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Davis ZR, Gossett PC, Wilson RL, Kim W, Mei Y, Butz KD, Emery NC, Nauman EA, Avril S, Neu CP, Chan DD. Intervertebral Disc Elastography to Relate Shear Modulus and Relaxometry in Compression and Bending. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.09.01.555817. [PMID: 37732250 PMCID: PMC10508717 DOI: 10.1101/2023.09.01.555817] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/22/2023]
Abstract
Intervertebral disc degeneration is the most recognized cause of low back pain, characterized by the decline of tissue structure and mechanics. Image-based mechanical parameters (e.g., strain, stiffness) may provide an ideal assessment of disc function that is lost with degeneration but unfortunately remains underdeveloped. Moreover, it is unknown whether strain or stiffness of the disc may be predicted by MRI relaxometry (e.g. T1 or T2), an increasingly accepted quantitative measure of disc structure. In this study, we quantified T1 and T2 relaxation times and in-plane strains using displacement-encoded MRI within the disc under physiological levels of compression and bending. We then estimated shear modulus in orthogonal image planes and compared these values to relaxation times and strains within regions of the disc. Intratissue strain depended on the loading mode, and shear modulus in the nucleus pulposus was typically an order of magnitude lower than the annulus fibrosis, except in bending, where the apparent stiffness depended on the loading. Relative shear moduli estimated from strain data derived under compression generally did not correspond with those from bending experiments, with no correlations in the sagittal plane and only 4 of 15 regions correlated in the coronal plane, suggesting that future inverse models should incorporate multiple loading conditions. Strain imaging and strain-based estimation of material properties may serve as imaging biomarkers to distinguish healthy and diseased discs. Additionally, image-based elastography and relaxometry may be viewed as complementary measures of disc structure and function to assess degeneration in longitudinal studies.
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Affiliation(s)
- Zachary R. Davis
- Weldon School of Biomedical Engineering, Purdue University, West Lafayette, IN, USA
| | - Paull C. Gossett
- Weldon School of Biomedical Engineering, Purdue University, West Lafayette, IN, USA
| | - Robert L. Wilson
- Paul M. Rady Department of Mechanical Engineering, University of Colorado, Boulder, CO, USA
| | - Woong Kim
- Weldon School of Biomedical Engineering, Purdue University, West Lafayette, IN, USA
| | - Yue Mei
- State Key Laboratory of Structural Analysis for Industrial Equipment and International Research Center for Computational Mechanics, Department of Engineering Mechanics, Dalian University of Technology, Dalian, China
- Mines Saint-Étienne, Université Jean Monnet, INSERM, U 1059 Sainbiose, 42023, SaintÉtienne, France
| | - Kent D. Butz
- Weldon School of Biomedical Engineering, Purdue University, West Lafayette, IN, USA
- School of Mechanical Engineering, Purdue University, West Lafayette, IN, USA
| | - Nancy C. Emery
- Department of Ecology and Evolutionary Biology, University of Colorado, Boulder, CO, USA
| | - Eric A. Nauman
- Weldon School of Biomedical Engineering, Purdue University, West Lafayette, IN, USA
- School of Mechanical Engineering, Purdue University, West Lafayette, IN, USA
- Department of Biomedical Engineering, University of Cincinnati, Cincinnati, OH, USA
| | - Stéphane Avril
- Mines Saint-Étienne, Université Jean Monnet, INSERM, U 1059 Sainbiose, 42023, SaintÉtienne, France
| | - Corey P. Neu
- Weldon School of Biomedical Engineering, Purdue University, West Lafayette, IN, USA
- Paul M. Rady Department of Mechanical Engineering, University of Colorado, Boulder, CO, USA
- Biomedical Engineering Program, University of Colorado, Boulder, CO, USA
- BioFrontiers Institute, University of Colorado, Boulder, CO, USA
| | - Deva D. Chan
- Weldon School of Biomedical Engineering, Purdue University, West Lafayette, IN, USA
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Lee W, Miller EY, Zhu H, Schneider SE, Reiter DA, Neu CP. Multi-frame biomechanical and relaxometry analysis during in vivo loading of the human knee by spiral dualMRI and compressed sensing. Magn Reson Med 2023; 90:995-1009. [PMID: 37213087 PMCID: PMC10330244 DOI: 10.1002/mrm.29690] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2023] [Revised: 03/27/2023] [Accepted: 04/14/2023] [Indexed: 05/23/2023]
Abstract
PURPOSE Knee cartilage experiences repetitive loading during physical activities, which is altered during the pathogenesis of diseases like osteoarthritis. Analyzing the biomechanics during motion provides a clear understanding of the dynamics of cartilage deformation and may establish essential imaging biomarkers of early-stage disease. However, in vivo biomechanical analysis of cartilage during rapid motion is not well established. METHODS We used spiral displacement encoding with stimulated echoes (DENSE) MRI on in vivo human tibiofemoral cartilage during cyclic varus loading (0.5 Hz) and used compressed sensing on the k-space data. The applied compressive load was set for each participant at 0.5 times body weight on the medial condyle. Relaxometry methods were measured on the cartilage before (T1ρ , T2 ) and after (T1ρ ) varus load. RESULTS Displacement and strain maps showed a gradual shift of displacement and strain in time. Compressive strain was observed in the medial condyle cartilage and shear strain was roughly half of the compressive strain. Male participants had more displacement in the loading direction compared to females, and T1ρ values did not change after cyclic varus load. Compressed sensing reduced the scanning time up to 25% to 40% when comparing the displacement maps and substantially lowered the noise levels. CONCLUSION These results demonstrated the ease of which spiral DENSE MRI could be applied to clinical studies because of the shortened imaging time, while quantifying realistic cartilage deformations that occur through daily activities and that could serve as biomarkers of early osteoarthritis.
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Affiliation(s)
- Woowon Lee
- Paul M. Rady Department of Mechanical Engineering, University of Colorado Boulder, Boulder, CO, USA
| | - Emily Y. Miller
- Biomedical Engineering Program, University of Colorado Boulder, Boulder, CO, USA
| | - Hongtian Zhu
- Paul M. Rady Department of Mechanical Engineering, University of Colorado Boulder, Boulder, CO, USA
| | - Stephanie E. Schneider
- Paul M. Rady Department of Mechanical Engineering, University of Colorado Boulder, Boulder, CO, USA
| | - David A. Reiter
- Department of Radiology & Imaging Sciences, Emory University, Atlanta, GA, USA
| | - Corey P. Neu
- Paul M. Rady Department of Mechanical Engineering, University of Colorado Boulder, Boulder, CO, USA
- Biomedical Engineering Program, University of Colorado Boulder, Boulder, CO, USA
- BioFrontiers Institute, University of Colorado Boulder, Boulder, CO, USA
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Ristaniemi A, Šećerović A, Dischl V, Crivelli F, Heub S, Ledroit D, Weder G, Grad S, Ferguson SJ. Physiological and degenerative loading of bovine intervertebral disc in a bioreactor: A finite element study of complex motions. J Mech Behav Biomed Mater 2023; 143:105900. [PMID: 37201227 DOI: 10.1016/j.jmbbm.2023.105900] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2022] [Revised: 04/28/2023] [Accepted: 05/07/2023] [Indexed: 05/20/2023]
Abstract
Intervertebral disc (IVD) degeneration and regenerative therapies are commonly studied in organ-culture experiments with uniaxial compressive loading. Recently, in our laboratory, we established a bioreactor system capable of applying loads in six degrees-of-freedom (DOF) to bovine IVDs, which replicates more closely the complex multi-axial loading of the IVD in vivo. However, the magnitudes of loading that are physiological (able to maintain cell viability) or mechanically degenerative are unknown for load cases combining several DOFs. This study aimed to establish physiological and degenerative levels of maximum principal strains and stresses in the bovine IVD tissue and to investigate how they are achieved under complex load cases related to common daily activities. The physiological and degenerative levels of maximum principal strains and stresses were determined via finite element (FE) analysis of bovine IVD subjected to experimentally established physiological and degenerative compressive loading protocols. Then, complex load cases, such as a combination of compression + flexion + torsion, were applied on the FE-model with increasing magnitudes of loading to discover when physiological and degenerative tissue strains and stresses were reached. When applying 0.1 MPa of compression and ±2-3° of flexion and ±1-2° of torsion the investigated mechanical parameters remained at physiological levels, but with ±6-8° of flexion in combination with ±2-4° of torsion, the stresses in the outer annulus fibrosus (OAF) exceeded degenerative levels. In the case of compression + flexion + torsion, the mechanical degeneration likely initiates at the OAF when loading magnitudes are high enough. The physiological and degenerative magnitudes can be used as guidelines for bioreactor experiments with bovine IVDs.
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Affiliation(s)
| | | | - Vincent Dischl
- Institute for Biomechanics, ETH Zürich, Zürich, Switzerland
| | - Francesco Crivelli
- CSEM, Swiss Center for Electronics and Microtechnology, Alpnach, Switzerland
| | - Sarah Heub
- CSEM, Swiss Center for Electronics and Microtechnology, Neuchâtel, Switzerland
| | - Diane Ledroit
- CSEM, Swiss Center for Electronics and Microtechnology, Neuchâtel, Switzerland
| | - Gilles Weder
- CSEM, Swiss Center for Electronics and Microtechnology, Neuchâtel, Switzerland
| | - Sibylle Grad
- AO Research Institute Davos, Davos, Switzerland; Institute for Biomechanics, ETH Zürich, Zürich, Switzerland.
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Sun T, Wang J, Suo M, Liu X, Huang H, Zhang J, Zhang W, Li Z. The Digital Twin: A Potential Solution for the Personalized Diagnosis and Treatment of Musculoskeletal System Diseases. Bioengineering (Basel) 2023; 10:627. [PMID: 37370558 DOI: 10.3390/bioengineering10060627] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2023] [Revised: 05/12/2023] [Accepted: 05/20/2023] [Indexed: 06/29/2023] Open
Abstract
Due to the high prevalence and rates of disability associated with musculoskeletal system diseases, more thorough research into diagnosis, pathogenesis, and treatments is required. One of the key contributors to the emergence of diseases of the musculoskeletal system is thought to be changes in the biomechanics of the human musculoskeletal system. However, there are some defects concerning personal analysis or dynamic responses in current biomechanical research methodologies. Digital twin (DT) was initially an engineering concept that reflected the mirror image of a physical entity. With the application of medical image analysis and artificial intelligence (AI), it entered our lives and showed its potential to be further applied in the medical field. Consequently, we believe that DT can take a step towards personalized healthcare by guiding the design of industrial personalized healthcare systems. In this perspective article, we discuss the limitations of traditional biomechanical methods and the initial exploration of DT in musculoskeletal system diseases. We provide a new opinion that DT could be an effective solution for musculoskeletal system diseases in the future, which will help us analyze the real-time biomechanical properties of the musculoskeletal system and achieve personalized medicine.
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Affiliation(s)
- Tianze Sun
- Department of Orthopedics, First Affiliated Hospital of Dalian Medical University, Dalian 116600, China
- Key Laboratory of Molecular Mechanism for Repair and Remodeling of Orthopedic Diseases, Dalian 116000, China
| | - Jinzuo Wang
- Department of Orthopedics, First Affiliated Hospital of Dalian Medical University, Dalian 116600, China
- Key Laboratory of Molecular Mechanism for Repair and Remodeling of Orthopedic Diseases, Dalian 116000, China
| | - Moran Suo
- Department of Orthopedics, First Affiliated Hospital of Dalian Medical University, Dalian 116600, China
- Key Laboratory of Molecular Mechanism for Repair and Remodeling of Orthopedic Diseases, Dalian 116000, China
| | - Xin Liu
- Department of Orthopedics, First Affiliated Hospital of Dalian Medical University, Dalian 116600, China
- Key Laboratory of Molecular Mechanism for Repair and Remodeling of Orthopedic Diseases, Dalian 116000, China
| | - Huagui Huang
- Department of Orthopedics, First Affiliated Hospital of Dalian Medical University, Dalian 116600, China
- Key Laboratory of Molecular Mechanism for Repair and Remodeling of Orthopedic Diseases, Dalian 116000, China
| | - Jing Zhang
- Department of Orthopedics, First Affiliated Hospital of Dalian Medical University, Dalian 116600, China
- Key Laboratory of Molecular Mechanism for Repair and Remodeling of Orthopedic Diseases, Dalian 116000, China
| | - Wentao Zhang
- Department of Orthopedics, First Affiliated Hospital of Dalian Medical University, Dalian 116600, China
- Key Laboratory of Molecular Mechanism for Repair and Remodeling of Orthopedic Diseases, Dalian 116000, China
| | - Zhonghai Li
- Department of Orthopedics, First Affiliated Hospital of Dalian Medical University, Dalian 116600, China
- Key Laboratory of Molecular Mechanism for Repair and Remodeling of Orthopedic Diseases, Dalian 116000, China
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Tavana S, Davis B, Canali I, Scott K, Leong JJH, Freedman BA, Newell N. A novel tool to quantify in vivo lumbar spine kinematics and 3D intervertebral disc strains using clinical MRI. J Mech Behav Biomed Mater 2023; 140:105730. [PMID: 36801782 DOI: 10.1016/j.jmbbm.2023.105730] [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: 09/23/2022] [Revised: 01/27/2023] [Accepted: 02/11/2023] [Indexed: 02/15/2023]
Abstract
Medical imaging modalities that calculate tissue morphology alone cannot provide direct information regarding the mechanical behaviour of load-bearing musculoskeletal organs. Accurate in vivo measurement of spine kinematics and intervertebral disc (IVD) strains can provide important information regarding the mechanical behaviour of the spine, help to investigate the effects of injuries on the mechanics of the spine, and assess the effectiveness of treatments. Additionally, strains can serve as a functional biomechanical marker for detecting normal and pathologic tissues. We hypothesised that combining digital volume correlation (DVC) with 3T clinical MRI can provide direct information regarding the mechanics of the spine. Here, we have developed a novel non-invasive tool for in vivo displacement and strain measurement within the human lumbar spine and we used this tool to calculate lumbar kinematics and IVD strains in six healthy subjects during lumbar extension. The proposed tool enabled spine kinematics and IVD strains to be measured with errors that did not exceed 0.17 mm and 0.5%, respectively. The findings of the kinematics study identified that during extension the lumbar spine of healthy subjects experiences total 3D translations ranging from 1 mm to 4.5 mm for different vertebral levels. The findings of strain analysis identified that the average of the maximum tensile, compressive, and shear strains for different lumbar levels during extension ranged from 3.5% to 7.2%. This tool can provide base-line data that can be used to describe the mechanical environment of healthy lumbar spine, which can help clinicians manage preventative treatments, define patient-specific treatments, and to monitor the effectiveness of surgical and non-surgical interventions.
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Affiliation(s)
- S Tavana
- Department of Bioengineering, Imperial College London, London, UK
| | - B Davis
- Fortius Clinic, Fitzhardinge Street, London, UK
| | - I Canali
- Fortius Clinic, Fitzhardinge Street, London, UK
| | - K Scott
- Fortius Clinic, Fitzhardinge Street, London, UK
| | - J J H Leong
- Royal National Orthopaedic Hospital, Stanmore, UK; UCL Institute of Orthopaedics and Musculoskeletal Science, London, UK
| | | | - N Newell
- Department of Bioengineering, Imperial College London, London, UK.
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Lee W, Miller EY, Zhu H, Luetkemeyer CM, Schneider SE, Neu CP. High frame rate deformation analysis of knee cartilage by spiral dualMRI and relaxation mapping. Magn Reson Med 2023; 89:694-709. [PMID: 36300860 PMCID: PMC10017275 DOI: 10.1002/mrm.29487] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2022] [Revised: 09/20/2022] [Accepted: 09/21/2022] [Indexed: 12/13/2022]
Abstract
PURPOSE Daily activities including walking impose high-frequency cyclic forces on cartilage and repetitive compressive deformation. Analyzing cartilage deformation during walking would provide spatial maps of displacement and strain and enable viscoelastic characterization, which may serve as imaging biomarkers for early cartilage degeneration when the damage is still reversible. However, the time-dependent biomechanics of cartilage is not well described, and how defects in the joint impact the viscoelastic response is unclear. METHODS We used spiral acquisition with displacement-encoding MRI to quantify displacement and strain maps at a high frame rate (25 frames/s) in tibiofemoral joints. We also employed relaxometry methods (T1 , T1ρ , T2 , T2 *) on the cartilage. RESULTS Normal and shear strains were concentrated on the bovine tibiofemoral contact area during loading, and the defected joint exhibited larger compressive strains. We also determined a positive correlation between the change of T1ρ in cartilage after cyclic loading and increased compressive strain on the defected joint. Viscoelastic behavior was quantified by the time-dependent displacement, where the damaged joint showed increased creep behavior compared to the intact joint. This technique was also successfully demonstrated on an in vivo human knee showing the gradual change of displacement during varus load. CONCLUSION Our results indicate that spiral scanning with displacement encoding can quantitatively differentiate the damaged from intact joint using the strain and creep response. The viscoelastic response identified with this methodology could serve as biomarkers to detect defects in joints in vivo and facilitate the early diagnosis of joint diseases such as osteoarthritis.
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Affiliation(s)
- Woowon Lee
- Paul M. Rady Department of Mechanical Engineering, University of Colorado Boulder, Boulder, CO, USA
| | - Emily Y. Miller
- Biomedical Engineering Program, University of Colorado Boulder, Boulder, CO, USA
| | - Hongtian Zhu
- Paul M. Rady Department of Mechanical Engineering, University of Colorado Boulder, Boulder, CO, USA
| | - Callan M. Luetkemeyer
- Paul M. Rady Department of Mechanical Engineering, University of Colorado Boulder, Boulder, CO, USA
| | - Stephanie E. Schneider
- Paul M. Rady Department of Mechanical Engineering, University of Colorado Boulder, Boulder, CO, USA
| | - Corey P. Neu
- Paul M. Rady Department of Mechanical Engineering, University of Colorado Boulder, Boulder, CO, USA
- Biomedical Engineering Program, University of Colorado Boulder, Boulder, CO, USA
- BioFrontiers Institute, University of Colorado Boulder, Boulder, CO, USA
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Coppock JA, Zimmer NE, Englander ZA, Danyluk ST, Kosinski AS, Spritzer CE, Goode AP, DeFrate LE. In vivo intervertebral disc mechanical deformation following a treadmill walking "stress test" is inversely related to T1rho relaxation time. Osteoarthritis Cartilage 2023; 31:126-133. [PMID: 36191831 PMCID: PMC10127291 DOI: 10.1016/j.joca.2022.09.008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/29/2022] [Revised: 09/12/2022] [Accepted: 09/24/2022] [Indexed: 02/02/2023]
Abstract
OBJECTIVE To assess the in vivo relationship between the mechanical response of intervertebral discs (IVDs) to dynamic activity and IVD biochemical composition assessed via T1rho relaxation imaging. DESIGN Eighteen asymptomatic participants with no history of low back pain (LBP), injury, or surgery underwent magnetic resonance (MR) imaging of their lumbar spine prior to and immediately following a treadmill walking "stress test." Anatomic (SPACE, FLASH) MR images were obtained pre- and post-exercise and utilized to measure IVD mechanical deformation. Quantitative (T1rho) imaging was performed pre-exercise to reflect IVD composition. Pre-exercise anatomic images were also utilized to assess IVD degenerative status based on the modified Pfirrmann scale. To quantify mechanical response, 3D surface models of the L1-L2-L5-S1 IVDs were created from manual segmentations of pre- and post-exercise anatomic images and utilized to assess changes in IVD height. IVD strain (%) was defined as change in IVD height normalized to pre-activity height. Linear mixed models were used to assess the relationships between IVD mechanical deformation (strain), composition (T1rho relaxation time), and degenerative status (Pfirrmann grade). RESULTS Increased compressive IVD strain was associated with lower T1rho relaxation times in the nucleus pulposus (NP) of the disc (βT1rho=5.07,CI:[1.52,7.77],Rmarg2=0.52,p=0.005). Thus, an inverse relationship between IVD strain and NP T1rho relaxation time was observed. CONCLUSION The in vivo mechanical response of the IVD to the "stress test" was sensitive to differences in NP composition. The results of this study suggest that quantification of in vivo IVD mechanical function and composition may provide insight into IVD health.
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Affiliation(s)
- J A Coppock
- Department of Biomedical Engineering, Duke University, Durham, NC, USA; Department of Orthopedic Surgery, Duke University School of Medicine, Durham, NC, USA
| | - N E Zimmer
- Department of Biomedical Engineering, Duke University, Durham, NC, USA; Department of Orthopedic Surgery, Duke University School of Medicine, Durham, NC, USA
| | - Z A Englander
- Department of Biomedical Engineering, Duke University, Durham, NC, USA; Department of Orthopedic Surgery, Duke University School of Medicine, Durham, NC, USA
| | - S T Danyluk
- Department of Orthopedic Surgery, Duke University School of Medicine, Durham, NC, USA
| | - A S Kosinski
- Department of Biostatistics & Bioinformatics, Duke University, Durham, NC, USA; Duke Clinical Research Institute, Duke University School of Medicine, Durham, NC, USA
| | - C E Spritzer
- Department of Radiology, Duke University School of Medicine, Durham, NC, USA
| | - A P Goode
- Department of Orthopedic Surgery, Duke University School of Medicine, Durham, NC, USA; Duke Clinical Research Institute, Duke University School of Medicine, Durham, NC, USA; Department of Population Health Sciences, Duke University, Durham, NC, USA
| | - L E DeFrate
- Department of Biomedical Engineering, Duke University, Durham, NC, USA; Department of Orthopedic Surgery, Duke University School of Medicine, Durham, NC, USA; Department of Mechanical Engineering and Materials Science, Duke University, Durham, NC, USA.
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Nikolov DP, Srivastava S, Abeid BA, Scheven UM, Arruda EM, Garikipati K, Estrada JB. Ogden material calibration via magnetic resonance cartography, parameter sensitivity and variational system identification. PHILOSOPHICAL TRANSACTIONS. SERIES A, MATHEMATICAL, PHYSICAL, AND ENGINEERING SCIENCES 2022; 380:20210324. [PMID: 36031828 DOI: 10.1098/rsta.2021.0324] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/31/2022] [Accepted: 07/17/2022] [Indexed: 06/15/2023]
Abstract
Contemporary material characterization techniques that leverage deformation fields and the weak form of the equilibrium equations face challenges in the numerical solution procedure of the inverse characterization problem. As material models and descriptions differ, so too must the approaches for identifying parameters and their corresponding mechanisms. The widely used Ogden material model can be comprised of a chosen number of terms of the same mathematical form, which presents challenges of parsimonious representation, interpretability and stability. Robust techniques for system identification of any material model are important to assess and improve experimental design, in addition to their centrality to forward computations. Using fully three-dimensional displacement fields acquired in silicone elastomers with our recently developed magnetic resonance cartography (MR-u) technique on the order of greater than [Formula: see text], we leverage partial differential equation-constrained optimization as the basis of variational system identification of our material parameters. We incorporate the statistical F-test to maintain parsimony of representation. Using a new, local deformation decomposition locally into mixtures of biaxial and uniaxial tensile states, we evaluate experiments based on an analytical sensitivity metric and discuss the implications for experimental design. This article is part of the theme issue 'The Ogden model of rubber mechanics: Fifty years of impact on nonlinear elasticity'.
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Affiliation(s)
- Denislav P Nikolov
- Department of Mechanical Engineering, University of Michigan, Ann Arbor, MI 48109, USA
| | - Siddhartha Srivastava
- Department of Mechanical Engineering, University of Michigan, Ann Arbor, MI 48109, USA
| | - Bachir A Abeid
- Department of Mechanical Engineering, University of Michigan, Ann Arbor, MI 48109, USA
| | - Ulrich M Scheven
- Department of Mechanical Engineering, University of Michigan, Ann Arbor, MI 48109, USA
- Department of Biomedical Engineering, University of Michigan, Ann Arbor, MI 48109, USA
| | - Ellen M Arruda
- Department of Mechanical Engineering, University of Michigan, Ann Arbor, MI 48109, USA
- Department of Biomedical Engineering, University of Michigan, Ann Arbor, MI 48109, USA
- Program in Macromolecular Science and Engineering, University of Michigan, Ann Arbor, MI 48109, USA
| | - Krishna Garikipati
- Department of Mechanical Engineering, University of Michigan, Ann Arbor, MI 48109, USA
- Department of Mathematics, University of Michigan, Ann Arbor, MI 48109, USA
- Michigan Institute for Computational Discovery and Engineering, University of Michigan, Ann Arbor, MI 48109, USA
| | - Jonathan B Estrada
- Department of Mechanical Engineering, University of Michigan, Ann Arbor, MI 48109, USA
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Tavakoli J, Geargeflia S, Tipper JL, Diwan AD. Magnetic resonance elastography: A non-invasive biomarker for low back pain studies. BIOMEDICAL ENGINEERING ADVANCES 2021. [DOI: 10.1016/j.bea.2021.100014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022] Open
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CAO FU, FU RONGCHANG, WANG WENYUAN. A BIOMECHANICAL STUDY OF THE EFFECTS OF FLEXION ANGLE ON THE INDUCTION MECHANISM OF CERVICAL SPONDYLOSIS. J MECH MED BIOL 2021. [DOI: 10.1142/s0219519421500536] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Lesions in facet joints such as bone hyperplasia and degenerative changes in the intervertebral discs, can compress nerve roots and the spinal cord, leading to cervical spondylosis (CS). Lesions in these parts of the spine are commonly related to abnormal loads caused by bad posture of the cervical spine. This study aimed to understand the potential mechanical effects of load amplitude on cervical spine motion to provide a theoretical basis for the biomechanical causes of CS, and to provide a reference for preventing of the condition. In this study, a finite element model of the normal human cervical spine (C1-C7) was established and validated using an infrared motion capture system to analyze the effects of flexion angle on the stresses experienced by intervertebral discs, the anterior edge of the vertebral body, the pedicle, uncinate and facet joints. Our analysis indicated that the intervertebral disc load increased by at least 70% during the 20∘ to 45∘ flexion of the neck with 121% load increase in the vertebrae. In the intervertebral discs, the stress was largest at C4-C5, and the stress was moderate at C5-C6. These results are consistent with clinical CS prone site research. According to Wolff’s law, when bones are placed under large stresses, hyperplasia can result to allow adaptation to large loads. Increased cervical spine flexion angles caused the proliferation of bone in the above-mentioned parts of the spine and can accelerate accelerating the appearance of CS.
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Affiliation(s)
- FU CAO
- School of Mechanical Engineering, Xinjiang University, Urumqi 830047, Urumqi, P. R. China
| | - RONGCHANG FU
- School of Mechanical Engineering, Xinjiang University, Urumqi 830047, Urumqi, P. R. China
| | - WENYUAN WANG
- School of Mechanical Engineering, Xinjiang University, Urumqi 830047, Urumqi, P. R. China
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Gkantsinikoudis N, Kapetanakis S, Magras I, Tsiridis E, Kritis A. Tissue-Engineering of Human Intervertebral Disc: A Concise Review. TISSUE ENGINEERING PART B-REVIEWS 2021; 28:848-860. [PMID: 34409867 DOI: 10.1089/ten.teb.2021.0090] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Intervertebral disc (IVD) represents a structure of crucial structural and functional importance for human spine. Pathology of IVD institutes a frequently encountered condition in current clinical practice. Degenerative Disc Disease (DDD), the principal clinical representative of IVD pathology, constitutes an increasingly diagnosed spinal disorder associated with substantial morbidity and mortality in recent years. Despite the considerable incidence and socioeconomic burden of DDD, existing treatment modalities including conservative and surgical methods have been demonstrated to provide a limited therapeutic effect, being not capable of interrupting or reversing natural progress of underlying disease. These limitations underline the requirement for development of novel, innovative and more effective therapeutic strategies for DDD management. Within this literature framework, compromised IVD replacement with a viable IVD construct manufactured with Tissue-Engineering (TE) methods has been recommended as a promising therapeutic strategy for DDD. Existing preliminary preclinical data demonstrate that proper combination of cells from various sources, different scaffold materials and appropriate signaling molecules renders manufacturing of whole-IVD tissue-engineered constructs a technically feasible process. Aim of this narrative review is to critically summarize current published evidence regarding particular aspects of IVD-TE, primarily emphasizing in providing researchers in this field with practicable knowledge in order to enhance clinical translatability of their research and informing clinical practitioners about the features and capabilities of innovative TE science in the field of IVD-TE.
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Affiliation(s)
- Nikolaos Gkantsinikoudis
- School of Medicine, Faculty of Health Sciences, Aristotle University of Thessaloniki (A.U.Th.), Department of Physiology and Pharmacology , Thessaloniki, Greece.,School of Medicine, Faculty of Health Sciences, Aristotle University of Thessaloniki (A.U.Th), cGMP Regenerative Medicine Facility, Department of Physiology and Pharmacology, Thessaloniki, Greece;
| | - Stylianos Kapetanakis
- Interbalkan European Medical Center, Spine Department and Deformities, Thessaloniki, Greece;
| | - Ioannis Magras
- AHEPA University General Hospital, Aristotle University of Thessaloniki, Department of Neurosurgery, Thessaloniki, Greece;
| | - Eleftherios Tsiridis
- Papageorgiou General Hospital, Aristotle University Medical School, Academic Orthopaedic Department, Thessaloniki Ring Road, Nea Efkarpia, Greece.,Aristotle University Thessaloniki, Balkan Center, Buildings A & B, Center of Orthopaedics and Regenerative Medicine (C.O.RE.), Center of Interdisciplinary Research and Innovation (C.I.R.I.), Thessaloniki, 10th km Thessaloniki-Thermi Rd, Greece;
| | - Aristeidis Kritis
- School of Medicine, Faculty of Health Sciences, Aristotle University of Thessaloniki (A.U.Th.), Department of Physiology and Pharmacology , Thessaloniki, Greece.,School of Medicine, Faculty of Health Sciences, Aristotle University of Thessaloniki (A.U.Th), cGMP Regenerative Medicine Facility, Department of Physiology and Pharmacology, Thessaloniki, Greece;
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