151
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Ni Y, Wang L, Liu X, Zhang H, Lin CY, Fan Y. Micro-mechanical properties of different sites on woodpecker’s skull. Comput Methods Biomech Biomed Engin 2017; 20:1483-1493. [DOI: 10.1080/10255842.2017.1378648] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Affiliation(s)
- Yikun Ni
- Key Laboratory for Biomechanics and Mechanobiology of Ministry of Education, School of Biological Science and Medical Engineering, Beihang University, Beijing, China
- Department of Biomedical, Chemical & Environmental Engineering, University of Cincinnati, Cincinnati, USA
| | - Lizhen Wang
- Key Laboratory for Biomechanics and Mechanobiology of Ministry of Education, School of Biological Science and Medical Engineering, Beihang University, Beijing, China
| | - Xiaoyu Liu
- Key Laboratory for Biomechanics and Mechanobiology of Ministry of Education, School of Biological Science and Medical Engineering, Beihang University, Beijing, China
| | - Hongquan Zhang
- School of Materials Science and Engineering, Wuhan University of Technology, Wuhan, China
| | - Chia-Ying Lin
- Key Laboratory for Biomechanics and Mechanobiology of Ministry of Education, School of Biological Science and Medical Engineering, Beihang University, Beijing, China
- Department of Biomedical, Chemical & Environmental Engineering, University of Cincinnati, Cincinnati, USA
- Department of Orthopaedic Surgery, University of Cincinnati, Cincinnati, USA
- Department of Neurosurgery, University of Cincinnati, Cincinnati, USA
| | - Yubo Fan
- Key Laboratory for Biomechanics and Mechanobiology of Ministry of Education, School of Biological Science and Medical Engineering, Beihang University, Beijing, China
- National Research Center for Rehabilitation Technical Aids, Beijing, China
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152
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Butz K, Spurlock C, Roy R, Bell C, Barrett P, Ward A, Xiao X, Shirley A, Welch C, Lister K. Development of the CAVEMAN Human Body Model: Validation of Lower Extremity Sub-Injurious Response to Vertical Accelerative Loading. STAPP CAR CRASH JOURNAL 2017; 61:175-209. [PMID: 29394439 DOI: 10.4271/2017-22-0007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Improving injury prediction accuracy and fidelity for mounted Warfighters has become an area of focus for the U.S. military in response to improvised explosive device (IED) use in both Iraq and Afghanistan. Although the Hybrid III anthropomorphic test device (ATD) has historically been used for crew injury analysis, it is only capable of predicting a few select skeletal injuries. The Computational Anthropomorphic Virtual Experiment Man (CAVEMAN) human body model is being developed to expand the injury analysis capability to both skeletal and soft tissues. The CAVEMAN model is built upon the Zygote 50th percentile male human CAD model and uses a finite element modeling approach developed for high performance computing (HPC). The lower extremity subset of the CAVEMAN human body model presented herein includes: 28 bones, 26 muscles, 40 ligaments, fascia, cartilage and skin. Sensitivity studies have been conducted with the CAVEMAN lower extremity model to determine the structures critical for load transmission through the leg in the underbody blast (UBB) environment. An evaluation of the CAVEMAN lower extremity biofidelity was also carried out using 14 unique data sets derived by the Warrior Injury Assessment Manikin (WIAMan) program cadaveric lower leg testing. Extension of the CAVEMAN lower extremity model into anatomical tissue failure will provide additional injury prediction capabilities, beyond what is currently achievable using ATDs, to improve occupant survivability analyses within military vehicles.
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153
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Singh D, Cronin DS. An investigation of dimensional scaling using cervical spine motion segment finite element models. INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN BIOMEDICAL ENGINEERING 2017; 33:e2872. [PMID: 28205412 DOI: 10.1002/cnm.2872] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/21/2016] [Revised: 02/07/2017] [Accepted: 02/12/2017] [Indexed: 06/06/2023]
Abstract
The paucity of experimental data for validating computational models of different statures underscores the need for appropriate scaling methods so that models can be verified and validated using experimental data. Scaling was investigated using 50th percentile male (M50) and 5th percentile female (F05) cervical spine motion segment (C4-C5) finite element models subject to tension, flexion, and extension loading. Two approaches were undertaken: geometric scaling of the models to investigate size effects (volumetric scaling) and scaling of the force-displacement or moment-angle model results (data scaling). Three sets of scale factors were considered: global (body mass), regional (neck dimensions), and local (segment tissue dimensions). Volumetric scaling of the segment models from M50 to F05, and vice versa, produced correlations that were good or excellent in both tension and flexion (0.825-0.991); however, less agreement was found in extension (0.550-0.569). The reduced correlation in extension was attributed to variations in shape between the models leading to nonlinear effects such as different time to contact for the facet joints and posterior processes. Data scaling of the responses between the M50 and F05 models produced similar trends to volumetric scaling, with marginally greater correlations. Overall, the local tissue level and neck region level scale factors produced better correlations than the traditional global scaling. The scaling methods work well for a given subject, but are limited in applicability between subjects with different morphology, where nonlinear effects may dominate the response.
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154
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Steiner JA, Christen P, Affentranger R, Ferguson SJ, van Lenthe GH. A novel in silico method to quantify primary stability of screws in trabecular bone. J Orthop Res 2017; 35:2415-2424. [PMID: 28240380 DOI: 10.1002/jor.23551] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/24/2016] [Accepted: 02/16/2017] [Indexed: 02/04/2023]
Abstract
Insufficient primary stability of screws in bone leads to screw loosening and failure. Unlike conventional continuum finite-element models, micro-CT based finite-element analysis (micro-FE) is capable of capturing the patient-specific bone micro-architecture, providing accurate estimates of bone stiffness. However, such in silico models for screws in bone highly overestimate the apparent stiffness. We hypothesized that a more accurate prediction of primary implant stability of screws in bone is possible by considering insertion-related bone damage. We assessed two different screw types and loading scenarios in 20 trabecular bone specimens extracted from 12 cadaveric human femoral heads (N = 5 for each case). In the micro-FE model, we predicted specimen-specific Young's moduli of the peri-implant bone damage region based on morphometric parameters such that the apparent stiffness of each in silico model matched the experimentally measured stiffness of the corresponding in vitro specimen as closely as possible. The standard micro-FE models assuming perfectly intact peri-implant bone overestimated the stiffness by over 330%. The consideration of insertion related damaged peri-implant bone corrected the mean absolute percentage error down to 11.4% for both loading scenarios and screw types. Cross-validation revealed a mean absolute percentage error of 14.2%. We present the validation of a novel micro-FE modeling technique to quantify the apparent stiffness of screws in trabecular bone. While the standard micro-FE model overestimated the bone-implant stiffness, the consideration of insertion-related bone damage was crucial for an accurate stiffness prediction. This approach provides an important step toward more accurate specimen-specific micro-FE models. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 35:2415-2424, 2017.
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Affiliation(s)
- Juri A Steiner
- Institute for Biomechanics, ETH Zurich, Vladimir-Prelog-Weg 3, 8093 Zurich, Switzerland
| | - Patrik Christen
- Institute for Biomechanics, ETH Zurich, Vladimir-Prelog-Weg 3, 8093 Zurich, Switzerland
| | - Remo Affentranger
- Institute for Biomechanics, ETH Zurich, Vladimir-Prelog-Weg 3, 8093 Zurich, Switzerland
| | - Stephen J Ferguson
- Institute for Biomechanics, ETH Zurich, Vladimir-Prelog-Weg 3, 8093 Zurich, Switzerland
| | - Gerrit Harry van Lenthe
- Institute for Biomechanics, ETH Zurich, Vladimir-Prelog-Weg 3, 8093 Zurich, Switzerland.,Biomechanics Section, KU Leuven-University of Leuven, Celestijnenlaan 300, 3001 Leuven, Belgium
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155
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Li J, Huang S, Tang Y, Wang X, Pan T. Biomechanical analysis of the posterior bony column of the lumbar spine. J Orthop Surg Res 2017; 12:132. [PMID: 28915925 PMCID: PMC5602923 DOI: 10.1186/s13018-017-0631-y] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/23/2016] [Accepted: 09/07/2017] [Indexed: 01/02/2023] Open
Abstract
Background Each part of the rear bone structure can become an anchor point for an attachment device. The objective of this study was to evaluate the stiffness and strength of different parts of the rear lumbar bone structure by axial compression damage experiments. Methods Five adult male lumbar bone structures from L2 to L5 were exposed. The superior and inferior articular processes, upper and lower edges of the lamina, and upper and lower edges of the spinous process were observed and isolated and then divided into six groups (n = 10). The specimens were placed between the compaction disc and the load platform in a universal testing machine, which was first preloaded to 5.0 N tension to eliminate water on the surface and then loaded to the specimen curve decline at a constant tension loading rate of 0.01 mm/s, until the specimens had been destroyed. Results Significant differences in mechanical properties were found among different parts of the rear lumbar bone structure. Compared with other parts, the lower edge of the lamina has good mechanical properties, which have a high modulus of elasticity; the superior and inferior articular processes have greater ultimate strength, which can withstand greater compressive loads; and the mechanical properties of the spinous process are poor, and it is significantly stiffer and weaker than the lamina and articular processes. Conclusion These data can be useful in future spinal biomechanics research leading to better biomechanical compatibility and provide theoretical references for spinal implant materials.
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Affiliation(s)
- Jiukun Li
- Department of Orthopaedic Surgery, The Sixth Affiliated Hospital of Sun Yat-sen University, 26 Yuancun Er Heng Road, Guangzhou, Guangdong, 510655, China
| | - Shuai Huang
- Department of Orthopaedic Surgery, The Second Affiliated Hospital of Guangzhou Medical University, Guangzhou, 510260, China
| | - Yubo Tang
- Department of Pharmacy, The First Affiliated Hospital of Sun Yat-sen University, Guangzhou, 510080, China
| | - Xi Wang
- Department of Orthopaedic Surgery, The Sixth Affiliated Hospital of Sun Yat-sen University, 26 Yuancun Er Heng Road, Guangzhou, Guangdong, 510655, China
| | - Tao Pan
- Department of Orthopaedic Surgery, The Sixth Affiliated Hospital of Sun Yat-sen University, 26 Yuancun Er Heng Road, Guangzhou, Guangdong, 510655, China.
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156
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Ren H, Shen G, Tang J, Qiu T, Zhang Z, Zhao W, Yu X, Huang J, Liang D, Yao Z, Yang Z, Jiang X. Promotion effect of extracts from plastrum testudinis on alendronate against glucocorticoid-induced osteoporosis in rat spine. Sci Rep 2017; 7:10617. [PMID: 28878388 PMCID: PMC5587701 DOI: 10.1038/s41598-017-10614-5] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2017] [Accepted: 08/11/2017] [Indexed: 12/21/2022] Open
Abstract
Alendronate (ALN) is a key therapeutic used to treat glucocorticoid-induced osteoporosis (GIOP), but may induce severe side effects. We showed earlier that plastrum testudinis extracts (PTE) prevented and treated GIOP in vivo. However, clinically, PTE is seldom used alone. Herein, we reveal the synergistic effect of ALN and PTE can treat GIOP of the rat spine and define the mechanism. Sprague-Dawley rats were randomly assigned to four groups: a vehicle group, a GIOP group, an ALN group, and an ALN+PTE group. Each group was further divided into two experimental phases, including dexamethasone (DXM) intervention and withdrawal. Bone mass, microarchitecture, biomechanics, bone-turnover markers, and histomorphology were evaluated. The mRNA and protein expression levels of CTSK and Runx2 were detemined. We found that ALN+PTE improved bone quantity and quality, bone strength, bone turnover; and mitigated histological damage during glucocorticoid intervention and withdrawal. The therapeutic effect was better than that afforded by ALN alone. ALN+PTE reduced CTSK protein expression, promoted Runx2 mRNA and protein expression to varying extents, and more strongly inhibited bone resorption than did ALN alone. Overall, the synergistic effect mediated by ALN+PTE reversed GIOP during DXM intervention and withdrawal via affecting CTSK and Runx2 expression at mRNA and protein levels.
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Affiliation(s)
- Hui Ren
- Department of Spinal Surgery, The First Affiliated Hospital of Guangzhou University of Chinese Medicine Guangzhou, Guangzhou, 510405, China
| | - Gengyang Shen
- Guangzhou University of Chinese Medicine Guangzhou , Guangzhou, 510405, China
| | - Jingjing Tang
- Department of Spinal Surgery, The First Affiliated Hospital of Guangzhou University of Chinese Medicine Guangzhou, Guangzhou, 510405, China
| | - Ting Qiu
- Guangzhou University of Chinese Medicine Guangzhou , Guangzhou, 510405, China
| | - Zhida Zhang
- Guangzhou University of Chinese Medicine Guangzhou , Guangzhou, 510405, China
| | - Wenhua Zhao
- Guangzhou University of Chinese Medicine Guangzhou , Guangzhou, 510405, China
| | - Xiang Yu
- Guangzhou University of Chinese Medicine Guangzhou , Guangzhou, 510405, China
| | - Jinjing Huang
- Guangzhou University of Chinese Medicine Guangzhou , Guangzhou, 510405, China
| | - De Liang
- Department of Spinal Surgery, The First Affiliated Hospital of Guangzhou University of Chinese Medicine Guangzhou, Guangzhou, 510405, China
| | - Zhensong Yao
- Department of Spinal Surgery, The First Affiliated Hospital of Guangzhou University of Chinese Medicine Guangzhou, Guangzhou, 510405, China
| | - Zhidong Yang
- Department of Spinal Surgery, The First Affiliated Hospital of Guangzhou University of Chinese Medicine Guangzhou, Guangzhou, 510405, China
| | - Xiaobing Jiang
- Department of Spinal Surgery, The First Affiliated Hospital of Guangzhou University of Chinese Medicine Guangzhou, Guangzhou, 510405, China. .,Laboratory Affiliated to National Key Discipline of Orthopaedic and Traumatology of Chinese Medicine, Guangzhou University of Chinese Medicine, Guangzhou, 510405, China.
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157
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Reznikov N, Phillips C, Cooke M, Garbout A, Ahmed F, Stevens MM. Functional Adaptation of the Calcaneus in Historical Foot Binding. J Bone Miner Res 2017; 32:1915-1925. [PMID: 28561380 PMCID: PMC5603983 DOI: 10.1002/jbmr.3185] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/23/2017] [Revised: 05/20/2017] [Accepted: 05/28/2017] [Indexed: 12/04/2022]
Abstract
The normal structure of human feet is optimized for shock dampening during walking and running. Foot binding was a historical practice in China aimed at restricting the growth of female feet for aesthetic reasons. In a bound foot the shock-dampening function normally facilitated by the foot arches is withdrawn, resulting in the foot functioning as a rigid extension of the lower leg. An interesting question inspiring this study regards the nature of adaptation of the heel bone to this nonphysiological function using the parameters of cancellous bone anisotropy and 3D fabric topology and a novel intertrabecular angle (ITA) analysis. We found that the trabecular microarchitecture of the normal heel bone, but not of the bound foot, adapts to function by increased anisotropy and preferred orientation of trabeculae. The anisotropic texture in the normal heel bone consistently follows the physiological stress trajectories. However, in the bound foot heel bone the characteristic anisotropy pattern fails to develop, reflecting the lack of a normal biomechanical input. Moreover, the basic topological blueprint of cancellous bone investigated by the ITA method is nearly invariant in both normal and bound foot. These findings suggest that the anisotropic cancellous bone texture is an acquired characteristic that reflects recurrent loading conditions; conversely, an inadequate biomechanical input precludes the formation of anisotropic texture. This opens a long-sought-after possibility to reconstruct bone function from its form. The conserved topological parameters characterize the generic 3D fabric of cancellous bone, which is to a large extent independent of its adaptation to recurrent loading and perhaps determines the mechanical competence of trabecular bone regardless of its functional adaptation. © 2017 American Society for Bone and Mineral Research.
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Affiliation(s)
- Natalie Reznikov
- Department of Materials, Department of Bioengineering and Institute for Biomedical Engineering, Imperial College London, London, UK
| | - Carina Phillips
- Imaging and Analysis Centre, Core Research Laboratories, The Natural History Museum, London, UK
| | - Martyn Cooke
- Imaging and Analysis Centre, Core Research Laboratories, The Natural History Museum, London, UK
| | - Amin Garbout
- The Hunterian Museum, The Royal College of Surgeons of England, London, UK
| | - Farah Ahmed
- The Hunterian Museum, The Royal College of Surgeons of England, London, UK
| | - Molly M Stevens
- Department of Materials, Department of Bioengineering and Institute for Biomedical Engineering, Imperial College London, London, UK
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158
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Boys AJ, McCorry MC, Rodeo S, Bonassar LJ, Estroff LA. Next Generation Tissue Engineering of Orthopedic Soft Tissue-to-Bone Interfaces. MRS COMMUNICATIONS 2017; 7:289-308. [PMID: 29333332 PMCID: PMC5761353 DOI: 10.1557/mrc.2017.91] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/18/2017] [Accepted: 08/28/2017] [Indexed: 05/17/2023]
Abstract
Soft tissue-to-bone interfaces are complex structures that consist of gradients of extracellular matrix materials, cell phenotypes, and biochemical signals. These interfaces, called entheses for ligaments, tendons, and the meniscus, are crucial to joint function, transferring mechanical loads and stabilizing orthopedic joints. When injuries occur to connected soft tissue, the enthesis must be re-established to restore function, but due to structural complexity, repair has proven challenging. Tissue engineering offers a promising solution for regenerating these tissues. This prospective review discusses methodologies for tissue engineering the enthesis, outlined in three key design inputs: materials processing methods, cellular contributions, and biochemical factors.
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Affiliation(s)
- Alexander J Boys
- Department of Materials Science and Engineering, Cornell University, Ithaca, NY
| | | | - Scott Rodeo
- Orthopedic Surgery, Hospital for Special Surgery, New York, NY
- Sports Medicine and Shoulder Service, Hospital for Special Surgery, New York, NY
- Tissue Engineering, Regeneration, and Repair Program, Hospital for Special Surgery, New York, NY
- Orthopedic Surgery, Weill Medical College of Cornell University, Cornell University, New York, NY
- New York Giants, East Rutherford, NJ
- Department of Orthopedic Surgery, Hospital for Special Surgery, New York, NY
| | - Lawrence J Bonassar
- Meinig School of Biomedical Engineering, Cornell University, Ithaca, NY
- Sibley School of Mechanical and Aerospace Engineering, Cornell University, Ithaca, NY
| | - Lara A Estroff
- Department of Materials Science and Engineering, Cornell University, Ithaca, NY
- Kavli Institute at Cornell, Cornell University, Ithaca, NY
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159
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Gao LL, Wei CL, Zhang CQ, Gao H, Yang N, Dong LM. Quasi-static and ratcheting properties of trabecular bone under uniaxial and cyclic compression. MATERIALS SCIENCE & ENGINEERING. C, MATERIALS FOR BIOLOGICAL APPLICATIONS 2017; 77:1050-1059. [DOI: 10.1016/j.msec.2017.03.214] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/19/2016] [Revised: 01/08/2017] [Accepted: 03/23/2017] [Indexed: 11/25/2022]
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160
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Arndt C, Görgner A, Klöhn C, Scholz R, Voigt C. Shear stress and von Mises stress distributions in the periphery of an embedded acetabular cup implant during impingement. BIOMED ENG-BIOMED TE 2017; 62:279-288. [PMID: 27505082 DOI: 10.1515/bmt-2016-0107] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2015] [Accepted: 07/05/2016] [Indexed: 11/15/2022]
Abstract
As literature implies, daily activities of total hip arthroplasty (THA) patients may include movements prone to implant-implant impingement. Thus, high shear stresses may be induced at the acetabular implant-bone interface, increasing the risk of implant loosening. The aim of the current study is to determine whether or not impingement events may pose an actual risk to acetabular periprosthetic bone. An existing experimental workflow was augmented to cover complete three-dimensional strain gage measurement. von Mises and shear stresses were calculated from 1620 measured strain values, collected around a hemispherical cup implant at 2.5 mm interface distance during worst-case impingement loading. A shear stress criterion for acetabular periprosthetic bone was derived from the literature. At the impingement site, magnitudes of von Mises stress amount to 0.57 MPa and tilting shear stress amount to -0.3 MPa at 2.5 mm interface distance. Conclusion can be drawn that worst-case impingement events are unlikely to pose a risk of bone material failure in the periphery around fully integrated cementless acetabular hip implants in otherwise healthy THA patients. As numerical predictions in the literature suggested, it can now be confirmed that impingement moments are unlikely to cause acetabular implant-bone interface fixation failures.
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161
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Barker JB, Cronin DS, Nightingale RW. Lower Cervical Spine Motion Segment Computational Model Validation: Kinematic and Kinetic Response for Quasi-Static and Dynamic Loading. J Biomech Eng 2017; 139:2619324. [DOI: 10.1115/1.4036464] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2016] [Indexed: 12/28/2022]
Abstract
Advanced computational human body models (HBM) enabling enhanced safety require verification and validation at different levels or scales. Specifically, the motion segments, which are the building blocks of a detailed neck model, must be validated with representative experimental data to have confidence in segment and, ultimately, full neck model response. In this study, we introduce detailed finite element motion segment models and assess the models for quasi-static and dynamic loading scenarios. Finite element segment models at all levels in the lower human cervical spine were developed from scans of a 26-yr old male subject. Material properties were derived from the in vitro experimental data. The segment models were simulated in quasi-static loading in flexion, extension, lateral bending and axial rotation, and at dynamic rates in flexion and extension in comparison to previous experimental studies and new dynamic experimental data introduced in this study. Single-valued experimental data did not provide adequate information to assess the model biofidelity, while application of traditional corridor methods highlighted that data sets with higher variability could lead to an incorrect conclusion of improved model biofidelity. Data sets with continuous or multiple moment–rotation measurements enabled the use of cross-correlation for an objective assessment of the model and highlighted the importance of assessing all motion segments of the lower cervical spine to evaluate the model biofidelity. The presented new segment models of the lower cervical spine, assessed for range of motion and dynamic/traumatic loading scenarios, provide a foundation to construct a biofidelic model of the spine and neck, which can be used to understand and mitigate injury for improved human safety in the future.
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Affiliation(s)
- Jeffrey B. Barker
- Department of Mechatronics and Mechanical Engineering, University of Waterloo, 200 University Avenue West, Waterloo, ON N2L 3G1, Canada e-mail:
| | - Duane S. Cronin
- Department of Mechatronics and Mechanical Engineering, University of Waterloo, 200 University Avenue West, Waterloo, ON N2L 3G1, Canada
- Department of Mechanical Engineering, University of Waterloo, 200 University Avenue West, Waterloo, ON N2L 3G1, Canada e-mails:
| | - Roger W. Nightingale
- Division of Orthopaedic Surgery, Department of Biomedical Engineering, Duke University, Box 90281, Durham, NC 27708-0281 e-mail:
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162
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Rosenberg N, Halevy-Politch J. Intraosseous monitoring of drilling in lumbar vertebrae by ultrasound: An experimental feasibility study. PLoS One 2017; 12:e0174545. [PMID: 28459809 PMCID: PMC5411065 DOI: 10.1371/journal.pone.0174545] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2016] [Accepted: 03/10/2017] [Indexed: 11/18/2022] Open
Abstract
The rationale for this project is to evaluate the efficiency of a novel sonographic method for measurements of interosseous distances. The method utilizes a propagating ultrasonic beam through aqueous milieu which is directed as a jet into a drilled tract. We used a plastic model of human L5 vertebra and ex vivo specimen of L5 porcine vertebra and generated 2 mm in diameter tracts in vertebral pedicles. The tracts were created in the "desired" central direction and in the "wrong" medial and lateral directions. The drilled tracts and the residual, up to opposite cortex, distances were measured sonographically and mechanically and compared statistically. We show that "true" mechanical measurements can be predicted from sonographic measurements with correction of 1-3 mm. The correct central route can be distinguished from the wrong misplaced routes. By using the sonographic measurements, a correct direction of drilling in the pedicle of lumbar L5 vertebra can be efficiently monitored.
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Affiliation(s)
- Nahum Rosenberg
- The Ruth and Bruce Rappaport Faculty of Medicine, Technion–Israel Institute of Technology, Bat Galim, Haifa, Israel
- * E-mail:
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163
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Xie S, Manda K, Wallace RJ, Levrero-Florencio F, Simpson AHRW, Pankaj P. Time Dependent Behaviour of Trabecular Bone at Multiple Load Levels. Ann Biomed Eng 2017; 45:1219-1226. [PMID: 28130701 PMCID: PMC5397450 DOI: 10.1007/s10439-017-1800-1] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2016] [Accepted: 01/19/2017] [Indexed: 11/02/2022]
Abstract
The deformation of bone when subjected to loads is not instantaneous but varies with time. To investigate this time-dependent behaviour sixteen bovine trabecular bone specimens were subjected to compressive loading, creep, unloading and recovery at multiple load levels corresponding to apparent strains of 2000-25,000 με. We found that: the time-dependent response of trabecular bone comprises of both recoverable and irrecoverable strains; the strain response is nonlinearly related to applied load levels; and the response is linked to bone volume fraction. Although majority of strain is recovered after the load-creep-unload-recovery cycle some residual strain always exists. The analysis of results indicates that trabecular bone becomes stiffer initially and then experiences stiffness degradation with the increasing load levels. Steady state creep rate was found to be dependent on applied stress level and bone volume fraction with a power law relationship.
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Affiliation(s)
- Shuqiao Xie
- Institute for Bioengineering, School of Engineering, The University of Edinburgh, King's Buildings, Edinburgh, EH9 3DW, UK
| | - Krishnagoud Manda
- Institute for Bioengineering, School of Engineering, The University of Edinburgh, King's Buildings, Edinburgh, EH9 3DW, UK
| | - Robert J Wallace
- Department of Orthopaedics, The University of Edinburgh, Chancellor's Building, Edinburgh, EH16 4SB, UK
| | - Francesc Levrero-Florencio
- Institute for Bioengineering, School of Engineering, The University of Edinburgh, King's Buildings, Edinburgh, EH9 3DW, UK
| | - A Hamish R W Simpson
- Department of Orthopaedics, The University of Edinburgh, Chancellor's Building, Edinburgh, EH16 4SB, UK
| | - Pankaj Pankaj
- Institute for Bioengineering, School of Engineering, The University of Edinburgh, King's Buildings, Edinburgh, EH9 3DW, UK.
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164
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Mimetization of the elastic properties of cancellous bone via a parameterized cellular material. Biomech Model Mechanobiol 2017; 16:1485-1502. [PMID: 28374083 DOI: 10.1007/s10237-017-0901-y] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2016] [Accepted: 03/16/2017] [Indexed: 10/19/2022]
Abstract
Bone tissue mechanical properties and trabecular microarchitecture are the main factors that determine the biomechanical properties of cancellous bone. Artificial cancellous microstructures, typically described by a reduced number of geometrical parameters, can be designed to obtain a mechanical behavior mimicking that of natural bone. In this work, we assess the ability of the parameterized microstructure introduced by Kowalczyk (Comput Methods Biomech Biomed Eng 9:135-147, 2006. doi: 10.1080/10255840600751473 ) to mimic the elastic response of cancellous bone. Artificial microstructures are compared with actual bone samples in terms of elasticity matrices and their symmetry classes. The capability of the parameterized microstructure to combine the dominant isotropic, hexagonal, tetragonal and orthorhombic symmetry classes in the proportions present in the cancellous bone is shown. Based on this finding, two optimization approaches are devised to find the geometrical parameters of the artificial microstructure that better mimics the elastic response of a target natural bone specimen: a Sequential Quadratic Programming algorithm that minimizes the norm of the difference between the elasticity matrices, and a Pattern Search algorithm that minimizes the difference between the symmetry class decompositions. The pattern search approach is found to produce the best results. The performance of the method is demonstrated via analyses for 146 bone samples.
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165
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Petfield JL, Hayeck GT, Kopperdahl DL, Nesti LJ, Keaveny TM, Hsu JR. Virtual stress testing of fracture stability in soldiers with severely comminuted tibial fractures. J Orthop Res 2017; 35:805-811. [PMID: 27302535 DOI: 10.1002/jor.23335] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/27/2016] [Accepted: 06/02/2016] [Indexed: 02/04/2023]
Abstract
Virtual stress testing (VST) provides a non-invasive estimate of the strength of a healing bone through a biomechanical analysis of a patient's computed tomography (CT) scan. We asked whether VST could improve management of patients who had a tibia fracture treated with external fixation. In a retrospective case-control study of 65 soldier-patients who had tibia fractures treated with an external fixator, we performed VST utilizing CT scans acquired prior to fixator removal. The strength of the healing bone and the amount of tissue damage after application of an overload were computed for various virtual loading cases. Logistic regression identified computed outcomes with the strongest association to clinical events related to nonunion within 2 months after fixator removal. Clinical events (n = 9) were associated with a low tibial strength for compression loading (p < 0.05, AUC = 0.74) or a low proportion of failed cortical bone tissue for torsional loading (p < 0.005, AUC = 0.84). Using post-hoc thresholds of a compressive strength of four times body-weight and a proportional of failed cortical bone tissue of 5%, the test identified all nine patients who failed clinically (100% sensitivity; 40.9% positive predictive value) and over three fourths of those (43 of 56) who progressed to successful healing (76.8% specificity; 100% negative predictive value). In this study, VST identified all patients who progressed to full, uneventful union after fixator removal; thus, we conclude that this new test has the potential to provide a quantitative, objective means of identifying tibia-fracture patients who can safely resume weight bearing. © 2016 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 35:805-811, 2017.
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Affiliation(s)
- Joseph L Petfield
- Department of Orthopaedics and Rehabilitation, San Antonio Military Medical Center, San Antonio, Texas
| | - Garry T Hayeck
- O. N. Diagnostics, 2150 Shattuck Ave. Ste 610, Berkeley, California, 94704
| | - David L Kopperdahl
- O. N. Diagnostics, 2150 Shattuck Ave. Ste 610, Berkeley, California, 94704
| | - Leon J Nesti
- Department of Orthopaedic Surgery, Walter Reed National Military Medical Center, Bethesda, Maryland.,Department of Surgery, Uniformed Services University of the Health Sciences, Bethesda, Maryland
| | - Tony M Keaveny
- O. N. Diagnostics, 2150 Shattuck Ave. Ste 610, Berkeley, California, 94704.,Departments of Mechanical Engineering and Bioengineering, University of California, Berkeley, California
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166
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Johnson JE, Troy KL. Validation of a new multiscale finite element analysis approach at the distal radius. Med Eng Phys 2017; 44:16-24. [PMID: 28373011 DOI: 10.1016/j.medengphy.2017.03.005] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2016] [Revised: 03/02/2017] [Accepted: 03/12/2017] [Indexed: 12/15/2022]
Abstract
High-resolution peripheral computed tomography is commonly used to evaluate mechanical behavior of the distal radius microstructure using micro-finite element (FE) modeling. However, only a 9mm section is considered and boundary conditions (BCs) are usually simplified (platen-compression), and may not represent physiologic loading. Regardless, these methods are increasingly being used for clinical evaluations. Our goal was to develop and validate a novel multiscale solution that allows for physiologically relevant loading simulations (such as bracing during a fall), and show that mechanical behavior in the distal radius is different under platen BCs. Our approach incorporated bone microstructure together with organ-level radius geometry, by replacing matching continuum regions with micro-FE sections in user-defined regions of interest. Multiscale model predicted strains showed a strong correlation and a significant relationship with measured strains (r=0.836, p<0.001; slope=0.881, intercept=-12.17 µε, p<0.001). Interestingly, platen BC simulated strains were almost 50% lower than measured strains (r=0.835, p<0.001), and strain distributions were clearly different. Our multiscale method demonstrated excellent potential as a computationally efficient alternative for observing true mechanical environment within distal radius microstructure under physiologically accurate loading.
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Affiliation(s)
- Joshua E Johnson
- Worcester Polytechnic Institute, Department of Biomedical Engineering, 100 Institute Road, Worcester, MA 01609, Unites States of America.
| | - Karen L Troy
- Worcester Polytechnic Institute, Department of Biomedical Engineering, 100 Institute Road, Worcester, MA 01609, Unites States of America.
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167
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Fürst D, Senck S, Hollensteiner M, Esterer B, Augat P, Eckstein F, Schrempf A. Characterization of synthetic foam structures used to manufacture artificial vertebral trabecular bone. MATERIALS SCIENCE & ENGINEERING. C, MATERIALS FOR BIOLOGICAL APPLICATIONS 2017; 76:1103-1111. [PMID: 28482474 DOI: 10.1016/j.msec.2017.03.158] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/08/2016] [Revised: 03/17/2017] [Accepted: 03/18/2017] [Indexed: 11/30/2022]
Abstract
Artificial materials reflecting the mechanical properties of human bone are essential for valid and reliable implant testing and design. They also are of great benefit for realistic simulation of surgical procedures. The objective of this study was therefore to characterize two groups of self-developed synthetic foam structures by static compressive testing and by microcomputed tomography. Two mineral fillers and varying amounts of a blowing agent were used to create different expansion behavior of the synthetic open-cell foams. The resulting compressive and morphometric properties thus differed within and also slightly between both groups. Apart from the structural anisotropy, the compressive and morphometric properties of the synthetic foam materials were shown to mirror the respective characteristics of human vertebral trabecular bone in good approximation. In conclusion, the artificial materials created can be used to manufacture valid synthetic bones for surgical training. Further, they provide novel possibilities for studying the relationship between trabecular bone microstructure and biomechanical properties.
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Affiliation(s)
- David Fürst
- Research Group for Surgical Simulators Linz, Upper Austria University of Applied Sciences, Linz, Austria.
| | - Sascha Senck
- Computed Tomography Research Group, Upper Austria University of Applied Sciences, Wels, Austria
| | - Marianne Hollensteiner
- Research Group for Surgical Simulators Linz, Upper Austria University of Applied Sciences, Linz, Austria
| | - Benjamin Esterer
- Research Group for Surgical Simulators Linz, Upper Austria University of Applied Sciences, Linz, Austria
| | - Peter Augat
- Institute of Biomechanics, Berufsgenossenschaftliche Unfallklinik Murnau and Paracelsus Medical University, Murnau, Germany; Institute of Anatomy, Paracelsus Medical University of Salzburg & Nuremberg, Salzburg, Austria
| | - Felix Eckstein
- Institute of Anatomy, Paracelsus Private Medical University of Salzburg, Salzburg, Austria; Institute of Anatomy, Paracelsus Medical University - Campus Nuremberg, Nuremberg, Austria
| | - Andreas Schrempf
- Research Group for Surgical Simulators Linz, Upper Austria University of Applied Sciences, Linz, Austria. http://ressl.fh-linz.at
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168
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Kim DG, Haghighi A, Kwon HJ, Coogan JS, Nicolella DP, Johnson TB, Kim HD, Kim N, Agnew AM. Sex dependent mechanical properties of the human mandibular condyle. J Mech Behav Biomed Mater 2017; 71:184-191. [PMID: 28342326 DOI: 10.1016/j.jmbbm.2017.03.012] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2016] [Revised: 02/24/2017] [Accepted: 03/14/2017] [Indexed: 01/14/2023]
Abstract
The mandibular condyle consists of articular cartilage and subchondral bone that play an important role in bearing loads at the temporomandibular joint (TMJ) during static occlusion and dynamic mastication. The objective of the current study was to examine effects of sex and cartilage on 1) static and dynamic mechanical analysis (DMA) based dynamic energy storage and dissipation for the cartilage-subchondral bone construct of the human mandibular condyle, and 2) their correlations with the tissue mineral density and trabecular morphological parameters of subchondral bone. Cartilage-subchondral bone constructs were obtained from 16 individual human cadavers (9 males, 7 females, 79.00±13.10 years). After scanning with micro-computed tomography, the specimens were subjected to a non-destructive compressive static loading up to 7N and DMA using a cyclic loading profile (-5±2N at 2Hz). After removing the cartilage from the same specimen, the series of loading experiments were repeated. Static stiffness (K) and energy dissipation (W), and dynamic storage (K'), loss (K'') stiffness, and energy dissipation (tan δ) were assessed. Gray values, which are proportional to degree of bone mineralization, and trabecular morphological parameters of the subchondral bone were also measured. After removal of the cartilage, static energy dissipation significantly decreased (p<0.009) but dynamic energy dissipation was not influenced (p>0.064). Many subchondral bone properties were significantly correlated with the overall mechanical behavior of the cartilage-subchondral bone constructs for males (p<0.047) but not females (p>0.054). However, after removal of cartilage from the constructs, all of the significant correlations were no longer found (p>0.057). The current findings indicate that the subchondral bone is responsible for bearing static and dynamic loading in males but not in females. This result indicates that the female condyle may have a mechanically disadvantageous TMJ loading environment.
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Affiliation(s)
- Do-Gyoon Kim
- Division of Orthodontics, College of Dentistry, The Ohio State University, 4088 Postle Hall 305 W. 12th Ave, Columbus, OH 43210, USA.
| | - Arman Haghighi
- Division of Orthodontics, College of Dentistry, The Ohio State University, 4088 Postle Hall 305 W. 12th Ave, Columbus, OH 43210, USA
| | - Hyun-Jung Kwon
- Division of Orthodontics, College of Dentistry, The Ohio State University, 4088 Postle Hall 305 W. 12th Ave, Columbus, OH 43210, USA
| | - Jessica S Coogan
- Musculoskeletal Biomechanics, Southwest Research Institute, 6220 Culebra Road, San Antonio, TX 78238, USA
| | - Daniel P Nicolella
- Musculoskeletal Biomechanics, Southwest Research Institute, 6220 Culebra Road, San Antonio, TX 78238, USA
| | - Trenton B Johnson
- Division of Orthodontics, College of Dentistry, The Ohio State University, 4088 Postle Hall 305 W. 12th Ave, Columbus, OH 43210, USA
| | - Hwan D Kim
- Division of Orthodontics, College of Dentistry, The Ohio State University, 4088 Postle Hall 305 W. 12th Ave, Columbus, OH 43210, USA
| | - Nari Kim
- Division of Orthodontics, College of Dentistry, The Ohio State University, 4088 Postle Hall 305 W. 12th Ave, Columbus, OH 43210, USA
| | - Amanda M Agnew
- Injury Biomechanics Research Center, College of Medicine, The Ohio State University, Columbus, OH 43210, USA
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169
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Kreipke TC, Niebur GL. Anisotropic Permeability of Trabecular Bone and its Relationship to Fabric and Architecture: A Computational Study. Ann Biomed Eng 2017; 45:1543-1554. [DOI: 10.1007/s10439-017-1805-9] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2016] [Accepted: 01/28/2017] [Indexed: 11/30/2022]
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170
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Banerjee A, Patra S, Ganguly S. Alginate-gelatin blend with embedded voids for controlled release applications. J Appl Polym Sci 2017. [DOI: 10.1002/app.44787] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Affiliation(s)
- Arindam Banerjee
- Department of Chemical Engineering; Indian Institute of Technology; Kharagpur 721302 India
| | - Subhajit Patra
- Department of Chemical Engineering; Indian Institute of Technology; Kharagpur 721302 India
| | - Somenath Ganguly
- Department of Chemical Engineering; Indian Institute of Technology; Kharagpur 721302 India
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171
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Nishimura AC, Russo GA. Does cortical bone thickness in the last sacral vertebra differ among tail types in primates? AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY 2017; 162:757-767. [PMID: 28075029 DOI: 10.1002/ajpa.23167] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/09/2016] [Revised: 11/11/2016] [Accepted: 12/21/2016] [Indexed: 12/24/2022]
Abstract
OBJECTIVES The external morphology of the sacrum is demonstrably informative regarding tail type (i.e., tail presence/absence, length, and prehensility) in living and extinct primates. However, little research has focused on the relationship between tail type and internal sacral morphology, a potentially important source of functional information when fossil sacra are incomplete. Here, we determine if cortical bone cross-sectional thickness of the last sacral vertebral body differs among tail types in extant primates and can be used to reconstruct tail types in extinct primates. MATERIALS AND METHODS Cortical bone cross-sectional thickness in the last sacral vertebral body was measured from high-resolution CT scans belonging to 20 extant primate species (N = 72) assigned to tail type categories ("tailless," "nonprehensile short-tailed," "nonprehensile long-tailed," and "prehensile-tailed"). The extant dataset was then used to reconstruct the tail types for four extinct primate species. RESULTS Tailless primates had significantly thinner cortical bone than tail-bearing primates. Nonprehensile short-tailed primates had significantly thinner cortical bone than nonprehensile long-tailed primates. Cortical bone cross-sectional thickness did not distinguish between prehensile-tailed and nonprehensile long-tailed taxa. Results are strongly influenced by phylogeny. Corroborating previous studies, Epipliopithecus vindobonensis was reconstructed as tailless, Archaeolemur edwardsi as long-tailed, Megaladapis grandidieri as nonprehensile short-tailed, and Palaeopropithecus kelyus as nonprehensile short-tailed or tailless. CONCLUSIONS Results indicate that, in the context of phylogenetic clade, measures of cortical bone cross-sectional thickness can be used to allocate extinct primate species to tail type categories.
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Affiliation(s)
- Abigail C Nishimura
- Interdepartmental Doctoral Program in Anthropological Sciences, Stony Brook University, Stony Brook, New York, 11794
| | - Gabrielle A Russo
- Department of Anthropology, Stony Brook University, Stony Brook, New York, 11794
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172
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Zhao N, Wang Y, Qin L, Guo Z, Li D. Effect of composition and macropore percentage on mechanical and in vitro cell proliferation and differentiation properties of 3D printed HA/β-TCP scaffolds. RSC Adv 2017. [DOI: 10.1039/c7ra07204j] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
HA/β-TCP scaffolds were fabricated by 3D printing and exhibited desirable biocompatibilityin vitro.
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Affiliation(s)
- Ningbo Zhao
- Key Laboratory of Shaanxi Province for Craniofacial Precision Medicine Research
- College of Stomatology
- Xi'an Jiaotong University
- Xi'an
- People's Republic of China
| | - Yanen Wang
- The Key Lab of Contemporary Design and Integrated Manufacturing Technology of Ministry of Education
- Northwestern Polytechnical University
- Xi'an 710072
- People's Republic of China
| | - Lei Qin
- State Key Laboratory of Military Stomatology
- Department of Oral Implants
- School of Stomatology
- Fourth Military Medical University
- Xi'an 710032
| | - Zhengze Guo
- State Key Laboratory of Military Stomatology
- Department of Oral Implants
- School of Stomatology
- Fourth Military Medical University
- Xi'an 710032
| | - Dehua Li
- State Key Laboratory of Military Stomatology
- Department of Oral Implants
- School of Stomatology
- Fourth Military Medical University
- Xi'an 710032
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173
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Coughlin TR, Romero-Moreno R, Mason DE, Nystrom L, Boerckel JD, Niebur GL, Littlepage LE. Bone: A Fertile Soil for Cancer Metastasis. Curr Drug Targets 2017; 18:1281-1295. [PMID: 28025941 PMCID: PMC7932754 DOI: 10.2174/1389450117666161226121650] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2016] [Revised: 09/06/2016] [Accepted: 10/26/2016] [Indexed: 02/08/2023]
Abstract
Bone is one of the most common and most dangerous sites for metastatic growth across cancer types, and bone metastasis remains incurable. Unfortunately, the processes by which cancers preferentially metastasize to bone are still not well understood. In this review, we summarize the morphological features, physical properties, and cell signaling events that make bone a unique site for metastasis and bone remodeling. The signaling crosstalk between the tumor cells and bone cells begins a vicious cycle - a self-sustaining feedback loop between the tumor cells and the bone microenvironment composed of osteoclasts, osteoblasts, other bone marrow cells, bone matrix, and vasculature to support both tumor growth and bone destruction. Through this crosstalk, bone provides a fertile microenvironment that can harbor dormant tumor cells, sometimes for long periods, and support their growth by releasing cytokines as the bone matrix is destroyed, similar to providing nutrients for a seed to germinate in soil. However, few models exist to study the late stages of bone colonization by metastatic tumor cells. We describe some of the current methodologies used to study bone metastasis, highlighting the limitations of these methods and alternative future strategies to be used to study bone metastasis. While <i>in vivo</i> animal and patient studies may provide the gold standard for studying metastasis, <i>ex vivo</i> models can be used as an alternative to enable more controlled experiments designed to study the late stages of bone metastasis.
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Affiliation(s)
- Thomas R. Coughlin
- Harper Cancer Research Institute, South Bend, IN
- Department of Aerospace and Mechanical Engineering, Bioengineering Graduate Program, University of Notre Dame, Notre Dame, IN
| | - Ricardo Romero-Moreno
- Harper Cancer Research Institute, South Bend, IN
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, IN
| | - Devon E. Mason
- Harper Cancer Research Institute, South Bend, IN
- Department of Aerospace and Mechanical Engineering, Bioengineering Graduate Program, University of Notre Dame, Notre Dame, IN
| | - Lukas Nystrom
- Department of Orthopaedic Surgery and Rehabilitation, Loyola University Chicago, Stritch School of Medicine, Maywood, IL
| | - Joel D. Boerckel
- Harper Cancer Research Institute, South Bend, IN
- Department of Aerospace and Mechanical Engineering, Bioengineering Graduate Program, University of Notre Dame, Notre Dame, IN
| | - Glen L. Niebur
- Harper Cancer Research Institute, South Bend, IN
- Department of Aerospace and Mechanical Engineering, Bioengineering Graduate Program, University of Notre Dame, Notre Dame, IN
| | - Laurie E. Littlepage
- Harper Cancer Research Institute, South Bend, IN
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, IN
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174
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Haj-Ali R, Massarwa E, Aboudi J, Galbusera F, Wolfram U, Wilke HJ. A new multiscale micromechanical model of vertebral trabecular bones. Biomech Model Mechanobiol 2016; 16:933-946. [PMID: 27913902 DOI: 10.1007/s10237-016-0862-6] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2016] [Accepted: 11/23/2016] [Indexed: 10/20/2022]
Abstract
A new three-dimensional (3D) multiscale micromechanical model has been suggested as adept at predicting the overall linear anisotropic mechanical properties of a vertebral trabecular bone (VTB) highly porous microstructure. A nested 3D modeling analysis framework spanning the multiscale nature of the VTB is presented herein. This hierarchical analysis framework employs the following micromechanical methods: the 3D parametric high-fidelity generalized method of cells (HFGMC) as well as the 3D sublaminate model. At the nanoscale level, the 3D HFGMC method is applied to obtain the effective elastic properties of a representative unit cell (RUC) representing the mineral collagen fibrils composite. Next at the submicron scale level, the 3D sublaminate model is used to generate the effective elastic properties of a repeated stack of multilayered lamellae demonstrating the nature of the trabeculae (bone-wall). Thirdly, at the micron scale level, the 3D HFGMC method is used again on a RUC of the highly porous VTB microstructure. The VTB-RUC geometries are taken from microcomputed tomography scans of VTB samples harvested from different vertebrae of human cadavers [Formula: see text]. The predicted anisotropic overall elastic properties for native VTBs are, then, examined as a function of age and sex. The predicted results of the VTBs longitudinal Young's modulus are compared to reported values found in the literature. The proposed 3D nested modeling analysis framework provides a good agreement with reported values of Young's modulus of single trabeculae as well as for VTB-RUC in the literature.
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Affiliation(s)
- Rami Haj-Ali
- Faculty of Engineering, Tel-Aviv University, 6997801, Tel Aviv, Israel.
| | - Eyass Massarwa
- Faculty of Engineering, Tel-Aviv University, 6997801, Tel Aviv, Israel
| | - Jacob Aboudi
- Faculty of Engineering, Tel-Aviv University, 6997801, Tel Aviv, Israel
| | - Fabio Galbusera
- Department of Spine Surgery III, IRCCS Istituto Ortopedico Galeazzi, Milan, Italy
| | - Uwe Wolfram
- Mechanical, Process and Energy Engineering, Heriot-Watt University, Edinburgh, UK
| | - Hans-Joachim Wilke
- Institute for Orthopedic Research and Biomechanics, Ulm University, Helmholtzstrasse. 14, 89081, Ulm, Germany
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175
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O'Rourke D, Martelli S, Bottema M, Taylor M. A Computational Efficient Method to Assess the Sensitivity of Finite-Element Models: An Illustration With the Hemipelvis. J Biomech Eng 2016; 138:2565257. [PMID: 27685017 DOI: 10.1115/1.4034831] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2016] [Indexed: 11/08/2022]
Abstract
Assessing the sensitivity of a finite-element (FE) model to uncertainties in geometric parameters and material properties is a fundamental step in understanding the reliability of model predictions. However, the computational cost of individual simulations and the large number of required models limits comprehensive quantification of model sensitivity. To quickly assess the sensitivity of an FE model, we built linear and Kriging surrogate models of an FE model of the intact hemipelvis. The percentage of the total sum of squares (%TSS) was used to determine the most influential input parameters and their possible interactions on the median, 95th percentile and maximum equivalent strains. We assessed the surrogate models by comparing their predictions to those of a full factorial design of FE simulations. The Kriging surrogate model accurately predicted all output metrics based on a training set of 30 analyses (R2 = 0.99). There was good agreement between the Kriging surrogate model and the full factorial design in determining the most influential input parameters and interactions. For the median, 95th percentile and maximum equivalent strain, the bone geometry (60%, 52%, and 76%, respectively) was the most influential input parameter. The interactions between bone geometry and cancellous bone modulus (13%) and bone geometry and cortical bone thickness (7%) were also influential terms on the output metrics. This study demonstrates a method with a low time and computational cost to quantify the sensitivity of an FE model. It can be applied to FE models in computational orthopaedic biomechanics in order to understand the reliability of predictions.
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Affiliation(s)
- Dermot O'Rourke
- Medical Device Research Institute, School of Computer Science, Engineering and Mathematics, Flinders University, 1284 South Road, Adelaide SA 5042, Australia e-mail:
| | - Saulo Martelli
- Medical Device Research Institute, School of Computer Science, Engineering and Mathematics, Flinders University, 1284 South Road, Adelaide SA 5042, Australia e-mail:
| | - Murk Bottema
- Medical Device Research Institute, School of Computer Science, Engineering and Mathematics, Flinders University, 1284 South Road, Adelaide SA 5042, Australia e-mail:
| | - Mark Taylor
- Medical Device Research Institute, School of Computer Science, Engineering and Mathematics, Flinders University, 1284 South Road, Adelaide SA 5042, Australia e-mail:
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176
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Caffrey JP, Cory E, Wong VW, Masuda K, Chen AC, Hunt JP, Ganey TM, Sah RL. Ex vivo loading of trussed implants for spine fusion induces heterogeneous strains consistent with homeostatic bone mechanobiology. J Biomech 2016; 49:4090-4097. [PMID: 27836500 DOI: 10.1016/j.jbiomech.2016.10.051] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2016] [Accepted: 10/30/2016] [Indexed: 10/20/2022]
Abstract
A truss structure was recently introduced as an interbody fusion cage. As a truss system, some of the connected elements may be in a state of compression and others in tension. This study aimed to quantify both the mean and variance of strut strains in such an implant when loaded in a simulated fusion condition with vertebral body or contoured plastic loading platens ex vivo. Cages were each instrumented with 78 fiducial spheres, loaded between platens (vertebral body or contoured plastic), imaged using high resolution micro-CT, and analyzed for deformation and strain of each of the 221 struts. With repeated loading of a cage by vertebral platens, the distribution (variance, indicated by SD) of strut strains widened from 50N control (4±114με, mean±SD) to 1000N (-23±273με) and 2000N (-48±414με), and between 1000N and 2000N. With similar loading of multiple cages, the strain distribution at 2000N (23±389με) increased from 50N control. With repeated loading by contoured plastic platens, induced strains at 2000N had a distribution similar to that induced by vertebral platens (84±426με). In all studies, cages exhibited increases in strut strain amplitude when loaded from 50N to 1000N or 2000N. Correspondingly, at 2000N, 59-64% of struts exhibited strain amplitudes consistent with mechanobiologically-regulated bone homeostasis. At 2000N, vertically-oriented struts exhibited deformation of -2.87±2.04μm and strain of -199±133με, indicating overall cage compression. Thus, using an ex vivo 3-D experimental biomechanical analysis method, a truss implant can have strains induced by physiological loading that are heterogeneous and of amplitudes consistent with mechanobiological bone homeostasis.
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Affiliation(s)
- Jason P Caffrey
- Department of Bioengineering, University of California-San Diego, 9500 Gilman Drive MC 0412, La Jolla, CA 92093-0412, USA
| | - Esther Cory
- Department of Bioengineering, University of California-San Diego, 9500 Gilman Drive MC 0412, La Jolla, CA 92093-0412, USA
| | - Van W Wong
- Department of Bioengineering, University of California-San Diego, 9500 Gilman Drive MC 0412, La Jolla, CA 92093-0412, USA
| | - Koichi Masuda
- Department of Orthopedic Surgery, University of California-San Diego, 9500 Gilman Drive MC 0863, La Jolla, CA 92093-0863, USA
| | - Albert C Chen
- Department of Bioengineering, University of California-San Diego, 9500 Gilman Drive MC 0412, La Jolla, CA 92093-0412, USA
| | - Jessee P Hunt
- 4WEB Medical, 6170 Research Road, Suite 219, Frisco, TX 75033, USA
| | - Timothy M Ganey
- Atlanta Medical Center, 303 Parkway Drive NE, Box 227, Atlanta, GA 30312, USA
| | - Robert L Sah
- Department of Bioengineering, University of California-San Diego, 9500 Gilman Drive MC 0412, La Jolla, CA 92093-0412, USA; Department of Orthopedic Surgery, University of California-San Diego, 9500 Gilman Drive MC 0863, La Jolla, CA 92093-0863, USA; Center for Musculoskeletal Research, Institute of Engineering in Medicine, University of California-San Diego, 9500 Gilman Dr. MC 0412, La Jolla, CA 92093-0412, USA.
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177
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Arkharova NA, Suvorova EI, Severin AV, Khripunov AK, Krasheninnikov SV, Klechkovskaya VV. SEM and TEM for structure and properties characterization of bacterial cellulose/hydroxyapatite composites. SCANNING 2016; 38:757-765. [PMID: 27171920 DOI: 10.1002/sca.21325] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/09/2016] [Accepted: 04/19/2016] [Indexed: 06/05/2023]
Abstract
Preparation of composites with different properties and gradient of components is aimed at better performance of materials for bone substitution. Bacterial cellulose-hydroxyapatite (BC-HAP) composites with various mass ratio of the components (BC-25HAP, BC-4HAP, and BC-HAP) were prepared by a novel method of growing HAP nanocrystals (the linear size ≤30 nm) in water solutions in the presence of the BC gel-film micro-fragments. Varying the BC-HAP ratios leads to a gradual change of the physical properties of the materials. It was found that an increase in the BC content results in a decrease of the HAP crystal length and specific surface area, porosity, and pore volume while the values of density and Young's modulus values increase. SCANNING 38:757-765, 2016. © 2016 Wiley Periodicals, Inc.
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Affiliation(s)
- Natalia A Arkharova
- Shubnikov Institute of Crystallography of FSRC "Crystallography and Photonics" of Russian Academy of Sciences, Moscow, Russia
| | - Elena I Suvorova
- Shubnikov Institute of Crystallography of FSRC "Crystallography and Photonics" of Russian Academy of Sciences, Moscow, Russia
| | | | - Albert K Khripunov
- Institute of Macromolecular Compounds of Russian Academy of Sciences, St. Petersburg, Russia
| | | | - Vera V Klechkovskaya
- Shubnikov Institute of Crystallography of FSRC "Crystallography and Photonics" of Russian Academy of Sciences, Moscow, Russia
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178
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Reznikov N, Chase H, Ben Zvi Y, Tarle V, Singer M, Brumfeld V, Shahar R, Weiner S. Inter-trabecular angle: A parameter of trabecular bone architecture in the human proximal femur that reveals underlying topological motifs. Acta Biomater 2016; 44:65-72. [PMID: 27554017 DOI: 10.1016/j.actbio.2016.08.040] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2016] [Revised: 08/15/2016] [Accepted: 08/19/2016] [Indexed: 10/21/2022]
Abstract
UNLABELLED Trabecular bone is an intricate 3D network of struts and plates. Although the structure-function relations in trabecular bone have been studied since the time of Julius Wolff, controversy still exists regarding the architectural parameters responsible for its stability and resilience. We present a parameter that measures the angle between two connected trabeculae - the Inter-Trabecular Angle (ITA). We studied the ITA values derived from μCT scans of different regions of the proximal femora of 5 individuals of different age and sex. We show that the ITA angle distribution of nodes with 3 connecting trabeculae has a mean close to 120°, nodes with 4 connecting trabeculae has a mean close to 109° and nodes of higher connectivity have mean ITA values around 100°. This tendency to spread the ITAs around geometrically symmetrical motifs is highly conserved. The implication is that the ITAs are optimized such that the smallest amount of material spans the maximal 3D volume, and possibly by so doing trabecular bone might be better adapted to multidirectional loading. We also draw a parallel between trabecular bone and tensegrity structures - where lightweight, resilient and stable tetrahedron-based shapes contribute to strain redistribution amongst all the elements and to collective impact dampening. STATEMENT OF SIGNIFICANCE The Inter-Trabecular Angle (ITA) is a new topological parameter of trabecular bone. The ITA characterizes the way trabeculae connect with each other at nodes, regardless of their thickness and shape. The mean ITA value of nodes with 3 trabeculae is close to 120°, of nodes with 4 trabeculae is just below 109°, and the mean ITA of nodes with 5 and more trabeculae is around 100°. Thus the connections of trabeculae trend towards adopting symmetrical shapes. This implies that trabeculae can maximally span 3D space using the minimal amount of material. We draw a parallel between this motif and the concept of tensegrity - an engineering premise to which many living creatures conform at multiple levels of organization.
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179
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Stephens NB, Kivell TL, Gross T, Pahr DH, Lazenby RA, Hublin JJ, Hershkovitz I, Skinner MM. Trabecular architecture in the thumb of Pan and Homo: implications for investigating hand use, loading, and hand preference in the fossil record. AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY 2016; 161:603-619. [PMID: 27500902 DOI: 10.1002/ajpa.23061] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/16/2015] [Revised: 06/14/2016] [Accepted: 07/24/2016] [Indexed: 12/31/2022]
Abstract
OBJECTIVES Humans display an 85-95% cross-cultural right-hand bias in skilled tasks, which is considered a derived behavior because such a high frequency is not reported in wild non-human primates. Handedness is generally considered to be an evolutionary byproduct of selection for manual dexterity and augmented visuo-cognitive capabilities within the context of complex stone tool manufacture/use. Testing this hypothesis requires an understanding of when appreciable levels of right dominant behavior entered the fossil record. Because bone remodels in vivo, skeletal asymmetries are thought to reflect greater mechanical loading on the dominant side, but incomplete preservation of external morphology and ambiguities about past loading environments complicate interpretations. We test if internal trabecular bone is capable of providing additional information by analyzing the thumb of Homo sapiens and Pan. MATERIALS AND METHODS We assess trabecular structure at the distal head and proximal base of paired (left/right) first metacarpals using micro-CT scans of Homo sapiens (n = 14) and Pan (n = 9). Throughout each epiphysis we quantify average and local bone volume fraction (BV/TV), degree of anisotropy (DA), and elastic modulus (E) to address bone volume patterning and directional asymmetry. RESULTS We find a right directional asymmetry in H. sapiens consistent with population-level handedness, but also report a left directional asymmetry in Pan that may be the result of postural and/or locomotor loading. CONCLUSION We conclude that trabecular bone is capable of detecting right/left directional asymmetry, but suggest coupling studies of internal structure with analyses of other skeletal elements and cortical bone prior to applications in the fossil record.
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Affiliation(s)
- Nicholas B Stephens
- Department of Human Evolution, Max Planck Institute for Evolutionary Anthropology, Deutscher Platz 6, Leipzig, 04103, Germany
| | - Tracy L Kivell
- Department of Human Evolution, Max Planck Institute for Evolutionary Anthropology, Deutscher Platz 6, Leipzig, 04103, Germany.,Skeletal Biology Research Centre, School of Anthropology and Conservation, University of Kent, Canterbury, CT2 7NR, United Kingdom
| | - Thomas Gross
- Institute of Lightweight Design and Structural Biomechanics, Vienna University of Technology, A-1060 Vienna, Getreidemarkt 9/BE, Vienna, Austria
| | - Dieter H Pahr
- Institute of Lightweight Design and Structural Biomechanics, Vienna University of Technology, A-1060 Vienna, Getreidemarkt 9/BE, Vienna, Austria
| | - Richard A Lazenby
- Department of Anthropology, University of Northern British Columbia, 3333 University Way, Prince George, BC, Canada, V2N 4Z9
| | - Jean-Jacques Hublin
- Department of Human Evolution, Max Planck Institute for Evolutionary Anthropology, Deutscher Platz 6, Leipzig, 04103, Germany
| | - Israel Hershkovitz
- Department of Anatomy and Anthropology, Sackler Faculty of Medicine, Tel-Aviv University, Tel-Aviv, Israel
| | - Matthew M Skinner
- Department of Human Evolution, Max Planck Institute for Evolutionary Anthropology, Deutscher Platz 6, Leipzig, 04103, Germany.,Skeletal Biology Research Centre, School of Anthropology and Conservation, University of Kent, Canterbury, CT2 7NR, United Kingdom
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180
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Osteogenic signaling on silk-based matrices. Biomaterials 2016; 97:133-53. [DOI: 10.1016/j.biomaterials.2016.04.020] [Citation(s) in RCA: 81] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2015] [Revised: 03/25/2016] [Accepted: 04/20/2016] [Indexed: 12/11/2022]
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181
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Suska F, Kjeller G, Tarnow P, Hryha E, Nyborg L, Snis A, Palmquist A. Electron Beam Melting Manufacturing Technology for Individually Manufactured Jaw Prosthesis: A Case Report. J Oral Maxillofac Surg 2016; 74:1706.e1-1706.e15. [DOI: 10.1016/j.joms.2016.03.046] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2015] [Revised: 03/28/2016] [Accepted: 03/31/2016] [Indexed: 01/26/2023]
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182
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Manda K, Wallace RJ, Xie S, Levrero-Florencio F, Pankaj P. Nonlinear viscoelastic characterization of bovine trabecular bone. Biomech Model Mechanobiol 2016; 16:173-189. [PMID: 27440127 PMCID: PMC5285425 DOI: 10.1007/s10237-016-0809-y] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2016] [Accepted: 07/08/2016] [Indexed: 11/24/2022]
Abstract
The time-independent elastic properties of trabecular bone have been extensively investigated, and several stiffness–density relations have been proposed. Although it is recognized that trabecular bone exhibits time-dependent mechanical behaviour, a property of viscoelastic materials, the characterization of this behaviour has received limited attention. The objective of the present study was to investigate the time-dependent behaviour of bovine trabecular bone through a series of compressive creep–recovery experiments and to identify its nonlinear constitutive viscoelastic material parameters. Uniaxial compressive creep and recovery experiments at multiple loads were performed on cylindrical bovine trabecular bone samples (\documentclass[12pt]{minimal}
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\begin{document}$$n = 19$$\end{document}n=19). Creep response was found to be significant and always comprised of recoverable and irrecoverable strains, even at low stress/strain levels. This response was also found to vary nonlinearly with applied stress. A systematic methodology was developed to separate recoverable (nonlinear viscoelastic) and irrecoverable (permanent) strains from the total experimental strain response. We found that Schapery’s nonlinear viscoelastic constitutive model describes the viscoelastic response of the trabecular bone, and parameters associated with this model were estimated from the multiple load creep–recovery (MLCR) experiments. Nonlinear viscoelastic recovery compliance was found to have a decreasing and then increasing trend with increasing stress level, indicating possible stiffening and softening behaviour of trabecular bone due to creep. The obtained parameters from MLCR tests, expressed as second-order polynomial functions of stress, showed a similar trend for all the samples, and also demonstrate stiffening–softening behaviour with increasing stress.
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Affiliation(s)
- Krishnagoud Manda
- School of Engineering, The University of Edinburgh, The King's Buildings, EH9 3DW, Edinburgh, UK.
| | - Robert J Wallace
- Department of Orthopaedics, The University of Edinburgh, Chancellors building, EH16 4SB, Edinburgh, UK
| | - Shuqiao Xie
- School of Engineering, The University of Edinburgh, The King's Buildings, EH9 3DW, Edinburgh, UK
| | | | - Pankaj Pankaj
- School of Engineering, The University of Edinburgh, The King's Buildings, EH9 3DW, Edinburgh, UK
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183
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Choudhari C, Herblum R, Akens MK, Moore S, Hardisty M, Whyne CM. Post-euthanasia micro-computed tomography-based strain analysis is able to represent quasi-static in vivo behavior of whole vertebrae. Proc Inst Mech Eng H 2016; 230:900-904. [PMID: 27422827 DOI: 10.1177/0954411916658679] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Three-dimensional image-based strain measurement in whole bones allows representation of physiological, albeit quasi-static, loading conditions. However, such work to date has been limited to specimens postmortem. The main purpose of this study is to verify the efficacy of deformable image registration of post-euthanasia strain to characterize the in vivo mechanical behavior of rat vertebrae. A micro-computed tomography-compatible custom loading device was used to apply 75 N load to a three-level caudal motion segment of a healthy rat. Loaded and unloaded micro-computed tomography scans were acquired in vivo and post-sacrifice. A micro-computed tomography-based deformable image registration algorithm was used to calculate vertebral strains live and post-euthanasia. No significant difference was found in the in vivo strains (-0.011 ± 0.001) and ex vivo strains (-0.012 ± 0.001) obtained from the comparisons of loaded and unloaded images (p = 0.3). Comparisons between unloaded-unloaded and loaded-loaded scans yielded significantly lower axial strains, representing the error of the method. Qualitatively, high strains were observed adjacent to growth plate regions in evaluating the loaded-unloaded images. Strain patterns in the loaded-loaded and unloaded-unloaded scans were inconsistent as would be expected in representing noise. Overall, live and dead loaded to unloaded comparisons yielded similar strain patterns and magnitudes. Point-wise differences in axial strain fields also supported this observation. This study demonstrated a proof of concept, suggesting that post-euthanasia micro-computed tomography-based strain analysis is able to represent the in vivo quasi-static behavior of rat tail vertebrae.
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Affiliation(s)
- Chetan Choudhari
- 1 Orthopaedic Biomechanics Lab, Sunnybrook Research Institute, Toronto, ON, Canada
- 2 Institute of Biomaterials and Biomedical Engineering, Toronto, ON, Canada
| | - Ryan Herblum
- 1 Orthopaedic Biomechanics Lab, Sunnybrook Research Institute, Toronto, ON, Canada
- 2 Institute of Biomaterials and Biomedical Engineering, Toronto, ON, Canada
| | - Margarete K Akens
- 3 TECHNA Institute, University Health Network, Toronto, ON, Canada
- 4 Department of Surgery, University of Toronto, Toronto, ON, Canada
| | - Sara Moore
- 1 Orthopaedic Biomechanics Lab, Sunnybrook Research Institute, Toronto, ON, Canada
| | - Michael Hardisty
- 1 Orthopaedic Biomechanics Lab, Sunnybrook Research Institute, Toronto, ON, Canada
| | - Cari M Whyne
- 1 Orthopaedic Biomechanics Lab, Sunnybrook Research Institute, Toronto, ON, Canada
- 2 Institute of Biomaterials and Biomedical Engineering, Toronto, ON, Canada
- 4 Department of Surgery, University of Toronto, Toronto, ON, Canada
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184
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Adams DJ, Rowe DW, Ackert-Bicknell CL. Genetics of aging bone. Mamm Genome 2016; 27:367-80. [PMID: 27272104 DOI: 10.1007/s00335-016-9650-y] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2016] [Accepted: 05/24/2016] [Indexed: 01/08/2023]
Abstract
With aging, the skeleton experiences a number of changes, which include reductions in mass and changes in matrix composition, leading to fragility and ultimately an increase of fracture risk. A number of aspects of bone physiology are controlled by genetic factors, including peak bone mass, bone shape, and composition; however, forward genetic studies in humans have largely concentrated on clinically available measures such as bone mineral density (BMD). Forward genetic studies in rodents have also heavily focused on BMD; however, investigations of direct measures of bone strength, size, and shape have also been conducted. Overwhelmingly, these studies of the genetics of bone strength have identified loci that modulate strength via influencing bone size, and may not impact the matrix material properties of bone. Many of the rodent forward genetic studies lacked sufficient mapping resolution for candidate gene identification; however, newer studies using genetic mapping populations such as Advanced Intercrosses and the Collaborative Cross appear to have overcome this issue and show promise for future studies. The majority of the genetic mapping studies conducted to date have focused on younger animals and thus an understanding of the genetic control of age-related bone loss represents a key gap in knowledge.
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Affiliation(s)
- Douglas J Adams
- Department of Orthopaedic Surgery, University of Connecticut Musculoskeletal Institute, University of Connecticut Health, Farmington, CT, 06030, USA
| | - David W Rowe
- Center for Regenerative Medicine and Skeletal Development, Department of Reconstructive Sciences, Biomaterials and Skeletal Development, University of Connecticut Health, Farmington, CT, USA
| | - Cheryl L Ackert-Bicknell
- Center for Musculoskeletal Research, Department of Orthopaedics and Rehabilitation, School of Medicine and Dentistry, University of Rochester, 601 Elmwood Ave, Box 665, Rochester, NY, 14624, USA.
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185
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Piper A, Brown CJ. A Computational Approximation to Model Variation in Cancellous Bone Screw Pull-Out. J Med Device 2016. [DOI: 10.1115/1.4032868] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
Cancellous bone screws are used to achieve good pull-out characteristics when connected to cancellous bone. This study examines some screw characteristics, including pitch and inner diameter, using a model of cancellous bone with a range of bone apparent densities (ADs). This was achieved using bone geometry based on microCT-scanned cancellous bone and converted into a geometric model using mimics® software. The finite element (FE) models were produced in ansys®. The calculated reaction force for pull-out of 0.2 mm shows the influence of design parameters. Change in the proximal half angle increased the stiffness by about 15% in line with the experimental findings of others. An increase in pull-out reaction force with an increase in bone AD was also observed. However, when a particular screw geometry in lower AD bone was modeled and then rotated through 180 deg on plan, a significant reduction in reaction force was noted. Further models with screws of similar geometry in the same location showed similar reductions in reaction force and hence pull-out stiffness. Examination of the geometry of the bone/screw interface indicates that in certain positions there is little cancellous bone to support the implant—leading to low pull-out reaction forces, which is very difficult to predict. The study also examined the effect of increasing the bone stiffness adjacent to the implant, and concluded that, even in bone of low AD, increases in pull-out stiffness might be achieved.
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Affiliation(s)
- A. Piper
- College of Engineering, Design and Physical Sciences, Brunel University London, Uxbridge UB8 3PH, UK
| | - C. J. Brown
- College of Engineering, Design and Physical Sciences, Brunel University London, Uxbridge UB8 3PH, UK
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186
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Abraham AC, Agarwalla A, Yadavalli A, Liu JY, Tang SY. Microstructural and compositional contributions towards the mechanical behavior of aging human bone measured by cyclic and impact reference point indentation. Bone 2016; 87:37-43. [PMID: 27021150 PMCID: PMC4862905 DOI: 10.1016/j.bone.2016.03.013] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/29/2015] [Revised: 03/23/2016] [Accepted: 03/24/2016] [Indexed: 02/05/2023]
Abstract
The assessment of fracture risk often relies primarily on measuring bone mineral density, thereby accounting for only a single pathology: the loss of bone mass. However, bone's ability to resist fracture is a result of its biphasic composition and hierarchical structure that imbue it with high strength and toughness. Reference point indentation (RPI) testing is designed to directly probe bone mechanical behavior at the microscale in situ, although it remains unclear which aspects of bone composition and structure influence the results at this scale. Therefore, our goal in this study was to investigate factors that contribute to bone mechanical behavior measured by cyclic reference point indentation, impact reference point indentation, and three-point bending. Twenty-eight female cadavers (ages 57-97) were subjected to cyclic and impact RPI in parallel at the unmodified tibia mid-diaphysis. After RPI, the middiaphyseal tibiae were removed, scanned using micro-CT to obtain cortical porosity (Ct.Po.) and tissue mineral density (TMD), then tested using three-point bending, and lastly assayed for the accumulation of advanced glycation end-products (AGEs). Both the indentation distance increase from cyclic RPI (IDI) and bone material strength index from impact RPI (BMSi) were significantly correlated with TMD (r=-0.390, p=0.006; r=0.430, p=0.002; respectively). Accumulation of AGEs was significantly correlated with IDI (r=0.281, p=0.046), creep indentation distance (CID, r=0.396, p=0.004), and BMSi (r=-0.613, p<0.001). There were no significant relationships between tissue TMD or AGEs accumulation with the quasi-static material properties. Toughness decreased with increasing tissue Ct.Po. (r=-0.621, p<0.001). Other three-point bending measures also correlated with tissue Ct.Po. including the bending modulus (r=-0.50, p<0.001) and ultimate stress (r=-0.56, p<0.001). The effects of Ct.Po. on indentation were less pronounced with IDI (r=0.290, p=0.043) and BMSi (r=-0.299, p=0.037) correlated modestly with tissue Ct.Po. These results suggest that RPI may be sensitive to bone quality changes relating to collagen.
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Affiliation(s)
- Adam C Abraham
- Department of Orthopedic Surgery, Washington University in St. Louis, 660 S. Euclid, Campus Box 8233, St. Louis, MO 63103, USA
| | - Avinesh Agarwalla
- Department of Biomedical Engineering, Washington University in St. Louis, One Brookings Drive, Whitaker Hall, Campus Box 1097, St. Louis, MO 63130, USA
| | - Aditya Yadavalli
- Department of Biomedical Engineering, Washington University in St. Louis, One Brookings Drive, Whitaker Hall, Campus Box 1097, St. Louis, MO 63130, USA
| | - Jenny Y Liu
- Department of Orthopedic Surgery, Washington University in St. Louis, 660 S. Euclid, Campus Box 8233, St. Louis, MO 63103, USA
| | - Simon Y Tang
- Department of Orthopedic Surgery, Washington University in St. Louis, 660 S. Euclid, Campus Box 8233, St. Louis, MO 63103, USA; Department of Biomedical Engineering, Washington University in St. Louis, One Brookings Drive, Whitaker Hall, Campus Box 1097, St. Louis, MO 63130, USA.
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187
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Choudhari C, Chan K, Akens MK, Whyne CM. μFE models can represent microdamaged regions of healthy and metastatically involved whole vertebrae identified through histology and contrast enhanced μCT imaging. J Biomech 2016; 49:1103-1110. [PMID: 26947031 DOI: 10.1016/j.jbiomech.2016.02.034] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2015] [Revised: 01/24/2016] [Accepted: 02/16/2016] [Indexed: 11/24/2022]
Abstract
Micro-damage formation within the skeleton is an important stimulant for bone remodeling, however abnormal build-up of micro-damage can lead to skeletal fragility. In this study, µCT imaging based micro finite element (μFE) models were used to evaluate tissue level damage criteria in whole healthy and metastatically-involved vertebrae. T13-L2 spinal segments were excised from osteolytic (n=3) and healthy (n=3) female athymic rnu/rnu rats. Osteolytic metastasis was generated by intercardiac injection of HeLa cancer cells. Micro-mechanical axial loading was applied to the spinal motion segments under μCT imaging. Vertebral samples underwent BaSO4 staining and sequential calcein/fuchsin staining to identify load induced micro-damage. μCT imaging was used generate specimen specific μFE models of the healthy and osteolytic whole rat vertebrae. Model boundary conditions were generated through deformable image registration of loaded and unloaded scans. Elevated stresses and strains were detected in regions of micro-damage identified through histological and BaSO4 staining within healthy and osteolytic vertebral models, as compared to undamaged regions. Additionally, damaged regions of metastatic vertebrae experienced significantly higher local stresses and strains than those in the damaged regions of healthy specimens. Areas identified by BaSO4 staining, however, yielded lower levels of stress and strain in damaged and undamaged regions of healthy and metastatic vertebrae as compared to fuschin staining. The multimodal (experimental, image-based and computational) techniques used in this study demonstrated the ability of local stresses and strains computed through µFE analysis to identify trabecular micro-damage, that can be applied to biomechanical analyses of healthy and diseased whole bones.
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Affiliation(s)
- Chetan Choudhari
- Sunnybrook Research Institute, Toronto, ON, Canada; Institute for Biomaterials and Biomedical Engineering, Toronto, ON, Canada
| | - Katelyn Chan
- Sunnybrook Research Institute, Toronto, ON, Canada
| | - Margarete K Akens
- TECHNA Institute, University Health Network, Toronto, ON, Canada; Department of Surgery, Toronto, ON, Canada
| | - Cari M Whyne
- Sunnybrook Research Institute, Toronto, ON, Canada; Department of Surgery, Toronto, ON, Canada; Institute for Biomaterials and Biomedical Engineering, Toronto, ON, Canada.
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188
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Kharmanda G, Kharma MY. Evaluating the Effect of Minimizing Screws on Stabilization of Symphysis Mandibular Fracture by 3D Finite Element Analysis. J Maxillofac Oral Surg 2016; 16:205-211. [PMID: 28439162 DOI: 10.1007/s12663-016-0903-9] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2015] [Accepted: 03/21/2016] [Indexed: 12/01/2022] Open
Abstract
PURPOSE The objective of this work is to integrate structural optimization and reliability concepts into mini-plate fixation strategy used in symphysis mandibular fractures. The structural reliability levels are next estimated when considering a single failure mode and multiple failure modes. PATIENTS AND METHODS A 3-dimensional finite element model is developed in order to evaluate the ability of reducing the negative effect due to the stabilization of the fracture. Topology optimization process is considered in the conceptual design stage to predict possible fixation layouts. In the detailed design stage, suitable mini-plates are selected taking into account the resulting topology and different anatomical considerations. Several muscle forces are considered in order to obtain realistic predictions. Since some muscles can be cut or harmed during the surgery and cannot operate at its maximum capacity, there is a strong motivation to introduce the loading uncertainties in order to obtain reliable designs. The structural reliability is carried out for a single failure mode and multiple failure modes. RESULTS The different results are validated with a clinical case of a male patient with symphysis fracture. In this case while use of the upper plate fixation with four holes, only two screws were applied to protect adjacent vital structure. This behavior does not affect the stability of the fracture. CONCLUSION The proposed strategy to optimize bone plates leads to fewer complications and second surgeries, less patient discomfort, and shorter time of healing.
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Affiliation(s)
| | - Mohamed-Yaser Kharma
- Department Oral Maxillofacial Surgery, Al-Farabi College for Dentistry, Jeddah, Kingdom of Saudi Arabia.,Department of Oral Maxillofacial Surgery, Dental School, Aleppo University, Aleppo, Syria
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189
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Ün K, Çalık A. Relevance of inhomogeneous–anisotropic models of human cortical bone: a tibia study using the finite element method. BIOTECHNOL BIOTEC EQ 2016. [DOI: 10.1080/13102818.2016.1154803] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
Affiliation(s)
- Kerem Ün
- Faculty of Engineering and Architecture, Department of Biomedical Engineering, Çukurova University, Adana, Turkey
| | - Ahmet Çalık
- Faculty of Engineering and Architecture, Department of Mechanical Engineering, Çukurova University, Adana, Turkey
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190
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Topological design and additive manufacturing of porous metals for bone scaffolds and orthopaedic implants: A review. Biomaterials 2016. [DOI: 10.1016/j.biomaterials.2016.01.012 pmid: 26773669] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
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191
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Hsieh WT, Liu YS, Lee YH, Rimando MG, Lin KH, Lee OK. Matrix dimensionality and stiffness cooperatively regulate osteogenesis of mesenchymal stromal cells. Acta Biomater 2016; 32:210-222. [PMID: 26790775 DOI: 10.1016/j.actbio.2016.01.010] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2015] [Revised: 12/14/2015] [Accepted: 01/10/2016] [Indexed: 11/16/2022]
Abstract
Osteogenic potential of mesenchymal stromal cells (MSCs) is mechanosensitive. It's affected by the mechanical properties of the cellular microenvironment, particularly its mechanical modulus. To explore the effect of mechanical modulus on osteogenesis in the third dimension (3D), this study used a novel polyacrylamide (PA) scaffold whose pores are monodisperse and spherical, the mechanical moduli of which can be tuned across a wide range. It was found that MSCs have similar proliferation rates in PA scaffolds independent of the matrix stiffness. The contractile force exerted by MSCs inside PA scaffolds was strong enough to deform the pores of scaffolds made of more compliant PAs (whose shear modulus, G'scaffold<4 kPa). Only scaffolds of the highest stiffness (G'scaffold=12 kPa) can withhold the contraction from MSCs. After osteogenic induction for 21 days, the expression profiles of marker genes showed that PA scaffolds of G'scaffold=12 kPa promoted osteogenesis of MSCs. Confocal image analysis demonstrated that there are more F-actin cytoskeletons and bundled stress fibers at higher matrix moduli in 2D and 3D. Moreover, the 3D porous structure promotes osteogenesis of MSCs more than 2D flat substrates. Together, the differences of cellular behaviors when cultured in 2D and 3D systems are evident. The PA scaffolds developed in the present study can be used for further investigation into the mechanism of MSC mechanosensing in the 3D context. STATEMENT OF SIGNIFICANCE Mechanical properties of the microenvironment affect cellular behaviors, such as matrix stiffness. Traditionally, cell biological investigations have mostly employed cells growing on 2D substrates. The 3D porous PA scaffolds with the same topological conformation and pore sizes but different stiffness generated in this study showed that the differences of cellular behaviors in 2D and 3D systems are evident. Our 3D scaffolds provide insights into tissue engineering when stem cells incorporated with 3D scaffolds and support the future studies of cellular mechanobiology as well as the elucidation the role mechanical factor plays on the physiology and fate determination of MSCs in the 3D context.
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Affiliation(s)
- Wen-Ting Hsieh
- Program in Molecular Medicine, National Yang-Ming University and Academia Sinica, Taipei, Taiwan
| | - Yi-Shiuan Liu
- Stem Cell Research Center, National Yang-Ming University, Taipei, Taiwan
| | - Yi-Hsuan Lee
- Institute of Physics, Academia Sinica, Taipei, Taiwan
| | - Marilyn G Rimando
- Taiwan International Graduate Program in Molecular Medicine, National Yang-Ming University and Academia Sinica, Taipei, Taiwan
| | - Keng-Hui Lin
- Institute of Physics, Academia Sinica, Taipei, Taiwan.
| | - Oscar K Lee
- Taipei City Hospital, Taipei, Taiwan; Institute of Clinical Medicine, National Yang-Ming University, Taipei, Taiwan; Department of Orthopedics and Traumatology, Taipei Veterans General Hospital, Taipei, Taiwan.
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192
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Lo YP, Liu YS, Rimando MG, Ho JHC, Lin KH, Lee OK. Three-dimensional spherical spatial boundary conditions differentially regulate osteogenic differentiation of mesenchymal stromal cells. Sci Rep 2016; 6:21253. [PMID: 26884253 PMCID: PMC4756701 DOI: 10.1038/srep21253] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2015] [Accepted: 01/20/2016] [Indexed: 01/09/2023] Open
Abstract
The spatial boundary condition (SBC) arising from the surrounding microenvironment imposes specific geometry and spatial constraints that affect organogenesis and tissue homeostasis. Mesenchymal stromal cells (MSCs) sensitively respond to alterations of mechanical cues generated from the SBC. However, mechanical cues provided by a three-dimensional (3D) environment are deprived in a reductionist 2D culture system. This study investigates how SBC affects osteogenic differentiation of MSCs using 3D scaffolds with monodispersed pores and homogenous spherical geometries. MSCs cultured under SBCs with diameters of 100 and 150 μm possessed the greatest capability of osteogenic differentiation. This phenomenon was strongly correlated with MSC morphology, organization of actin cytoskeleton, and distribution of focal adhesion involving α2 and α5 integrins. Further silencing either α2 or α5 integrin significantly reduced the above mentioned mechanosensitivity, indicating that the α2 and α5 integrins as mechano-sensitive molecules mediate MSCs' ability to provide enhanced osteogenic differentiation in response to different spherical SBCs. Taken together, the findings provide new insights regarding how MSCs respond to mechanical cues from the surrounding microenvironment in a spherical SBC, and such biophysical stimuli should be taken into consideration in tissue engineering and regenerative medicine in conjunction with biochemical cues.
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Affiliation(s)
- Yin-Ping Lo
- Program in Molecular Medicine, National Yang-Ming University and Academia Sinica, Taipei 11221, Taiwan
| | - Yi-Shiuan Liu
- Stem Cell Research Center, National Yang-Ming University, Taipei 11221, Taiwan
| | - Marilyn G Rimando
- Taiwan International Graduate Program in Molecular Medicine, National Yang-Ming University and Academia Sinica, Taipei 11221, Taiwan
| | - Jennifer Hui-Chun Ho
- Center for Stem Cell Research, Wan Fang Hospital, Taipei Medical University, Taipei 11696, Taiwan.,Graduate Institute of Clinical Medicine, Taipei Medical University, Taipei 11031, Taiwan.,Department of Ophthalmology, Wan Fang Hospital, Taipei Medical University, Taipei 11696, Taiwan
| | - Keng-Hui Lin
- Institute of Physics, Academia Sinica, Taipei 11529, Taiwan
| | - Oscar K Lee
- Taipei City Hospital, Taipei 10341, Taiwan.,Institute of Clinical Medicine, National Yang-Ming University, Taipei 11221, Taiwan.,Department of Orthopaedics and Traumatology, Taipei Veterans General Hospital, Taipei 11217, Taiwan
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193
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Kivell TL. A review of trabecular bone functional adaptation: what have we learned from trabecular analyses in extant hominoids and what can we apply to fossils? J Anat 2016; 228:569-94. [PMID: 26879841 DOI: 10.1111/joa.12446] [Citation(s) in RCA: 117] [Impact Index Per Article: 14.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/04/2016] [Indexed: 12/31/2022] Open
Abstract
Many of the unresolved debates in palaeoanthropology regarding evolution of particular locomotor or manipulative behaviours are founded in differing opinions about the functional significance of the preserved external fossil morphology. However, the plasticity of internal bone morphology, and particularly trabecular bone, allowing it to respond to mechanical loading during life means that it can reveal greater insight into how a bone or joint was used during an individual's lifetime. Analyses of trabecular bone have been commonplace for several decades in a human clinical context. In contrast, the study of trabecular bone as a method for reconstructing joint position, joint loading and ultimately behaviour in extant and fossil non-human primates is comparatively new. Since the initial 2D studies in the late 1970s and 3D analyses in the 1990 s, the utility of trabecular bone to reconstruct behaviour in primates has grown to incorporate experimental studies, expanded taxonomic samples and skeletal elements, and improved methodologies. However, this work, in conjunction with research on humans and non-primate mammals, has also revealed the substantial complexity inherent in making functional inferences from variation in trabecular architecture. This review addresses the current understanding of trabecular bone functional adaptation, how it has been applied to hominoids, as well as other primates and, ultimately, how this can be used to better interpret fossil hominoid and hominin morphology. Because the fossil record constrains us to interpreting function largely from bony morphology alone, and typically from isolated bones, analyses of trabecular structure, ideally in conjunction with that of cortical structure and external morphology, can offer the best resource for reconstructing behaviour in the past.
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Affiliation(s)
- Tracy L Kivell
- Animal Postcranial Evolution Laboratory, Skeletal Biological Research Centre, School of Anthropology and Conservation, University of Kent, Canterbury, UK.,Department of Human Evolution, Max Planck Institute for Evolutionary Anthropology, Leipzig, Germany
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194
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Neves N, Campos BB, Almeida IF, Costa PC, Cabral AT, Barbosa MA, Ribeiro CC. Strontium-rich injectable hybrid system for bone regeneration. MATERIALS SCIENCE & ENGINEERING. C, MATERIALS FOR BIOLOGICAL APPLICATIONS 2016; 59:818-827. [DOI: 10.1016/j.msec.2015.10.038] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/17/2015] [Revised: 09/10/2015] [Accepted: 10/12/2015] [Indexed: 12/21/2022]
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195
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Wang X, Xu S, Zhou S, Xu W, Leary M, Choong P, Qian M, Brandt M, Xie YM. Topological design and additive manufacturing of porous metals for bone scaffolds and orthopaedic implants: A review. Biomaterials 2016; 83:127-41. [PMID: 26773669 DOI: 10.1016/j.biomaterials.2016.01.012] [Citation(s) in RCA: 634] [Impact Index Per Article: 79.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2015] [Revised: 12/31/2015] [Accepted: 01/01/2016] [Indexed: 02/06/2023]
Abstract
One of the critical issues in orthopaedic regenerative medicine is the design of bone scaffolds and implants that replicate the biomechanical properties of the host bones. Porous metals have found themselves to be suitable candidates for repairing or replacing the damaged bones since their stiffness and porosity can be adjusted on demands. Another advantage of porous metals lies in their open space for the in-growth of bone tissue, hence accelerating the osseointegration process. The fabrication of porous metals has been extensively explored over decades, however only limited controls over the internal architecture can be achieved by the conventional processes. Recent advances in additive manufacturing have provided unprecedented opportunities for producing complex structures to meet the increasing demands for implants with customized mechanical performance. At the same time, topology optimization techniques have been developed to enable the internal architecture of porous metals to be designed to achieve specified mechanical properties at will. Thus implants designed via the topology optimization approach and produced by additive manufacturing are of great interest. This paper reviews the state-of-the-art of topological design and manufacturing processes of various types of porous metals, in particular for titanium alloys, biodegradable metals and shape memory alloys. This review also identifies the limitations of current techniques and addresses the directions for future investigations.
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Affiliation(s)
- Xiaojian Wang
- Centre for Innovative Structures and Materials, School of Engineering, RMIT University, GPO Box 2476, Melbourne 3001, Victoria, Australia
| | - Shanqing Xu
- Centre for Innovative Structures and Materials, School of Engineering, RMIT University, GPO Box 2476, Melbourne 3001, Victoria, Australia
| | - Shiwei Zhou
- Centre for Innovative Structures and Materials, School of Engineering, RMIT University, GPO Box 2476, Melbourne 3001, Victoria, Australia
| | - Wei Xu
- Centre for Additive Manufacturing, School of Engineering, RMIT University, GPO Box 2476, Melbourne 3001, Victoria, Australia
| | - Martin Leary
- Centre for Additive Manufacturing, School of Engineering, RMIT University, GPO Box 2476, Melbourne 3001, Victoria, Australia
| | - Peter Choong
- Department of Surgery, University of Melbourne, St. Vincent's Hospital, Melbourne 3001, Victoria, Australia
| | - M Qian
- Centre for Additive Manufacturing, School of Engineering, RMIT University, GPO Box 2476, Melbourne 3001, Victoria, Australia
| | - Milan Brandt
- Centre for Additive Manufacturing, School of Engineering, RMIT University, GPO Box 2476, Melbourne 3001, Victoria, Australia
| | - Yi Min Xie
- Centre for Innovative Structures and Materials, School of Engineering, RMIT University, GPO Box 2476, Melbourne 3001, Victoria, Australia; Centre for Additive Manufacturing, School of Engineering, RMIT University, GPO Box 2476, Melbourne 3001, Victoria, Australia.
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196
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Mirzaali M, Libonati F, Vena P, Mussi V, Vergani L, Strano M. Investigation of the Effect of Internal Pores Distribution on the Elastic Properties of Closed-Cell Aluminum Foam: A Comparison with Cancellous Bone. ACTA ACUST UNITED AC 2016. [DOI: 10.1016/j.prostr.2016.06.164] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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197
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Comparative sacral morphology and the reconstructed tail lengths of five extinct primates: Proconsul heseloni, Epipliopithecus vindobonensis, Archaeolemur edwardsi, Megaladapis grandidieri, and Palaeopropithecus kelyus. J Hum Evol 2016; 90:135-62. [DOI: 10.1016/j.jhevol.2015.10.007] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2015] [Revised: 10/14/2015] [Accepted: 10/15/2015] [Indexed: 12/20/2022]
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198
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Zysset P, Pahr D, Engelke K, Genant HK, McClung MR, Kendler DL, Recknor C, Kinzl M, Schwiedrzik J, Museyko O, Wang A, Libanati C. Comparison of proximal femur and vertebral body strength improvements in the FREEDOM trial using an alternative finite element methodology. Bone 2015; 81:122-130. [PMID: 26141837 DOI: 10.1016/j.bone.2015.06.025] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/09/2015] [Revised: 06/23/2015] [Accepted: 06/29/2015] [Indexed: 01/15/2023]
Abstract
Denosumab reduced the incidence of new fractures in postmenopausal women with osteoporosis by 68% at the spine and 40% at the hip over 36 months compared with placebo in the FREEDOM study. This efficacy was supported by improvements from baseline in vertebral (18.2%) strength in axial compression and femoral (8.6%) strength in sideways fall configuration at 36 months, estimated in Newtons by an established voxel-based finite element (FE) methodology. Since FE analyses rely on the choice of meshes, material properties, and boundary conditions, the aim of this study was to independently confirm and compare the effects of denosumab on vertebral and femoral strength during the FREEDOM trial using an alternative smooth FE methodology. Unlike the previous FE study, effects on femoral strength in physiological stance configuration were also examined. QCT data for the proximal femur and two lumbar vertebrae were analyzed by smooth FE methodology at baseline, 12, 24, and 36 months for 51 treated (denosumab) and 47 control (placebo) subjects. QCT images were segmented and converted into smooth FE models to compute bone strength. L1 and L2 vertebral bodies were virtually loaded in axial compression and the proximal femora in both fall and stance configurations. Denosumab increased vertebral body strength by 10.8%, 14.0%, and 17.4% from baseline at 12, 24, and 36 months, respectively (p<0.0001). Denosumab also increased femoral strength in the fall configuration by 4.3%, 5.1%, and 7.2% from baseline at 12, 24, and 36 months, respectively (p<0.0001). Similar improvements were observed in the stance configuration with increases of 4.2%, 5.2%, and 5.2% from baseline (p≤0.0007). Differences between the increasing strengths with denosumab and the decreasing strengths with placebo were significant starting at 12 months (vertebral and femoral fall) or 24 months (femoral stance). Using an alternative smooth FE methodology, we confirmed the significant improvements in vertebral body and proximal femur strength previously observed with denosumab. Estimated increases in strength with denosumab and decreases with placebo were highly consistent between both FE techniques.
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Affiliation(s)
| | - Dieter Pahr
- Vienna University of Technology, Vienna, Austria
| | - Klaus Engelke
- University of Erlangen, Erlangen, Germany and Synarc Germany, Hamburg, Germany
| | | | | | | | | | | | | | - Oleg Museyko
- University of Erlangen-Nuremberg, Erlangen-Nuremberg, Germany
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199
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Bettamer A, Hambli R, Allaoui S, Almhdie-Imjabber A. Using visual image measurements to validate a novel finite element model of crack propagation and fracture patterns of proximal femur. COMPUTER METHODS IN BIOMECHANICS AND BIOMEDICAL ENGINEERING-IMAGING AND VISUALIZATION 2015. [DOI: 10.1080/21681163.2015.1079505] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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200
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Metzger TA, Schwaner SA, LaNeve AJ, Kreipke TC, Niebur GL. Pressure and shear stress in trabecular bone marrow during whole bone loading. J Biomech 2015; 48:3035-43. [PMID: 26283413 DOI: 10.1016/j.jbiomech.2015.07.028] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2015] [Revised: 07/12/2015] [Accepted: 07/24/2015] [Indexed: 11/27/2022]
Abstract
Skeletal adaptation to mechanical loading is controlled by mechanobiological signaling. Osteocytes are highly responsive to applied strains, and are the key mechanosensory cells in bone. However, many cells residing in the marrow also respond to mechanical cues such as hydrostatic pressure and shear stress, and hence could play a role in skeletal adaptation. Trabecular bone encapsulates marrow, forming a poroelastic solid. According to the mechanical theory, deformation of the pores induces motion in the fluid-like marrow, resulting in pressure and velocity gradients. The latter results in shear stress acting between the components of the marrow. To characterize the mechanical environment of trabecular bone marrow in situ, pore pressure within the trabecular compartment of whole porcine femurs was measured with miniature pressure transducers during stress-relaxation and cyclic loading. Pressure gradients ranging from 0.013 to 0.46 kPa/mm were measured during loading. This range was consistent with calculated pressure gradients from continuum scale poroelastic models with the same permeability. Micro-scale computational fluid dynamics models created from computed tomography images were used to calculate the micromechanical stress in the marrow using the measured pressure differentials as boundary conditions. The volume averaged shear stress in the marrow ranged from 1.67 to 24.55 Pa during cyclic loading, which exceeds the mechanostimulatory threshold for mesenchymal lineage cells. Thus, the loading of bone through activities of daily living may be an essential component of bone marrow health and mechanobiology. Additional studies of cell-level interactions during loading in healthy and disease conditions will provide further incite into marrow mechanobiology.
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Affiliation(s)
- Thomas A Metzger
- Tissue Mechanics Laboratory, Bioengineering Graduate Program, University of Notre Dame, United States
| | - Stephen A Schwaner
- Department of Aerospace and Mechanical Engineering, University of Notre Dame, United States
| | - Anthony J LaNeve
- Department of Aerospace and Mechanical Engineering, University of Notre Dame, United States
| | - Tyler C Kreipke
- Tissue Mechanics Laboratory, Bioengineering Graduate Program, University of Notre Dame, United States
| | - Glen L Niebur
- Tissue Mechanics Laboratory, Bioengineering Graduate Program, University of Notre Dame, United States.
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