Relation of vertebral deformities to bone density, structure, and strength

Authors

  • L Joseph Melton III,

    Corresponding author
    1. Division of Epidemiology, Department of Health Sciences Research, College of Medicine, Mayo Clinic, Rochester, MN, USA
    2. Division of Endocrinology, Metabolism and Nutrition, Department of Internal Medicine, College of Medicine, Mayo Clinic, Rochester, MN, USA
    • Division of Epidemiology, Department of Health Sciences Research, Mayo Clinic, 200 First Street Southwest, Rochester, MN 55905, USA
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  • B Lawrence Riggs,

    1. Division of Endocrinology, Metabolism and Nutrition, Department of Internal Medicine, College of Medicine, Mayo Clinic, Rochester, MN, USA
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  • Tony M Keaveny,

    1. Departments of Mechanical Engineering and Bioengineering, University of California, Berkeley, CA, USA
    2. O. N. Diagnostics, Berkeley, CA, USA
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  • Sara J Achenbach,

    1. Division of Biostatistics, Department of Health Sciences Research, College of Medicine, Mayo Clinic, Rochester, MN, USA
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  • David Kopperdahl,

    1. O. N. Diagnostics, Berkeley, CA, USA
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  • Jon J Camp,

    1. Biomedical Imaging Resource, Department of Radiology, College of Medicine, Mayo Clinic, Rochester, MN, USA
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  • Peggy A Rouleau,

    1. Division of Computed Tomography, Department of Radiology, College of Medicine, Mayo Clinic, Rochester, MN, USA
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  • Shreyasee Amin,

    1. Division of Rheumatology, Department of Internal Medicine, College of Medicine, Mayo Clinic, Rochester, MN, USA
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  • Elizabeth J Atkinson,

    1. Division of Biostatistics, Department of Health Sciences Research, College of Medicine, Mayo Clinic, Rochester, MN, USA
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  • Richard A Robb,

    1. Biomedical Imaging Resource, Department of Radiology, College of Medicine, Mayo Clinic, Rochester, MN, USA
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  • Terry M Therneau,

    1. Division of Biostatistics, Department of Health Sciences Research, College of Medicine, Mayo Clinic, Rochester, MN, USA
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  • Sundeep Khosla

    1. Division of Endocrinology, Metabolism and Nutrition, Department of Internal Medicine, College of Medicine, Mayo Clinic, Rochester, MN, USA
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Abstract

Because they are not reliably discriminated by areal bone mineral density (aBMD) measurements, it is unclear whether minimal vertebral deformities represent early osteoporotic fractures. To address this, we compared 90 postmenopausal women with no deformity (controls) with 142 women with one or more semiquantitative grade 1 (mild) deformities and 51 women with any grade 2–3 (moderate/severe) deformities. aBMD was measured by dual-energy X-ray absorptiometry (DXA), lumbar spine volumetric bone mineral density (vBMD) and geometry by quantitative computed tomography (QCT), bone microstructure by high-resolution peripheral QCT at the radius (HRpQCT), and vertebral compressive strength and load-to-strength ratio by finite-element analysis (FEA) of lumbar spine QCT images. Compared with controls, women with grade 1 deformities had significantly worse values for many bone density, structure, and strength parameters, although deficits all were much worse for the women with grade 2–3 deformities. Likewise, these skeletal parameters were more strongly associated with moderate to severe than with mild deformities by age-adjusted logistic regression. Nonetheless, grade 1 vertebral deformities were significantly associated with four of the five main variable categories assessed: bone density (lumbar spine vBMD), bone geometry (vertebral apparent cortical thickness), bone strength (overall vertebral compressive strength by FEA), and load-to-strength ratio (45-degree forward bending ÷ vertebral compressive strength). Thus significantly impaired bone density, structure, and strength compared with controls indicate that many grade 1 deformities do represent early osteoporotic fractures, with corresponding implications for clinical decision making. © 2010 American Society for Bone and Mineral Research

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