A great percentage of the elderly population is at the risk of a vertebral fracture due to osteoporosis. Fractures of thoracic 12 and lumbar 1 constitute the majority of these vertebral fractures. External factors, such as loading, being aside, bone quality is the major determinant of a fracture. The measure of bone quality that is relevant to fracture is bone strength. However, current measures of bone quality, such as bone mineral density, are only surrogates of bone strength and have variable diagnostic success. New technologies with potentially high diagnostic value that are under development make use of the observation that bone stiffness and strength are highly correlated, i. e., how much load the bone can carry before fracture is related to how flexible the bone is under a given load. How these two apparent properties are related through bone's microstructural organization and to what extent bone stiffness is related to bone strength are very fundamental questions of bone biology. We believe that the close relationship between the apparent strength and apparent stiffness of cancellous bone is a result of an adaptation where tissue (trabeculae) stress magnitude and variability is controlled through microstructural organization such that the average and the scatter of the tissue stresses are correlated. This project will determine the relationships between bone microstructure, tissue stress distributions and bone apparent properties at a tissue and organ level for T4-L5 vertebrae from human spines using microcomputed tomography, large-scale finite element analysis and mechanical testing. The results of this project will reveal: (i) whether greater levels of damaging stresses are generated in the tissue from T12-L1 junction independent of external factors, (ii) whether the association between tissue stresses and bone apparent properties is sensitive to the choice of within-patient and between-patient samples, (iii) microstructural features of bone that give rise to damaging forms of stresses in the tissue, and (iv) whether vertebral bone strength at the organ level can be predicted by stiffness measurements using the concepts introduced for cancellous bone tissue. The long-term goal of this research is to enhance our ability to diagnose and develop strategies for prevention of bone disease and failure through a better understanding of the stress-regulated structure of vertebral bone.

Agency
National Institute of Health (NIH)
Institute
National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS)
Type
Research Project (R01)
Project #
1R01AR049343-01
Application #
6561112
Study Section
Orthopedics and Musculoskeletal Study Section (ORTH)
Program Officer
Lester, Gayle E
Project Start
2003-01-10
Project End
2006-12-31
Budget Start
2003-01-10
Budget End
2003-12-31
Support Year
1
Fiscal Year
2003
Total Cost
$200,956
Indirect Cost
Name
Henry Ford Health System
Department
Orthopedics
Type
Schools of Medicine
DUNS #
073134603
City
Detroit
State
MI
Country
United States
Zip Code
48202
Yeni, Yener N; Zinno, Matthew J; Yerramshetty, Janardhan S et al. (2011) Variability of trabecular microstructure is age-, gender-, race- and anatomic site-dependent and affects stiffness and stress distribution properties of human vertebral cancellous bone. Bone 49:886-94
Nekkanty, Srikant; Yerramshetty, Janardhan; Kim, Do-Gyoon et al. (2010) Stiffness of the endplate boundary layer and endplate surface topography are associated with brittleness of human whole vertebral bodies. Bone 47:783-9
Yeni, Yener N; Dong, X Neil; Zhang, Bingbing et al. (2009) Cancellous bone properties and matrix content of TGF-beta2 and IGF-I in human tibia: a pilot study. Clin Orthop Relat Res 467:3079-86
Yerramshetty, Janardhan; Kim, Do-Gyoon; Yeni, Yener N (2009) Increased microstructural variability is associated with decreased structural strength but with increased measures of structural ductility in human vertebrae. J Biomech Eng 131:094501
Yeni, Yener N; Kim, Do-Gyoon; Divine, George W et al. (2009) Human cancellous bone from T12-L1 vertebrae has unique microstructural and trabecular shear stress properties. Bone 44:130-6
Yeni, Yener N; Zelman, Eric A; Divine, George W et al. (2008) Trabecular shear stress amplification and variability in human vertebral cancellous bone: relationship with age, gender, spine level and trabecular architecture. Bone 42:591-6
Sterba, William; Kim, Do-Gyoon; Fyhrie, David P et al. (2007) Biomechanical analysis of differing pedicle screw insertion angles. Clin Biomech (Bristol, Avon) 22:385-91
Yeni, Yener N; Shaffer, Richard R; Baker, Kevin C et al. (2007) The effect of yield damage on the viscoelastic properties of cortical bone tissue as measured by dynamic mechanical analysis. J Biomed Mater Res A 82:530-7
Kim, Do-Gyoon; Hunt, Christine A; Zauel, Roger et al. (2007) The effect of regional variations of the trabecular bone properties on the compressive strength of human vertebral bodies. Ann Biomed Eng 35:1907-13
Yeni, Y N; Yerramshetty, J; Akkus, O et al. (2006) Effect of fixation and embedding on Raman spectroscopic analysis of bone tissue. Calcif Tissue Int 78:363-71

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