1
|
Fu J, Meng H, Zhang C, Liu Y, Chen D, Wang A, Main RP, Yang H. Effects of tissue heterogeneity on trabecular micromechanics examined by microCT-based finite element analysis and digital volume correlation. MEDICINE IN NOVEL TECHNOLOGY AND DEVICES 2021. [DOI: 10.1016/j.medntd.2021.100088] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
|
2
|
Goff MG, Lambers FM, Nguyen TM, Sung J, Rimnac CM, Hernandez CJ. Fatigue-induced microdamage in cancellous bone occurs distant from resorption cavities and trabecular surfaces. Bone 2015; 79:8-14. [PMID: 26008609 PMCID: PMC4501884 DOI: 10.1016/j.bone.2015.05.020] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/29/2015] [Revised: 04/29/2015] [Accepted: 05/15/2015] [Indexed: 10/23/2022]
Abstract
Impaired bone toughness is increasingly recognized as a contributor to fragility fractures. At the tissue level, toughness is related to the ability of bone tissue to resist the development of microscopic cracks or other tissue damage. While most of our understanding of microdamage is derived from studies of cortical bone, the majority of fragility fractures occur in regions of the skeleton dominated by cancellous bone. The development of tissue microdamage in cancellous bone may differ from that in cortical bone due to differences in microstructure and tissue ultrastructure. To gain insight into how microdamage accumulates in cancellous bone we determined the changes in number, size and location of microdamage sites following different amounts of cyclic compressive loading. Human vertebral cancellous bone specimens (n=32, 10 male donors, 6 female donors, age 76 ± 8.8, mean ± SD) were subjected to sub-failure cyclic compressive loading and microdamage was evaluated in three-dimensions. Only a few large microdamage sites (the largest 10%) accounted for 70% of all microdamage caused by cyclic loading. The number of large microdamage sites was a better predictor of reductions in Young's modulus caused by cyclic loading than overall damage volume fraction (DV/BV). The majority of microdamage volume (69.12 ± 7.04%) was located more than 30 μm (the average erosion depth) from trabecular surfaces, suggesting that microdamage occurs primarily within interstitial regions of cancellous bone. Additionally, microdamage was less likely to be near resorption cavities than other bone surfaces (p<0.05), challenging the idea that stress risers caused by resorption cavities influence fatigue failure of cancellous bone. Together, these findings suggest that reductions in apparent level mechanical performance during fatigue loading are the result of only a few large microdamage sites and that microdamage accumulation in fatigue is likely dominated by heterogeneity in tissue material properties rather than stress concentrations caused by micro-scale geometry.
Collapse
Affiliation(s)
- M G Goff
- Department of Biomedical Engineering, Cornell University, Ithaca, NY, USA; Sibley School of Mechanical and Aerospace Engineering, Cornell University, Ithaca, NY, USA
| | - F M Lambers
- Sibley School of Mechanical and Aerospace Engineering, Cornell University, Ithaca, NY, USA
| | - T M Nguyen
- Sibley School of Mechanical and Aerospace Engineering, Cornell University, Ithaca, NY, USA
| | - J Sung
- College of Veterinary Medicine, Cornell University, Ithaca, NY, USA
| | - C M Rimnac
- Departments of Mechanical and Aerospace Engineering and Orthopaedics, Case Western Reserve University, Cleveland, OH, USA
| | - C J Hernandez
- Department of Biomedical Engineering, Cornell University, Ithaca, NY, USA; Sibley School of Mechanical and Aerospace Engineering, Cornell University, Ithaca, NY, USA; Hospital for Special Surgery, New York City, NY, USA.
| |
Collapse
|
3
|
Hardisty MR, Kienle DF, Kuhl TL, Stover SM, Fyhrie DP. Strain-induced optical changes in demineralized bone. JOURNAL OF BIOMEDICAL OPTICS 2014; 19:35001. [PMID: 24604533 PMCID: PMC3945466 DOI: 10.1117/1.jbo.19.3.035001] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/27/2013] [Revised: 01/07/2014] [Accepted: 02/03/2014] [Indexed: 06/03/2023]
Abstract
Bone "stress-whitens," becoming visibly white during mechanical loading, immediately prior to failure. Stress-whitening is known to make materials tougher by dissipating mechanical energy. A greater understanding of stress-whitening, both an optical and mechanical phenomenon, may help explain age-related increases in fracture risk that occur without changes in bone mineralization. In this work, we directly measure the optical properties of demineralized bone as a function of deformation and immersing fluid (with different hydrogen-bonding potentials, water, and ethanol). The change in refractive index of demineralized bone was linear: with deformation and not applied force. Changes in refractive index were likely due to pushing low-refractive-index fluid out of specimens and secondarily due to changes in the refractive index of the collagenous phase. Results were consistent with stress-whitening of demineralized bone previously observed. In ethanol, the refractive index values were lower and less sensitive to deformation compared with deionized water, corroborating the sensitivity to fluid hydration. Differences in refractive index were consistent with structural changes in the collagenous phase such as densification that may also occur under mechanical loading. Understanding bone quality, particularly stress-whitening investigated here, may lead to new therapeutic targets and noninvasive methods to assess bone quality.
Collapse
Affiliation(s)
- Michael R. Hardisty
- University of California-Davis, School of Medicine, Lawrence J. Ellison Musculoskeletal Research Laboratory, Department of Orthopaedic Surgery, Sacramento, California, 95817
- University of California-Davis, Biomedical Engineering Graduate Group, Davis, California, 95616
| | - Daniel F. Kienle
- University of California-Davis, Department of Chemical Engineering and Materials Science, Biomedical Engineering Graduate Group, Davis, California, 95616
| | - Tonya L. Kuhl
- University of California-Davis, Biomedical Engineering Graduate Group, Davis, California, 95616
- University of California-Davis, Department of Chemical Engineering and Materials Science, Biomedical Engineering Graduate Group, Davis, California, 95616
| | - Susan M. Stover
- University of California-Davis, Biomedical Engineering Graduate Group, Davis, California, 95616
- University of California-Davis, School of Veterinary Medicine, JD Wheat Veterinary Orthopedic Research Laboratory, Biomedical Engineering Graduate Group, Davis, 95616
| | - David P. Fyhrie
- University of California-Davis, Biomedical Engineering Graduate Group, Davis, California, 95616
- University of California-Davis, Department of Biomedical Engineering, Davis, California, 95616
| |
Collapse
|
4
|
Kersh ME, Pandy MG, Bui QM, Jones AC, Arns CH, Knackstedt MA, Seeman E, Zebaze RM. The heterogeneity in femoral neck structure and strength. J Bone Miner Res 2013. [PMID: 23197364 DOI: 10.1002/jbmr.1827] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Most measures of femoral neck strength derived using dual-energy X-ray absorptiometry or computed tomography (CT) assume the femoral neck is a cylinder with a single cortical thickness. We hypothesized that these simplifications introduce errors in estimating strength and that detailed analyses will identify new parameters that more accurately predict femoral neck strength. High-resolution CT data were used to evaluate 457 cross-sectional slices along the femoral neck of 12 postmortem specimens. Cortical morphology was measured in each cross-section. The distribution of cortical thicknesses was evaluated to determine whether the mean or median better estimated central tendency. Finite-element models were used to calculate the stresses in each cross-section resulting from the peak hip joint forces created during a sideways fall. The relationship between cortical morphology and peak bone stress along the femoral neck was analyzed using multivariate regression analysis. In all cross-sections, cortical thicknesses were non-normally distributed and skewed toward smaller thicknesses (p < 0.0001). The central tendency of cortical thickness was best estimated by the median, not the mean. Stress increased as the median cortical thickness decreased along the femoral neck. The median, not mean, cortical thickness combined with anterior-posterior diameter best predicted peak bone stress generated during a sideways fall (R(2) = 0.66, p < 0.001). Heterogeneity in the structure of the femoral neck determines the diversity of its strength. The median cortical thickness best predicted peak femoral neck stress and is likely to be a relevant predictor of femoral neck fragility.
Collapse
Affiliation(s)
- Mariana E Kersh
- Department of Mechanical Engineering, University of Melbourne, Parkville, Australia.
| | | | | | | | | | | | | | | |
Collapse
|
5
|
Hansen S, Hauge EM, Rasmussen L, Jensen JEB, Brixen K. Parathyroidectomy improves bone geometry and microarchitecture in female patients with primary hyperparathyroidism: a one-year prospective controlled study using high-resolution peripheral quantitative computed tomography. J Bone Miner Res 2012; 27:1150-8. [PMID: 22228118 DOI: 10.1002/jbmr.1540] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Following parathyroidectomy (PTX), bone mineral density (BMD) increases in patients with primary hyperparathyroidism (PHPT), yet information is scarce concerning changes in bone structure and strength following normalization of parathyroid hormone levels postsurgery. In this 1-year prospective controlled study, high-resolution peripheral quantitative computed tomography (HR-pQCT) was used to evaluate changes in bone geometry, volumetric BMD (vBMD), microarchitecture, and estimated strength in female patients with PHPT before and 1 year after PTX, compared to healthy controls. Twenty-seven women successfully treated with PTX (median age 62 years; range, 44-75 years) and 31 controls (median age 63 years; range, 40-76 years) recruited by random sampling from the general population were studied using HR-pQCT of the distal radius and tibia as well as with dual-energy X-ray absorptiometry (DXA) of the forearm, spine, and hip. The two groups were comparable with respect to age, height, weight, and menopausal status. In both radius and tibia, cortical (Ct.) vBMD and Ct. thickness increased or were maintained in patients and decreased in controls (p < 0.01). Radius cancellous bone architecture was improved in patients through increased trabecular number and decreased trabecular spacing compared with changes in controls (p < 0.05). No significant cancellous bone changes were observed in tibia. Estimated bone failure load by finite element modeling increased in patients in radius but declined in controls (p < 0.001). Similar, albeit borderline significant changes in estimated failure load were found in tibia (p = 0.06). This study showed that females with PHPT had improvements in cortical bone geometry and increases in cortical and trabecular vBMD in both radius and tibia along with improvements in cancellous bone architecture and estimated strength in radius 1 year after PTX, reversing or attenuating age-related changes observed in controls.
Collapse
Affiliation(s)
- Stinus Hansen
- Department of Endocrinology, Odense University Hospital, Odense, Denmark.
| | | | | | | | | |
Collapse
|
6
|
Mineral heterogeneity affects predictions of intratrabecular stress and strain. J Biomech 2011; 44:402-7. [DOI: 10.1016/j.jbiomech.2010.10.004] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2010] [Revised: 10/11/2010] [Accepted: 10/11/2010] [Indexed: 11/21/2022]
|
7
|
Yokoyama M, Atsumi T, Tsuchiya M, Koyama S, Sasaki K. Dynamic changes in bone metabolism in the rat temporomandibular joint after molar extraction using bone scintigraphy. Eur J Oral Sci 2009; 117:374-9. [DOI: 10.1111/j.1600-0722.2009.00635.x] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
|
8
|
Fajardo RJ, Cory E, Patel ND, Nazarian A, Laib A, Manoharan RK, Schmitz JE, DeSilva JM, MacLatchy LM, Snyder BD, Bouxsein ML. Specimen size and porosity can introduce error into microCT-based tissue mineral density measurements. Bone 2009; 44:176-84. [PMID: 18822398 PMCID: PMC4286574 DOI: 10.1016/j.bone.2008.08.118] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/10/2008] [Revised: 08/13/2008] [Accepted: 08/19/2008] [Indexed: 12/17/2022]
Abstract
The accurate measurement of tissue mineral density, rho(m), in specimens of unequal size or quantities of bone mineral using polychromatic microCT systems is important, since studies often compare samples with a range of sizes and bone densities. We assessed the influence of object size on microCT measurements of rho(m) using (1) hydroxyapatite rods (HA), (2) precision-manufactured aluminum foams (AL) simulating trabecular bone structure, and (3) bovine cortical bone cubes (BCt). Two beam-hardening correction (BHC) algorithms, determined using a 200 and 1200 mg/cm(3) HA wedge phantom, were used to calculate rho(m) of the HA and BCt. The 200 mg/cm(3) and an aluminum BHC algorithm were used to calculate the linear attenuation coefficients of the AL foams. Equivalent rho(m) measurements of 500, 1000, and 1500 mg HA/cm(3) rods decreased (r(2)>0.96, p<0.05 for all) as HA rod diameter increased in the 200 mg/cm(3) BHC data. Errors averaged 8.2% across these samples and reached as high as 29.5%. Regression analyses suggested no size effects in the 1200 mg/cm(3) BHC data but differences between successive sizes still reached as high as 13%. The linear attenuation coefficients of the AL foams increased up to approximately 6% with increasing volume fractions (r(2)>0.81, p<0.05 for all) but the strength of the size-related error was also BHC dependent. Equivalent rho(m) values were inversely correlated with BCt cube size (r(2)>0.92, p<0.05). Use of the 1200 mg/cm(3) BHC ameliorated the size-related artifact compared to the 200 mg/cm(3) BHC but errors with this BHC were still significant and ranged between 5% and 12%. These results demonstrate that object size, structure, and BHC algorithm can influence microCT measurements of rho(m). Measurements of rho(m) of specimens of unequal size or quantities of bone mineral must be interpreted with caution unless appropriate steps are taken to minimize these potential artifacts.
Collapse
Affiliation(s)
- Roberto J Fajardo
- Orthopedic Biomechanics Laboratory, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA, USA.
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
9
|
Christopher JJ, Ramakrishnan S. Assessment and classification of mechanical strength components of human femur trabecular bone using texture analysis and neural network. J Med Syst 2008; 32:117-22. [PMID: 18461815 DOI: 10.1007/s10916-007-9114-8] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
In this work the mechanical strength components of human femur trabecular bone are analyzed and classified using planar radiographic images and neural network. The mechanical strength regions such as Primary Compressive, Primary Tensile, Secondary Tensile and Ward Triangle in femur trabecular bone images (N = 100) are delineated by semi-automatic image processing procedure. First and higher order texture parameters and parameters such as apparent mineralization and total area associated with the strength regions are derived for normal and abnormal images. The statistically derived significant parameters corresponding to the primary strength regions are fed to the neural network for training and validation. The classifications are carried out using feed forward network that is trained with standard back propagation algorithm. Results demonstrate that the apparent mineralization of normal samples is always high as (71%) compared to abnormal samples (64%). Entropy shows a high value (7.3) for normal samples and variation between the mean intensity and apparent mineralization for the primary strength zone is statistically significant (p < 0.0005). The classified outputs are validated by sensitivity and specificity measurements and are found to be 66.66% and 80% respectively. Further it appears that it is possible to differentiate normal and abnormal samples from the conventional radiographic images. As trabecular architecture in the human femur is an important factor contributing to bone strength, the procedure adopted here could be a useful supplement to the clinical observations for bone loss and fracture risk.
Collapse
Affiliation(s)
- Joseph Jesu Christopher
- Department of Instrumentation Engineering, MIT Campus, Anna University, Chromepet, Chennai 600 044, India
| | | |
Collapse
|
10
|
Mulder L, Koolstra JH, den Toonder JMJ, van Eijden TMGJ. Intratrabecular distribution of tissue stiffness and mineralization in developing trabecular bone. Bone 2007; 41:256-65. [PMID: 17567548 DOI: 10.1016/j.bone.2007.04.188] [Citation(s) in RCA: 56] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/16/2007] [Revised: 04/11/2007] [Accepted: 04/13/2007] [Indexed: 11/29/2022]
Abstract
The purpose of this study was to investigate the relation between bone tissue stiffness and degree of mineralization distribution and to examine possible changes during prenatal development. Understanding this may provide insight into adaptation processes and into deformation mechanisms of the bone microstructure. Mandibular condyles from four fetal and newborn pigs were used. Tissue stiffness was measured using nanoindentation, the degree of mineralization with microCT. Eight indents were made over the trabecular width of 15 trabeculae in each specimen, leading to a total of 960 indents. Subsequently, the degree of mineralization of these locations was determined. Intratrabecular variations in bone tissue stiffness and degree of mineralization showed a similar pattern; low at trabecular surfaces and higher in the cores. A strong correlation was found between the two variables, which remained unchanged during development. It was concluded that bone tissue in fetal and newborn trabecular cores resembles adult trabecular bone tissue properties and is distributed in a regular radial pattern in trabeculae. For the first time, it was shown that the intratrabecular tissue stiffness develops along the same path as the degree of mineralization. Knowledge regarding intratrabecular tissue stiffness and mineralization results in a better understanding of trabecular bone mechanical behavior on a structural and tissue level.
Collapse
Affiliation(s)
- Lars Mulder
- Department of Functional Anatomy, Academic Centre for Dentistry Amsterdam (ACTA), Universiteit van Amsterdam and Vrije Universiteit, Meibergdreef 15, 1105 AZ Amsterdam, The Netherlands.
| | | | | | | |
Collapse
|