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Xu ML, Yang YT, Zeng HZ, Cao YT, Zheng LD, Jin C, Zhu SJ, Zhu R. Finite element modeling and analysis of effect of preexisting cervical degenerative disease on the spinal cord during flexion and extension. Med Biol Eng Comput 2024; 62:1089-1104. [PMID: 38148413 DOI: 10.1007/s11517-023-02993-x] [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: 06/17/2023] [Accepted: 12/07/2023] [Indexed: 12/28/2023]
Abstract
Recent studies have emphasized the importance of dynamic activity in the development of myelopathy. However, current knowledge of how degenerative factors affect the spinal cord during motion is still limited. This study aimed to investigate the effect of various types of preexisting herniated cervical disc and the ligamentum flavum ossification on the spinal cord during cervical flexion and extension. A detailed dynamic fluid-structure interaction finite element model of the cervical spine with the spinal cord was developed and validated. The changes of von Mises stress and maximum principal strain within the spinal cord in the period of normal, hyperflexion, and hyperextension were investigated, considering various types and grades of disc herniation and ossification of the ligamentum flavum. The flexion and extension of the cervical spine with spinal canal encroachment induced high stress and strain inside the spinal cord, and this effect was also amplified by increased canal encroachments and cervical hypermobility. The spinal cord might evade lateral encroachment, leading to a reduction in the maximum stress and principal strain within the spinal cord in local-type herniation. Although the impact was limited in the case of diffuse type, the maximum stress tended to appear in the white matter near the encroachment site while compression from both ventral and dorsal was essential to make maximum stress appear in the grey matter. The existence of canal encroachment can reduce the safe range for spinal cord activities, and hypermobility activities may induce spinal cord injury. Besides, the ligamentum flavum plays an important role in the development of central canal syndrome.Significance. This model will enable researchers to have a better understanding of the influence of cervical degenerative diseases on the spinal cord during extension and flexion.
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Affiliation(s)
- Meng-Lei Xu
- Shanghai YangZhi Rehabilitation Hospital (Shanghai Sunshine Rehabilitation Center), School of Medicine, Tongji University, Shanghai, 200092, China
- Key Laboratory of Spine and Spinal Cord Injury Repair and Regeneration of the Ministry of Education, Tongji Hospital, School of Medicine, Tongji University, 389 Xincun Road, Shanghai, 200065, China
| | - Yi-Ting Yang
- Shanghai YangZhi Rehabilitation Hospital (Shanghai Sunshine Rehabilitation Center), School of Medicine, Tongji University, Shanghai, 200092, China
| | - Hui-Zi Zeng
- Shanghai YangZhi Rehabilitation Hospital (Shanghai Sunshine Rehabilitation Center), School of Medicine, Tongji University, Shanghai, 200092, China
| | - Yu-Ting Cao
- Shanghai YangZhi Rehabilitation Hospital (Shanghai Sunshine Rehabilitation Center), School of Medicine, Tongji University, Shanghai, 200092, China
| | - Liang-Dong Zheng
- Shanghai YangZhi Rehabilitation Hospital (Shanghai Sunshine Rehabilitation Center), School of Medicine, Tongji University, Shanghai, 200092, China
| | - Chen Jin
- Shanghai YangZhi Rehabilitation Hospital (Shanghai Sunshine Rehabilitation Center), School of Medicine, Tongji University, Shanghai, 200092, China
- Key Laboratory of Spine and Spinal Cord Injury Repair and Regeneration of the Ministry of Education, Tongji Hospital, School of Medicine, Tongji University, 389 Xincun Road, Shanghai, 200065, China
| | - Shi-Jie Zhu
- Shanghai YangZhi Rehabilitation Hospital (Shanghai Sunshine Rehabilitation Center), School of Medicine, Tongji University, Shanghai, 200092, China
| | - Rui Zhu
- Shanghai YangZhi Rehabilitation Hospital (Shanghai Sunshine Rehabilitation Center), School of Medicine, Tongji University, Shanghai, 200092, China.
- Key Laboratory of Spine and Spinal Cord Injury Repair and Regeneration of the Ministry of Education, Tongji Hospital, School of Medicine, Tongji University, 389 Xincun Road, Shanghai, 200065, China.
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Nazari AR. Simulation of cancer progression in bone by a virtual thermal flux with a case study on lumbar vertebrae with multiple myeloma. Med Eng Phys 2024; 126:104147. [PMID: 38621839 DOI: 10.1016/j.medengphy.2024.104147] [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: 11/02/2023] [Revised: 02/15/2024] [Accepted: 03/09/2024] [Indexed: 04/17/2024]
Abstract
BACKGROUND Two main problems examining the mechanism of cancer progression in the tissues using the computational models are lack of enough knowledge on the effective factors for such events in vivo environments and lack of specific parameters in the available computational models to simulate such complicated reactions. METHODS In this study, it was tried to simulate the progression of cancerous lesions in the bone tissues by an independent parameter from the anatomical and physiological characteristics of the tissues, so to degrade the orthotropic mechanical properties of the bone tissues, a virtual temperature was determined to be used by a well-known framework for simulation of damages in the composite materials. First, the reliability of the FE model to simulate hyperelastic response in the intervertebral discs (IVDs) and progressive failure in the bony components were verified by simulation of some In-Vitro tests, available in the literature. Then, the progression of the osteolytic damage was simulated in a clinical case with multiple myeloma in the lumbar vertebrae. RESULTS The FE model could simulate stress-shielding and diffusion of lesion in the posterior elements of the damaged vertebra which led to spinal stenosis. The load carrying shares associated with the anterior half and the posterior half of the examined vertebral body and the posterior elements were estimated equal to 41 %, 47 % and 12 %, respectively for the intact condition, that changed to 14 %, 16 % and 70 %, when lesion occupied one third of the vertebral body. CONCLUSION Correlation of the FE results with the deformation shapes, observed in the MRIs for the clinical case study, indicated appropriateness of the procedure, proposed for simulation of the progressive osteolytic damage in the vertebral segments. The future studies may follow simulation of tumor growth for various metastatic tissues using the method, established here.
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Affiliation(s)
- A R Nazari
- Department of Civil Engineering, Technical & Vocational University, Tehran, Iran; Biomechanics Research Lab, Technical & Vocational University, Tehran, Iran.
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Davies B, Schaefer S, Rafati Fard A, Newcombe V, Sutcliffe M. Finite Element Analysis for Degenerative Cervical Myelopathy: Scoping Review of the Current Findings and Design Approaches, Including Recommendations on the Choice of Material Properties. JMIR BIOMEDICAL ENGINEERING 2024; 9:e48146. [PMID: 38875683 PMCID: PMC11041437 DOI: 10.2196/48146] [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: 04/13/2023] [Revised: 10/31/2023] [Accepted: 02/15/2024] [Indexed: 06/16/2024] Open
Abstract
BACKGROUND Degenerative cervical myelopathy (DCM) is a slow-motion spinal cord injury caused via chronic mechanical loading by spinal degenerative changes. A range of different degenerative changes can occur. Finite element analysis (FEA) can predict the distribution of mechanical stress and strain on the spinal cord to help understand the implications of any mechanical loading. One of the critical assumptions for FEA is the behavior of each anatomical element under loading (ie, its material properties). OBJECTIVE This scoping review aims to undertake a structured process to select the most appropriate material properties for use in DCM FEA. In doing so, it also provides an overview of existing modeling approaches in spinal cord disease and clinical insights into DCM. METHODS We conducted a scoping review using qualitative synthesis. Observational studies that discussed the use of FEA models involving the spinal cord in either health or disease (including DCM) were eligible for inclusion in the review. We followed the PRISMA-ScR (Preferred Reporting Items for Systematic Reviews and Meta-Analyses extension for Scoping Reviews) guidelines. The MEDLINE and Embase databases were searched to September 1, 2021. This was supplemented with citation searching to retrieve the literature used to define material properties. Duplicate title and abstract screening and data extraction were performed. The quality of evidence was appraised using the quality assessment tool we developed, adapted from the Newcastle-Ottawa Scale, and shortlisted with respect to DCM material properties, with a final recommendation provided. A qualitative synthesis of the literature is presented according to the Synthesis Without Meta-Analysis reporting guidelines. RESULTS A total of 60 papers were included: 41 (68%) "FEA articles" and 19 (32%) "source articles." Most FEA articles (33/41, 80%) modeled the gray matter and white matter separately, with models typically based on tabulated data or, less frequently, a hyperelastic Ogden variant or linear elastic function. Of the 19 source articles, 14 (74%) were identified as describing the material properties of the spinal cord, of which 3 (21%) were considered most relevant to DCM. Of the 41 FEA articles, 15 (37%) focused on DCM, of which 9 (60%) focused on ossification of the posterior longitudinal ligament. Our aggregated results of DCM FEA indicate that spinal cord loading is influenced by the pattern of degenerative changes, with decompression alone (eg, laminectomy) sufficient to address this as opposed to decompression combined with other procedures (eg, laminectomy and fusion). CONCLUSIONS FEA is a promising technique for exploring the pathobiology of DCM and informing clinical care. This review describes a structured approach to help future investigators deploy FEA for DCM. However, there are limitations to these recommendations and wider uncertainties. It is likely that these will need to be overcome to support the clinical translation of FEA to DCM.
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Affiliation(s)
- Benjamin Davies
- Department of Medicine, University of Cambridge, Cambridge, United Kingdom
| | - Samuel Schaefer
- Department of Engineering, University of Cambridge, Cambridge, United Kingdom
| | - Amir Rafati Fard
- Department of Medicine, University of Cambridge, Cambridge, United Kingdom
| | - Virginia Newcombe
- Department of Medicine, University of Cambridge, Cambridge, United Kingdom
| | - Michael Sutcliffe
- Department of Engineering, University of Cambridge, Cambridge, United Kingdom
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Singhal I, Harinathan B, Warraich A, Purushothaman Y, Budde MD, Yoganandan N, Vedantam A. Finite element modeling of the human cervical spinal cord and its applications: A systematic review. NORTH AMERICAN SPINE SOCIETY JOURNAL 2023; 15:100246. [PMID: 37636342 PMCID: PMC10448221 DOI: 10.1016/j.xnsj.2023.100246] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/31/2023] [Revised: 07/01/2023] [Accepted: 07/23/2023] [Indexed: 08/29/2023]
Abstract
Background Context Finite element modeling (FEM) is an established tool to analyze the biomechanics of complex systems. Advances in computational techniques have led to the increasing use of spinal cord FEMs to study cervical spinal cord pathology. There is considerable variability in the creation of cervical spinal cord FEMs and to date there has been no systematic review of the technique. The aim of this study was to review the uses, techniques, limitations, and applications of FEMs of the human cervical spinal cord. Methods A literature search was performed through PubMed and Scopus using the words finite element analysis, spinal cord, and biomechanics. Studies were selected based on the following inclusion criteria: (1) use of human spinal cord modeling at the cervical level; (2) model the cervical spinal cord with or without the osteoligamentous spine; and (3) the study should describe an application of the spinal cord FEM. Results Our search resulted in 369 total publications, 49 underwent reviews of the abstract and full text, and 23 were included in the study. Spinal cord FEMs are used to study spinal cord injury and trauma, pathologic processes, and spine surgery. Considerable variation exists in the derivation of spinal cord geometries, mathematical models, and material properties. Less than 50% of the FEMs incorporate the dura mater, cerebrospinal fluid, nerve roots, and denticulate ligaments. Von Mises stress, and strain of the spinal cord are the most common outputs studied. FEM offers the opportunity for dynamic simulation, but this has been used in only four studies. Conclusions Spinal cord FEM provides unique insight into the stress and strain of the cervical spinal cord in various pathological conditions and allows for the simulation of surgical procedures. Standardization of modeling parameters, anatomical structures and inclusion of patient-specific data are necessary to improve the clinical translation.
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Affiliation(s)
- Ishan Singhal
- Department of Neurosurgery, Medical College of Wisconsin, 9200 W Wisconsin Ave, Milwaukee, WI 53226, United States
| | - Balaji Harinathan
- Department of Neurosurgery, Medical College of Wisconsin, 9200 W Wisconsin Ave, Milwaukee, WI 53226, United States
| | - Ali Warraich
- University of Chicago, 1413 East 57 St, Chicago, IL 60637, United States
| | - Yuvaraj Purushothaman
- Department of Neurosurgery, Medical College of Wisconsin, 9200 W Wisconsin Ave, Milwaukee, WI 53226, United States
| | - Matthew D. Budde
- Department of Neurosurgery, Medical College of Wisconsin, 9200 W Wisconsin Ave, Milwaukee, WI 53226, United States
| | - Narayan Yoganandan
- Department of Neurosurgery, Medical College of Wisconsin, 9200 W Wisconsin Ave, Milwaukee, WI 53226, United States
| | - Aditya Vedantam
- Department of Neurosurgery, Medical College of Wisconsin, 9200 W Wisconsin Ave, Milwaukee, WI 53226, United States
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Frantsuzov R, Mondal S, Walsh CM, Reynolds JP, Dooley D, MacManus DB. A finite element model of contusion spinal cord injury in rodents. J Mech Behav Biomed Mater 2023; 142:105856. [PMID: 37087955 DOI: 10.1016/j.jmbbm.2023.105856] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2023] [Revised: 04/02/2023] [Accepted: 04/12/2023] [Indexed: 04/25/2023]
Abstract
Traumatic spinal cord injuries result from high impact forces acting on the spine and are proceeded by an extensive secondary inflammatory response resulting in motor, sensory, and autonomic dysfunction. Experimental in vivo traumatic spinal cord injuries in rodents using a contusion model have been extremely useful in elucidating the underlying pathophysiology of these injuries. However, the relationship between the pathophysiology and the biomechanical factors is still not well understood. Therefore, the aim of this research is to provide a comprehensive analysis of the biomechanics of traumatic spinal cord injury in a rat contusion model. This is achieved through the development and validation of a finite element model of the thoracic rat spinal cord and subsequently simulating controlled cortical impact-induced traumatic spinal cord injury. The effects of impactor velocity, depth, and geometry on the resulting stresses and strains within the spinal cord are investigated. Our results show that increasing impactor depth results in larger stresses and strains within the spinal cord tissue as expected. Further, for the first time ever our results show that impactor geometry (spherical versus cylindrical) plays an important role in the distribution and magnitude of stresses and strains within the cord. Therefore, finite element modelling can be a powerful tool used to predict stresses and strains that occur in spinal cord tissue during trauma.
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Affiliation(s)
- Roman Frantsuzov
- School of Mechanical & Manufacturing Engineering, Dublin City University, Dublin, Ireland
| | - Subrata Mondal
- School of Mechanical & Manufacturing Engineering, Dublin City University, Dublin, Ireland
| | - Ciara M Walsh
- School of Medicine, University College Dublin, Dublin, Ireland; Conway Institute of Biomolecular and Biomedical Research, University College Dublin, Ireland
| | - James P Reynolds
- School of Medicine, University College Dublin, Dublin, Ireland; Conway Institute of Biomolecular and Biomedical Research, University College Dublin, Ireland
| | - Dearbhaile Dooley
- School of Medicine, University College Dublin, Dublin, Ireland; Conway Institute of Biomolecular and Biomedical Research, University College Dublin, Ireland
| | - David B MacManus
- School of Mechanical & Manufacturing Engineering, Dublin City University, Dublin, Ireland; MEDeng Research Centre, Dublin City University, Dublin, Ireland; Biodesign Europe, Dublin City University, Dublin, Ireland; School of Mechanical & Materials Engineering, University College Dublin, Dublin, Ireland.
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Effect of degenerative factors on cervical spinal cord during flexion and extension: a dynamic finite element analysis. Biomech Model Mechanobiol 2022; 21:1743-1759. [PMID: 35931861 DOI: 10.1007/s10237-022-01617-x] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2021] [Accepted: 07/13/2022] [Indexed: 11/02/2022]
Abstract
Spinal cord injury (SCI) is a global problem that brings a heavy burden to both patients and society. Recent investigations indicated degenerative disease is taking an increasing part in SCI with the growth of the aging population. However, little insight has been gained about the effect of cervical degenerative disease on the spinal cord during dynamic activities. In this work, a dynamic fluid-structure interaction model was developed and validated to investigate the effect of anterior and posterior encroachment caused by degenerative disease on the spinal cord during normal extension and flexion. Maximum von-Mises stress and maximum principal strain were observed at the end of extension and flexion. The abnormal stress distribution caused by degenerative factors was concentrated in the descending tracts of the spinal cord. Our finding indicates that the excessive motion of the cervical spine could potentially exacerbate spinal cord injury and enlarge injury areas. Stress and strain remained low compared to extension during moderate flexion. This suggests that patients with cervical degenerative disease should avoid frequent or excessive flexion and extension which could result in motor function impairment, whereas moderate flexion is safe. Besides, encroachment caused by degenerative factors that are not significant in static imaging could also cause cord compression during normal activities.
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Singh V, Garg A, Dewangan HK. Recent Advances in Drug Design and Delivery Across Biological Barriers using Computational Models. LETT DRUG DES DISCOV 2022. [DOI: 10.2174/1570180819999220204110306] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Abstract:
The systemic delivery of pharmacological substances generally exhibits several significant limitations associated with the bio-distribution of active drugs in the body. As per consequence, human body’s defense mechanisms become impediments to drug delivery. Various technologies to overcome these limitations have been evolved including computational approaches and advanced drug delivery. As the body of human has evolved to defend itself from hostile biological as well as chemical invaders, along with that these biological barriers such as ocular barriers, blood-brain barriers, intestinal and skin barriers also limit the passage of drugs across desired sites. Therefore, efficient delivery remains an utmost challenge for researchers and scientists. The present review focuses on the techniques to deliver the drugs with efficient therapeutic efficacy at the targeted sites. This review article considered the insights into main biological barriers along with the application of computational or numerical methods dealing with different barriers by determining the drug flow, temperature and various other parameters. It also summarizes the advanced implantable drug delivery system to circumvent the inherent resistance showed by these biological barriers and in turn to improve the drug delivery.
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Affiliation(s)
- Vanshita Singh
- Institute of Pharmaceutical Research, GLA University Mathura, NH-2 Delhi Mathura Road, PO-Chaumuhan, Mathura, UttarPradesh, India 281406
| | - Akash Garg
- Institute of Pharmaceutical Research, GLA University Mathura, NH-2 Delhi Mathura Road, PO-Chaumuhan, Mathura, UttarPradesh, India 281406
| | - Hitesh Kumar Dewangan
- University Institute of Pharma Sciences (UIPS), Chandigarh University NH-95, Chandigarh Ludhiyana Highway, Mohali Punjab, India
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Wang JJ, Xu ML, Zeng HZ, Zheng LD, Zhu SJ, Jin C, Zeng ZL, Cheng LM, Zhu R. The biomechanical effect of preexisting different types of disc herniation in cervical hyperextension injury. J Orthop Surg Res 2021; 16:527. [PMID: 34429142 PMCID: PMC8383414 DOI: 10.1186/s13018-021-02677-y] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/25/2021] [Accepted: 08/15/2021] [Indexed: 11/10/2022] Open
Abstract
OBJECTIVE Preexisting severe cervical spinal cord compression is a significant risk factor in cervical hyperextension injury, and the neurological function may deteriorate after a slight force to the forehead. There are few biomechanical studies regarding the influence of pathological factors in hyperextension loading condition. The aim of this study is to analyze the effects of preexisting different types of cervical disc herniation and different degrees of compression on the spinal cord in cervical hyperextension. METHOD A 3D finite element (FE) model of cervical spinal cord was modeled. Local type with median herniation, local type with lateral herniation, diffuse type with median herniation, and diffuse type with lateral herniation were simulated in neutral and extention positions. The compressions which were equivalent to 10%, 20%, 30%, and 40% of the sagittal diameter of the spinal cord were modeled. RESULTS The results of normal FE model were consistent with those of previous studies. The maximum von Mises stresses appeared in the pia mater for all 32 loading conditions. The maximum von Mises stresses in extension position were much higher than in neutral position. In most cases, the maximum von Mises stresses in diffuse type were higher than in local type. CONCLUSION Cervical spinal cord with preexisting disc herniation is more likely to be compressed in hyperextension situation than in neutral position. Diffuse type with median herniation may cause more severe compression with higher von Mises stresses concentrated at the anterior horn and the peripheral white matter, resulting in acute central cord syndrome from biomechanical point of view.
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Affiliation(s)
- Jian-Jie Wang
- Key Laboratory of Spine and Spinal Cord Injury Repair and Regeneration of Ministry of Education, Orthopaedic Department of Tongji Hospital, Tongji University School of Medicine, 389 Xincun Road, 200065, Shanghai, People's Republic of China
| | - Meng-Lei Xu
- Key Laboratory of Spine and Spinal Cord Injury Repair and Regeneration of Ministry of Education, Orthopaedic Department of Tongji Hospital, Tongji University School of Medicine, 389 Xincun Road, 200065, Shanghai, People's Republic of China
| | - Hui-Zi Zeng
- Key Laboratory of Spine and Spinal Cord Injury Repair and Regeneration of Ministry of Education, Orthopaedic Department of Tongji Hospital, Tongji University School of Medicine, 389 Xincun Road, 200065, Shanghai, People's Republic of China
| | - Liang-Dong Zheng
- Key Laboratory of Spine and Spinal Cord Injury Repair and Regeneration of Ministry of Education, Orthopaedic Department of Tongji Hospital, Tongji University School of Medicine, 389 Xincun Road, 200065, Shanghai, People's Republic of China
| | - Shi-Jie Zhu
- Key Laboratory of Spine and Spinal Cord Injury Repair and Regeneration of Ministry of Education, Orthopaedic Department of Tongji Hospital, Tongji University School of Medicine, 389 Xincun Road, 200065, Shanghai, People's Republic of China
| | - Chen Jin
- Key Laboratory of Spine and Spinal Cord Injury Repair and Regeneration of Ministry of Education, Orthopaedic Department of Tongji Hospital, Tongji University School of Medicine, 389 Xincun Road, 200065, Shanghai, People's Republic of China
| | - Zhi-Li Zeng
- Key Laboratory of Spine and Spinal Cord Injury Repair and Regeneration of Ministry of Education, Orthopaedic Department of Tongji Hospital, Tongji University School of Medicine, 389 Xincun Road, 200065, Shanghai, People's Republic of China
| | - Li-Ming Cheng
- Key Laboratory of Spine and Spinal Cord Injury Repair and Regeneration of Ministry of Education, Orthopaedic Department of Tongji Hospital, Tongji University School of Medicine, 389 Xincun Road, 200065, Shanghai, People's Republic of China.
| | - Rui Zhu
- Key Laboratory of Spine and Spinal Cord Injury Repair and Regeneration of Ministry of Education, Orthopaedic Department of Tongji Hospital, Tongji University School of Medicine, 389 Xincun Road, 200065, Shanghai, People's Republic of China.
- Shanghai Clinical Research Center for Aging and Medicine, Shanghai, 200040, People's Republic of China.
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Zuo XH, Chen YB, Xie P, Zhang WD, Xue XY, Zhang QX, Shan B, Zhang XB, Bao HG, Si YN. Finite element analysis of wedge and biconcave deformity in four different height restoration after augmentation of osteoporotic vertebral compression fractures. J Orthop Surg Res 2021; 16:138. [PMID: 33588890 PMCID: PMC7885256 DOI: 10.1186/s13018-021-02225-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/24/2020] [Accepted: 01/11/2021] [Indexed: 11/29/2022] Open
Abstract
Purpose Biomechanical comparison of wedge and biconcave deformity of different height restoration after augmentation of osteoporotic vertebral compression fractures was analyzed by three-dimensional finite element analysis (FEA). Methods Three-dimensional finite element model (FEM) of T11-L2 segment was constructed from CT scan of elderly osteoporosis patient. The von Mises stresses of vertebrae, intervertebral disc, facet joints, displacement, and range of motion (ROM) of wedge and biconcave deformity were compared at four different heights (Genant 0–3 grade) after T12 vertebral augmentation. Results In wedge deformity, the stress of T12 decreased as the vertebral height in neutral position, flexion, extension, and left axial rotation, whereas increased sharply in bending at Genant 0; L1 and L2 decreased in all positions excluding flexion of L2, and T11 increased in neutral position, flexion, extension, and right axial rotation at Genant 0. No significant changes in biconcave deformity. The stress of T11-T12, T12-L1, and L1-L2 intervertebral disc gradually increased or decreased under other positions in wedge fracture, whereas L1-L2 no significant change in biconcave fracture. The utmost overall facet joint stress is at Genant 3, whereas there is no significant change under the same position in biconcave fracture. The displacement and ROM of the wedge fracture had ups and downs, while a decline in all positions excluding extension in biconcave fracture. Conclusions The vertebral restoration height after augmentation to Genant 0 affects the von Mises stress, displacement, and ROM in wedge deformity, which may increase the risk of fracture, whereas restored or not in biconcave deformity.
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Affiliation(s)
- Xiao-Hua Zuo
- Department of Anesthesiology, Nanjing First Hospital, Nanjing Medical University, Nanjing, 210006, China.,Department of Pain Management, The Affiliated Huai'an Hospital of Xuzhou Medical University and The Second People's Hospital of Huai'an, Huai'an, 223002, China
| | - Yin-Bing Chen
- Department of Orthopedic Surgery, The Affiliated Haian Hospital of Nantong University, Haian, 226600, China
| | - Peng Xie
- Department of Neurosurgery, The Affiliated Huai'an Hospital of Xuzhou Medical University and The Second People's Hospital of Huai'an, Huai'an, 223002, China
| | - Wen-Dong Zhang
- Department of Orthopedics, Northern Jiangsu People's Hospital, Yangzhou, 225001, China
| | - Xiang-Yun Xue
- Department of Pain Management, Yancheng No.1 People's Hospital, Yancheng, 224000, China
| | - Qian-Xi Zhang
- Department of Pain Management, The Affiliated Huai'an Hospital of Xuzhou Medical University and The Second People's Hospital of Huai'an, Huai'an, 223002, China
| | - Ben Shan
- Department of Radiology, The Affiliated Huai'an Hospital of Xuzhou Medical University and The Second People's Hospital of Huai'an, Huai'an, 223002, China
| | - Xiao-Bing Zhang
- Department of Radiology, The Affiliated Huai'an Hospital of Xuzhou Medical University and The Second People's Hospital of Huai'an, Huai'an, 223002, China.
| | - Hong-Guang Bao
- Department of Anesthesiology, Nanjing First Hospital, Nanjing Medical University, Nanjing, 210006, China.
| | - Yan-Na Si
- Department of Anesthesiology, Nanjing First Hospital, Nanjing Medical University, Nanjing, 210006, China.
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A comprehensive finite element model of surgical treatment for cervical myelopathy. Clin Biomech (Bristol, Avon) 2020; 74:79-86. [PMID: 32145673 DOI: 10.1016/j.clinbiomech.2020.02.009] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/11/2019] [Revised: 02/09/2020] [Accepted: 02/13/2020] [Indexed: 02/07/2023]
Abstract
BACKGROUND Cervical myelopathy is a common and debilitating chronic spinal cord dysfunction. Treatment includes anterior and/or posterior surgical intervention to decompress the spinal cord and stabilize the spine, but no consensus has been made as to the preferable surgical intervention. The objective of this study was to develop an finite element model of the healthy and myelopathic C2-T1 cervical spine and common anterior and posterior decompression techniques to determine how spinal cord stress and strain is altered in healthy and diseased states. METHODS A finite element model of the C2-T1 cervical spine, spinal cord, pia, dura, cerebral spinal fluid, and neural ligaments was developed and validated against in vivo human displacement data. To model cervical myelopathy, disc herniation and osteophytes were created at the C4-C6 levels. Three common surgical interventions were then incorporated at these levels. FINDINGS The finite element model accurately predicted healthy and myelopathic spinal cord displacement compared to motions observed in vivo. Spinal cord strain increased during extension in the cervical myelopathy finite element model. All surgical techniques affected spinal cord stress and strain. Specifically, adjacent levels had increased stress and strain, especially in the anterior cervical discectomy and fusion case. INTERPRETATIONS This model is the first biomechanically validated, finite element model of the healthy and myelopathic C2-T1 cervical spine and spinal cord which predicts spinal cord displacement, stress, and strain during physiologic motion. Our findings show surgical intervention can cause increased strain in the adjacent levels of the spinal cord which is particularly worse following anterior cervical discectomy and fusion.
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Diotalevi L, Bailly N, Wagnac É, Mac-Thiong JM, Goulet J, Petit Y. Dynamics of spinal cord compression with different patterns of thoracolumbar burst fractures: Numerical simulations using finite element modelling. Clin Biomech (Bristol, Avon) 2020; 72:186-194. [PMID: 31901589 DOI: 10.1016/j.clinbiomech.2019.12.023] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/21/2018] [Revised: 12/15/2019] [Accepted: 12/23/2019] [Indexed: 02/07/2023]
Abstract
BACKGROUND In thoracolumbar burst fractures, spinal cord primary injury involves a direct impact and energy transfer from bone fragments to the spinal cord. Unfortunately, imaging studies performed after the injury only depict the residual bone fragments position and pattern of spinal cord compression, with little insight on the dynamics involved during traumas. Knowledge of underlying mechanisms could be helpful in determining the severity of the primary injury, hence the extent of spinal cord damage and associated potential for recovery. Finite element models are often used to study dynamic processes, but have never been used specifically to simulate different severities of thoracolumbar burst fractures. METHODS Previously developed thoracolumbar spine and spinal cord finite element models were used and further validated, and representative vertebral fragments were modelled. A full factorial design was used to investigate the effects of comminution of the superior fragment, presence of an inferior fragment, fragments rotation and velocity, on maximum Von Mises stress and strain, maximum major strain, and pressure in the spinal cord. FINDINGS Fragment velocity clearly was the most influential factor. Fragments rotation and presence of an inferior fragment increased pressure, but rotation decreased both strains outputs. Although significant for both strains outputs, comminution of the superior fragment isn't estimated to influence outputs. INTERPRETATION This study is the first, to the authors' knowledge, to examine a detailed spinal cord model impacted in situ by fragments from burst fractures. This numeric model could be used in the future to comprehensively link traumatic events or imaging study characteristics to known spinal cord injuries severity and potential for recovery.
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Affiliation(s)
- Lucien Diotalevi
- Department of Mechanical Engineering, École de Technologie Supérieure, 1100 Notre-Dame Street West, Montréal, Québec H3C 1K3, Canada; Research Center, Hôpital du Sacré-Cœur de Montréal, 5400 Gouin blvd, Montréal H4J 1C5, Québec, Canada; International Laboratory on Spine Imaging and Biomechanics (iLab-Spine), Canada
| | - Nicolas Bailly
- Department of Mechanical Engineering, École de Technologie Supérieure, 1100 Notre-Dame Street West, Montréal, Québec H3C 1K3, Canada; Research Center, Hôpital du Sacré-Cœur de Montréal, 5400 Gouin blvd, Montréal H4J 1C5, Québec, Canada; International Laboratory on Spine Imaging and Biomechanics (iLab-Spine), Canada
| | - Éric Wagnac
- Department of Mechanical Engineering, École de Technologie Supérieure, 1100 Notre-Dame Street West, Montréal, Québec H3C 1K3, Canada; Research Center, Hôpital du Sacré-Cœur de Montréal, 5400 Gouin blvd, Montréal H4J 1C5, Québec, Canada; International Laboratory on Spine Imaging and Biomechanics (iLab-Spine), Canada.
| | - Jean-Marc Mac-Thiong
- Research Center, Hôpital du Sacré-Cœur de Montréal, 5400 Gouin blvd, Montréal H4J 1C5, Québec, Canada; Department of Orthopaedic Surgery, Université de Montréal, P.O. box 6128, Station Centre-Ville, Montréal, Québec H3C 3J7, Canada
| | - Julien Goulet
- Research Center, Hôpital du Sacré-Cœur de Montréal, 5400 Gouin blvd, Montréal H4J 1C5, Québec, Canada; Department of Orthopaedic Surgery, Université de Montréal, P.O. box 6128, Station Centre-Ville, Montréal, Québec H3C 3J7, Canada.
| | - Yvan Petit
- Department of Mechanical Engineering, École de Technologie Supérieure, 1100 Notre-Dame Street West, Montréal, Québec H3C 1K3, Canada; Research Center, Hôpital du Sacré-Cœur de Montréal, 5400 Gouin blvd, Montréal H4J 1C5, Québec, Canada; International Laboratory on Spine Imaging and Biomechanics (iLab-Spine), Canada.
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Shityakov S, Förster CY. Computational simulation and modeling of the blood-brain barrier pathology. Histochem Cell Biol 2018; 149:451-459. [PMID: 29721642 DOI: 10.1007/s00418-018-1665-x] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/30/2018] [Indexed: 10/17/2022]
Abstract
In silico methods and models in the pathology of the blood-brain barrier (BBB) or also called BBB "computational pathology", are based on using mathematical approaches together with complex, high-dimensional experimental data to evaluate and predict disease-related impacts on the CNS. These computational methods and tools have been designed to deal with BBB-linked neuropathology at the molecular, cellular, tissue, and organ levels. The molecular and cellular levels mainly include molecular docking and molecular dynamics simulations (atomistic and coarse-grain) of mutated or misfolded tight junction proteins, receptors, and various BBB transporters. The tissue and organ levels encompass the mechanistic and pharmacokinetic models as well as finite-element method and pathway analyses enriched with multiple sources of raw data (e.g., in vitro and in vivo, histopathological records, "-omics", and imaging data). Overall, this review discusses comprehensive computational techniques and strategies at different levels of complexity, providing new insights and future directions for diagnosis, treatment improvement, and a deeper understanding of BBB-related neuropathological events.
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Affiliation(s)
- Sergey Shityakov
- Department of Anesthesia and Critical Care, University of Würzburg, 97080, Würzburg, Germany.
| | - Carola Y Förster
- Department of Anesthesia and Critical Care, University of Würzburg, 97080, Würzburg, Germany.
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Fradet L, Cliche F, Petit Y, Mac-Thiong JM, Arnoux PJ. Strain rate dependent behavior of the porcine spinal cord under transverse dynamic compression. Proc Inst Mech Eng H 2016; 230:858-866. [DOI: 10.1177/0954411916655373] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
The accurate description of the mechanical properties of spinal cord tissue benefits to clinical evaluation of spinal cord injuries and is a required input for analysis tools such as finite element models. Unfortunately, available data in the literature generally relate mechanical properties of the spinal cord under quasi-static loading conditions, which is not adapted to the study of traumatic behavior, as neurological tissue adopts a viscoelastic behavior. Thus, the objective of this study is to describe mechanical properties of the spinal cord up to mechanical damage, under dynamic loading conditions. A total of 192 porcine cervical to lumbar spinal cord samples were compressed in a transverse direction. Loading conditions included ramp tests at 0.5, 5 or 50 s−1 and cyclic loading at 1, 10 or 20 Hz. Results showed that spinal cord behavior was significantly influenced by strain rate. Mechanical damage occurred at 0.64, 0.68 and 0.73 strains for 0.5, 5 or 50 s−1 loadings, respectively. Variations of behavior between the tested strain rates were explained by cyclic loading results, which revealed behavior more or less viscous depending on strain rate. Also, a parameter (stress multiplication factor) was introduced to allow transcription of a stress–strain behavior curve to different strain rates. This factor was described and was significantly different for cervical, thoracic and lumbar vertebral heights, and for the strain rates evaluated in this study.
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Affiliation(s)
- Léo Fradet
- Département de Génie Mécanique, École Polytechnique de Montréal, Montréal, QC, Canada
- iLab-Spine (International Laboratory - Spine Imaging and Biomechanics), Montreal, Canada and Marseille, France
| | - Francis Cliche
- iLab-Spine (International Laboratory - Spine Imaging and Biomechanics), Montreal, Canada and Marseille, France
- Département de Génie Mécanique, École de technologie supérieure, Montréal, QC, Canada
- Research Center, Hôpital du Sacré-Coeur de Montréal, Montréal, QC, Canada
| | - Yvan Petit
- iLab-Spine (International Laboratory - Spine Imaging and Biomechanics), Montreal, Canada and Marseille, France
- Département de Génie Mécanique, École de technologie supérieure, Montréal, QC, Canada
- Research Center, Hôpital du Sacré-Coeur de Montréal, Montréal, QC, Canada
- Laboratoire de Biomécanique Appliquée, UMRT24 IFSTTAR, Université de la Méditerranée Aix-Marseille II, Marseille, France
| | - Jean-Marc Mac-Thiong
- iLab-Spine (International Laboratory - Spine Imaging and Biomechanics), Montreal, Canada and Marseille, France
- Research Center, Hôpital du Sacré-Coeur de Montréal, Montréal, QC, Canada
- Department of Surgery, Université de Montréal, Montréal, QC, Canada
| | - Pierre-Jean Arnoux
- iLab-Spine (International Laboratory - Spine Imaging and Biomechanics), Montreal, Canada and Marseille, France
- Laboratoire de Biomécanique Appliquée, UMRT24 IFSTTAR, Université de la Méditerranée Aix-Marseille II, Marseille, France
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Yaldiz C, Asil K, Özkal B, Ceylan D, Kacira T. Thoracolumbar burst fractures requiring instrumented fusion: Should reducted bone fragments be removed? A retrospective study. Neurol Neurochir Pol 2015; 49:358-66. [PMID: 26652869 DOI: 10.1016/j.pjnns.2015.08.005] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2015] [Revised: 08/13/2015] [Accepted: 08/26/2015] [Indexed: 11/26/2022]
Abstract
BACKGROUND Thoracolumbar burst fractures are common clinical entity encountered in neurosurgical practice, accounting for 10-20% of all spinal fractures. Clinical picture could be devastating due to severe neurological deficits which lead the patients dependent both socially and emotionally. MATERIALS AND METHODS This study compared two groups of patients who were operated because of thoracolumbar burst fracture secondary to spinal trauma in terms of neurologic deficits, degree of improvement, and radiologic measurements at one-year follow-up. The first group (group I) included the patients who underwent posterior total laminectomy, peroperative reduction of intracanal bone fragments, and posterior spinal instrumentation and the second group (group II) included the patients who underwent total laminectomy, and spinal instrumentation without reduction of free bone fragments. RESULTS Neither group showed significant correlation with any measurement parameter. Radiological assessments and clinical improvements did not disclosed significant difference between the two groups at one-year follow-up. CONCLUSION Retropulsion of free bone fragments extend the time of surgery and causes complications. This study found that there is no need to retropulse the bone fragments in the spinal canal in patients with unstable burst fractures who underwent total laminectomy and posterior long segment stabilization.
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Affiliation(s)
- Can Yaldiz
- Sakarya University Training and Research Hospital, Department of Neurosurgery, Sakarya, Turkey.
| | - Kıyasettin Asil
- Sakarya University Training and Research Hospital, Department of Radiology, Sakarya, Turkey
| | - Birol Özkal
- Alanya Government Hospital, Clinic of Neurosurgery, Alanya, Turkey
| | - Davut Ceylan
- Sakarya University Training and Research Hospital, Department of Neurosurgery, Sakarya, Turkey
| | - Tibet Kacira
- Sakarya University Training and Research Hospital, Department of Neurosurgery, Sakarya, Turkey
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Bhatnagar T, Liu J, Yung A, Cripton P, Kozlowski P, Tetzlaff W, Oxland T. Quantifying the internal deformation of the rodent spinal cord during acute spinal cord injury – the validation of a method. Comput Methods Biomech Biomed Engin 2015; 19:386-95. [DOI: 10.1080/10255842.2015.1032944] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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Deng Z, Zou H, Cai L, Ping A, Wang Y, Ai Q. The retrospective analysis of posterior short-segment pedicle instrumentation without fusion for thoracolumbar burst fracture with neurological deficit. ScientificWorldJournal 2014; 2014:457634. [PMID: 24723809 PMCID: PMC3958728 DOI: 10.1155/2014/457634] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2013] [Accepted: 12/19/2013] [Indexed: 11/25/2022] Open
Abstract
This study aims to investigate the efficacy of posterior short-segment pedicle instrumentation without fusion in curing thoracolumbar burst fracture. All of the 53 patients were treated with short-segment pedicle instrumentation and laminectomy without fusion, and the restoration of retropulsed bone fragments was conducted by a novel custom-designed repositor (RRBF). The mean operation time and blood loss during surgery were analyzed; the radiological index and neurological status were compared before and after the operation. The mean operation time was 93 min (range: 62-110 min) and the mean intraoperative blood loss was 452 mL in all cases. The average canal encroachment was 50.04% and 10.92% prior to the surgery and at last followup, respectively (P < 0.01). The preoperative kyphotic angle was 17.2 degree (± 6.87 degrees), whereas it decreased to 8.42 degree (± 4.99 degrees) at last followup (P < 0.01). Besides, the mean vertebral body height increased from 40.15% (± 9.40%) before surgery to 72.34% (± 12.32%) at last followup (P < 0.01). 45 patients showed 1-2 grades improvement in Frankel's scale at last followup. This technique allows for satisfactory canal clearance and restoration of vertebral body height and kyphotic angle, and it may promote the recovery of neurological function. However, further research is still necessary to confirm the efficacy of this treatment.
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Affiliation(s)
- Zhouming Deng
- Department of Orthopaedic, Zhongnan Hospital of Wuhan University, No. 169 Donghu Road, Wuhan, Hubei Province 430071, China
| | - Hui Zou
- Department of Orthopaedic, Central Hospital of Huanggang City, Huanggang, China
| | - Lin Cai
- Department of Orthopaedic, Zhongnan Hospital of Wuhan University, No. 169 Donghu Road, Wuhan, Hubei Province 430071, China
| | - Ansong Ping
- Department of Orthopaedic, Zhongnan Hospital of Wuhan University, No. 169 Donghu Road, Wuhan, Hubei Province 430071, China
| | - Yongzhi Wang
- Department of Urology, Zhongnan Hospital of Wuhan University, Wuhan, China
| | - Qiyong Ai
- Department of Orthopaedic, Zhongnan Hospital of Wuhan University, No. 169 Donghu Road, Wuhan, Hubei Province 430071, China
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