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Dumont M, Herrel A, Courant J, Padilla P, Shahar R, Milgram J. Femoral bone structure and mechanics at the edge and core of an expanding population of the invasive frog Xenopus laevis. J Exp Biol 2024; 227:jeb246419. [PMID: 38904393 DOI: 10.1242/jeb.246419] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2023] [Accepted: 06/07/2024] [Indexed: 06/22/2024]
Abstract
Understanding how living tissues respond to changes in their mechanical environment is a key question in evolutionary biology. Invasive species provide an ideal model for this as they are often transplanted between environments that differ drastically in their ecological and environmental context. Spatial sorting, the name given to the phenomenon driving differences between individuals at the core and edge of an expanding range, has been demonstrated to impact the morphology and physiology of Xenopus laevis from the invasive French population. Here, we combined a structural analysis using micro-CT scanning and a functional analysis by testing the mechanical properties of the femur to test whether the increased dispersal at the range edge drives differences in bone morphology and function. Our results show significant differences in the inner structure of the femur as well as bone material properties, with frogs from the centre of the range having more robust and resistant bones. This is suggestive of an energy allocation trade-off between locomotion and investment in bone formation, or alternatively, may point to selection for fast locomotion at the range edge. Overall, our results provide insights on the growth of the long bones and the formation of trabecular bone in frogs.
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Affiliation(s)
- Maïtena Dumont
- Laboratory of Bone Biomechanics, Koret School of Veterinary Medicine, The Robert H. Smith Faculty of Agriculture, Food and Environment, PO Box 12, 7610001 Rehovot, Israel
- Max-Planck Institute for Sustainable Materials, MPISM, D-40237, Düsseldorf, Germany
| | - Anthony Herrel
- UMR 7179 CNRS/MNHN, Département Adaptations du Vivant, Bâtiment d'Anatomie Comparée, 55 rue Buffon, 75005 Paris, France
- Department of Biology, Evolutionary Morphology of Vertebrates, Ghent University, Ghent 9000, Belgium
- Department of Biology, University of Antwerp, Wilrijk 2610, Belgium
- Naturhistorisches Museum Bern, 3005 Bern, Switzerland
| | - Julien Courant
- UMR 7179 CNRS/MNHN, Département Adaptations du Vivant, Bâtiment d'Anatomie Comparée, 55 rue Buffon, 75005 Paris, France
| | - Pablo Padilla
- UMR 7179 CNRS/MNHN, Département Adaptations du Vivant, Bâtiment d'Anatomie Comparée, 55 rue Buffon, 75005 Paris, France
- Laboratory of Ecology and Conservation of Amphibians (LECA), Freshwater and Oceanic Science Unit of Research (FOCUS), University of Liège, Liège, Liege 4000, Belgium
| | - Ron Shahar
- Laboratory of Bone Biomechanics, Koret School of Veterinary Medicine, The Robert H. Smith Faculty of Agriculture, Food and Environment, PO Box 12, 7610001 Rehovot, Israel
| | - Joshua Milgram
- Laboratory of Bone Biomechanics, Koret School of Veterinary Medicine, The Robert H. Smith Faculty of Agriculture, Food and Environment, PO Box 12, 7610001 Rehovot, Israel
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Walle M, Yeritsyan D, Abbasian M, Oftadeh R, Müller R, Nazarian A. A graph model to describe the network connectivity of trabecular plates and rods. Front Bioeng Biotechnol 2024; 12:1384280. [PMID: 38770275 PMCID: PMC11103010 DOI: 10.3389/fbioe.2024.1384280] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2024] [Accepted: 04/19/2024] [Indexed: 05/22/2024] Open
Abstract
Introduction: The trabecular network is perceived as a collection of interconnected plate- (P) and rod-like (R) elements. Previous research has highlighted how these elements and their connectivity influence the mechanical properties of bone, yet further work is required to elucidate better the deeply interconnected nature of the trabecular network with distinct element formations conducting forces per their mechanical boundary conditions. Within this network, forces act through elements: a rod or plate with force applied to one end will transmit this force to a component connected to the other end, defining the boundary conditions for the loading of each element. To that end, this study has two aims: First, to investigate the connectivity of individually segmented elements of trabecular bone with respect to their local boundary conditions as defined by the surrounding trabecular network and linking them directly to the bone's overall mechanical response during loading using a mathematical graph model of the plate and rod (PR) Network. Second, we use this model to quantify side artifacts, a known artifact when testing an excised specimen of trabecular bone, where vertical trabeculae lose their load-bearing capacity due to a loss of connectivity, ultimately resulting in a change of the trabecular network topology. Resuts: Connected elements derived from our model predicted apparent elastic modulus by fitting a linear regression (R 2 = 0.81). In comparison, prediction using conventional bone volume fraction results in a lower accuracy (R 2 = 0.72), demonstrating the ability of the PR Network to estimate compressive elastic modulus independent of specimen size or loading boundary condition. Discussion: PR Network models are a novel approach to describing connectivity within the trabecular network and incorporating mechanical boundary conditions within the morphological analysis, thus enabling the study of intrinsic material properties of trabecular bone. Ultimately, PR Network models may be an early predictor or provide further insights into osteo-degenerative diseases.
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Affiliation(s)
- Matthias Walle
- Musculoskeletal Translational Innovation Initiative, Carl J. Shapiro Department of Orthopaedic Surgery, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA, United States
- Institute for Biomechanics, ETH Zürich, Zürich, Switzerland
| | - Diana Yeritsyan
- Musculoskeletal Translational Innovation Initiative, Carl J. Shapiro Department of Orthopaedic Surgery, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA, United States
| | - Mohammadreza Abbasian
- Musculoskeletal Translational Innovation Initiative, Carl J. Shapiro Department of Orthopaedic Surgery, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA, United States
| | - Ramin Oftadeh
- Musculoskeletal Translational Innovation Initiative, Carl J. Shapiro Department of Orthopaedic Surgery, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA, United States
| | - Ralph Müller
- Institute for Biomechanics, ETH Zürich, Zürich, Switzerland
| | - Ara Nazarian
- Musculoskeletal Translational Innovation Initiative, Carl J. Shapiro Department of Orthopaedic Surgery, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA, United States
- Department of Orthopaedic Surgery, Yerevan State Medical University, Yerevan, Armenia
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3
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Zhang G, Jia X, Li Z, Wang Q, Gu H, Liu Y, Bai Z, Mao H. Comprehensively characterizing heterogeneous and transversely isotropic properties of femur cortical bones. J Mech Behav Biomed Mater 2024; 151:106387. [PMID: 38246092 DOI: 10.1016/j.jmbbm.2024.106387] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2023] [Revised: 12/23/2023] [Accepted: 01/07/2024] [Indexed: 01/23/2024]
Abstract
Comprehensive characterization of the transversely isotropic mechanical properties of long bones along both the longitudinal and circumferential gradients is crucial for developing accurate mathematical models and studying bone biomechanics. In addition, mechanical testing to derive elastic, plastic, and failure properties of bones is essential for modeling plastic deformation and failure of bones. To achieve these, we machined a total of 336 cortical specimens, including 168 transverse and 168 longitudinal specimens, from four different quadrants of seven different sections of 3 bovine femurs. We conducted three-point bending tests of these specimens at a loading rate of 0.02 mm/s. Young's modulus, yield stress, tangential modulus, and effective plastic strain for each specimen were derived from correction equations based on classical beam theory. Our statistical analysis reveals that the longitudinal gradient has a significant effect on the Young's modulus, yield stress, and tangential modulus of both longitudinal and transverse specimens, whereas the circumferential gradient significantly influences the Young's modulus, yield stress, and tangential modulus of transverse specimens only. The differences in Young's modulus and yield stress between longitudinal specimens from different sections are greater than 40%, whereas those between transverse specimens are approximately 30%. The Young's modulus and yield stress of transverse specimens in the anterior quadrant were 18.81%/15.46% and 18.34%/14.88% higher than those in the posterior and lateral quadrants, respectively. There is no significant interaction between the longitudinal gradient and the circumferential gradient. Considering the transverse isotropy, it is crucial to consider loading direction when investigating the impact of circumferential gradients in the anterior, lateral, medial, and posterior directions. Our findings indicate that the conventional assumption of homogeneity in simulating the cortical bone of long bones may have limitations, and researchers should consider the anatomical position and loading direction of femur specimens for precise prediction of mechanical responses.
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Affiliation(s)
- Guanjun Zhang
- State Key Laboratory of Advanced Design and Manufacturing for Vehicle Body, Hunan University, Changsha, 410082, China
| | - Xiaohang Jia
- State Key Laboratory of Advanced Design and Manufacturing for Vehicle Body, Hunan University, Changsha, 410082, China
| | - Zhentao Li
- State Key Laboratory of Advanced Design and Manufacturing for Vehicle Body, Hunan University, Changsha, 410082, China
| | - Qinhuai Wang
- State Key Laboratory of Advanced Design and Manufacturing for Vehicle Body, Hunan University, Changsha, 410082, China
| | - Hongyue Gu
- State Key Laboratory of Advanced Design and Manufacturing for Vehicle Body, Hunan University, Changsha, 410082, China
| | - Yu Liu
- State Key Laboratory of Advanced Design and Manufacturing for Vehicle Body, Hunan University, Changsha, 410082, China
| | - Zhonghao Bai
- State Key Laboratory of Advanced Design and Manufacturing for Vehicle Body, Hunan University, Changsha, 410082, China
| | - Haojie Mao
- Department of Mechanical and Materials Engineering, Faculty of Engineering, School of Biomedical Engineering, Western University, London, ON, N6A 5B9, Canada.
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Wolff S, Adler S, Eppler E, Fischer K, Lux A, Rothkötter HJ, Skalej M. Correlation of CT-based bone mineralization with drilling-force measurements in anatomical specimens is suitable to investigate planning of trans-pedicular spine interventions. Sci Rep 2024; 14:1579. [PMID: 38238459 PMCID: PMC10796759 DOI: 10.1038/s41598-023-50204-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2023] [Accepted: 12/16/2023] [Indexed: 01/22/2024] Open
Abstract
This interdisciplinary study examined the relationship between bone density and drilling forces required during trans-pedicular access to the vertebra using fresh-frozen thoraco-lumbar vertebrae from two female body donors (A, B). Before and after biomechanical examination, samples underwent high-resolution CT-quantification of total bone density followed by software-based evaluation and processing. CT density measurements (n = 4818) were calculated as gray values (GV), which were highest in T12 for both subjects (GVmaxA = 3483.24, GVmaxB = 3160.33). Trans-pedicular drilling forces F (Newton N) were highest in L3 (FmaxB = 5.67 N) and L4 (FmaxA = 5.65 N). In 12 out of 13 specimens, GVs significantly (p < 0.001) correlated with force measurements. Among these, Spearman correlations r were poor in two lumbar vertebrae, fair in five specimens, and moderately strong in another five specimens, and highest for T11 (rA = 0.721) and L5 (rB = 0.690). Our results indicate that CT-based analysis of vertebral bone density acquired in anatomical specimens is a promising approach to predict the drilling force appearance as surrogate parameter of its biomechanical properties by e.g., linear regression analysis. The study may be of value as basis for biomechanical investigations to improve planning of the optimal trajectory and to define safety margins for drilling forces during robotic-assisted trans-pedicular interventions on the spine in the future.
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Affiliation(s)
- Stefanie Wolff
- Clinic for Internal Medicine, Municipal Hospital St. Georg Leipzig, Delitzscher Straße 141, 04129, Leipzig, Germany
- Clinic of Neuroradiology, University Hospital Magdeburg, Leipziger Straße 44, 39120, Magdeburg, Germany
| | - Simon Adler
- Automatisation and Informatics, Harz University of Applied Sciences, Friedrichstraße 57-59, 38855, Wernigerode, Germany
- Fraunhofer Institute for Factory Operation and Automation IFF, Sandtorstraße 22, 39106, Magdeburg, Germany
| | - Elisabeth Eppler
- Institute of Anatomy, University of Bern, Baltzerstraße 2, 3012, Bern, Switzerland
- Institute of Anatomy and Cell Biology, University of Halle-Wittenberg, Große Steinstraße 52, 06108, Halle (Saale), Germany
| | - Karin Fischer
- Institute of Anatomy, Otto-von-Guericke University Magdeburg, Leipziger Straße 44, 39120, Magdeburg, Germany
| | - Anke Lux
- Institute of Biometry and Medical Informatics, Otto-von-Guericke University Magdeburg, Leipziger Str. 44, 39120, Magdeburg, Germany
| | - Hermann-Josef Rothkötter
- Institute of Anatomy, Otto-von-Guericke University Magdeburg, Leipziger Straße 44, 39120, Magdeburg, Germany
| | - Martin Skalej
- Clinic of Neuroradiology, University Hospital Magdeburg, Leipziger Straße 44, 39120, Magdeburg, Germany.
- Neuroradiology, Martin-Luther-University Halle-Wittenberg, Ernst-Grube-Straße 40, 06120, Halle (Saale), Germany.
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5
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Shin M, Pelletier MH, Lovric V, Walsh WR, Martens PJ, Kruzic JJ, Gludovatz B. Effect of gamma irradiation and supercritical carbon dioxide sterilization with Novakill™ or ethanol on the fracture toughness of cortical bone. J Biomed Mater Res B Appl Biomater 2024; 112:e35356. [PMID: 38247241 DOI: 10.1002/jbm.b.35356] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2023] [Revised: 09/15/2023] [Accepted: 11/11/2023] [Indexed: 01/23/2024]
Abstract
Sterilization of structural bone allografts is a critical process prior to their clinical use in large cortical bone defects. Gamma irradiation protocols are known to affect tissue integrity in a dose dependent manner. Alternative sterilization treatments, such as supercritical carbon dioxide (SCCO2 ), are gaining popularity due to advantages such as minimal exposure to denaturants, the lack of toxic residues, superior tissue penetration, and minor impacts on mechanical properties including strength and stiffness. The impact of SCCO2 on the fracture toughness of bone tissue, however, remains unknown. Here, we evaluate crack initiation and growth toughness after 2, 6, and 24 h SCCO2 -treatment using Novakill™ and ethanol as additives on ~11 samples per group obtained from a pair of femur diaphyses of a canine. All mechanical testing was performed at ambient air after 24 h soaking in Hanks' balanced salt solution (HBSS). Results show no statistically significant difference in the failure characteristics of the Novakill™-treated groups whereas crack growth toughness after 6 and 24 h of treatment with ethanol significantly increases by 37% (p = .010) and 34% (p = .038), respectively, compared to an untreated control group. In contrast, standard 25 kGy gamma irradiation causes significantly reduced crack growth resistance by 40% (p = .007) compared to untreated bone. FTIR vibrational spectroscopy, conducted after testing, reveals a consistent trend of statistically significant differences (p < .001) with fracture toughness. These trends align with variations in the ratios of enzymatic mature to immature crosslinks in the collagen structure, suggesting a potential association with fracture toughness. Additional Raman spectroscopy after testing shows a similar trend with statistically significant differences (p < .005), which further supports that collagen structural changes occur in the SCF-treated groups with ethanol after 6 and 24 h. Our work reveals the benefits of SCCO2 sterilization compared to gamma irradiation.
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Affiliation(s)
- Mihee Shin
- School of Mechanical and Manufacturing Engineering, University of New South Wales (UNSW Sydney), Sydney, New South Wales, Australia
| | - Matthew H Pelletier
- Surgical and Orthopedic Research Laboratories, Prince of Wales Clinical School, University of New South Wales (UNSW Sydney), Sydney, New South Wales, Australia
| | - Vedran Lovric
- Surgical and Orthopedic Research Laboratories, Prince of Wales Clinical School, University of New South Wales (UNSW Sydney), Sydney, New South Wales, Australia
| | - William R Walsh
- Surgical and Orthopedic Research Laboratories, Prince of Wales Clinical School, University of New South Wales (UNSW Sydney), Sydney, New South Wales, Australia
| | - Penny J Martens
- Graduate School of Biomedical Engineering, University of New South Wales (UNSW Sydney), Sydney, New South Wales, Australia
| | - Jamie J Kruzic
- School of Mechanical and Manufacturing Engineering, University of New South Wales (UNSW Sydney), Sydney, New South Wales, Australia
| | - Bernd Gludovatz
- School of Mechanical and Manufacturing Engineering, University of New South Wales (UNSW Sydney), Sydney, New South Wales, Australia
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6
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Kurtz T, Woitrain T, Godio-Raboutet Y, Ribeiro FLB, Arnoux PJ, Tailhan JL. Method for Evaluating Cortical Bone Young's Modulus: Numerical Twin Reconstruction, Finite Element Calculation, and Microstructure Analysis. J Biomech Eng 2023; 145:111013. [PMID: 37542711 DOI: 10.1115/1.4063100] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2023] [Accepted: 07/17/2023] [Indexed: 08/07/2023]
Abstract
The determination of bone mechanical properties remains crucial, especially to feed up numerical models. An original methodology of inverse analysis has been developed to determine the longitudinal elastic modulus of femoral cortical bone. The method is based on a numerical twin of a specific three-point bending test. It has been designed to be reproducible on each test result. In addition, the biofidelity of the geometric acquisition method has been quantified. As the assessment is performed at the scale of a bone shaft segment, the Young's modulus values obtained (between 9518.29 MPa and 14181.15 MPa) are considered average values for the whole tissue, highlighting some intersubject variability. The material microstructure has also been studied through histological analysis, and bone-to-bone comparisons highlighted discrepancies in quadrants microstructures. Furthermore, significant intrasubject variability exists since differences between the bone's medial-lateral and anterior-posterior quadrants have been observed. Thus, the study of microstructures can largely explain the differences between the elastic modulus values obtained. However, a more in-depth study of bone mineral density would also be necessary and would provide some additional information. This study is currently being setup, alongside an investigation of the local variations of the elastic modulus.
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Affiliation(s)
- T Kurtz
- Aix Marseille Univ, Univ Gustave Eiffel, LBA, Marseille 13015, France
| | - T Woitrain
- Aix Marseille Univ, Univ Gustave Eiffel, LBA, Marseille 13015, France
| | - Y Godio-Raboutet
- Aix Marseille Univ, Univ Gustave Eiffel, LBA, Marseille 13015, France
| | - F L B Ribeiro
- Department of Civil Engineering, COPPE, Federal University of Rio de Janeiro, Centro de Tecnologia - Ilha do Fundao, Rio de Janeiro 21941, Brazil
| | - P-J Arnoux
- Aix Marseille Univ, Univ Gustave Eiffel, LBA, Marseille 13015, France
| | - J-L Tailhan
- Univ Gustave Eiffel, MAST-EMGCU, Marne la Vallée 77454, France
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7
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Buccino F, Zagra L, Longo E, D'Amico L, Banfi G, Berto F, Tromba G, Vergani LM. Osteoporosis and Covid-19: Detected similarities in bone lacunar-level alterations via combined AI and advanced synchrotron testing. MATERIALS & DESIGN 2023; 231:112087. [PMID: 37323219 PMCID: PMC10257887 DOI: 10.1016/j.matdes.2023.112087] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/17/2023] [Revised: 05/03/2023] [Accepted: 06/09/2023] [Indexed: 06/17/2023]
Abstract
While advanced imaging strategies have improved the diagnosis of bone-related pathologies, early signs of bone alterations remain difficult to detect. The Covid-19 pandemic has brought attention to the need for a better understanding of bone micro-scale toughening and weakening phenomena. This study used an artificial intelligence-based tool to automatically investigate and validate four clinical hypotheses by examining osteocyte lacunae on a large scale with synchrotron image-guided failure assessment. The findings indicate that trabecular bone features exhibit intrinsic variability related to external loading, micro-scale bone characteristics affect fracture initiation and propagation, osteoporosis signs can be detected at the micro-scale through changes in osteocyte lacunar features, and Covid-19 worsens micro-scale porosities in a statistically significant manner similar to the osteoporotic condition. Incorporating these findings with existing clinical and diagnostic tools could prevent micro-scale damages from progressing into critical fractures.
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Affiliation(s)
- Federica Buccino
- Department of Mechanical Engineering, Politecnico di Milano, 20156, Italy
| | - Luigi Zagra
- I.R.C.C.S Ospedale Galeazzi - Sant'Ambrogio, Milano 20157, Italy
| | - Elena Longo
- Elettra-Sincrotrone Trieste SCpA, Basovizza, Trieste 34149, Italy
| | - Lorenzo D'Amico
- Elettra-Sincrotrone Trieste SCpA, Basovizza, Trieste 34149, Italy
| | - Giuseppe Banfi
- I.R.C.C.S Ospedale Galeazzi - Sant'Ambrogio, Milano 20157, Italy
| | - Filippo Berto
- Università La Sapienza, Rome 00185, Italy
- NTNU, Norway
| | - Giuliana Tromba
- Elettra-Sincrotrone Trieste SCpA, Basovizza, Trieste 34149, Italy
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8
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Albert DL, Katzenberger MJ, Hunter RL, Agnew AM, Kemper AR. Effects of loading rate, age, and morphology on the material properties of human rib trabecular bone. J Biomech 2023; 156:111670. [PMID: 37352737 DOI: 10.1016/j.jbiomech.2023.111670] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2022] [Revised: 04/21/2023] [Accepted: 06/01/2023] [Indexed: 06/25/2023]
Abstract
The material and morphometric properties of trabecular bone have been studied extensively in bones bearing significant weight, such as the appendicular long bones and spine. Less attention has been devoted to the ribs, where quantification of material properties is vital to understanding thoracic injury. The objective of this study was to quantify the compressive material properties of human rib trabecular bone and assess the effects of loading rate, age, and morphology on the material properties. Material properties were quantified via uniaxial compression tests performed on trabecular bone samples at two loading rates: 0.005 s-1 and 0.5 s-1. Morphometric parameters of each sample were quantified before testing using micro-computed tomography. Rib trabecular bone material properties were lower on average compared to trabecular bone from other anatomical locations. Morphometric parameters indicated an anisotropic structure with low connectivity and a sparser density of trabeculae in the rib compared to other locations. No significant differences in material properties were observed between the tested loading rates. Material properties were only significantly correlated with age at the 0.005 s-1 loading rate, and no morphometric parameter was significantly correlated with age. Trabecular separation and thickness were most strongly correlated with the material properties, indicating the sparser trabecular matrix likely contributed to the lower material property values compared to other sites. The novel trabecular bone material properties reported in this study can be used to improve the thoracic response and injury prediction of computational models.
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Affiliation(s)
- Devon L Albert
- Virginia Tech, Center for Injury Biomechanics, United States.
| | | | - Randee L Hunter
- The Ohio State University, Injury Biomechanics Research Center, United States
| | - Amanda M Agnew
- The Ohio State University, Injury Biomechanics Research Center, United States
| | - Andrew R Kemper
- Virginia Tech, Center for Injury Biomechanics, United States
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Haupt S, Cornaz F, Falkowski AL, Farshad M, Widmer J. The biomechanical consequence of posterior interventions at the thoracolumbar spine on the passively stabilized flexed posture. J Biomech 2023; 153:111599. [PMID: 37137272 DOI: 10.1016/j.jbiomech.2023.111599] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2022] [Revised: 03/28/2023] [Accepted: 04/21/2023] [Indexed: 05/05/2023]
Abstract
In the flexed end-of-range position (e.g., during slumped sitting), the trunk is passively stabilized. Little is known about the biomechanical consequence of posterior approaches on passive stabilization. The aim of this study is to investigate the effect of posterior surgical interventions on local and distant spinal regions. While being fixed at the pelvis, five human torsos were passively flexed. The change in spinal angulation at Th4, Th12, L4 and S1 was measured after level-wise longitudinal incisions of the thoracolumbar fascia, the paraspinal muscles, horizontal incisions of the inter- & supraspinous ligaments (ISL/SSL) and horizontal incision of the thoracolumbar fascia and the paraspinal muscles. Lumbar angulation (Th12-S1) was increased by 0.3° for fascia, 0.5° for muscle and 0.8° for ISL/SSL-incisions per lumbar level. The effect of level-wise incisions at the lumbar spine was 1.4, 3.5 and 2.6 times greater compared to thoracic interventions for fascia, muscle and ISL/SSL respectively. The combined midline interventions at the lumbar spine were associated with 2.2° extension of the thoracic spine. Horizontal incision of the fascia increased spinal angulation by 0.3°, while horizontal muscle incision resulted in a collapse of 4/5 specimens. The thoracolumbar fascia, the paraspinal muscle and the ISL/SSL are important passive stabilizers for the trunk in the flexed end-of-range position. Lumbar interventions needed for approaches to the spine have a larger effect on spinal posture than thoracic interventions and the increase of spinal angulation at the level of the intervention is partially compensated at the neighboring spinal regions.
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Affiliation(s)
- Samuel Haupt
- University Spine Center Zürich, Balgrist University Hospital, University of Zurich, Zurich, Switzerland.
| | - Frédéric Cornaz
- University Spine Center Zürich, Balgrist University Hospital, University of Zurich, Zurich, Switzerland; Spine Biomechanics, Department of Orthopedics, Balgrist University Hospital, Zurich, Switzerland
| | - Anna L Falkowski
- Radiology, Balgrist University Hospital, University of Zurich, Zurich, Switzerland
| | - Mazda Farshad
- University Spine Center Zürich, Balgrist University Hospital, University of Zurich, Zurich, Switzerland
| | - Jonas Widmer
- Spine Biomechanics, Department of Orthopedics, Balgrist University Hospital, Zurich, Switzerland
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10
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Schonhoff M, Beckmann NA, Schwarze M, Eissler M, Kretzer JP, Renkawitz T, Jaeger S. Is TKA femoral implant stability improved by pressure applied cement? a comparison of 2 cementing techniques. BMC Musculoskelet Disord 2023; 24:51. [PMID: 36670400 PMCID: PMC9863212 DOI: 10.1186/s12891-023-06151-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/02/2022] [Accepted: 01/09/2023] [Indexed: 01/22/2023] Open
Abstract
BACKGROUND The majority of knee endoprostheses are cemented. In an earlier study the effects of different cementing techniques on cement penetration were evaluated using a Sawbone model. In this study we used a human cadaver model to study the effect of different cementing techniques on relative motion between the implant and the femoral shaft component under dynamic loading. METHODS Two different cementing techniques were tested in a group of 15 pairs of human fresh frozen legs. In one group a conventional cementation technique was used and, in another group, cementation was done using a pressurizing technique. Under dynamic loading that simulated real life conditions relative motion at the bone-implant interface were studied at 20 degrees and 50 degrees flexion. RESULTS In both scenarios, the relative motion anterior was significantly increased by pressure application. Distally, it was the same with higher loads. No significant difference could be measured posteriorly at 20°. At 50° flexion, however, pressurization reduced the posterior relative motion significantly at each load level. CONCLUSION The use of the pressurizer does not improve the overall fixation compared to an adequate manual cement application. The change depends on the loading, flexion angle and varies in its proportion in between the interface zones.
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Affiliation(s)
- Mareike Schonhoff
- grid.5253.10000 0001 0328 4908Laboratory of Biomechanics and Implant Research, Department of Orthopaedics, Heidelberg University Hospital, 69118 Heidelberg, Germany
| | - Nicholas A. Beckmann
- grid.5253.10000 0001 0328 4908Department of Orthopaedics, Heidelberg University Hospital, 69118 Heidelberg, Germany
| | - Martin Schwarze
- grid.5253.10000 0001 0328 4908Laboratory of Biomechanics and Implant Research, Department of Orthopaedics, Heidelberg University Hospital, 69118 Heidelberg, Germany
| | - Marvin Eissler
- grid.5253.10000 0001 0328 4908Department of Diagnostic and Interventional Radiology, Heidelberg University Hospital, Heidelberg, Germany
| | - J. Philippe Kretzer
- grid.5253.10000 0001 0328 4908Laboratory of Biomechanics and Implant Research, Department of Orthopaedics, Heidelberg University Hospital, 69118 Heidelberg, Germany
| | - Tobias Renkawitz
- grid.5253.10000 0001 0328 4908Department of Orthopaedics, Heidelberg University Hospital, 69118 Heidelberg, Germany
| | - Sebastian Jaeger
- grid.5253.10000 0001 0328 4908Laboratory of Biomechanics and Implant Research, Department of Orthopaedics, Heidelberg University Hospital, 69118 Heidelberg, Germany
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11
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Lee H, Kim SA, Jo S, Jo S. Biomechanical analysis analyzing association between bone mineral density and lag screw migration. Sci Rep 2023; 13:747. [PMID: 36639718 PMCID: PMC9839704 DOI: 10.1038/s41598-023-27860-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2022] [Accepted: 01/09/2023] [Indexed: 01/15/2023] Open
Abstract
A proximal femoral nail using a helical blade (HB) is commonly utilized to treat proximal femoral fracture but cut through failure of the lag screws is one of the devastating complications following the surgery. While controversial, one of the potential risk factors for cut through failure is poor bone strength which can be predicted by measuring bone mineral density (BMD). In this study, we performed a biomechanical test on the fractured femoral head to validate whether the indirectly measured BMD from the contralateral hip or that measured directly from the retrieved femoral head can elucidate the structural strength of the fractured femoral head and thereby can be used to predict migration of lag screws. Our result showed that directly measured BMD has a significant correlation with the HB migration on the osteoporotic femoral head. However, while the BMDs measured from the contralateral femoral neck or total hip is the most widely used parameter to predict the bone strength of the fractured femur, this may have limited usability to predict HB migration.
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Affiliation(s)
- Hyeonjoon Lee
- Department of Orthopedic Surgery, Chosun University Hospital, Gwangju, South Korea
| | - Soo Ah Kim
- School of Medicine, Chosun University, 365 Pilmundae-Ro, Dong-Gu, Gwangju, 61453, South Korea.,Osteoporosis Study Group, Chosun University, Gwangju, South Korea.,Department of Obstetrics and Gynecology, Chosun University, Gwangju, South Korea
| | - Sungmin Jo
- Department of Orthopedic Surgery, Chosun University Hospital, Gwangju, South Korea
| | - Suenghwan Jo
- Department of Orthopedic Surgery, Chosun University Hospital, Gwangju, South Korea. .,School of Medicine, Chosun University, 365 Pilmundae-Ro, Dong-Gu, Gwangju, 61453, South Korea. .,Osteoporosis Study Group, Chosun University, Gwangju, South Korea.
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12
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Wang F, Metzner F, Osterhoff G, Zheng L, Schleifenbaum S. The role of bone marrow on the mechanical properties of trabecular bone: a systematic review. Biomed Eng Online 2022; 21:80. [PMID: 36419171 PMCID: PMC9686043 DOI: 10.1186/s12938-022-01051-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2022] [Accepted: 11/10/2022] [Indexed: 11/26/2022] Open
Abstract
Background Accurate evaluation of the mechanical properties of trabecular bone is important, in which the internal bone marrow plays an important role. The aim of this systematic review is to investigate the roles of bone marrow on the mechanical properties of trabecular bone to better support clinical work and laboratory research. Methods A systematic review of the literature published up to June 2022 regarding the role of bone marrow on the mechanical properties of trabecular bone was performed, using PubMed and Web of Science databases. The journal language was limited to English. A total of 431 articles were selected from PubMed (n = 186), Web of Science (n = 244) databases, and other sources (n = 1). Results After checking, 38 articles were finally included in this study. Among them, 27 articles discussed the subject regarding the hydraulic stiffening of trabecular bone due to the presence of bone marrow. Nine of them investigated the effects of bone marrow on compression tests with different settings, i.e., in vitro experiments under unconfined and confined conditions, and computer model simulations. Relatively few controlled studies reported the influence of bone marrow on the shear properties of trabecular bone. Conclusion Bone marrow plays a non-neglectable role in the mechanical properties of trabecular bone, its contribution varies depending on the different loading types and test settings. To obtain the mechanical properties of trabecular bone comprehensively and accurately, the solid matrix (trabeculae) and fluid-like component (bone marrow) should be considered in parallel rather than tested separately. Supplementary Information The online version contains supplementary material available at 10.1186/s12938-022-01051-1.
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Affiliation(s)
- Fangxing Wang
- grid.9647.c0000 0004 7669 9786ZESBO - Center for Research on Musculoskeletal Systems, Department of Orthopedic Surgery, Traumatology and Plastic Surgery, Leipzig University, Semmelweisstraße 14, 04103 Leipzig, Germany ,grid.9647.c0000 0004 7669 9786Department of Orthopedic Surgery, Traumatology and Plastic Surgery, Leipzig University, Liebigstraße 20 Haus 4, 04103 Leipzig, Germany
| | - Florian Metzner
- grid.9647.c0000 0004 7669 9786ZESBO - Center for Research on Musculoskeletal Systems, Department of Orthopedic Surgery, Traumatology and Plastic Surgery, Leipzig University, Semmelweisstraße 14, 04103 Leipzig, Germany ,grid.9647.c0000 0004 7669 9786Department of Orthopedic Surgery, Traumatology and Plastic Surgery, Leipzig University, Liebigstraße 20 Haus 4, 04103 Leipzig, Germany
| | - Georg Osterhoff
- grid.9647.c0000 0004 7669 9786Department of Orthopedic Surgery, Traumatology and Plastic Surgery, Leipzig University, Liebigstraße 20 Haus 4, 04103 Leipzig, Germany
| | - Leyu Zheng
- grid.9647.c0000 0004 7669 9786Department of Orthopedic Surgery, Traumatology and Plastic Surgery, Leipzig University, Liebigstraße 20 Haus 4, 04103 Leipzig, Germany
| | - Stefan Schleifenbaum
- grid.9647.c0000 0004 7669 9786ZESBO - Center for Research on Musculoskeletal Systems, Department of Orthopedic Surgery, Traumatology and Plastic Surgery, Leipzig University, Semmelweisstraße 14, 04103 Leipzig, Germany ,grid.9647.c0000 0004 7669 9786Department of Orthopedic Surgery, Traumatology and Plastic Surgery, Leipzig University, Liebigstraße 20 Haus 4, 04103 Leipzig, Germany
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13
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Sosa EM, Moure MM. Mechanical Characterization of Synthetic Gels for Creation of Surrogate Hands Subjected to Low-Velocity Impacts. Gels 2022; 8:gels8090559. [PMID: 36135273 PMCID: PMC9498611 DOI: 10.3390/gels8090559] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2022] [Revised: 08/18/2022] [Accepted: 08/31/2022] [Indexed: 11/24/2022] Open
Abstract
The development of human body simulators that can be used as surrogates for testing protective devices and measures requires selecting synthetic materials with mechanical properties closely representative of the human tissues under consideration. For impact tests, gelatinous materials are often used to represent the soft tissues as a whole without distinguishing layers such as skin, fat, or muscles. This research focuses on the mechanical characterization of medical-grade synthetic gels that can be implemented to represent the soft tissues of the hand. Six grades of commercially available gels are selected for quasi-static hardness and firmness tests as well as for controlled low-velocity impact tests, which are not routinely conducted by gel manufacturers and require additional considerations such as energy level and specimen sizes relevant to the specific application. Specimens subject to impacts represent the hand thicknesses at the fingers, knuckles, and mid-metacarpal regions. Two impact test configurations are considered: one with the gel specimens including a solid insert representing a bone and one without this insert. The impact behavior of the candidate gels is evaluated by the coefficient of restitution, the energy loss percentage, and the peak reaction force at the time of impact. The resulting values are compared with similar indicators reported for experiments with cadaveric hands. Relatively softer gels, characterized by Shore OOO hardness in the range of 32.6 ± 0.9 to 34.4 ± 2.0, closely matched the impact behavior of cadaveric specimens. These results show that softer gels would be the most suitable gels to represent soft tissues in the creation of surrogate hands that can be used for extensive impact testing, thus, minimizing the need for cadaveric specimens.
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Affiliation(s)
- Eduardo M. Sosa
- Department of Mechanical and Aerospace Engineering, West Virginia University, Morgantown, WV 26506, USA
- Correspondence:
| | - Marta M. Moure
- Aerospace Systems and Transport Research Group, Rey Juan Carlos University, 28942 Fuenlabrada, Madrid, Spain
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Zhalniarovich Y, Przyborowska-Zhalniarovich P, Tobolska A, Mieszkowska M, Abako J, Morawska-Kozłowska M, Mieszkowski M, Onichimowski D. Mechanical Testing of the New Cage for Tibial Tuberosity Advancement with the Cranial Implant Fixation (TTA CF) Technique—Ex Vivo Study on Sheep Model. Animals (Basel) 2022; 12:ani12162013. [PMID: 36009606 PMCID: PMC9404418 DOI: 10.3390/ani12162013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2022] [Revised: 08/02/2022] [Accepted: 08/05/2022] [Indexed: 11/16/2022] Open
Abstract
Simple Summary Tibial tuberosity advancement is a method of surgical treatment of cranial cruciate ligament rupture in animals.. In previous reports, the biomechanical effectiveness of tibial tuberosity advancement surgeries was evaluated by axial pressure on the tibial tuberosity to test the strength and resistance of the fixation or by pulling on the tuberosity. To our knowledge, there are no reports that examined the strength that is needed to pull out an implant from the tibia after tibial advancement. This study is the first report that focuses on pulling out the TTA implant, which corresponds to the biointegrity and ingrowth of the TTA cage with the tibia. Abstract Background: Modifications of tibial tuberosity advancement are well accepted for cranial cruciate rupture repair. We compared the loads that were needed to pull the TTA CF cage out in the two groups. The first group consisted of five sheep in which osteotomy and TTA CF cage fixation were performed as assumed preoperatively. The second group consisted of five sheep in which intraoperative or postoperative discrepancies from preoperative planning were found. This is also the first report describing biomechanical testing after tibial tuberosity advancement with cranial implant fixation (TTA CF) surgical procedures. Results: A total of 10 ovine proximal tibiae were tested biomechanically by tearing out TTA CF implants from the bone. The mean maximal loaded forces to pull out the cage in Group 1, in which fixation of the implant was performed as assumed preoperatively, was 878 ± 61 N, and in Group 2, in which discrepancies from preoperative planning were found, was 330 ± 55 N. The mean implant displacement under maximal load to failure was 2.6 mm and 2.2 mm in Groups 1 and 2, respectively. There was a significant difference between Group 1 and Group 2 in the maximal loads-to-failure; however, the difference in the displacement at maximal loaded forces to pull out the cage was not significant between the groups. Conclusions: The mean maximal loaded forces to pull out the cage was significantly lower in Group 2, where discrepancies from preoperative planning were found (878 ± 61 N vs. 330 ± 55 N). The lower forces that were needed to extract the TTA CF implant from the tibia can lead to the conclusion that biointegration of the implant is also weaker. Correct positioning of the osteotomy line and TTA CF implant is essential for good biointegrity and thus for limiting complications in the form of tibial tuberosity avulsion fracture or tibial shaft fracture.
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Affiliation(s)
- Yauheni Zhalniarovich
- Department of Surgery and Radiology, Faculty of Veterinary Medicine, University of Warmia and Mazury in Olsztyn, Oczapowskiego 14, 10-718 Olsztyn, Poland
- Correspondence: (Y.Z.); (M.M.-K.)
| | - Paulina Przyborowska-Zhalniarovich
- Department of Surgery and Radiology, Faculty of Veterinary Medicine, University of Warmia and Mazury in Olsztyn, Oczapowskiego 14, 10-718 Olsztyn, Poland
| | - Angelika Tobolska
- Department of Surgery and Radiology, Faculty of Veterinary Medicine, University of Warmia and Mazury in Olsztyn, Oczapowskiego 14, 10-718 Olsztyn, Poland
| | - Marta Mieszkowska
- Department of Surgery and Radiology, Faculty of Veterinary Medicine, University of Warmia and Mazury in Olsztyn, Oczapowskiego 14, 10-718 Olsztyn, Poland
| | - Justyna Abako
- Department of Surgery and Radiology, Faculty of Veterinary Medicine, University of Warmia and Mazury in Olsztyn, Oczapowskiego 14, 10-718 Olsztyn, Poland
| | - Magdalena Morawska-Kozłowska
- Department of Surgery and Radiology, Faculty of Veterinary Medicine, University of Warmia and Mazury in Olsztyn, Oczapowskiego 14, 10-718 Olsztyn, Poland
- Correspondence: (Y.Z.); (M.M.-K.)
| | - Marcin Mieszkowski
- Department of Anesthesiology and Intensive Care, School of Medicine, Collegium Medicum, University of Warmia and Mazury in Olsztyn, Warszawska 30, 11-082 Olsztyn, Poland
| | - Dariusz Onichimowski
- Department of Anesthesiology and Intensive Care, School of Medicine, Collegium Medicum, University of Warmia and Mazury in Olsztyn, Warszawska 30, 11-082 Olsztyn, Poland
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15
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Wang F, Metzner F, Zheng L, Osterhoff G, Schleifenbaum S. Selected mechanical properties of human cancellous bone subjected to different treatments: short-term immersion in physiological saline and acetone treatment with subsequent immersion in physiological saline. J Orthop Surg Res 2022; 17:376. [PMID: 35933396 PMCID: PMC9357305 DOI: 10.1186/s13018-022-03265-4] [Citation(s) in RCA: 4] [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: 05/18/2022] [Accepted: 07/22/2022] [Indexed: 11/10/2022] Open
Abstract
Background Physiological saline (0.9% NaCl) and acetone are extensively used for storage (as well as hydration) and removal of bone marrow, respectively, of cancellous bone during preparation and mechanical testing. Our study aimed to investigate the mechanical properties of cancellous bone subjected to short-term immersion in saline and acetone treatment with subsequent immersion in saline. Methods Cylindrical samples (Ø6 × 12 mm) were harvested from three positions (left, middle, and right) of 1 thoracic vertebral body, 19 lumbar vertebral bodies, and 5 sacral bones, as well as from 9 femoral heads. All samples were divided into two groups according to the different treatments, (i) samples from the left and middle sides were immersed in saline at 4℃ for 43 h (saline-immersed group, n = 48); (ii) samples from the respective right side were treated with a combination of acetone and ultrasonic bath (4 h), air-dried at room temperature (21℃, 15 h), and then immersed in saline at room temperature (21℃, 24 h) (acetone and saline-treated group, n = 38). All samples were subjected, both before and after treatment, to a non-destructive compression test with a strain of 0.45%, and finally destructive tests with a strain of 50%. Actual density (ρact), initial modulus (E0), maximum stress (σmax), energy absorption (W), and plateau stress (σp) were calculated as evaluation indicators. Results Based on visual observation, a combination of acetone and ultrasonic bath for 4 h failed to completely remove bone marrow from cancellous bone samples. The mean values of ρact, σmax, W, and σp were significantly higher in the femoral head than in the spine. There was no significant difference in E0 between non-treated and saline-immersed samples (non-treated 63.98 ± 20.23 vs. saline-immersed 66.29 ± 20.61, p = 0.132). The average E0 of acetone and saline-treated samples was significantly higher than that of non-treated ones (non-treated 62.17 ± 21.08 vs. acetone and saline-treated 74.97 ± 23.98, p = 0.043). Conclusion Short-term storage in physiological saline is an appropriate choice and has no effect on the E0 of cancellous bone. Treatment of cancellous bone with acetone resulted in changes in mechanical properties that could not be reversed by subsequent immersion in physiological saline. Supplementary Information The online version contains supplementary material available at 10.1186/s13018-022-03265-4.
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Affiliation(s)
- Fangxing Wang
- ZESBO - Center for Research on Musculoskeletal Systems, Department of Orthopedic Surgery, Traumatology and Plastic Surgery, Leipzig University, Semmelweisstraße 14, 04103, Leipzig, Germany. .,Department of Orthopedic Surgery, Traumatology and Plastic Surgery, Leipzig University, Liebigstraße. 20 Haus 4, 04103, Leipzig, Germany.
| | - Florian Metzner
- ZESBO - Center for Research on Musculoskeletal Systems, Department of Orthopedic Surgery, Traumatology and Plastic Surgery, Leipzig University, Semmelweisstraße 14, 04103, Leipzig, Germany.,Department of Orthopedic Surgery, Traumatology and Plastic Surgery, Leipzig University, Liebigstraße. 20 Haus 4, 04103, Leipzig, Germany
| | - Leyu Zheng
- Department of Orthopedic Surgery, Traumatology and Plastic Surgery, Leipzig University, Liebigstraße. 20 Haus 4, 04103, Leipzig, Germany
| | - Georg Osterhoff
- Department of Orthopedic Surgery, Traumatology and Plastic Surgery, Leipzig University, Liebigstraße. 20 Haus 4, 04103, Leipzig, Germany
| | - Stefan Schleifenbaum
- ZESBO - Center for Research on Musculoskeletal Systems, Department of Orthopedic Surgery, Traumatology and Plastic Surgery, Leipzig University, Semmelweisstraße 14, 04103, Leipzig, Germany.,Department of Orthopedic Surgery, Traumatology and Plastic Surgery, Leipzig University, Liebigstraße. 20 Haus 4, 04103, Leipzig, Germany
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16
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Koser J, Chirvi S, Banerjee A, Pintar FA, Hampton C, Kleinberger M. Repeated measures analysis of projectile penetration in porcine legs as a function of storage condition. J Forensic Leg Med 2022; 90:102395. [PMID: 35863258 DOI: 10.1016/j.jflm.2022.102395] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2022] [Revised: 06/27/2022] [Accepted: 06/28/2022] [Indexed: 12/30/2022]
Abstract
Buried blast explosions create small projectiles which can become lodged in the tissue of personnel as far away as hundreds of meters. Without appropriate treatment, these lodged projectiles can become a source of infection and prolonged injury to soldiers in modern combat. Human cadavers can be used as surrogates for living humans for ballistic penetration testing, but human cadavers are frozen during transport and storage. The process of freezing and thawing the tissue before testing may change the biomechanical properties of the tissue. The goal of the current study was to understand penetration threshold differences between fresh, refrigerated, and frozen tissue and investigate factors that may contribute to these differences. A custom-built pneumatic launcher was used to accelerate 3/16″ stainless steel ball bearings toward porcine legs that were either tested fresh, following refrigerated storage, or following frozen storage. A generalized linear mixed model, accounting for within-animal dependence, owing to repeated observations, was found to be the most appropriate for these data and was used for analysis. The "generalized" model accommodated non-continuous observations, provided a straight-forward way to implement the repeated measures, and provided a risk estimate for projectile penetration. Both storage condition (p = 0.48) and leg (p = 0.07) were shown to be not significant and the confidence intervals for those variables were overlapping. As all covariates were found to be non-significant, a single model containing all impacts was used to develop a V50, or velocity at which 50% of impacts are expected to penetrate. From this model, 50% probability of penetration occurs at 137.3 m/s with 95% confidence intervals at 132.0 and 144.0 m/s. In this study, the fresh legs and previously frozen legs allowed penetration at similar velocities indicating that previously frozen legs were acceptable surrogates for fresh legs. This study only compared the penetration threshold in tissues that had been stored in differing conditions. To truly study penetration, more conditions will need to be studied including the effects of projectile mass and material, the effects of projectile shape, and the effects of clothing or protective layers on penetration threshold.
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Affiliation(s)
- Jared Koser
- Medical College of Wisconsin, Milwaukee, WI, USA; Zablocki Veterans Affairs Medical Center, Milwaukee, WI, USA; Marquette University, Milwaukee, WI, USA.
| | - Sajal Chirvi
- Medical College of Wisconsin, Milwaukee, WI, USA; Zablocki Veterans Affairs Medical Center, Milwaukee, WI, USA
| | | | - Frank A Pintar
- Medical College of Wisconsin, Milwaukee, WI, USA; Zablocki Veterans Affairs Medical Center, Milwaukee, WI, USA; Marquette University, Milwaukee, WI, USA
| | - Carolyn Hampton
- DEVCOM Army Research Laboratory, Aberdeen Proving Ground, MD, USA
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Klinger S, Greinwald M, Augat P, Hollensteiner M. Mechanical and morphometric characterization of custom-made trabecular bone surrogates. J Mech Behav Biomed Mater 2022; 129:105146. [PMID: 35247861 DOI: 10.1016/j.jmbbm.2022.105146] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2021] [Revised: 10/14/2021] [Accepted: 02/26/2022] [Indexed: 10/19/2022]
Abstract
Synthetic bones for biomechanical testing and surgeon training have become more important due to their numerous advantages compared to human bones. Several bone models are already available on the market, but most of them do not reflect the full range of versatile properties that characterize human bone like population-level influences, size, stiffness, bone-implant-interface or morphometry. Thus, the objectives of this study were to develop synthetic trabecular bone surrogates from polyurethane and varying additives and to determine their elastic and plastic mechanical compressive and additionally morphometric properties. Another aim was to investigate the influence of varying additives on aforementioned properties and finally compare the results with published data from human trabecular bone. Additives used were blowing agents to create a porous structure, mineral fillers to manipulate the basic polyurethane resin, and cell stabilizers to achieve an open porous composition. Mechanical properties were obtained from static compression tests until failure while morphometric analysis was carried out using microcomputed tomography. Thereby, the blowing agent showed the strongest influence on mechanical and morphometric properties with mean Young's moduli ranging from 627 ± 37 MPa (0% blowing agent) to 154 ± 15 MPa (0.25% blowing agent) while the variation of mineral filler content resulted in small standard deviations of approximately 10-20 MPa with a constant proportion of blowing agent. The achieved mechanical properties of the developed synthetic bones, such as the Young's modulus, ultimate stress and yield stress were in accordance with human trabecular bone, while yield strain for all groups was noticeably higher compared to human trabecular bone. Additionally, morphometric analysis showed results indicating similar morphometry of the custom-made synthetic bone and human cancellous bone. Although recreating bone structures in physiological conditions is not simple, the results of the current study show the possibility of developing synthetic bone materials with characteristics like human trabecular bone.
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Affiliation(s)
- Simon Klinger
- Institute for Biomechanics, BG Unfallklinik Murnau and Paracelsus Medical University Salzburg, Prof.-Küntscher-Straße 8, 82418, Murnau, Germany; Ostbayerische Technische Hochschule Regensburg, Galgenbergstraße 30, 93053, Regensburg, Germany
| | - Markus Greinwald
- Institute for Biomechanics, BG Unfallklinik Murnau and Paracelsus Medical University Salzburg, Prof.-Küntscher-Straße 8, 82418, Murnau, Germany
| | - Peter Augat
- Institute for Biomechanics, BG Unfallklinik Murnau and Paracelsus Medical University Salzburg, Prof.-Küntscher-Straße 8, 82418, Murnau, Germany
| | - Marianne Hollensteiner
- Institute for Biomechanics, BG Unfallklinik Murnau and Paracelsus Medical University Salzburg, Prof.-Küntscher-Straße 8, 82418, Murnau, Germany.
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Schröder G, Reichel M, Spiegel S, Schulze M, Götz A, Bugaichuk S, Andresen JR, Kullen CM, Andresen R, Schober HC. Breaking strength and bone microarchitecture in osteoporosis: a biomechanical approximation based on load tests in 104 human vertebrae from the cervical, thoracic, and lumbar spines of 13 body donors. J Orthop Surg Res 2022; 17:228. [PMID: 35410435 PMCID: PMC8996654 DOI: 10.1186/s13018-022-03105-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/31/2021] [Accepted: 03/29/2022] [Indexed: 11/24/2022] Open
Abstract
Background The purpose of the study was to investigate associations between biomechanical resilience (failure load, failure strength) and the microarchitecture of cancellous bone in the vertebrae of human cadavers with low bone density with or without vertebral fractures (VFx). Methods Spines were removed from 13 body donors (approval no. A 2017-0072) and analyzed in regard to bone mineral density (BMD), Hounsfield units (HU), and fracture count (Fx) with the aid of high-resolution CT images. This was followed by the puncture of cancellous bone in the vertebral bodies of C2 to L5 using a Jamshidi™ needle. The following parameters were determined on the micro-CT images: bone volume fraction (BVF), trabecular thickness (Tb.Th), trabecular separation (Tb.Sp), degree of anisotropy (DA), trabecular number (Tb.N), trabecular pattern factor (Tb.Pf), and connectivity density (Conn.D). The axial load behavior of 104 vertebral specimens (C5, C6, T7, T8, T9, T12, L1, L3) was investigated with a servohydraulic testing machine. Results Individuals with more than 2 fractures had a significantly lower trabecular pattern factor (Tb.Pf), which also proved to be an important factor for a reduced failure load in the regression analysis with differences between the parts of the spine. The failure load (FL) and endplate sizes of normal vertebrae increased with progression in the craniocaudal direction, while the HU was reduced. Failure strength (FS) was significantly greater in the cervical spine than in the thoracic or lumbar spine (p < 0.001), independent of sex. BVF, Tb.Th, Tb.N, and Conn.D were significantly higher in the cervical spine than in the other spinal segments. In contrast, Tb.Sp and Tb.Pf were lowest in the cervical spine. BVF was correlated with FL (r = 0.600, p = 0.030) and FS (r = 0.763, p = 0.002). Microarchitectural changes were also detectable in the cervical spine at lower densities. Conclusions Due to the unique microarchitecture of the cervical vertebrae, fractures occur much later in this region than they do in the thoracic or lumbar spine. Trial registration Approval no. A 2017-0072.
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Gupta SD, Workman J, Finnilä MA, Saarakkala S, Thambyah A. Subchondral bone plate thickness is associated with micromechanical and microstructural changes in the bovine patella osteochondral junction with different levels of cartilage degeneration. J Mech Behav Biomed Mater 2022; 129:105158. [PMID: 35279448 DOI: 10.1016/j.jmbbm.2022.105158] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2021] [Revised: 10/07/2021] [Accepted: 02/27/2022] [Indexed: 10/19/2022]
Abstract
The influence of joint degeneration on the biomechanical properties of calcified cartilage and subchondral bone plate at the osteochondral junction is relatively unknown. Common experimental difficulties include accessibility to and visualization of the osteochondral junction, application of mechanical testing at the appropriate length scale, and availability of tissue that provides a consistent range of degenerative changes. This study addresses these challenges. A well-established bovine patella model of early joint degeneration was employed, in which micromechanical testing of fully hydrated osteochondral sections was carried out in conjunction with high-resolution imaging using differential interference contrast (DIC) optical light microscopy. A total of forty-two bovine patellae with different grades of tissue health ranging from healthy to mild, moderate, and severe cartilage degeneration, were selected. From the distal-lateral region of each patella, two adjacent osteochondral sections were obtained for the mechanical testing and the DIC imaging, respectively. Mechanical testing was carried out using a robotic micro-force acquisition system, applying compression tests over an array (area: 200 μm × 1000 μm, step size: 50 μm) across the osteochondral junction to obtain a stiffness map. Morphometric analysis was performed for the DIC images of fully hydrated cryo-sections. The levels of cartilage degeneration, DIC images, and the stiffness maps were used to associate the mechanical properties onto the specific tissue regions of cartilage, calcified cartilage, and subchondral bone plate. The results showed that there were up to 20% and 24% decreases (p < 0.05) in the stiffness of calcified cartilage and subchondral bone plate, respectively, in the severely degenerated group compared to the healthy group. Furthermore, there were increases (p < 0.05) in the number of tidemarks, bone spicules at the cement line, and the mean thickness of the subchondral bone plate with increasing levels of degeneration. The decreasing stiffness in the subchondral bone plate coupled with the presence of bone spicules may be indicative of a subchondral remodeling process involving new bone formation. Moreover, the mean thickness of the subchondral bone plate was found to be the strongest indicator of mechanical and associated structural changes in the osteochondral joint tissues.
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Ding M, Overgaard S. Degenerations in Global Morphometry of Cancellous Bone in Rheumatoid Arthritis, Osteoarthritis and Osteoporosis of Femoral Heads are Similar but More Severe than in Ageing Controls. Calcif Tissue Int 2022; 110:57-64. [PMID: 34244838 DOI: 10.1007/s00223-021-00889-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/19/2021] [Accepted: 07/03/2021] [Indexed: 10/20/2022]
Abstract
We have recently revealed significant differences in microarchitectural properties (i.e. global and local morphometries) and mechanical properties between rheumatoid arthritis (RA), osteoarthritis (OA) and osteoporosis (OP) in cancellous bones. This study compared these properties with those of ageing controls by matching bone volume fraction (BV/TV), the most important determinant for bones' mechanical properties, to investigate whether these bones have similar properties and degenerative potentials. RA, OA and OP femoral heads were harvested from patients undergoing total hip replacement surgery. The selected patients were matched by similar cancellous bone BV/TV, with seven patients in each group. Four samples were prepared from each femoral head and scanned with micro-CT to quantify microarchitectural properties and compression tested to determine mechanical properties. In terms of global morphometry, no significant differences were observed between these diseased bones. In terms of local morphometry, the number of plates in the RA group was significantly greater than that of the OP and control groups. Plate volume density in the RA group was significantly greater than in the control group. Interestingly, the ultimate stresses in the three diseased groups were 77% to 195% lower than in the control group (p < 0.001). Degenerations of global morphometry of cancellous bones in these diseased femoral heads are similar but more severe than in ageing controls matched by BV/TV, as evidenced by pronounced reduction in bone strength. This phenomenon suggests that some local morphometric parameters, along with other factors, such as abnormal collagen, mineralisation, erosion and microdamage, may contribute to further compromising mechanical properties.
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Affiliation(s)
- Ming Ding
- Orthopaedic Research Laboratory, Department of Orthopaedic Surgery & Traumatology, Odense University Hospital, J.B. Winsloewsvej 15, 3rd Floor, 5000, Odense, Denmark.
- Department of Clinical Research, University of Southern Denmark, 5000, Odense, Denmark.
| | - Søren Overgaard
- Orthopaedic Research Laboratory, Department of Orthopaedic Surgery & Traumatology, Odense University Hospital, J.B. Winsloewsvej 15, 3rd Floor, 5000, Odense, Denmark
- Department of Clinical Research, University of Southern Denmark, 5000, Odense, Denmark
- Department of Orthopaedic Surgery & Traumatology, Copenhagen University Hospital, Bispebjerg, 2400, Copenhagen, Denmark
- Department of Clinical Medicine, University of Copenhagen, 2400, Copenhagen, Denmark
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21
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Spartacus V, Shojaeizadeh M, Raffault V, Shoults J, Van Wieren K, Sparrey CJ. In vivo soft tissue compressive properties of the human hand. PLoS One 2021; 16:e0261008. [PMID: 34898632 PMCID: PMC8668133 DOI: 10.1371/journal.pone.0261008] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2021] [Accepted: 11/22/2021] [Indexed: 12/25/2022] Open
Abstract
Background/Purpose Falls onto outstretched hands are the second most common sports injury and one of the leading causes of upper extremity injury. Injury risk and severity depends on forces being transmitted through the palmar surface to the upper extremity. Although the magnitude and distribution of forces depend on the soft tissue response of the palm, the in vivo properties of palmar tissue have not been characterized. The purpose of this study was to characterize the large deformation palmar soft tissue properties. Methods In vivo dynamic indentations were conducted on 15 young adults (21–29 years) to quantify the soft tissue characteristics of over the trapezium. The effects of loading rate, joint position, tissue thickness and sex on soft tissue responses were assessed. Results Energy absorbed by the soft tissue and peak force were affected by loading rate and joint angle. Energy absorbed was 1.7–2.8 times higher and the peak force was 2–2.75 times higher at high rate loading than quasistatic rates. Males had greater energy absorbed than females but not at all wrist positions. Damping characteristics were the highest in the group with the thickest soft tissue while damping characteristics were the lowest in group with the thinnest soft tissues. Conclusion Palmar tissue response changes with joint position, loading rate, sex, and tissue thickness. Accurately capturing these tissue responses is important for developing effective simulations of fall and injury biomechanics and assessing the effectiveness of injury prevention strategies.
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Affiliation(s)
- Victoria Spartacus
- Mechatronic Systems Engineering, Simon Fraser University, Surrey, British Columbia, Canada
- * E-mail:
| | - Maedeh Shojaeizadeh
- Mechatronic Systems Engineering, Simon Fraser University, Surrey, British Columbia, Canada
| | - Vincent Raffault
- Mechatronic Systems Engineering, Simon Fraser University, Surrey, British Columbia, Canada
| | - James Shoults
- Science Technical Center, Simon Fraser University, Burnaby, BC, Canada
| | - Ken Van Wieren
- Science Technical Center, Simon Fraser University, Burnaby, BC, Canada
| | - Carolyn J. Sparrey
- Mechatronic Systems Engineering, Simon Fraser University, Surrey, British Columbia, Canada
- International Collaboration on Repair Discoveries (ICORD), Vancouver, British Columbia, Canada
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22
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Spiegl UJ, Weidling M, Nitsch V, Heilmann R, Heilemann M, Wendler T, Schleifenbaum S, Reinhardt M, Heyde CE. Restricted cement augmentation in unstable geriatric midthoracic fractures treated by long-segmental posterior stabilization leads to a comparable construct stability. Sci Rep 2021; 11:23816. [PMID: 34893697 PMCID: PMC8664925 DOI: 10.1038/s41598-021-03336-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2021] [Accepted: 11/24/2021] [Indexed: 11/23/2022] Open
Abstract
The goal of this study is to compare the construct stability of long segmental dorsal stabilization in unstable midthoracic osteoporotic fractures with complete pedicle screw cement augmentation (ComPSCA) versus restricted pedicle screw cement augmentation (ResPSCA) of the most cranial and caudal pedicle screws under cyclic loading. Twelve fresh frozen human cadaveric specimens (Th4–Th10) from individuals aged 65 years and older were tested in a biomechanical cadaver study. All specimens received a DEXA scan and computer tomography (CT) scan prior to testing. All specimens were matched into pairs. These pairs were randomized into the ComPSCA group and ResPSCA group. An unstable Th7 fracture was simulated. Periodic bending in flexion direction with a torque of 2.5 Nm and 25,000 cycles was applied. Markers were applied to the vertebral bodies to measure segmental movement. After testing, a CT scan of all specimens was performed. The mean age of the specimens was 87.8 years (range 74–101). The mean T-score was − 3.6 (range − 1.2 to − 5.3). Implant failure was visible in three specimens, two of the ComPSCA group and one of the ResPSCA group, affecting only one pedicle screw in each case. Slightly higher segmental movement could be evaluated in these three specimens. No further statistically significant differences were observed between the study groups. The construct stability under cyclic loading in flexion direction of long segmental posterior stabilization of an unstable osteoporotic midthoracic fracture using ResPSCA seems to be comparable to ComPSCA.
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Affiliation(s)
- Ulrich J Spiegl
- Department of Orthopaedic, Trauma and Plastic Surgery, University Hospital Leipzig, Liebigstr. 20, 04103, Leipzig, Germany.
| | - Martin Weidling
- Center for Research On Musculoskeletal Systems (ZESBO), Faculty of Medicine, University of Leipzig, Leipzig, Germany
| | - Viktoria Nitsch
- Center for Research On Musculoskeletal Systems (ZESBO), Faculty of Medicine, University of Leipzig, Leipzig, Germany
| | - Robin Heilmann
- Center for Research On Musculoskeletal Systems (ZESBO), Faculty of Medicine, University of Leipzig, Leipzig, Germany
| | - Martin Heilemann
- Center for Research On Musculoskeletal Systems (ZESBO), Faculty of Medicine, University of Leipzig, Leipzig, Germany
| | - Toni Wendler
- Center for Research On Musculoskeletal Systems (ZESBO), Faculty of Medicine, University of Leipzig, Leipzig, Germany
| | - Stefan Schleifenbaum
- Center for Research On Musculoskeletal Systems (ZESBO), Faculty of Medicine, University of Leipzig, Leipzig, Germany
| | - Martin Reinhardt
- Department of Diagnostic and Interventional Radiology, University Hospital Leipzig, Leipzig, Germany
| | - Christoph-E Heyde
- Department of Orthopaedic, Trauma and Plastic Surgery, University Hospital Leipzig, Liebigstr. 20, 04103, Leipzig, Germany.,Center for Research On Musculoskeletal Systems (ZESBO), Faculty of Medicine, University of Leipzig, Leipzig, Germany
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23
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Long EB, Barak MM, Frost VJ. The effect of Staphylococcus aureus exposure on white-tailed deer trabecular bone stiffness and yield. J Mech Behav Biomed Mater 2021; 126:105000. [PMID: 34894499 DOI: 10.1016/j.jmbbm.2021.105000] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2021] [Revised: 11/08/2021] [Accepted: 11/24/2021] [Indexed: 10/19/2022]
Abstract
With a growing number of osteomyelitis diagnoses, many of which are linked to Staphylococcus aureus (S. aureus), it is imperative to understand the pathology of S. aureus in relation to bone to provide better diagnostics and patient care. While the cellular mechanisms of S. aureus and osteomyelitis have been studied, little information exists on the biomechanical effects of such infections. The aim of this study was to determine the effect of S. aureus exposure on the stiffness and yield of trabecular bone tissue. S. aureus-ATCC-12600, a confirmed biofilm producer, along with one hundred and three trabecular cubes (5 × 5 × 5 mm) from the proximal tibiae of Odocoileus virginianus (white-tailed deer) were used in this experiment. Bone cubes were disinfected and then swabbed to confirm no residual living microbes or endospore contamination before inoculation with S. aureus (test group) or sterile nutrient broth (control group) for 72 h. All cubes were then tested in compression until yield using an Instron 5942 Single-Column machine. Structural stiffness (N/mm) and yield (MPa) were calculated and compared between the two groups. Our results revealed that acute exposure to S. aureus, within the context of our deer tibia model, does not significantly decrease trabecular bone stiffness or yield. The results of this study may be of value clinically when assessing fracture risks for osteomyelitis or other patients whose cultures test positive for S. aureus.
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Affiliation(s)
- Emily Brooke Long
- Department of Biology, Winthrop University, Rock Hill, SC, 29733, USA.
| | - Meir Max Barak
- Department of Veterinary Biomedical Sciences, College of Veterinary Medicine, Long Island University, Brookville, NY, 11548, USA
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Amini M, Reisinger A, Hirtler L, Pahr D. Which experimental procedures influence the apparent proximal femoral stiffness? A parametric study. BMC Musculoskelet Disord 2021; 22:815. [PMID: 34556078 PMCID: PMC8461859 DOI: 10.1186/s12891-021-04656-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/16/2021] [Accepted: 08/26/2021] [Indexed: 11/10/2022] Open
Abstract
Background Experimental validation is the gold standard for the development of FE predictive models of bone. Employing multiple loading directions could improve this process. To capture the correct directional response of a sample, the effect of all influential parameters should be systematically considered. This study aims to determine the impact of common experimental parameters on the proximal femur’s apparent stiffness. Methods To that end, a parametric approach was taken to study the effects of: repetition, pre-loading, re-adjustment, re-fixation, storage, and μCT scanning as random sources of uncertainties, and loading direction as the controlled source of variation in both stand and side-fall configurations. Ten fresh-frozen proximal femoral specimens were prepared and tested with a novel setup in three consecutive sets of experiments. The neutral state and 15-degree abduction and adduction angles in both stance and fall configurations were tested for all samples and parameters. The apparent stiffness of the samples was measured using load-displacement data from the testing machine and validated against marker displacement data tracked by DIC cameras. Results Among the sources of uncertainties, only the storage cycle affected the proximal femoral apparent stiffness significantly. The random effects of setup manipulation and intermittent μCT scanning were negligible. The 15∘ deviation in loading direction had a significant effect comparable in size to that of switching the loading configuration from neutral stance to neutral side-fall. Conclusion According to these results, comparisons between the stiffness of the samples under various loading scenarios can be made if there are no storage intervals between the different load cases on the same samples. These outcomes could be used as guidance in defining a highly repeatable and multi-directional experimental validation study protocol.
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Affiliation(s)
- Morteza Amini
- Institute of Lightweight Design and Structural Biomechanics, TU Wien, Getreidemarkt 9, Vienna, 1060, Austria.,Division Biomechanics, Karl Landsteiner University of Health Sciences, Dr.-Karl-Dorrek-Straße 30, Krems an der Donau, 3500, Austria
| | - Andreas Reisinger
- Institute of Lightweight Design and Structural Biomechanics, TU Wien, Getreidemarkt 9, Vienna, 1060, Austria.,Division Biomechanics, Karl Landsteiner University of Health Sciences, Dr.-Karl-Dorrek-Straße 30, Krems an der Donau, 3500, Austria
| | - Lena Hirtler
- Center for Anatomy and Cell Biology, Medical University of Vienna, Währinger Straße 13, Vienna, 1090, Austria
| | - Dieter Pahr
- Institute of Lightweight Design and Structural Biomechanics, TU Wien, Getreidemarkt 9, Vienna, 1060, Austria. .,Division Biomechanics, Karl Landsteiner University of Health Sciences, Dr.-Karl-Dorrek-Straße 30, Krems an der Donau, 3500, Austria.
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25
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KHAN K, SEVİL KİLİMCİ F, KARA M. Biomechanical tests: applications and their reliability for the prediction of bone strength in broiler chicken. MEHMET AKIF ERSOY ÜNIVERSITESI VETERINER FAKÜLTESI DERGISI 2021. [DOI: 10.24880/maeuvfd.936262] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
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26
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Gehweiler D, Schultz M, Schulze M, Riesenbeck O, Wähnert D, Raschke MJ. Material properties of human vertebral trabecular bone under compression can be predicted based on quantitative computed tomography. BMC Musculoskelet Disord 2021; 22:709. [PMID: 34407777 PMCID: PMC8375123 DOI: 10.1186/s12891-021-04571-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/12/2021] [Accepted: 07/27/2021] [Indexed: 11/26/2022] Open
Abstract
Background The prediction of the stability of bones is becoming increasingly important. Especially osteoporotic vertebral body fractures are a growing problem and an increasing burden on the health system. Therefore, the aim of this study was to provide the best possible description of the relationship between the material properties of human vertebral trabecular bone measured under the most physiological conditions possible and the bone mineral density (BMD) determined by clinical quantitative computed tomography (QCT). Methods Forty eight cylindric cancellous bone samples with a diameter of 7.2 mm obtained from 13 human fresh-frozen lumbar vertebrae from 5 donors (3 men, 2 women) have been used for this study. After the specimens were temporarily reinserted into the vertebral body, the QCT was performed. For mechanical testing, the samples were embedded in a load-free manner using polymethylmetacrylate (PMMA). The surrounding test chamber was filled with phosphate buffered saline (PBS) and heated to 37 °C during the test. After 10 preconditioning load cycles, destructive testing was performed under axial compression. After determining the fracture site, BMD has been evaluated in this region only. Regression analyses have been performed. Results Fracture site had an average length of 2.4 (±1.4) mm and a position of 43.9 (±10.9) percent of the measurement length from the cranial end. No fracture reached the embedding. The average BMD at the fracture site was 80.2 (±28.7 | min. 14.5 | max. 137.8) mgCaHA/ml. In summary the results of the regression analyses showed for all three parameters a very good quality of fit by a power regression. Conclusion The results of this study show that QCT-based bone density measurements have a good predictive power for the material properties of the vertebral cancellous bone measured under near to physiological conditions. The mechanical bone properties of vertebral cancellous bone could be modelled with high accuracy in the investigated bone density range.
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Affiliation(s)
- Dominic Gehweiler
- AO Research Institute Davos, Clavadelerstrasse 8, 7270, Davos, Switzerland.,University Hospital Muenster, Department of Trauma, Hand and Reconstructive Surgery, Albert-Schweitzer-Campus 1, Building W1, 48149, Muenster, Germany
| | - Marius Schultz
- University Hospital Muenster, Department of Trauma, Hand and Reconstructive Surgery, Albert-Schweitzer-Campus 1, Building W1, 48149, Muenster, Germany
| | - Martin Schulze
- Department of Orthopedics, University Hospital Muenster, Albert-Schweitzer-Campus 1, 48149, Muenster, Germany
| | - Oliver Riesenbeck
- University Hospital Muenster, Department of Trauma, Hand and Reconstructive Surgery, Albert-Schweitzer-Campus 1, Building W1, 48149, Muenster, Germany
| | - Dirk Wähnert
- University Hospital Muenster, Department of Trauma, Hand and Reconstructive Surgery, Albert-Schweitzer-Campus 1, Building W1, 48149, Muenster, Germany. .,Department of Trauma Surgery and Orthopedics, Protestant Hospital of Bethel Foundation, University Hospital OWL of Bielefeld University, Campus Bielefeld-Bethel, Burgsteig 13, 33627, Bielefeld, Germany.
| | - Michael J Raschke
- University Hospital Muenster, Department of Trauma, Hand and Reconstructive Surgery, Albert-Schweitzer-Campus 1, Building W1, 48149, Muenster, Germany
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27
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Albert DL, Katzenberger MJ, Agnew AM, Kemper AR. A comparison of rib cortical bone compressive and tensile material properties: Trends with age, sex, and loading rate. J Mech Behav Biomed Mater 2021; 122:104668. [PMID: 34265671 DOI: 10.1016/j.jmbbm.2021.104668] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2021] [Revised: 06/16/2021] [Accepted: 06/26/2021] [Indexed: 11/18/2022]
Abstract
The objectives of this study were to develop novel methods for quantifying human rib cortical bone material properties in compression and to compare the compressive material property data to existing tensile data for matched subjects. Cylindrical coupons were obtained from the rib cortical bone of 30 subjects (M = 19, F = 11) ranging from 18 to 95 years of age (Avg. = 48.5 ± 24.3). Two coupons were obtained from each subject. One coupon was tested in compression at 0.005 strain/s, while the other coupon was tested in compression at 0.5 strain/s. Load and displacement data were recorded so that the elastic modulus, yield stress, yield strain, ultimate stress, ultimate strain, elastic strain energy density (SED), plastic SED, and total SED could be calculated. All compressive material properties were significantly different between the two loading rates. An ANOVA revealed that sex alone had no significant effect on the compressive material properties. The interaction between sex and age was significant for some material properties, but this may have been a consequence of the lack of older females in the subject pool. None of the compressive material properties were significantly correlated with age, but were more correlated with sample density. This finding differed for the tensile material properties, which showed stronger correlations with age. When comparing between tension and compression, significant differences were observed for all material properties except for the total SED, once the effects of loading rate and age had been accounted for. This was the first study to quantify the material properties of human rib cortical bone in compression. The results of this study demonstrated that rib and thorax finite element models should consider the effects of loading rate, loading mode, and age when incorporating material properties published in the literature.
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Affiliation(s)
- Devon L Albert
- Virginia Tech - Wake Forest, Center for Injury Biomechanics, USA
| | | | - Amanda M Agnew
- The Ohio State University, Injury Biomechanics Research Center, USA
| | - Andrew R Kemper
- Virginia Tech - Wake Forest, Center for Injury Biomechanics, USA.
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28
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Schleifenbaum S, Heilmann R, Riemer E, Reise R, Heyde CE, Jarvers JS, Pieroh P, Völker A, von der Hoeh NH. A Biomechanical Model for Testing Cage Subsidence in Spine Specimens with Osteopenia or Osteoporosis Under Permanent Maximum Load. World Neurosurg 2021; 152:e540-e548. [PMID: 34129990 DOI: 10.1016/j.wneu.2021.05.131] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2021] [Accepted: 05/31/2021] [Indexed: 10/21/2022]
Abstract
BACKGROUND Intervertebral fusions in cases of reduced bone density are a tough challenge. From a biomechanical point of view, most current studies have focused on the range of motion or have shown test setups for single-component tests. Definitive setups for biomechanical testing of the primary stability of a 360° fusion using a screw-rod system and cage on osteoporotic spine are missing. The aim of this study was to develop a test stand to provide information about the bone-implant interface under reproducible conditions. METHODS After pretesting with artificial bone, functional spine units were tested with 360° fusion in the transforaminal lumbar interbody fusion technique. The movement sequences were conducted in flexion/extension, right and left lateral bending, and right and left axial rotation on a human model with osteopenia or osteoporosis under permanent maximum load with 7.5 N-m. RESULTS During the testing of human cadavers, 4 vertebrae were fully tested and were inconspicuous even after radiological and macroscopic examination. One vertebra showed a subsidence of 2 mm, and 1 vertebra had a cage collapsed into the vertebra. CONCLUSIONS This setup is suitable for biomechanical testing of cyclical continuous loads on the spine with reduced bone quality or osteoporosis. The embedding method is stable and ensures a purely single-level setup with different trajectories, especially when using the cortical bone trajectory. Optical monitoring provides a very accurate indication of cage movement, which correlates with the macroscopic and radiological results.
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Affiliation(s)
- Stefan Schleifenbaum
- Zentrum zur Erforschung der Stuetz- und Bewegungsorgane, University of Leipzig, Leipzig, Germany; Department of Orthopedic, Trauma and Plastic Surgery, University Hospital Leipzig, Leipzig, Germany
| | - Robin Heilmann
- Zentrum zur Erforschung der Stuetz- und Bewegungsorgane, University of Leipzig, Leipzig, Germany; Department of Orthopedic, Trauma and Plastic Surgery, University Hospital Leipzig, Leipzig, Germany
| | - Elena Riemer
- Zentrum zur Erforschung der Stuetz- und Bewegungsorgane, University of Leipzig, Leipzig, Germany; Department of Orthopedic, Trauma and Plastic Surgery, University Hospital Leipzig, Leipzig, Germany
| | - Rebekka Reise
- Zentrum zur Erforschung der Stuetz- und Bewegungsorgane, University of Leipzig, Leipzig, Germany; Department of Orthopedic, Trauma and Plastic Surgery, University Hospital Leipzig, Leipzig, Germany
| | - Christoph-Eckhard Heyde
- Department of Orthopedic, Trauma and Plastic Surgery, University Hospital Leipzig, Leipzig, Germany
| | - Jan-Sven Jarvers
- Department of Orthopedic, Trauma and Plastic Surgery, University Hospital Leipzig, Leipzig, Germany
| | - Philipp Pieroh
- Department of Orthopedic, Trauma and Plastic Surgery, University Hospital Leipzig, Leipzig, Germany
| | - Anna Völker
- Department of Orthopedic, Trauma and Plastic Surgery, University Hospital Leipzig, Leipzig, Germany
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Is the 0.2%-Strain-Offset Approach Appropriate for Calculating the Yield Stress of Cortical Bone? Ann Biomed Eng 2021; 49:1747-1760. [PMID: 33479788 DOI: 10.1007/s10439-020-02719-2] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2020] [Accepted: 12/28/2020] [Indexed: 11/26/2022]
Abstract
The 0.2% strain offset approach is mostly used to calculate the yield stress and serves as an efficient method for cross-lab comparisons of measured material properties. However, it is difficult to accurately determine the yield of the bone. Especially when computational models require accurate material parameters, clarification of the yield point is needed. We tested 24 cortical specimens harvested from six bovine femora in three-point bending mode, and 11 bovine femoral cortical specimens in the tensile mode. The Young's modulus and yield stress for each specimen derived from the specimen-specific finite element (FE) optimization method was regarded as the most ideal constitutive parameter. Then, the strain offset optimization method was used to find the strain offset closest to the ideal yield stress for the 24 specimens. The results showed that the 0 strain offsets underestimated (- 25%) the yield stress in bending and tensile tests, while the 0.2% strain offsets overestimated the yield stress (+ 65%) in three-point bending tests. Instead, the yield stress determined by 0.007 and 0.05% strain offset for bending and tensile loading respectively, can effectively characterize the biomechanical responses of the bone, thereby helping to build an accurate FE model.
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Mechanical Properties. Biomed Mater 2021. [DOI: 10.1007/978-3-030-49206-9_8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Ryan MK, Oliviero S, Costa MC, Wilkinson JM, Dall’Ara E. Heterogeneous Strain Distribution in the Subchondral Bone of Human Osteoarthritic Femoral Heads, Measured with Digital Volume Correlation. MATERIALS 2020; 13:ma13204619. [PMID: 33081288 PMCID: PMC7603047 DOI: 10.3390/ma13204619] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/30/2020] [Revised: 10/06/2020] [Accepted: 10/12/2020] [Indexed: 11/16/2022]
Abstract
Osteoarthritis (OA) is a chronic disease, affecting approximately one third of people over the age of 45. Whilst the etiology and pathogenesis of the disease are still not well understood, mechanics play an important role in both the initiation and progression of osteoarthritis. In this study, we demonstrate the application of stepwise compression, combined with microCT imaging and digital volume correlation (DVC) to measure and evaluate full-field strain distributions within osteoarthritic femoral heads under uniaxial compression. A comprehensive analysis showed that the microstructural features inherent in OA bone did not affect the level of uncertainties associated with the applied methods. The results illustrate the localization of strains at the loading surface as well as in areas of low bone volume fraction and subchondral cysts. Trabecular thickness and connectivity density were identified as the only microstructural parameters with any association to the magnitude of local strain measured at apparent yield strain or the volume of bone exceeding yield strain. This work demonstrates a novel approach to evaluating the mechanical properties of the whole human femoral head in case of severe OA.
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Affiliation(s)
- Melissa K. Ryan
- Department of Oncology and Metabolism, Mellanby Centre for Bone Research, University of Sheffield, Sheffield S10 2TN, UK; (S.O.); (M.C.C.); (J.M.W.); (E.D.)
- INSIGNEO Institute for in silico Medicine, University of Sheffield, Sheffield S10 2TN, UK
- Medical Device Research Institute, Flinders University, Adelaide 5042, Australia
- Correspondence: ; Tel.: +61-8-8201-3208
| | - Sara Oliviero
- Department of Oncology and Metabolism, Mellanby Centre for Bone Research, University of Sheffield, Sheffield S10 2TN, UK; (S.O.); (M.C.C.); (J.M.W.); (E.D.)
- INSIGNEO Institute for in silico Medicine, University of Sheffield, Sheffield S10 2TN, UK
| | - Maria Cristiana Costa
- Department of Oncology and Metabolism, Mellanby Centre for Bone Research, University of Sheffield, Sheffield S10 2TN, UK; (S.O.); (M.C.C.); (J.M.W.); (E.D.)
- INSIGNEO Institute for in silico Medicine, University of Sheffield, Sheffield S10 2TN, UK
| | - J. Mark Wilkinson
- Department of Oncology and Metabolism, Mellanby Centre for Bone Research, University of Sheffield, Sheffield S10 2TN, UK; (S.O.); (M.C.C.); (J.M.W.); (E.D.)
| | - Enrico Dall’Ara
- Department of Oncology and Metabolism, Mellanby Centre for Bone Research, University of Sheffield, Sheffield S10 2TN, UK; (S.O.); (M.C.C.); (J.M.W.); (E.D.)
- INSIGNEO Institute for in silico Medicine, University of Sheffield, Sheffield S10 2TN, UK
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Different storage times and their effect on the bending load to failure testing of murine bone tissue. Sci Rep 2020; 10:17412. [PMID: 33060685 PMCID: PMC7562872 DOI: 10.1038/s41598-020-74498-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2020] [Accepted: 09/28/2020] [Indexed: 12/04/2022] Open
Abstract
Cryopreservation is a well-established method for bone storage. However, the ideal timing of mechanical testing after sacrificing the experimental animals is still under discussion and of significant importance to the presentation of accurate results. Therefore, the aim of this study was to investigate and compare different cryopreservation durations to native murine bone and whether there was an influence on mechanical bone testing. For this study the tibias of 57 female C57BL/6 mice—18-weeks of age—were harvested and randomly allocated to one of four groups with varying storage times: (1) frozen at −80 °C for 3 months, (2) frozen at −80 °C for 6 months, (3) frozen at −80 °C for 12 months and (4) native group. The native group was immediately tested after harvesting. The comparison of the mean strength and load to failure rates demonstrated a significant difference between the storage groups compared to the native control (p = 0.007). However, there was no difference in the strength and the load to failure values of bones of all storage groups when compared against each other. Once cryopreservation at −80 °C is performed, no differences of mechanical bone properties are seen up to 12 months of storage. When actual in vivo data is of close interest, immediate testing should be considered and is preferred. If comparison of groups is required and long-time storage is necessary, cryopreservation seems to be an accurate method at present.
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Kraxenberger M, Dreu M, Sadoghi P, Birkenmaier C, Teske W, von Schulze Pellengahr C, Büttner A, Wegener B. Influence of different fixation methods on the fracture force of osteoporotic human lumbar vertebral bodies in the generation of vertebral compression fractures. Technol Health Care 2020; 29:589-594. [PMID: 32925121 DOI: 10.3233/thc-202354] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
BACKGROUND The use of fresh-frozen (FF) specimens represents the gold standard for biomechanical investigations. Since FF specimens are often difficult to obtain, chemical-fixed specimens (formalin (FA), Thiel (TH)) are also used. OBJECTIVE Since fixation methods can alter the mechanical properties of bone tissue, the purpose of this study was to examine their influence on the fracture force of lumbar vertebral bodies (VB). METHODS First the VB were subdivided into three focus groups: FF, TH, and FA. After removing the soft tissue and the processus transverses of all VB, the endplates were planned with a thin layer of epoxy resin, in order to apply a constant strain to the surface and sub-surface. The VB were subjected to axial compression tests in order to determine fracture force. Lastly a standardized compression fracture was generated. RESULTS The mean values of the fracture force of the focus groups were 4529.5 N (FF), 3211.3N (TH) and 2947.9N (FA). Consequently a significant difference between the FF and the other two groups could be demonstrated (p< 0.05). CONCLUSION The preliminary tests showed that the fraction force of fresh-frozen VB were significantly higher than TH/FA-fixed VB. Therefore, these fixation methods could potentially have an influence on the biomechanical properties of VB. This leads to the assumption that if load-to-failure tests are performed, it is probably recommended to use fresh-frozen specimens.
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Affiliation(s)
- Michael Kraxenberger
- Department of Orthopedic Surgery, Physical Medicine and Rehabilitation, Ludwig Maximilians University of Munich, Munich, Germany
| | - Manuel Dreu
- Institute of Macroscopic and Clinical Anatomy, Graz, Austria
| | - Patrick Sadoghi
- Department of Orthopedic and Trauma Surgery, Medical University of Graz, Graz, Austria
| | - Christof Birkenmaier
- Department of Orthopedic Surgery, Physical Medicine and Rehabilitation, Ludwig Maximilians University of Munich, Munich, Germany
| | - Wolfram Teske
- Center of Orthopedic and Trauma Surgery, Catholic Hospital Hagen, Hagen, Germany
| | | | - Andreas Büttner
- Institute of Legal Medicine, University of Rostock, Rostock, Germany
| | - Bernd Wegener
- Department of Orthopedic Surgery, Physical Medicine and Rehabilitation, Ludwig Maximilians University of Munich, Munich, Germany
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Schierjott RA, Hettich G, Ringkamp A, Baxmann M, Morosato F, Damm P, Grupp TM. A method to assess primary stability of acetabular components in association with bone defects. J Orthop Res 2020; 38:1769-1778. [PMID: 31944372 DOI: 10.1002/jor.24591] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/30/2019] [Accepted: 01/13/2020] [Indexed: 02/04/2023]
Abstract
The objectives of this study were to develop a simplified acetabular bone defect model based on a representative clinical case, derive four bone defect increments from the simplified defect to establish a step-wise testing procedure, and analyze the impact of bone defect and bone defect filling on primary stability of a press-fit cup in the smallest defined bone defect increment. The original bone defect was approximated with nine reaming procedures and by exclusion of specific procedures, four defect increments were derived. The smallest increment was used in an artificial acetabular test model to test primary stability of a press-fit cup in combination with bone graft substitute (BGS). A primary acetabular test model and a defect model without filling were used as reference. Load was applied in direction of level walking in sinusoidal waveform with an incrementally increasing maximum load (300 N/1000 cycles from 600 to 3000 N). Relative motions (inducible displacement, migration, and total motion) between cup and test model were assessed with an optical measurement system. Original and simplified bone defect volume showed a conformity of 99%. Maximum total motion in the primary setup at 600 N (45.7 ± 5.6 µm) was in a range comparable to tests in human donor specimens (36.0 ± 16.8 µm). Primary stability was reduced by the bone defect, but could mostly be reestablished by BGS-filling. The presented method could be used as platform to test and compare different treatment strategies for increasing bone defect severity in a standardized way.
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Affiliation(s)
- Ronja A Schierjott
- Research & Development, Aesculap AG, Am Aesculap-Platz, Tuttlingen, Germany.,Department of Orthopaedic Surgery, Physical Medicine & Rehabilitation, Ludwig-Maximilians-University Munich, Munich, Germany
| | - Georg Hettich
- Research & Development, Aesculap AG, Am Aesculap-Platz, Tuttlingen, Germany
| | - Alexandra Ringkamp
- Department of Biomechatronics, Faculty of Mechanical Engineering, Technische Universität Ilmenau, Ilmenau, Germany
| | - Marc Baxmann
- Research & Development, Aesculap AG, Am Aesculap-Platz, Tuttlingen, Germany
| | - Federico Morosato
- Department of Industrial Engineering, School of Engineering and Architecture, Università di Bologna, Bologna, Italy
| | - Philipp Damm
- Julius Wolff Institute, Joint Loading & Musculoskeletal Analysis, Charité-Universitätsmedizin Berlin, Berlin, Germany
| | - Thomas M Grupp
- Research & Development, Aesculap AG, Am Aesculap-Platz, Tuttlingen, Germany.,Department of Orthopaedic Surgery, Physical Medicine & Rehabilitation, Ludwig-Maximilians-University Munich, Munich, Germany
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Blondel M, Abidine Y, Assemat P, Palierne S, Swider P. Identification of effective elastic modulus using modal analysis; application to canine cancellous bone. J Biomech 2020; 110:109972. [PMID: 32827789 DOI: 10.1016/j.jbiomech.2020.109972] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2020] [Revised: 07/03/2020] [Accepted: 07/20/2020] [Indexed: 10/23/2022]
Abstract
Mechanical properties of cancellous bone is of increasing interest due to its involvement in aging pathologies and oncology. Characterization of fragile bone tissue is challenging and available methodologies include quasi-static compressive tests of small size specimens, ultrasound and indentation techniques. We hypothesized that modal analysis of flexure beams could be a complementary methodology to obtain Young modulus. The sampling methodology was adapted such that the uniqueness of the linear dynamic response was available to determine the elastic modulus from natural frequencies and mode shapes. In a first step, the methodology was validated using a synthetic bone model as control. Then, water-jet cutting allowed collecting fourteen small beam-like specimens in canine distal femurs. X-ray microtomography confirmed the microarchitecture preservation, the homogeneity and the isotropy at the specimen scale to derive effective properties. The first natural frequency in clamped-free boundary conditions was used to obtain mean values of Young modulus, which ranged from 210 MPa to 280 MPa depending on the specimen collection site. Experimental tests were rapid and reproducible and our preliminary results were in good agreement with literature data. In conclusion, beam modal analysis could be considered for exploring mechanical properties of fragile and scarce biological tissues.
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Affiliation(s)
- M Blondel
- National Veterinary School, Toulouse, France
| | - Y Abidine
- IMFT UMR 5502, Toulouse University, Toulouse, France
| | - P Assemat
- IMFT UMR 5502, Toulouse University, Toulouse, France
| | - S Palierne
- National Veterinary School, Toulouse, France
| | - P Swider
- IMFT UMR 5502, Toulouse University, Toulouse, France.
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36
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Hogue M, Fairgrieve SI, Lievers WB. Stabbing angle alters peak force and work during sharp force trauma of porcine ribs. Forensic Sci Int 2020; 314:110373. [PMID: 32615394 DOI: 10.1016/j.forsciint.2020.110373] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2020] [Revised: 06/10/2020] [Accepted: 06/15/2020] [Indexed: 11/29/2022]
Abstract
Forensic anthropologists have traditionally relied on a qualitative scale (mild, moderate, severe) for describing the forces required to generate a bony injury; however, recently efforts have focused on providing more quantitative data. The current study considers the effects of blade angle on the peak force, average force, and work measured during an instrumented sharp force impact. Sixty-two porcine side ribs were stabbed with the long axis of the blade perpendicular to the convex surface and the blade edge in one of three orientations (0°, 45°, 90°). Peak force was highest when the cutting edge was perpendicular to the long axis of the rib (90°) and lowest when it was aligned (0°). Conversely, work was highest when the blade was at an oblique angle (45°) to the rib. These results confirm that the orientation of a sharp force event must be considered when estimating the mechanical loading required to generate an injury.
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Affiliation(s)
- Maxime Hogue
- Bharti School of Engineering, Laurentian University, Sudbury, Ontario, Canada
| | - Scott I Fairgrieve
- Policing & Security Program, Rabdan Academy, Abu Dhabi, United Arab Emirates
| | - W Brent Lievers
- Bharti School of Engineering, Laurentian University, Sudbury, Ontario, Canada.
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37
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Brazda IJ, Reeves J, Langohr GDG, Crookshank MC, Schemitsch EH, Zdero R. Biomechanical properties and thermal characteristics of frozen versus thawed whole bone. Proc Inst Mech Eng H 2020; 234:874-883. [PMID: 32515277 DOI: 10.1177/0954411920929455] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Biomechanics research often requires cadaveric whole bones to be stored in a freezer and then thawed prior to use; however, the literature shows a variety of practices for thawing. Consequently, this is the first study to report the mechanical properties of fully frozen versus fully thawed whole bone as 'proof of principle'. Two groups of 10 porcine ribs each were statistically equivalent at baseline in length, cross-sectional area, and bone mineral density. The two groups were stored in a freezer for at least 24 h, thawed in air at 23 °C for 4 h while temperature readings were taken to establish the time needed for thawing, and once again returned to the freezer for at least 24 h. Mechanical tests to failure using three-point bending were then done on the 'frozen' group immediately after removal from the freezer and the 'thawed' group when steady-state ambient air temperature was reached. Temperature readings over the entire thawing period were described by the line-of-best-fit formula T = (28.34t - 6.69)/(t + 0.38), where T = temperature in degree Celsius and t = time in hours, such that frozen specimens at t = 0 h had a temperature of -17 °C and thawed specimens at t = 1.75 h reached a steady-state temperature of 20 °C-23 °C. Mechanical tests showed that frozen versus thawed specimens had an average of 32% higher stiffness k, 34% higher ultimate force Fu, 28% lower ultimate displacement δu, 40% lower ultimate work Wu, 43% higher elastic modulus E, 37% higher ultimate normal stress σu, and 33% higher ultimate shear stress τu. Whole ribs failed at midspan primarily by transverse cracking (16 of 20 cases), oblique cracking (three of 20 cases), or surface denting (one of 20 cases), each having unique shapes for force versus displacement graphs differentiated mainly by ultimate force location.
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Affiliation(s)
- Ignace J Brazda
- Orthopaedic Biomechanics Lab, Victoria Hospital, London, ON, Canada
| | - Jacob Reeves
- Department of Mechanical and Materials Engineering, Western University, London, ON, Canada
| | - G Daniel G Langohr
- Department of Mechanical and Materials Engineering, Western University, London, ON, Canada
| | | | - Emil H Schemitsch
- Orthopaedic Biomechanics Lab, Victoria Hospital, London, ON, Canada.,Division of Orthopaedic Surgery, Western University, London, ON, Canada
| | - Radovan Zdero
- Orthopaedic Biomechanics Lab, Victoria Hospital, London, ON, Canada.,Department of Mechanical and Materials Engineering, Western University, London, ON, Canada.,Division of Orthopaedic Surgery, Western University, London, ON, Canada.,Department of Mechanical and Industrial Engineering, Ryerson University, Toronto, ON, Canada
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Ryan M, Barnett L, Rochester J, Wilkinson JM, Dall'Ara E. A new approach to comprehensively evaluate the morphological properties of the human femoral head: example of application to osteoarthritic joint. Sci Rep 2020; 10:5538. [PMID: 32218496 PMCID: PMC7098981 DOI: 10.1038/s41598-020-62614-7] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2019] [Accepted: 03/17/2020] [Indexed: 11/25/2022] Open
Abstract
Osteoarthritis affects the morphological properties of the femoral head. The goal of this study was to develop a method to elucidate whether these changes are localised to discrete regions, or if the reported trends in microstructural changes may be identified throughout the subchondral bone of the human femoral head. Whole femoral heads extracted from osteoarthritic (n = 5) and healthy controls (n = 5) underwent microCT imaging 39 μm voxel size. The subchondral bone plate was virtually isolated to evaluate the plate thickness and plate porosity. The trabecular bone region was divided into 37 volumes of interest spatially distributed in the femoral head, and bone morphometric properties were determined in each region. The study showed how the developed approach can be used to study the heterogeneous properties of the human femoral head affected by a disease such as osteoarthritis. As example, in the superior femoral head osteoarthritic specimens exhibited a more heterogeneous micro-architecture, with trends towards thicker cortical bone plate, higher trabecular connectivity density, higher trabecular bone density and thicker structures, something that could only be observed with the newly developed approach. Bone cysts were mostly confined to the postero-lateral quadrants extending from the subchondral region into the mid trabecular region. Nevertheless, in order to generalise these findings, a larger sample size should be analysed in the future. This novel method allowed a comprehensive evaluation of the heterogeneous micro-architectural properties of the human femoral head, highlighting effects of OA in the superior subchondral cortical and trabecular bone. Further investigations on different stages of OA would be needed to identify early changes in the bone.
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Affiliation(s)
- M Ryan
- Department of Oncology and Metabolism, Mellanby Centre for bone Research, University of Sheffield, Sheffield, UK.,INSIGNEO Institute for in silico Medicine, University of Sheffield, Sheffield, UK
| | - L Barnett
- INSIGNEO Institute for in silico Medicine, University of Sheffield, Sheffield, UK
| | - J Rochester
- Academic Unit of Medical Education, Medical School, University of Sheffield, Sheffield, UK
| | - J M Wilkinson
- Department of Oncology and Metabolism, Mellanby Centre for bone Research, University of Sheffield, Sheffield, UK
| | - E Dall'Ara
- Department of Oncology and Metabolism, Mellanby Centre for bone Research, University of Sheffield, Sheffield, UK. .,INSIGNEO Institute for in silico Medicine, University of Sheffield, Sheffield, UK.
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Ingle DN, Porter ME. Developmental changes in bone mechanics from Florida manatees ( Trichechus manatus latirostris), obligate swimming mammals. J Exp Biol 2020; 223:jeb213009. [PMID: 32098877 DOI: 10.1242/jeb.213009] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2019] [Accepted: 02/12/2020] [Indexed: 08/26/2023]
Abstract
Mammals living in aquatic environments load their axial skeletons differently from their terrestrial counterparts. The structure and mechanical behavior of trabecular bone can be especially indicative of varying habitual forces. Here, we investigated vertebral trabecular bone mechanical properties (yield strength, stiffness and toughness) throughout development in Florida manatees (Trichechus manatus latirostris), obligate undulatory swimmers. Thoracic, lumbar and caudal vertebrae were dissected from manatees (N=20) during necropsies. We extracted 6 mm3 samples from vertebral bodies and tested them in compression in three orientations (rostrocaudal, dorsoventral and mediolateral) at 2 mm min-1 We determined variation in mechanical properties between sexes, and among developmental stages, vertebral regions and testing orientations. We also investigated the relationships between vertebral process lengths and properties of dorsoventrally and mediolaterally tested bone. Rostrocaudally tested bone was the strongest, stiffest and toughest, suggesting that this is the principal direction of stress. Our results showed that bone from female subadults was stronger and stiffer than that of their male counterparts; based on these data, we hypothesize that hormonal shifts at sexual maturity may partially drive these differences. In calves, bone from the posterior region was stronger and tougher than that from the anterior region. We hypothesize that as animals grow rapidly throughout early development, bone in the posterior region would be the most ossified to support the rostrocaudal force propagation associated with undulatory swimming.
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Affiliation(s)
- Danielle N Ingle
- Department of Biological Sciences, Florida Atlantic University, Boca Raton, FL 33431, USA
| | - Marianne E Porter
- Department of Biological Sciences, Florida Atlantic University, Boca Raton, FL 33431, USA
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40
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Katzenberger MJ, Albert DL, Agnew AM, Kemper AR. Effects of sex, age, and two loading rates on the tensile material properties of human rib cortical bone. J Mech Behav Biomed Mater 2020; 102:103410. [DOI: 10.1016/j.jmbbm.2019.103410] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2019] [Revised: 08/03/2019] [Accepted: 08/26/2019] [Indexed: 10/26/2022]
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41
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Bravo AE, Osnaya LC, Ramírez EI, Jacobo VH, Ortiz A. The effect of bone marrow on the mechanical behavior of porcine trabecular bone. Biomed Phys Eng Express 2019. [DOI: 10.1088/2057-1976/ab4dc0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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42
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Duginski GA, Ross CJ, Laurence DW, Johns CH, Lee CH. An investigation of the effect of freezing storage on the biaxial mechanical properties of excised porcine tricuspid valve anterior leaflets. J Mech Behav Biomed Mater 2019; 101:103438. [PMID: 31542570 PMCID: PMC8008703 DOI: 10.1016/j.jmbbm.2019.103438] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2019] [Revised: 07/27/2019] [Accepted: 09/15/2019] [Indexed: 01/03/2023]
Abstract
The atrioventricular heart valve (AHV) leaflets are critical to the facilitation of proper unidirectional blood flow through the heart. Previously, studies have been conducted to understand the tissue mechanics of healthy AHV leaflets to inform the development of valve-specific computational models and replacement materials for use in diagnosing and treating valvular heart disease. Generally, these studies involved biaxial mechanical testing of the AHV leaflet tissue specimens to extract relevant mechanical properties. Most of those studies considered freezing-based storage systems based on previous findings for other connective tissues such as aortic tissue or skin. However, there remains no study that specifically examines the effects of freezing storage on the characterized mechanical properties of the AHV leaflets. In this study, we aimed to address this gap in knowledge by performing biaxial mechanical characterizations of the tricuspid valve anterior leaflet (TVAL) tissue both before and after a 48-h freezing period. Primary findings of this study include: (i) a statistically insignificant change in the tissue extensibilities, with the frozen tissues being slightly stiffer and more anisotropic than the fresh tissues; and (ii) minimal variations in the stress relaxation behaviors between the fresh and frozen tissues, with the frozen tissues demonstrating slightly lessened relaxation. The findings from this study suggested that freezing-based storage does not significantly impact the observed mechanical properties of one of the five AHV leaflets-the TVAL. The results from this study are useful for reaffirming the experimental methodologies in the previous studies, as well as informing the tissue preservation methods of future investigations of AHV leaflet mechanics.
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Affiliation(s)
- Grace A Duginski
- Biomechanics and Biomaterials Design Laboratory (BBDL), School of Aerospace and Mechanical Engineering, The University of Oklahoma, Norman, OK, 73019, USA.
| | - Colton J Ross
- Biomechanics and Biomaterials Design Laboratory (BBDL), School of Aerospace and Mechanical Engineering, The University of Oklahoma, Norman, OK, 73019, USA.
| | - Devin W Laurence
- Biomechanics and Biomaterials Design Laboratory (BBDL), School of Aerospace and Mechanical Engineering, The University of Oklahoma, Norman, OK, 73019, USA.
| | - Cortland H Johns
- Biomechanics and Biomaterials Design Laboratory (BBDL), School of Aerospace and Mechanical Engineering, The University of Oklahoma, Norman, OK, 73019, USA.
| | - Chung-Hao Lee
- Biomechanics and Biomaterials Design Laboratory (BBDL), School of Aerospace and Mechanical Engineering, The University of Oklahoma, Norman, OK, 73019, USA; Institute for Biomedical Engineering, Science and Technology, School of Aerospace and Mechanical Engineering (IBEST), The University of Oklahoma, Norman, OK, 73019, USA.
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Pharmacologic targeting of β-catenin improves fracture healing in old mice. Sci Rep 2019; 9:9005. [PMID: 31227757 PMCID: PMC6588693 DOI: 10.1038/s41598-019-45339-0] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2019] [Accepted: 06/05/2019] [Indexed: 02/06/2023] Open
Abstract
β-catenin protein needs to be precisely regulated for effective fracture repair. The pace of fracture healing slows with age, associated with a transient increase in β-catenin during the initial phase of the repair process. Here we examined the ability of pharmacologic agents that target β-catenin to improve the quality of fracture repair in old mice. 20 month old mice were treated with Nefopam or the tankyrase inhibitor XAV939 after a tibia fracture. Fractures were examined 21 days later by micro-CT and histology, and 28 days later using mechanical testing. Daily treatment with Nefopam for three or seven days but not ten days improved the amount of bone present at the fracture site, inhibited β-catenin protein level, and increased colony forming units osteoblastic from bone marrow cells. At 28 days, treatment increased the work to fracture of the injured tibia. XAV939 had a more modest effect on β-catenin protein, colony forming units osteoblastic, and the amount of bone at the fracture site. This data supports the notion that high levels of β-catenin in the early phase of fracture healing in old animals slows osteogenesis, and suggests a pharmacologic approach that targets β-catenin to improve fracture repair in the elderly.
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Williams C, Stayton CT. Effects of Sutured Pelvic Elements on Turtle Shell Strength: A Comparison of Pleurodire and Cryptodire Shell Mechanics. HERPETOLOGICA 2019. [DOI: 10.1655/d-17-00066] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Affiliation(s)
- Cameron Williams
- Department of Biology, Bucknell University, Lewisburg, PA 17837, USA
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Effect of two (short-term) storage methods on load to failure testing of murine bone tissue. Sci Rep 2019; 9:5961. [PMID: 30976119 PMCID: PMC6459877 DOI: 10.1038/s41598-019-42476-4] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2018] [Accepted: 03/27/2019] [Indexed: 11/08/2022] Open
Abstract
Since mechanical testing of bone quality is often delayed following euthanasia, the method of bone storage is of high importance in animal studies. Different storage methods may cause a change in the properties of bone tissue during mechanical testing. Therefore, the aim of this study was to investigate the biomechanical effects of two different fixation methods for bone tissue. We hypothesized that there is a difference between the load to failure values between the two groups. The tibias of fifteen 18-week-old female C57BL/6 mice were harvested and randomly allocated to three different groups with varying storage methods: (1) frozen at -80 °C, (2) paraformaldehyde working solution, and (3) native group. A storage time of two weeks prior to testing was chosen for groups 1 and 2. In group 3, referred to as the "native group", bones were immediately tested after the harvesting procedure. The comparison of the mean load to failure of all 3 groups (group 1: 28.7 N ± 6.1 N, group 2: 23.8 N ± 3.8 N and group 3: 23.7 N ± 5.7 N) did not reveal a significant difference. There was also no difference in strength or stiffness. The findings of the present study demonstrate that the two most common storage methods, do not have an influence on the biomechanical properties of murine bone over a two week period.
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Messer-Hannemann P, Bätz J, Lampe F, Klein A, Püschel K, Campbell GM, Morlock M. The influence of cavity preparation and press-fit cup implantation on restoring the hip rotation center. Clin Biomech (Bristol, Avon) 2019; 63:185-192. [PMID: 30913461 DOI: 10.1016/j.clinbiomech.2019.03.006] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/23/2019] [Revised: 03/04/2019] [Accepted: 03/11/2019] [Indexed: 02/07/2023]
Abstract
BACKGROUND Reaming of the acetabular cavity and cup implantation directly influence the hip rotation center and contact area between implant and bone. Previous studies have reported on an altered rotation center after total hip arthroplasty, but have not studied the influence of reaming and cup implantation separately. Aim of this study was therefore to analyze the individual influence of acetabular reaming and subsequent cup implantation on the rotation center and how this influences the contact conditions at the bone-implant interface. METHODS Acetabular press-fit cups were implanted into the left and right hips of three full cadavers (n = 6). CT scans were performed to calculate the change in hip rotation center after reaming and prior to liner insertion. 3D models of the cups were used to determine the polar gap, the contact conditions and the effective press-fit. FINDINGS Reaming the acetabular cavity shifted the rotation center medially (median 5.8 mm, range 4.8-9.1), superiorly (5.3 mm, 3.0-7.0) and posteriorly (2.9 mm, 1.0-5.3). With cup implantation, the rotation center shifted back towards the native position, but no full restoration was observed. The degree of shift increased with the size of polar gap (rs = 0.829, P = .042), which inversely reduced the contact area (rs = 0.886, P = .019). INTERPRETATION This study reveals that the dominant factor in hip rotation center restoration is the reaming process, while the cup implantation for a given nominal press-fit has only a small influence. Increasing the press-fit would improve the restoration but bares the danger of insufficient bone coverage and periprosthetic fractures due to the high forces needed.
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Affiliation(s)
- Philipp Messer-Hannemann
- TUHH, Hamburg University of Technology, Institute of Biomechanics, Denickestrasse 15, 21073 Hamburg, Germany.
| | - Johanna Bätz
- TUHH, Hamburg University of Technology, Institute of Biomechanics, Denickestrasse 15, 21073 Hamburg, Germany
| | - Frank Lampe
- Hamburg University of Applied Sciences, Department of Life Sciences, Ulmenliet 20, 21033 Hamburg, Germany
| | - Anke Klein
- University Medical Center Hamburg-Eppendorf, Department of Legal Medicine, Butenfeld 34, 22529 Hamburg, Germany
| | - Klaus Püschel
- University Medical Center Hamburg-Eppendorf, Department of Legal Medicine, Butenfeld 34, 22529 Hamburg, Germany
| | - Graeme M Campbell
- TUHH, Hamburg University of Technology, Institute of Biomechanics, Denickestrasse 15, 21073 Hamburg, Germany
| | - Michael Morlock
- TUHH, Hamburg University of Technology, Institute of Biomechanics, Denickestrasse 15, 21073 Hamburg, Germany
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Peña Fernández M, Dall'Ara E, Kao AP, Bodey AJ, Karali A, Blunn GW, Barber AH, Tozzi G. Preservation of Bone Tissue Integrity with Temperature Control for In Situ SR-MicroCT Experiments. MATERIALS 2018; 11:ma11112155. [PMID: 30388813 PMCID: PMC6266162 DOI: 10.3390/ma11112155] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/28/2018] [Revised: 10/24/2018] [Accepted: 10/30/2018] [Indexed: 01/08/2023]
Abstract
Digital volume correlation (DVC), combined with in situ synchrotron microcomputed tomography (SR-microCT) mechanics, allows for 3D full-field strain measurement in bone at the tissue level. However, long exposures to SR radiation are known to induce bone damage, and reliable experimental protocols able to preserve tissue properties are still lacking. This study aims to propose a proof-of-concept methodology to retain bone tissue integrity, based on residual strain determination using DVC, by decreasing the environmental temperature during in situ SR-microCT testing. Compact and trabecular bone specimens underwent five consecutive full tomographic data collections either at room temperature or 0 °C. Lowering the temperature seemed to reduce microdamage in trabecular bone but had minimal effect on compact bone. A consistent temperature gradient was measured at each exposure period, and its prolonged effect over time may induce localised collagen denaturation and subsequent damage. DVC provided useful information on irradiation-induced microcrack initiation and propagation. Future work is necessary to apply these findings to in situ SR-microCT mechanical tests, and to establish protocols aiming to minimise the SR irradiation-induced damage of bone.
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Affiliation(s)
- Marta Peña Fernández
- Zeiss Global Centre, School of Mechanical and Design Engineering, University of Portsmouth, PO1 3DJ, Portsmouth, UK.
| | - Enrico Dall'Ara
- Department of Oncology and Metabolism and INSIGNEO Institute for in Silico Medicine, University of Sheffield, S1 3DJ, Sheffield, UK.
| | - Alexander P Kao
- Zeiss Global Centre, School of Mechanical and Design Engineering, University of Portsmouth, PO1 3DJ, Portsmouth, UK.
| | | | - Aikaterina Karali
- Zeiss Global Centre, School of Mechanical and Design Engineering, University of Portsmouth, PO1 3DJ, Portsmouth, UK.
| | - Gordon W Blunn
- School of Pharmacy and Biomedical Sciences, University of Portsmouth, PO1 2DT, Portsmouth, UK.
| | - Asa H Barber
- Zeiss Global Centre, School of Mechanical and Design Engineering, University of Portsmouth, PO1 3DJ, Portsmouth, UK.
- School of Engineering, London South Bank University, SE1 0AA, London, UK.
| | - Gianluca Tozzi
- Zeiss Global Centre, School of Mechanical and Design Engineering, University of Portsmouth, PO1 3DJ, Portsmouth, UK.
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Stayton CT. Warped finite element models predict whole shell failure in turtle shells. J Anat 2018; 233:666-678. [PMID: 30058131 PMCID: PMC6182993 DOI: 10.1111/joa.12871] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/12/2018] [Indexed: 01/08/2023] Open
Abstract
Finite element (FE) models have become increasingly popular in comparative biomechanical studies, with researchers continually developing methods such as 'warping' preexisting models to facilitate analyses. However, few studies have investigated how well FE models can predict biologically crucial whole-structure performance or whether 'warped' models can provide useful information about the mechanical behavior of actual specimens. This study addresses both of these issues through a validation of warped FE models of turtle shells. FE models for 40 turtle specimens were built using 3D landmark coordinates and thin-plate spline interpolations to warp preexisting turtle shell models. Each actual turtle specimen was loaded to failure, and the load at failure and mode of fracture were then compared with the behavior predicted by the models. Overall, the models performed very well, despite the fact that many simplifying assumptions were made for analysis. Regressions of observed on predicted loads were significant for the dataset as a whole, as well as in separate analyses within two turtle species, and the direction of fracture was generally consistent with the patterns of stresses observed in the models. This was true even when size (an important factor in determining strength) was removed from analyses - the models were also able to predict which shells would be relatively stronger or weaker. Although some residual variation remains unexplained, this study supports the idea that warped FE models run with simplifying assumptions at least can provide useful information for comparative biomechanical studies.
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Agnew AM, Murach MM, Dominguez VM, Sreedhar A, Misicka E, Harden A, Bolte JH, Kang YS, Stammen J, Moorhouse K. Sources of Variability in Structural Bending Response of Pediatric and Adult Human Ribs in Dynamic Frontal Impacts. STAPP CAR CRASH JOURNAL 2018; 62:119-192. [PMID: 30608995 DOI: 10.4271/2018-22-0004] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Despite safety advances, thoracic injuries in motor vehicle crashes remain a significant source of morbidity and mortality, and rib fractures are the most prevalent of thoracic injuries. The objective of this study was to explore sources of variation in rib structural properties in order to identify sources of differential risk of rib fracture between vehicle occupants. A hierarchical model was employed to quantify the effects of demographic differences and rib geometry on structural properties including stiffness, force, displacement, and energy at failure and yield. Three-hundred forty-seven mid-level ribs from 182 individual anatomical donors were dynamically (~2 m/s) tested to failure in a simplified bending scenario mimicking a frontal thoracic impact. Individuals ranged in age from 4 - 108 years (mean 53 ± 23 years) and included 59 females and 123 males of diverse body sizes. Age, sex, body size, aBMD, whole rib geometry and cross-sectional geometry were explored as predictors of rib structural properties. Measures of cross-sectional rib size (Tt.Ar), bone quantity (Ct.Ar), and bone distribution (Z) generally explained more variation than any other predictors, and were further improved when normalized by rib length (e.g., robustness and WBSI). Cortical thickness (Ct.Th) was not found to be a useful predictor. Rib level predictors performed better than individual level predictors. These findings moderately explain differential risk for rib fracture and with additional exploration of the rib's role in thoracic response, may be able contribute to ATD and HBM development and alterations in addition to improvements to thoracic injury criteria and scaling methods.
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Affiliation(s)
- Amanda M Agnew
- Injury Biomechanics Research Center, The Ohio State University
| | | | | | | | - Elina Misicka
- Injury Biomechanics Research Center, The Ohio State University
| | - Angela Harden
- Injury Biomechanics Research Center, The Ohio State University
| | - John H Bolte
- Injury Biomechanics Research Center, The Ohio State University
| | - Yun-Seok Kang
- Injury Biomechanics Research Center, The Ohio State University
| | - Jason Stammen
- National Highway Traffic Safety Administration, Vehicle Research and Test Center
| | - Kevin Moorhouse
- National Highway Traffic Safety Administration, Vehicle Research and Test Center
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Singh A, Scholze M, Hammer N. On the influence of surface coating on tissue biomechanics - effects on rat bones under routine conditions with implications for image-based deformation detection. BMC Musculoskelet Disord 2018; 19:387. [PMID: 30368235 PMCID: PMC6204271 DOI: 10.1186/s12891-018-2308-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/27/2018] [Accepted: 10/17/2018] [Indexed: 11/10/2022] Open
Abstract
Background Biomechanical testing using image-based deformation detection techniques such as digital image correlation (DIC) offer optical contactless methods for strain and displacement measurements of biological tissues. However, given the need of most samples to be speckled for image correlation using sprays, chemical alterations with impact on tissue mechanicals may result. The aim of this study was to assess the impact of such surface coating on the mechanical properties of rat bones, under routine laboratory conditions including multiple freeze-thaw cycles. Methods Two groups of rat bones, highly-uniform and mixed-effects, were assigned to six subgroups consisting of three types of surface coating (uncoated, commercially-available water- and solvent-based sprays) and two types of bone conditions (periosteum attached and removed). The mixed-effects group had undergone an additional freeze-thaw cycle at − 20 degrees. All bones underwent a three-point bending test ranging until material failure. Results Coating resulted in similar and non-significantly different mechanical properties of rat bones, indicated by elastic moduli, maximum force and bending stress. Scanning electron microscopy showed more pronounced mechanical alterations related to the additional freeze-thaw cycle, with fewer cracks being present in a bone from the highly-uniform group. Conclusions This study has concluded that surface coating with water- or solvent-based sprays for enhancing image correlation for DIC and having an additional freeze-thaw cycle do not significantly alter mechanical properties of rat bones. Therefore, this method may be recommended as an effective way of obtaining a speckled pattern.
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Affiliation(s)
- Aqeeda Singh
- Department of Anatomy, University of Otago, Lindo Ferguson Building, 270 Great King St, Dunedin, 9016, New Zealand
| | - Mario Scholze
- Department of Anatomy, University of Otago, Lindo Ferguson Building, 270 Great King St, Dunedin, 9016, New Zealand.,Institute of Materials Science and Engineering, Chemnitz University of Technology, Chemnitz, Germany
| | - Niels Hammer
- Department of Anatomy, University of Otago, Lindo Ferguson Building, 270 Great King St, Dunedin, 9016, New Zealand. .,Department of Orthopedic and Trauma Surgery, University Clinics of Leipzig, Leipzig, Germany. .,Fraunhofer IWU, Dresden, Germany.
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