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Che M, Wang Y, Zhao Y, Zhang S, Yu J, Gong W, Zhang D, Liu M. Finite Element Analysis of a New Type of Spinal Protection Device for the Prevention and Treatment of Osteoporotic Vertebral Compression Fractures. Orthop Surg 2022; 14:577-586. [PMID: 35147295 PMCID: PMC8926982 DOI: 10.1111/os.13220] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/06/2021] [Revised: 12/06/2021] [Accepted: 12/20/2021] [Indexed: 12/13/2022] Open
Abstract
OBJECTIVE To study the effectiveness of a new spinal protection device for preventing and treating osteoporotic vertebral compression fractures (OVCFs) by finite element analysis (FEA). METHODS One healthy volunteer and one patient with 1-segment lumbar vertebral compression fractures were included in this experimental study. The DICOM files of two different lumbar spiral computed tomography (CT) scans were converted into STL files, and 3D finite element models of the lumbar spine were generated for normal and L1 vertebral fracture spines. A new type of spinal protection device was applied to reduce the stress on the anterior vertebral edge and direct the center of gravity posteriorly. The stress distribution characteristics of different finite element models of the lumbar spine were analyzed, revealing the characteristics of the stress distributed along the spine under the action of the new spinal protection device. RESULTS Under normal conditions, the stress was mainly distributed in the middle and posterior columns of the spine. When the anterior border of the L1 vertebral body was fractured and collapsed, the stress distribution shifted toward the anterior column due to the center of gravity being directed forward. According to finite element analysis of the spine with the new protection device, the stress in the middle and posterior columns tended to increase, and that in the anterior column decreased. After the new type of spinal fixation device was applied, the stress at the L1 and L2 vertebral endplates decreased to a certain extent, especially that at the L1 vertebral body. The maximum stress on the L1 vertebral body decreased by 20% after the auxiliary device was applied. CONCLUSIONS According to the FEA results, the new spinal protection device can effectively prevent and treat osteoporotic vertebral compression fractures (OVCFs), and can alter the stress distribution in the spine and reduce the stress in the anterior column of the vertebral body, especially in vertebral compression fractures.
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Affiliation(s)
- Mingxue Che
- Department of Spinal SurgeryThe First Hospital of Jilin UniversityChangchunChina
- Jilin Engineering Research Center for Spine and Spinal Cord InjuryChangchunChina
| | - Yongjie Wang
- Department of Spinal SurgeryThe First Hospital of Jilin UniversityChangchunChina
- Jilin Engineering Research Center for Spine and Spinal Cord InjuryChangchunChina
| | - Yao Zhao
- Department of Joint SurgeryThe First Hospital of Jilin UniversityChangchunChina
| | - Shaokun Zhang
- Department of Spinal SurgeryThe First Hospital of Jilin UniversityChangchunChina
- Jilin Engineering Research Center for Spine and Spinal Cord InjuryChangchunChina
| | - Jun Yu
- Department of medical imagingJilin Provincial Armed Police Corps HospitalChangchunChina
| | - Weiquan Gong
- Department of Spinal SurgeryThe First Hospital of Jilin UniversityChangchunChina
- Jilin Engineering Research Center for Spine and Spinal Cord InjuryChangchunChina
| | - Debao Zhang
- Department of Joint SurgeryThe First Hospital of Jilin UniversityChangchunChina
| | - Mingxi Liu
- Department of Orthopaedic TraumatologyThe First Hospital of Jilin UniversityChangchunChina
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Liao JC. Impact of Osteoporosis on Different Type of Short-Segment Posterior Instrumentation for Thoracolumbar Burst Fracture-A Finite Element Analysis. World Neurosurg 2020; 139:e643-e651. [PMID: 32325261 DOI: 10.1016/j.wneu.2020.04.056] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2019] [Revised: 04/07/2020] [Accepted: 04/09/2020] [Indexed: 10/24/2022]
Abstract
OBJECTIVE In Taiwan (my country), the proportion of people 65 years or older was over 14% in 2018, which is known as entering "aged society." More and more thoracolumbar burst fractures in the setting of osteoporosis happen nowadays. In this study, a finite element model on thoracolumbar burst fracture was established and 4 types of posterior short-segment fixations were tested under normal bone quality and osteoporotic conditions. METHODS The intact T11-L1 spine finite element model was created, and one-half of the spongy bone of the T12 vertebra was removed to simulate burst fracture. Four fixation models with posterior fusion devices were established: 1) a link (S-L); 2) intermediate bilateral screws (S-I); 3) a link and calcium sulfate cement (S-L-C); and 4) intermediate bilateral screws and calcium sulfate cement (S-I-C). The Young modulus of the osteoporotic cancellous bone was set at 70 MPa. Range of motion, as well as the maximum value and distribution of the implant stress on T11 and L1, were compared between normal bone and osteoporotic status. RESULTS The strongest construct was the S-I-C group of both normal bone and osteoporosis condition. In osteoporotic status, the range of motion of construct in 4 types would be increased when comparing with normal bone. The stress on pedicle screws at the T11 and L1 level would also be increased in osteoporosis. The value of the maximal von Mises stress on the superior vertebral body (T11) for all loading conditions was larger than that on the inferior vertebral body (L1) in both normal bone and osteoporosis. CONCLUSIONS The S-I-C provided the strongest construct even in osteoporosis status. But osteoporosis would result in weakness for spinal construct, which might lead to implant failure.
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Affiliation(s)
- Jen-Chung Liao
- Department of Orthopedic Surgery, Bone and Joint Research Center, Chang Gung Memorial Hospital, Chang Gung University, Taoyuan, Taiwan.
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Population-based design and 3D finite element analysis of transforaminal thoracic interbody fusion cages. J Orthop Translat 2020; 21:35-40. [PMID: 32071873 PMCID: PMC7013106 DOI: 10.1016/j.jot.2019.12.006] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/08/2019] [Revised: 12/12/2019] [Accepted: 12/16/2019] [Indexed: 11/23/2022] Open
Abstract
OBJECTIVE To compare the biomechanical characteristics of two transforaminal thoracic interbody fusion cages based on the Chinese population thoracic anatomy. METHOD Computed tomography scans of the thoracic spine of 150 patients from our institution were collected and analysed. Two cages were designed based on the anatomical parameters of these patients. Further, we used 3D finite element analysis models to compare the stability of two cages by using Mimics 17.0 and ANSYS 15.0 software. RESULT Two kinds of thoracic cages (box and kidney-shaped) were designed. Under the displacement working condition, the two new fusion cages could achieve immediate postoperative stability, but the kidney-shaped cage was better than the box-shaped cage. Under the stress working condition, no highly focused stress area was found in either cages, but the kidney-shaped cage experienced less stress than the box-shaped cage. CONCLUSION The kidney-shaped cage is more stable and experiences lesser stress than the box-shaped cage after thoracic intervertebral fusion, and it is more suitable for Chinese transforaminal thoracic interbody fusion. THE TRANSLATIONAL POTENTIAL OF THIS ARTICLE This article is about thoracic fusion cage design and finite element analysis (FEA) analysis based on the thoracic anatomy parameters. For there is currently no suitable thoracic fusion cage for transforaminal thoracic interbody fusion, the results in this article may have the potential of transferring the two designed cages into clinical use.
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Estrogen Deficiency Exacerbates Intervertebral Disc Degeneration Induced by Spinal Instability in Rats. Spine (Phila Pa 1976) 2019; 44:E510-E519. [PMID: 30325885 DOI: 10.1097/brs.0000000000002904] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
STUDY DESIGN An experimental animal study of osteoporosis (OP) and intervertebral disc degeneration (IDD). OBJECTIVE The aim of this study was to clarify the effects of estrogen deficiency and supplement on cervical IDD induced by bilateral facetectomy in rats. SUMMARY OF BACKGROUND DATA The relationship between IDD and OP is still controversy with the wide prevalence in aged people. METHODS Seventy-two Sprague-Dawley female rats were randomly divided into ovariectomy (OVX) group, facet joints resection of C4-6 (FR), FR-OVX group, estrogen replacement therapy (ERT, based on the FR-OVX group) group, and sham group. Specimens of C4-6 segment were harvested at 12 and 24 weeks. The microstructures of C5 vertebrae, vertebral endplate lesions and calcification, and IDD of C5/6 disc were evaluated by micro-computed tomography (micro-CT) and histology. The protein and gene levels of aggrecan, Col2α1, matrix metalloprotease (MMP)-3, and MMP-13 in the C5/6 and C4/5 discs were measured. RESULTS Microstructures of C5 vertebral body were weakened significantly after ovariectomy, while restored effectively with estradiol supplementation. The facetectomy led to significant IDD, and the IDD was aggravated when combined with OVX. The IDD of the ERT group was alleviated effectively and similar to that of the FR group in intervertebral disc height, vertebral endplate lesions and calcification, and disc degeneration scores. In addition, the estrogen supplement maintained the extracellular matrix by decreasing MMP-3 and MMP-13, and increasing aggrecan and Col2α1 expression. CONCLUSION The present study demonstrated that estrogen deficiency exacerbated IDD induced by spinal instability, while estrogen supplementation alleviated the progression of disc degeneration related to osteoporosis. LEVEL OF EVIDENCE N/A.
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Optimizing bone cement stiffness for vertebroplasty through biomechanical effects analysis based on patient-specific three-dimensional finite element modeling. Med Biol Eng Comput 2018; 56:2137-2150. [DOI: 10.1007/s11517-018-1844-x] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2018] [Accepted: 05/09/2018] [Indexed: 12/24/2022]
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Wu CC, Jin HM, Yan YZ, Chen J, Wang K, Wang JL, Zhang ZJ, Wu AM, Wang XY. Biomechanical Role of the Thoracolumbar Ligaments of the Posterior Ligamentous Complex: A Finite Element Study. World Neurosurg 2018; 112:e125-e133. [DOI: 10.1016/j.wneu.2017.12.171] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2017] [Revised: 12/27/2017] [Accepted: 12/30/2017] [Indexed: 10/18/2022]
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Zhao WT, Qin DP, Zhang XG, Wang ZP, Tong Z. Biomechanical effects of different vertebral heights after augmentation of osteoporotic vertebral compression fracture: a three-dimensional finite element analysis. J Orthop Surg Res 2018; 13:32. [PMID: 29422073 PMCID: PMC5806350 DOI: 10.1186/s13018-018-0733-1] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/09/2017] [Accepted: 01/25/2018] [Indexed: 02/07/2023] Open
Abstract
Background Clinical results have shown that different vertebral heights have been restored post-augmentation of osteoporotic vertebral compression fractures (OVCFs) and the treatment results are consistent. However, no significant results regarding biomechanical effects post-augmentation have been found with different types of vertebral deformity or vertebral heights by biomechanical analysis. Therefore, the present study aimed to investigate the biomechanical effects between different vertebral heights of OVCFs before and after augmentation using three-dimensional finite element analysis. Methods Four patients with OVCFs of T12 underwent computed tomography (CT) of the T11-L1 levels. The CT images were reconstructed as simulated three-dimensional finite-element models of the T11-L1 levels (before and after the T12 vertebra was augmented with cement). Four different kinds of vertebral height models included Genant semi-quantitative grades 0, 1, 2, and 3, which simulated unilateral augmentation. These models were assumed to represent vertical compression and flexion, left flexion, and right flexion loads, and the von Mises stresses of the T12 vertebral body were assessed under different vertebral heights before and after bone cement augmentation. Results Data showed that the von Mises stresses significantly increased under four loads of OVCFs of the T12 vertebral body before the operation from grade 0 to grade 3 vertebral heights. The maximum stress of grade 3 vertebral height pre-augmentation was produced at approximately 200%, and at more than 200% for grade 0. The von Mises stresses were significantly different between different vertebral heights preoperatively. The von Mises stresses of the T12 vertebral body significantly decreased in four different loads and at different vertebral body heights (grades 0–3) after augmentation. There was no significant difference between the von Mises stresses of grade 0, 1, and 3 vertebral heights postoperatively. The von Mises stress significantly decreased between pre-augmentation and post-augmentation in T12 OVCF models of grade 0–3 vertebral heights. Conclusion Vertebral augmentation can sufficiently reduce von Mises stresses at different heights of OVCFs of the vertebral body, although this technique does not completely restore vertebral height to the anatomical criteria.
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Affiliation(s)
- Wen-Tao Zhao
- Gansu University of Chinese Medicine, No. 35, Dingxi East Rd., Chengguan District, Lanzhou, 730000, Gansu Province, People's Republic of China.,Yunnan University of Traditional Chinese Medicine, No. 1076, Yuhua Rd., Chenggong District, Kunming, 650500, Yunnan Province, People's Republic of China
| | - Da-Ping Qin
- Gansu University of Chinese Medicine, No. 35, Dingxi East Rd., Chengguan District, Lanzhou, 730000, Gansu Province, People's Republic of China.,Affiliated Hospital of Gansu University of Chinese Medicine, No. 735, Jiayuguan West Rd., Chengguan District, Lanzhou, 730000, Gansu Province, People's Republic of China
| | - Xiao-Gang Zhang
- Gansu University of Chinese Medicine, No. 35, Dingxi East Rd., Chengguan District, Lanzhou, 730000, Gansu Province, People's Republic of China. .,Affiliated Hospital of Gansu University of Chinese Medicine, No. 735, Jiayuguan West Rd., Chengguan District, Lanzhou, 730000, Gansu Province, People's Republic of China.
| | - Zhi-Peng Wang
- Gansu University of Chinese Medicine, No. 35, Dingxi East Rd., Chengguan District, Lanzhou, 730000, Gansu Province, People's Republic of China.,Affiliated Hospital of Gansu University of Chinese Medicine, No. 735, Jiayuguan West Rd., Chengguan District, Lanzhou, 730000, Gansu Province, People's Republic of China
| | - Zun Tong
- Gansu University of Chinese Medicine, No. 35, Dingxi East Rd., Chengguan District, Lanzhou, 730000, Gansu Province, People's Republic of China.,Affiliated Hospital of Gansu University of Chinese Medicine, No. 735, Jiayuguan West Rd., Chengguan District, Lanzhou, 730000, Gansu Province, People's Republic of China
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Liao JC, Chen WP, Wang H. Treatment of thoracolumbar burst fractures by short-segment pedicle screw fixation using a combination of two additional pedicle screws and vertebroplasty at the level of the fracture: a finite element analysis. BMC Musculoskelet Disord 2017; 18:262. [PMID: 28619021 PMCID: PMC5472982 DOI: 10.1186/s12891-017-1623-0] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/01/2017] [Accepted: 06/09/2017] [Indexed: 11/10/2022] Open
Abstract
Background Traditional one-above and one-below four-screw posterior short-segment instrumentation is used for unstable thoracolumbar burst fractures. However, this method has a high rate of implant failure and early loss of reduction. The purpose of this study was to use finite element (FE) analysis to determine the effect of treating thoracolumbar burst fractures by short-segment pedicle screw fixation using a combination of two additional pedicle screws and vertebroplasty at the level of the fracture. Methods An intact T11-L1 spine FE model was created from the computed tomography images of a male subject. Four fixation models with posterior fusion devices (pedicle screws, rods, cross-link) were established to simulate an unstable thoracolumbar fracture with different fusion surgeries: short-segment fixation with: 1) a link (S-L); 2) intermediate bilateral screws (S-I); 3) a link and calcium sulfate cement (S-L-C); 4) intermediate bilateral screws and calcium sulfate cement (S-I-C). Different loading conditions (flexion, extension, lateral bending, and axial rotation) were applied on the models and analyzed with a FE package. The range of motion (ROM), and the maximum value and distribution of the implant stress, and the stress in the facet joint, were compared between the intact and fixation models. Results The ROM in flexion, extension, axial rotation, and lateral bending was the smallest in the S-I-C model, followed by the S-I, S-L-C, and S-L models. Maximum von Mises stress values were larger under lateral bending and axial rotation loadings than under flexion and extension loading. High stress was concentrated at the crosslink and rod junctions. Maximal von Mises stress on the superior vertebral body for all loading conditions was larger than that on the inferior vertebral body. The maximal von Mises stress of the pedicle screws during all states of motion were 265.3 MPa in S-L fixation, 192.9 MPa in S-I fixation, 258.4 MPa in S-L-C fixation, and 162.3 MPa in S-I-C fixation. Conclusions Short-segment fixation with two intermediate pedicle screws together with calcium sulfate cement at the fractured vertebrae may provide a stiffer construct and less von Mises stress of the pedicle screws and rods as compared to other types of short-segment fixation.
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Affiliation(s)
- Jen-Chung Liao
- Department of Orthopedic Surgery, Bone and Joint Research Center, Chang Gung Memorial Hospital, Chang Gung University, Taoyuan, Taiwan
| | - Weng-Pin Chen
- Department of Mechanical Engineering, National Taipei University of Technology, 1, Sec. 3, Chung-Hsiao E. Rd, Taipei, 10608, Taiwan.
| | - Hao Wang
- Department of Mechanical Engineering, National Taipei University of Technology, 1, Sec. 3, Chung-Hsiao E. Rd, Taipei, 10608, Taiwan
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Liang D, Ye LQ, Jiang XB, Yang P, Zhou GQ, Yao ZS, Zhang SC, Yang ZD. Biomechanical effects of cement distribution in the fractured area on osteoporotic vertebral compression fractures: a three-dimensional finite element analysis. J Surg Res 2015; 195:246-56. [PMID: 25634828 DOI: 10.1016/j.jss.2014.12.053] [Citation(s) in RCA: 49] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2014] [Revised: 12/07/2014] [Accepted: 12/31/2014] [Indexed: 12/17/2022]
Abstract
BACKGROUND According to some clinical studies, insufficient cement distribution (ID) in the fractured area and asymmetrical cement distribution around the fractured area were thought to be the reasons for unrelieved pain and recollapse after percutaneous vertebral augmentation (PVA) in the treatment of symptomatic osteoporotic vertebral compression fractures. METHODS Finite element methods were used to investigate the biomechanical variance among three patterns of cement distribution (ID and sufficient cement distribution in the fractured area and asymmetrical cement distribution around the fractured area including upward [BU] and downward [BD] cement distribution). RESULTS Compared with fractured vertebra before PVA, distribution of von Mises stress in the cancellous bone was transferred to be concentrated at the cancellous bone surrounding cement after PVA, whereas it was not changed in the cortical bone. Compared with sufficient cement distribution group, maximum von Mises stress in the cancellous bone and cortical bone and maximum displacement of augmented vertebra increased significantly in the ID group, whereas asymmetrical cement distribution around the fractured area in BU and BD groups mainly increased maximum von Mises stress in the cancellous bone significantly. Similar results could be seen in all loading conditions. CONCLUSIONS ID in the fractured area may lead to unrelieved pain after PVA in the treatment of symptomatic osteoporotic vertebral compression fractures as maximum displacement of augmented vertebral body increased significantly. Both ID in the fractured area and asymmetrical cement distribution around the fractured area are more likely to induce recollapse of augmented vertebra because they increased maximum von Mises stress in the cancellous bone and cortical bone of augmented vertebra significantly.
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Affiliation(s)
- De Liang
- Department of Spinal Surgery, The First Affiliated Hospital of Guangzhou University of Chinese Medicine, Guangzhou, Guangdong, People's Republic of China
| | - Lin-Qiang Ye
- Department of Spinal Surgery, The First Affiliated Hospital of Guangzhou University of Chinese Medicine, Guangzhou, Guangdong, People's Republic of China; Guangzhou University of Chinese Medicine, Guangzhou, Guangdong, People's Republic of China
| | - Xiao-Bing Jiang
- Department of Spinal Surgery, The First Affiliated Hospital of Guangzhou University of Chinese Medicine, Guangzhou, Guangdong, People's Republic of China; Department of Digital Orthopaedics and Biomechanics, Laboratory Affiliated to National Key Discipline of Orthopaedics and Traumatology of Chinese Medicine, Guangzhou University of Chinese Medicine, Guangzhou, Guangdong, People's Republic of China.
| | - Pan Yang
- Guangzhou University of Chinese Medicine, Guangzhou, Guangdong, People's Republic of China; Orthopaedics Hospital, Guangzhou General Hospital of Guangzhou Military Command of PLA, Guangzhou, Guangdong, People's Republic of China
| | - Guang-Quan Zhou
- Department of Spinal Surgery, The First Affiliated Hospital of Guangzhou University of Chinese Medicine, Guangzhou, Guangdong, People's Republic of China; Department of Digital Orthopaedics and Biomechanics, Laboratory Affiliated to National Key Discipline of Orthopaedics and Traumatology of Chinese Medicine, Guangzhou University of Chinese Medicine, Guangzhou, Guangdong, People's Republic of China
| | - Zhen-Song Yao
- Department of Spinal Surgery, The First Affiliated Hospital of Guangzhou University of Chinese Medicine, Guangzhou, Guangdong, People's Republic of China
| | - Shun-Cong Zhang
- Department of Spinal Surgery, The First Affiliated Hospital of Guangzhou University of Chinese Medicine, Guangzhou, Guangdong, People's Republic of China
| | - Zhi-Dong Yang
- Department of Spinal Surgery, The First Affiliated Hospital of Guangzhou University of Chinese Medicine, Guangzhou, Guangdong, People's Republic of China
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Xu G, Fu X, Du C, Ma J, Li Z, Tian P, Zhang T, Ma X. Biomechanical comparison of mono-segment transpedicular fixation with short-segment fixation for treatment of thoracolumbar fractures: A finite element analysis. Proc Inst Mech Eng H 2014; 228:1005-13. [PMID: 25267283 DOI: 10.1177/0954411914552308] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Mono-segment transpedicular fixation is a method for the treatment of certain types of thoracolumbar spinal fracture. Finite element models were constructed to evaluate the biomechanics of mono-segment transpedicular fixation of thoracolumbar fracture. Spinal motion (T10–L2) was scanned and used to establish the models. The superior half of the cortical bone of T12 was removed and the superior half of the cancellous bone of the T12 body was assigned the material properties of injured bone to mimic vertebral fracture. Transpedicular fixation of T11 and T12 was performed to produce a mono-segment fixation model; T11 and L1 were fixed to produce a short-segment fixation model. Motion differences between functional units and von Mises stress on the spine and implants were measured under axial compression, anterior bending, extensional bending, lateral bending and axial rotation. We found no significant difference between mono- and short-segment fixations in the motion of any functional unit. Stress on the T10/T11 nucleus pulposus and T10/T11 and L1/L2 annulus fibrosus increased significantly by about 75% on anterior bending, extensional bending and lateral bending. In the fracture model, stress was increased by 24% at the inferior endplate of T10 and by 43% at the superior endplate of L2. All increased stresses were reduced after fixation and lower stress was observed with mono-segment fixation. In summary, the biomechanics of mono-segment pedicle screw instrumentation was similar to that of conventional short-segment fixation. As a minimally invasive treatment, mono-segment fixation would be appropriate for the treatment of selected thoracolumbar spinal fractures.
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Affiliation(s)
- Guijun Xu
- Department of Orthopaedics, Tianjin Hospital, Tianjin, People’s Republic of China
| | - Xin Fu
- Department of Orthopaedics, Tianjin Hospital, Tianjin, People’s Republic of China
| | - Changling Du
- Department of Orthopedics, Binzhou Medical University Hospital, Shandong, People’s Republic of China
| | - Jianxiong Ma
- Biomechanics Labs of Orthopaedic Institute, Tianjin Hospital, Tianjin, People’s Republic of China
| | - Zhijun Li
- Department of Orthopaedics, Tianjin Medical University General Hospital, Tianjin, People’s Republic of China
- Department of Immunology, Tianjin Medical University, Tianjin, People’s Republic of China
| | - Peng Tian
- Department of Orthopaedics, Tianjin Hospital, Tianjin, People’s Republic of China
| | - Tao Zhang
- Department of Orthopaedics, Tianjin Medical University General Hospital, Tianjin, People’s Republic of China
| | - Xinlong Ma
- Biomechanics Labs of Orthopaedic Institute, Tianjin Hospital, Tianjin, People’s Republic of China
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Mustafy T, El-Rich M, Mesfar W, Moglo K. Investigation of impact loading rate effects on the ligamentous cervical spinal load-partitioning using finite element model of functional spinal unit C2–C3. J Biomech 2014; 47:2891-903. [DOI: 10.1016/j.jbiomech.2014.07.016] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2014] [Revised: 07/17/2014] [Accepted: 07/22/2014] [Indexed: 10/25/2022]
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Xu G, Fu X, Du C, Ma J, Li Z, Ma X. Biomechanical effects of vertebroplasty on thoracolumbar burst fracture with transpedicular fixation: a finite element model analysis. Orthop Traumatol Surg Res 2014; 100:379-83. [PMID: 24835003 DOI: 10.1016/j.otsr.2014.03.016] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/10/2013] [Revised: 12/17/2013] [Accepted: 03/13/2014] [Indexed: 02/02/2023]
Abstract
OBJECTIVE To investigate the biomechanical effects of augmentation of the fractured vertebrae after posterior instrumentation. METHODS By simulating internal fixation plus augmentation with cement, eight tridimensional, anatomically detailed finite element models of the T11-L1 functional spinal junction were developed. Two kinds of models for mimicking different severity of the fracture were established according to the Denis' classification. Augmentation with cement was conducted after reduction with posterior fixation using a universal spine system. These models assumed a three-column loading configuration as follows: compression, anteflexion, extension, lateroflexion and axial rotation. Stress of the implants and spine was evaluated. RESULTS Data showed that for severely fractured models, augmentation apparently decreased the von Mises stresses by 50% for the rods and 40% for the screws, about 40% for the inferior endplate of T11, and 50% for the superior endplate of L1 in vertical compression and other load situations. CONCLUSION We should only apply vertebroplasty to prevent correction loss and implants failure based on the fact that it could significantly decrease stress of the instrumentations and spine when the vertebrae are severely fractured. LEVEL OF EVIDENCE Level IV, biomechanical study.
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Affiliation(s)
- G Xu
- Biomechanics Labs of Orthopaedic Institute, Tianjin Hospital, 406, Jiefang Nan Street, Hexi District, 300211 Tianjin, China
| | - X Fu
- Biomechanics Labs of Orthopaedic Institute, Tianjin Hospital, 406, Jiefang Nan Street, Hexi District, 300211 Tianjin, China
| | - C Du
- Department of Orthopaedics, Binzhou Medical University Hospital, 661 Yellow River Road, 256603 Binzhou, China
| | - J Ma
- Biomechanics Labs of Orthopaedic Institute, Tianjin Hospital, 406, Jiefang Nan Street, Hexi District, 300211 Tianjin, China
| | - Z Li
- Department of Orthopaedics, Tianjin Medical University General Hospital, 154 Anshan Street, Heping District, 300052 Tianjin, China; Department of Immunology, Tianjin Medical University, 22 Qixiangtai Road, Heping District, 300070 Tianjin, China
| | - X Ma
- Biomechanics Labs of Orthopaedic Institute, Tianjin Hospital, 406, Jiefang Nan Street, Hexi District, 300211 Tianjin, China.
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Jaumard NV, Welch WC, Winkelstein BA. Spinal facet joint biomechanics and mechanotransduction in normal, injury and degenerative conditions. J Biomech Eng 2011; 133:071010. [PMID: 21823749 DOI: 10.1115/1.4004493] [Citation(s) in RCA: 200] [Impact Index Per Article: 15.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
The facet joint is a crucial anatomic region of the spine owing to its biomechanical role in facilitating articulation of the vertebrae of the spinal column. It is a diarthrodial joint with opposing articular cartilage surfaces that provide a low friction environment and a ligamentous capsule that encloses the joint space. Together with the disc, the bilateral facet joints transfer loads and guide and constrain motions in the spine due to their geometry and mechanical function. Although a great deal of research has focused on defining the biomechanics of the spine and the form and function of the disc, the facet joint has only recently become the focus of experimental, computational and clinical studies. This mechanical behavior ensures the normal health and function of the spine during physiologic loading but can also lead to its dysfunction when the tissues of the facet joint are altered either by injury, degeneration or as a result of surgical modification of the spine. The anatomical, biomechanical and physiological characteristics of the facet joints in the cervical and lumbar spines have become the focus of increased attention recently with the advent of surgical procedures of the spine, such as disc repair and replacement, which may impact facet responses. Accordingly, this review summarizes the relevant anatomy and biomechanics of the facet joint and the individual tissues that comprise it. In order to better understand the physiological implications of tissue loading in all conditions, a review of mechanotransduction pathways in the cartilage, ligament and bone is also presented ranging from the tissue-level scale to cellular modifications. With this context, experimental studies are summarized as they relate to the most common modifications that alter the biomechanics and health of the spine-injury and degeneration. In addition, many computational and finite element models have been developed that enable more-detailed and specific investigations of the facet joint and its tissues than are provided by experimental approaches and also that expand their utility for the field of biomechanics. These are also reviewed to provide a more complete summary of the current knowledge of facet joint mechanics. Overall, the goal of this review is to present a comprehensive review of the breadth and depth of knowledge regarding the mechanical and adaptive responses of the facet joint and its tissues across a variety of relevant size scales.
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Affiliation(s)
- Nicolas V Jaumard
- Dept. of Neurosurgery, University of Pennsylvania, Philadelphia, PA 19104, USA.
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