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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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Zheng LD, Cao YT, Yang YT, Xu ML, Zeng HZ, Zhu SJ, Jin C, Yuan Q, Zhu R. Effect of Different Types of Ossification of the Posterior Longitudinal Ligament on the Dynamic Biomechanical Response of the Spinal Cord: A Finite Element Analysis. J Biomech Eng 2023; 145:121002. [PMID: 37578172 DOI: 10.1115/1.4063194] [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: 04/08/2023] [Accepted: 08/09/2023] [Indexed: 08/15/2023]
Abstract
Ossification of the posterior longitudinal ligament (OPLL) has been identified as an important cause of cervical myelopathy. However, the biomechanical mechanism between the OPLL type and the clinical characteristics of myelopathy remains unclear. The aim of this study was to evaluate the effect of different types of OPLL on the dynamic biomechanical response of the spinal cord. A three-dimensional finite element model of the fluid-structure interaction of the cervical spine with spinal cord was established and validated. The spinal cord stress and strain, cervical range of motion (ROM) in different types of OPLL models were predicted during dynamic flexion and extension activity. Different types of OPLL models showed varying degrees of increase in stress and strain under the process of flexion and extension, and there was a surge toward the end of extension. Larger spinal cord stress was observed in segmental OPLL. For continuous and mixed types of OPLL, the adjacent segments of OPLL showed a dramatic increase in ROM, while the ROM of affected segments was limited. As a dynamic factor, flexion and extension of the cervical spine play an amplifying role in OPLL-related myelopathy, while appropriate spine motion is safe and permitted. Segmental OPLL patients are more concerned about the spinal cord injury induced by large stress, and patients with continuous OPLL should be noted to progressive injuries of adjacent level.
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Affiliation(s)
- Liang-Dong Zheng
- 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
| | - Yu-Ting Cao
- 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;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
| | - 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
| | - Hui-Zi Zeng
- 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;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
| | - 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
| | - Qing Yuan
- 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
| | - 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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3
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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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Harinathan B, Jebaseelan D, Yoganandan N, Vedantam A. Effect of Cervical Stenosis and Rate of Impact on Risk of Spinal Cord Injury During Whiplash Injury. Spine (Phila Pa 1976) 2023; 48:1208-1215. [PMID: 37341525 DOI: 10.1097/brs.0000000000004759] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/26/2023] [Accepted: 06/09/2023] [Indexed: 06/22/2023]
Abstract
STUDY DESIGN Finite Element Study. OBJECTIVE To determine the risk of spinal cord injury with pre-existing cervical stenosis during a whiplash injury. SUMMARY OF BACKGROUND DATA Patients with cervical spinal stenosis are often cautioned on the potential increased risk of spinal cord injury (SCI) from minor trauma such as rear impact whiplash injuries. However, there is no consensus on the degree of canal stenosis or the rate of impact that predisposes cervical SCI from minor trauma. METHODS A previously validated three-dimensional finite element model of the human head-neck complex with the spinal cord and activated cervical musculature was used. Rear impact acceleration was applied at 1.8 m/s and 2.6 m/s. Progressive spinal stenosis was simulated at the C5 to C6 segment, from 14 mm to 6 mm, at 2 mm intervals of ventral disk protrusion. Spinal cord von Mises stress and maximum principal strain were extracted and normalized with respect to the 14 mm spine at each cervical spine level from C2 to C7. RESULTS The mean segmental range of motion was 7.3 degrees at 1.8 m/s and 9.3 degrees at 2.6 m/s. Spinal cord stress above the threshold for SCI was noted at C5 to C6 for 6 mm stenosis at 1.8 m/s and 2.6 m/s. The segment (C6-C7) inferior to the level of maximum stenosis also showed increasing stress and strain with a higher rate of impact. For 8 mm stenosis, spinal cord stress exceeded SCI thresholds only at 2.6 m/s. Spinal cord strain above SCI thresholds were only noted in the 6 mm stenosis model at 2.6 m/s. CONCLUSION Increased spinal stenosis and rate of impact are associated with greater magnitude and spatial distribution of spinal cord stress and strain during a whiplash injury. Spinal canal stenosis of 6 mm was associated with consistent elevation of spinal cord stress and strain above SCI thresholds at 2.6 m/s.
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Affiliation(s)
- Balaji Harinathan
- Department of Neurosurgery, Medical College of Wisconsin, Milwaukee, WI
- School of Mechanical Engineering, Vellore Institute of Technology, Chennai, India
| | - Davidson Jebaseelan
- School of Mechanical Engineering, Vellore Institute of Technology, Chennai, India
| | | | - Aditya Vedantam
- Department of Neurosurgery, Medical College of Wisconsin, Milwaukee, WI
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Tang T, Zhu Z, He Z, Wang F, Chen H, Liu S, Zhan M, Wang J, Tian W, Chen D, Wu X, Liu X, Zhou Z, Liu S. DLX5 regulates the osteogenic differentiation of spinal ligaments cells derived from ossification of the posterior longitudinal ligament patients via NOTCH signaling. JOR Spine 2023; 6:e1247. [PMID: 37361333 PMCID: PMC10285757 DOI: 10.1002/jsp2.1247] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/14/2022] [Revised: 01/01/2023] [Accepted: 01/08/2023] [Indexed: 01/30/2023] Open
Abstract
Background Ossification of the posterior longitudinal ligaments (OPLL) is common disorder characterized by heterotopic ossification of the spinal ligaments. Mechanical stimulation (MS) plays an important role in OPLL. DLX5 is an essential transcription factor required for osteoblast differentiation. However, the role of DLX5 during in OPLL is unclear. This study aims to investigate whether DLX5 is associated with OPLL progression under MS. Methods Stretch stimulation was applied to spinal ligaments cells derived from OPLL (OPLL cells) and non-OPLL (non-OPLL cells) patients. Expression of DLX5 and osteogenesis-related genes were determined by quantitative real-time polymerase chain reaction and Western blot. The osteogenic differentiation ability of the cells was measured using alkaline phosphatase (ALP) staining and alizarin red staining. The protein expression of DLX5 in the tissues and the nuclear translocation of NOTCH intracellular domain (NICD) was examined by immunofluorescence. Results Compared with non-OPLL cells, OPLL cells expressed higher levels of DLX5 in vitro and vivo (p < 0.01). Upregulated expression of DLX5 and osteogenesis-related genes (OSX, RUNX2, and OCN) were observed in OPLL cells induced with stretch stimulation and osteogenic medium, whereas there was no change in the non-OPLL cells (p < 0.01). Cytoplasmic NICD protein translocated from the cytoplasm to the nucleus inducing DLX5 under stretch stimulation, which was reduced by the NOTCH signaling inhibitors (DAPT) (p < 0.01). Conclusions These data suggest that DLX5 play a critical role in MS-induced progression of OPLL through NOTCH signaling, which provides a new insight into the pathogenesis of OPLL.
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Affiliation(s)
- Tao Tang
- Innovation Platform of Regeneration and Repair of Spinal Cord and Nerve Injury, Department of Orthopaedic Surgery, The Seventh Affiliated HospitalSun Yat‐sen UniversityShenzhenChina
- Guangdong Provincial Key Laboratory of Orthopedics and Traumatology, Orthopaedic Research Institute/Department of Spinal SurgeryThe First Affiliated Hospital of Sun Yat‐sen UniversityGuangzhouChina
| | - Zhengya Zhu
- Innovation Platform of Regeneration and Repair of Spinal Cord and Nerve Injury, Department of Orthopaedic Surgery, The Seventh Affiliated HospitalSun Yat‐sen UniversityShenzhenChina
| | - Zhongyuan He
- Innovation Platform of Regeneration and Repair of Spinal Cord and Nerve Injury, Department of Orthopaedic Surgery, The Seventh Affiliated HospitalSun Yat‐sen UniversityShenzhenChina
- Guangdong Provincial Key Laboratory of Orthopedics and Traumatology, Orthopaedic Research Institute/Department of Spinal SurgeryThe First Affiliated Hospital of Sun Yat‐sen UniversityGuangzhouChina
| | - Fuan Wang
- Innovation Platform of Regeneration and Repair of Spinal Cord and Nerve Injury, Department of Orthopaedic Surgery, The Seventh Affiliated HospitalSun Yat‐sen UniversityShenzhenChina
- Guangdong Provincial Key Laboratory of Orthopedics and Traumatology, Orthopaedic Research Institute/Department of Spinal SurgeryThe First Affiliated Hospital of Sun Yat‐sen UniversityGuangzhouChina
| | - Hongkun Chen
- Innovation Platform of Regeneration and Repair of Spinal Cord and Nerve Injury, Department of Orthopaedic Surgery, The Seventh Affiliated HospitalSun Yat‐sen UniversityShenzhenChina
| | - Shengkai Liu
- Guangdong Provincial Key Laboratory of Orthopedics and Traumatology, Orthopaedic Research Institute/Department of Spinal SurgeryThe First Affiliated Hospital of Sun Yat‐sen UniversityGuangzhouChina
| | - Mingbin Zhan
- Guangdong Provincial Key Laboratory of Orthopedics and Traumatology, Orthopaedic Research Institute/Department of Spinal SurgeryThe First Affiliated Hospital of Sun Yat‐sen UniversityGuangzhouChina
| | - Jianmin Wang
- Innovation Platform of Regeneration and Repair of Spinal Cord and Nerve Injury, Department of Orthopaedic Surgery, The Seventh Affiliated HospitalSun Yat‐sen UniversityShenzhenChina
| | - Wei Tian
- Laboratory of Bone Tissue Engineering, Beijing Laboratory of Biomedical MaterialsBeijing Research Institute of Orthopaedics and Traumatology, Beijing Jishuitan HospitalBeijingChina
| | - Dafu Chen
- Laboratory of Bone Tissue Engineering, Beijing Laboratory of Biomedical MaterialsBeijing Research Institute of Orthopaedics and Traumatology, Beijing Jishuitan HospitalBeijingChina
| | - Xinbao Wu
- Laboratory of Bone Tissue Engineering, Beijing Laboratory of Biomedical MaterialsBeijing Research Institute of Orthopaedics and Traumatology, Beijing Jishuitan HospitalBeijingChina
| | - Xizhe Liu
- Guangdong Provincial Key Laboratory of Orthopedics and Traumatology, Orthopaedic Research Institute/Department of Spinal SurgeryThe First Affiliated Hospital of Sun Yat‐sen UniversityGuangzhouChina
| | - Zhiyu Zhou
- Innovation Platform of Regeneration and Repair of Spinal Cord and Nerve Injury, Department of Orthopaedic Surgery, The Seventh Affiliated HospitalSun Yat‐sen UniversityShenzhenChina
- Guangdong Provincial Key Laboratory of Orthopedics and Traumatology, Orthopaedic Research Institute/Department of Spinal SurgeryThe First Affiliated Hospital of Sun Yat‐sen UniversityGuangzhouChina
| | - Shaoyu Liu
- Innovation Platform of Regeneration and Repair of Spinal Cord and Nerve Injury, Department of Orthopaedic Surgery, The Seventh Affiliated HospitalSun Yat‐sen UniversityShenzhenChina
- Guangdong Provincial Key Laboratory of Orthopedics and Traumatology, Orthopaedic Research Institute/Department of Spinal SurgeryThe First Affiliated Hospital of Sun Yat‐sen UniversityGuangzhouChina
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Xue F, Deng H, Chen Z, Yang H, Li Y, Yuan S, Zheng N, Chen M. Effects of cervical rotatory manipulation on the cervical spinal cord complex with ossification of the posterior longitudinal ligament in the vertebral canal: A finite element study. Front Bioeng Biotechnol 2023; 11:1095587. [PMID: 36714008 PMCID: PMC9880201 DOI: 10.3389/fbioe.2023.1095587] [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: 11/11/2022] [Accepted: 01/03/2023] [Indexed: 01/15/2023] Open
Abstract
Background: There are few studies focusing on biomechanism of spinal cord injury according to the ossification of the posterior longitudinal ligament (OPLL) during cervical rotatory manipulation (CRM). This study aimed to explore the biomechanical effects of CRM on the spinal cord, dura matter and nerve roots with OPLL in the cervical vertebral canal. Methods: Three validated FE models of the craniocervical spine and spinal cord complex were constructed by adding mild, moderate, and severe OPLL to the healthy FE model, respectively. We simulated the static compression of the spinal cord by OPLL and the dynamic compression during CRM in the flexion position. The stress distribution of the spinal cord complex was investigated. Results: The cervical spinal cord experienced higher von Mises stress under static compression by the severe OPLL. A higher von Mises stress was observed on the spinal cord in the moderate and severe OPLL models during CRM. The dura matter and nerve roots had a higher von Mises stress in all three models during CRM. Conclusion: The results show a high risk in performing CRM in the flexion position on patients with OPLL, in that different occupying ratios in the vertebral canal due to OPLL could significantly increase the stress on the spinal cord complex.
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Affiliation(s)
- Fan Xue
- School of Traditional Chinese Medicine, Southern Medical University, Guangzhou, Guangdong, China
| | - Hao Deng
- Department of Orthopaedics, Jiashan Hospital of Traditional Chinese Medicine, Jiaxing, Zhejiang, China
| | - Zujiang Chen
- School of Traditional Chinese Medicine, Southern Medical University, Guangzhou, Guangdong, China
| | - Han Yang
- School of Traditional Chinese Medicine, Southern Medical University, Guangzhou, Guangdong, China
| | - Yikai Li
- School of Traditional Chinese Medicine, Southern Medical University, Guangzhou, Guangdong, China,*Correspondence: Yikai Li, ; Shiguo Yuan,
| | - Shiguo Yuan
- Department of Orthopaedics, Hainan Traditional Chinese Medicine Hospital, Haikou, Hainan, China,*Correspondence: Yikai Li, ; Shiguo Yuan,
| | - Nansheng Zheng
- Department of Orthopaedics, Hainan Traditional Chinese Medicine Hospital, Haikou, Hainan, China
| | - Meixiong Chen
- Department of Orthopaedics, Hainan Traditional Chinese Medicine Hospital, Haikou, Hainan, China
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Sim O, Ryu D, Lee J, Lee C. Stress Distribution on Spinal Cord According to Type of Laminectomy for Large Focal Cervical Ossification of Posterior Longitudinal Ligament Based on Finite Element Method. Bioengineering (Basel) 2022; 9:519. [PMID: 36290487 PMCID: PMC9598727 DOI: 10.3390/bioengineering9100519] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2022] [Revised: 09/15/2022] [Accepted: 09/29/2022] [Indexed: 11/06/2022] Open
Abstract
Most studies on the ossification of the posterior longitudinal ligament (OPLL) using the finite element method were conducted in the neutral state, and the resulting decompression was judged to be good. As these studies do not reflect the actual behavior of the cervical spine, this study conducted an analysis in the neutral state and a biomechanical analysis during flexion and extension behaviors. After validation via the construction of an intact cervical spine model, the focal OPLL model was inserted into the C4-C5 segment and a simulation was performed. The neutral state was shown by applying a fixed condition to the lower part of the T1 and Y-axis fixed condition of the spinal cord and simulating spinal cord compression with OPLL. For flexion and extension simulation, a ±30-degree displacement was additionally applied to the top of the C2 dens. Accordingly, it was confirmed that spinal cord decompression did not work well during the flexion and extension behaviors, but rather increased. Thus, if patients with focal OPLL inevitably need to undergo posterior decompression, additional surgery using an anterior approach should be considered.
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Affiliation(s)
- On Sim
- Department of Biomedical Engineering, Graduate School, Pusan National University, Busan 46241, Korea
| | - Dongman Ryu
- Medical Research Institute, Pusan National University, Busan 46241, Korea
| | - Junghwan Lee
- Department of Neurosurgery, School of Medicine, Pusan National University, Busan 46241, Korea
| | - Chiseung Lee
- Department of Convergence Medicine and Biomedical Engineering, School of Medicine, Pusan National University, Busan 46241, Korea
- Biomedical Research Institute, Pusan National University Hospital, Busan 49241, Korea
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Biomechanical comparison of spinal cord compression types occurring in Degenerative Cervical Myelopathy. Clin Biomech (Bristol, Avon) 2021; 81:105174. [PMID: 33279293 DOI: 10.1016/j.clinbiomech.2020.105174] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/21/2020] [Revised: 08/28/2020] [Accepted: 09/03/2020] [Indexed: 02/07/2023]
Abstract
BACKGROUND Degenerative Cervical Myelopathy results from spine degenerations narrowing the spinal canal and inducing cord compressions. Prognosis is challenging. This study aimed at simulating typical spinal cord compressions observed in patients with a realistic model to better understand pathogenesis for later prediction of patients' evolution. METHODS A 30% reduction in cord cross-sectional area at C5-C6 was defined as myelopathy threshold based on Degenerative Cervical Myelopathy features from literature and MRI measurements in 20 patients. Four main compression types were extracted from MRIs and simulated with a comprehensive three-dimensional finite element spine model. Median diffuse, median focal and lateral types were modelled as disk herniation while circumferential type additionally involved ligamentum flavum hypertrophy. All stresses were quantified along inferior-superior axis, compression development and across atlas-defined spinal cord regions. FINDINGS Anterior gray and white matter globally received the highest stress while lateral pathways were the least affected. Median diffuse compression induced the highest stresses. Circumferential type focused stresses in posterior gray matter. Along inferior-superior axis, those two types showed a peak of constraints at compression site while median focal and lateral types showed lower values but extending further. INTERPRETATION Median diffuse type would be the most detrimental based on stress amplitude. Anterior regions would be the most at risk, except for circumferential type where posterior regions would be equally affected. In addition to applying constraints, ischemia could be a significant component explaining the early demyelination reported in lateral pathways. Moving towards patient-specific simulations, biomechanical models could become strong predictors for degenerative changes.
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Khuyagbaatar B, Kim K, Purevsuren T, Lee SH, Kim YH. Biomechanical Effects on Cervical Spinal Cord and Nerve Root Following Laminoplasty for Ossification of the Posterior Longitudinal Ligament in the Cervical Spine: A Comparison Between Open-Door and Double-Door Laminoplasty Using Finite Element Analysis. J Biomech Eng 2019; 140:2677755. [PMID: 29677281 DOI: 10.1115/1.4039826] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2017] [Indexed: 11/08/2022]
Abstract
Many clinical case series have reported the predisposing factors for C5 palsy and have presented comparisons of the two types of laminoplasty. However, there have been no biomechanical studies focusing on cervical spinal cord and nerve root following laminoplasty. The purpose of this study is to investigate biomechanical changes in the spinal cord and nerve roots following the two most common types of laminoplasty, open-door and double-door laminoplasty, for cervical ossification of the posterior longitudinal ligament (OPLL). A finite element (FE) model of the cervical spine and spinal cord with nerve root complex structures was developed. Stress changes in the spinal cord and nerve roots, posterior shift of the spinal cord, and displacement of the cervical nerve roots were analyzed with two types of cervical laminoplasty models for variations in the degree of canal occupying ratio and shape of the OPLL. The shape and degree of spinal cord compression caused by the OPLL had more influence on the changes in stress, posterior shift of the spinal cord, and displacement of the nerve root than the type of laminoplasty. The lateral-type OPLL resulted in imbalanced stress on the nerve roots and the highest nerve root displacement. Type of laminoplasty and shape and degree of spinal cord compression caused by OPLL were found to influence the changes in stress and posterior displacement of the cervical spinal cord and nerve roots. Lateral-type OPLL might contribute to the development of C5 palsy due to the imbalanced stress and tension on the nerve roots after laminoplasty.
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Affiliation(s)
- Batbayar Khuyagbaatar
- Department of Mechanical Engineering, Kyung Hee University, Yongin 17104, South Korea e-mail:
| | - Kyungsoo Kim
- Department of Applied Mathematics, Kyung Hee University, Yongin 17104, South Korea e-mail:
| | - Tserenchimed Purevsuren
- Department of Mechanical Engineering, Kyung Hee University, Yongin 17104, South Korea e-mail:
| | - Sang-Hun Lee
- Department of Orthopedic Surgery, Johns Hopkins University, Baltimore, MD 21287 e-mail:
| | - Yoon Hyuk Kim
- Department of Mechanical Engineering, Kyung Hee University, Yongin 17104, South Korea e-mail:
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Khuyagbaatar B, Kim K, Park WM, Lee S, Kim YH. Increased stress and strain on the spinal cord due to ossification of the posterior longitudinal ligament in the cervical spine under flexion after laminectomy. Proc Inst Mech Eng H 2017; 231:898-906. [PMID: 28660796 DOI: 10.1177/0954411917718222] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Myelopathy in the cervical spine due to cervical ossification of the posterior longitudinal ligament could be induced by static compression and/or dynamic factors. It has been suggested that dynamic factors need to be considered when planning and performing the decompression surgery on patients with the ossification of the posterior longitudinal ligament. A finite element model of the C2-C7 cervical spine in the neutral position was developed and used to generate flexion and extension of the cervical spine. The segmental ossification of the posterior longitudinal ligament on the C5 was assumed, and laminectomy was performed on C4-C6 according to a conventional surgical technique. For various occupying ratios of the ossified ligament between 20% and 60%, von-Mises stresses, maximum principal strains in the spinal cord, and cross-sectional area of the cord were investigated in the pre-operative and laminectomy models under flexion, neutral position, and extension. The results were consistent with previous experimental and computational studies in terms of stress, strain, and cross-sectional area. Flexion leads to higher stresses and strains in the cord than the neutral position and extension, even after decompression surgery. These higher stresses and strains might be generated by residual compression occurring at the segment with the ossification of the posterior longitudinal ligament. This study provides fundamental information under different neck positions regarding biomechanical characteristics of the spinal cord in cervical ossification of the posterior longitudinal ligament.
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Affiliation(s)
| | - Kyungsoo Kim
- 2 Department of Applied Mathematics, Kyung Hee University, Yongin, Korea
| | - Won Man Park
- 1 Department of Mechanical Engineering, Kyung Hee University, Yongin, Korea
| | - SuKyoung Lee
- 3 Department of Computer Science, Yonsei University, Seoul, Korea
| | - Yoon Hyuk Kim
- 1 Department of Mechanical Engineering, Kyung Hee University, Yongin, Korea
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Khuyagbaatar B, Kim K, Park WM, Kim YH. Biomechanical investigation of post-operative C5 palsy due to ossification of the posterior longitudinal ligament in different types of cervical spinal alignment. J Biomech 2017; 57:54-61. [DOI: 10.1016/j.jbiomech.2017.03.019] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2016] [Revised: 03/20/2017] [Accepted: 03/24/2017] [Indexed: 11/15/2022]
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