromatosis type 1. In 2011, he established an independent research program on the role of bound water in bone mechanics and the effect of diabetes on fracture resistance.