Article: Lambers FM, Bouman AR, Tkachenko EV Keaveny TM Hernandez CJ (2014) “The Effects of Tensile-Compressive Loading Mode and Microarchitecture on Microdamage in Human Vertebral Cancellous Bone”, Journal of Biomechanics, 47(15):3605-3612
Abstract: The amount of microdamage in bone tissue impairs mechanical performance and may act as a stimulus for bone remodeling. Here we determine how loading mode (tension vs. compression) and microstructure (trabecular microarchitecture, local trabecular thickness, and presence of resorption cavities) influence the number and volume of microdamage sites generated in cancellous bone following a single overload. Twenty paired cylindrical specimens of human vertebral cancellous bone from 10 donors (47-78 years) were mechanically loaded to apparent yield in either compression or tension, and imaged in three dimensions for microarchitecture and microdamage (voxel size 0.7 x 0.7 x 5.0 mu m(3)).
We found that the overall proportion of damaged tissue was greater (p =0.01) for apparent tension loading (3.9 +/- 2.4%, mean +/- SD) than for apparent compression loading (1.9 +/- 1.3%). Individual microdamage sites generated in tension were larger in volume (p < 0.001) but not more numerous (p = 0.64) than sites in compression. For both loading modes, the proportion of damaged tissue varied more across donors than with bone volume fraction, traditional measures of microarchitecture (trabecular thickness, trabecular separation, etc.), apparent Young’s modulus, or strength. Microdamage tended to occur in regions of greater trabecular thickness but not near observable resorption cavities. Taken together, these findings indicate that, regardless of loading mode, accumulation of microdamage in cancellous bone after monotonic loading to yield is influenced by donor characteristics other than traditional measures of microarchitecture, suggesting a possible role for tissue material properties. (C) 2014 Elsevier Ltd. All rights reserved.
Funding Acknowledgement: National Institute of Arthritis and Musculoskeletal and Skin Diseases of the National Institutes of Health (U.S) [AR057362]; NIH [8U42OD011158-22]
Funding Text: Research reported in this publication was supported by the National Institute of Arthritis and Musculoskeletal and Skin Diseases of the National Institutes of Health (U.S) under Award Number AR057362 (PI CJH). The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health. We acknowledge use of human vertebral bodies provided by the National Disease Research Interchange (NDRI), with support from NIH grant 8U42OD011158-22. We thank Ivana H. Yi and Michael G. Jekir for performing the mechanical tests.