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Bereczki F, Turbucz M, Pokorni AJ, Hajnal B, Ronai M, Klemencsics I, Lazary A, Eltes PE. The effect of polymethylmethacrylate augmentation on the primary stability of stand-alone implant construct versus posterior stabilization in oblique lumbar interbody fusion with osteoporotic bone quality- a finite element study. Spine J 2024; 24:1323-1333. [PMID: 38307174 DOI: 10.1016/j.spinee.2024.01.021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/08/2023] [Revised: 01/26/2024] [Accepted: 01/27/2024] [Indexed: 02/04/2024]
Abstract
BACKGROUND CONTEXT Oblique lumbar interbody fusion (OLIF) can provide an ideal minimally invasive solution for achieving spinal fusion in an older, more frail population where decreased bone quality can be a limiting factor. Stabilization can be achieved with bilateral pedicle screws (BPS), which require additional incisions and longer operative time. Alternatively, a novel self-anchoring stand-alone lateral plate system (SSA) can be used, where no additional incisions are required. Based on the relevant literature, BPS constructs provide greater primary biomechanical stability compared to lateral plate constructs, including SSA. This difference is further increased by osteoporosis. Screw augmentation in spinal fusion surgeries is commonly used; however, in the case of OLIF, it is a fairly new concept, lacking a consensus-based guideline. PURPOSE This comparative finite element (FE) study aimed to investigate the effect of PMMA screw augmentation on the primary stability of a stand-alone implant construct versus posterior stabilization in OLIF with osteoporotic bone quality. STUDY DESIGN The biomechanical effect of screw augmentation was studied inside an in-silico environment using computer-aided FE analysis. METHODS A previously validated and published L2-L4 FE model with normal and osteoporotic bone material properties was used. Geometries based on the OLIF implants (BPS, SSA) were created and placed inside the L3-L4 motion segment with increasing volumes (1-6 cm3) of PMMA augmentation. A follower load of 400 N and 10 Nm bending moment (in the three anatomical planes) were applied to the surgical FE models with different bone material properties. The operated L3-L4 segmental range of motion (ROM), the inserted cage's maximal caudal displacements, and L4 cranial bony endplate principal stress values were measured. RESULTS The nonaugmented values for the BPS construct were generally lower compared to SSA, and the difference was increased by osteoporosis. In osteoporotic bone, PMMA augmentation gradually decreased the investigated parameters and the difference between the two constructs as well. Between 3 cm3 and 4 cm3 of injected PMMA volume per screw, the difference between augmented SSA and standard BPS became comparable. CONCLUSIONS Based on this study, augmentation can enhance the primary stability of the constructs and decrease the difference between them. Considering leakage as a possible complication, between 3 cm3 and 4 cm3 of injected PMMA per screw can be an adequate amount for SSA augmentation. However, further in silico, and possibly in vitro and clinical testing is required to thoroughly understand the investigated biomechanical aspects. CLINICAL SIGNIFICANCE This study sheds light on the possible biomechanical advantage offered by augmented OLIF implants and provides a theoretical augmentation amount for the SSA construct. Based on the findings, the concept of an SSA device with PMMA augmentation capability is desirable.
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Affiliation(s)
- Ferenc Bereczki
- In Silico Biomechanics Laboratory, National Center for Spinal Disorders, Királyhágó Str. 1-3, Budapest, Hungary; School of PhD Studies, Semmelweis University, Üllői Str. 26, Budapest, Hungary
| | - Mate Turbucz
- In Silico Biomechanics Laboratory, National Center for Spinal Disorders, Királyhágó Str. 1-3, Budapest, Hungary; School of PhD Studies, Semmelweis University, Üllői Str. 26, Budapest, Hungary
| | - Agoston Jakab Pokorni
- In Silico Biomechanics Laboratory, National Center for Spinal Disorders, Királyhágó Str. 1-3, Budapest, Hungary; School of PhD Studies, Semmelweis University, Üllői Str. 26, Budapest, Hungary
| | - Benjamin Hajnal
- In Silico Biomechanics Laboratory, National Center for Spinal Disorders, Királyhágó Str. 1-3, Budapest, Hungary; School of PhD Studies, Semmelweis University, Üllői Str. 26, Budapest, Hungary
| | - Marton Ronai
- National Center for Spinal Disorders, Királyhágó Str. 1-3, Budapest, Hungary
| | - Istvan Klemencsics
- National Center for Spinal Disorders, Királyhágó Str. 1-3, Budapest, Hungary
| | - Aron Lazary
- In Silico Biomechanics Laboratory, National Center for Spinal Disorders, Királyhágó Str. 1-3, Budapest, Hungary; Department of Spine Surgery, Department of Orthopaedics, Semmelweis University, Üllői Str. 78/b, Budapest, Hungary
| | - Peter Endre Eltes
- In Silico Biomechanics Laboratory, National Center for Spinal Disorders, Királyhágó Str. 1-3, Budapest, Hungary; Department of Spine Surgery, Department of Orthopaedics, Semmelweis University, Üllői Str. 78/b, Budapest, Hungary.
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Andriamifidy HF, Rohde M, Swami P, Liang H, Grande D, Virk S. Influence of Placement of Lumbar Interbody Cage on Subsidence Risk: Biomechanical Study. World Neurosurg 2024; 183:e440-e446. [PMID: 38154684 DOI: 10.1016/j.wneu.2023.12.118] [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: 10/25/2023] [Revised: 12/20/2023] [Accepted: 12/21/2023] [Indexed: 12/30/2023]
Abstract
OBJECTIVE Lumbar spinal fusion is a common surgical procedure that can be done with a variety of different instrumentation and techniques. Despite numerous research studies investigating subsidence risk factors, the impact of cage placement on subsidence is not fully elucidated. This study aims to determine whether placement of an expandable transforaminal lumbar interbody fusion cage at the center end plate or at the anterior apophyseal ring affects cage subsidence. METHODS A transforaminal lumbar interbody fusion cage was placed centrally or peripherally between 2 synthetic vertebral models of L3 and L4. A compression plate attached to a 10 KN load cell was used to uniaxially compress the assembly. The ultimate force required for the assembly to fail and subsidence stiffness were analyzed. Computed tomography scans of each L3 and L4 were obtained, and maximum end plate subsidence was measured in the frontal plane. RESULTS Anterior apophyseal cage placement resulted in higher stiffness of the vertebrae-cage assembly (Ks, 962.89 N/mm) and a higher subsidence stiffness (Kb,987.21 N/mm) compared with central placement (P < 0.05). Ultimate compressive load of the vertebrae-cage assembly did not increase. Moreover, the maximum subsidence depth did not significantly vary between placements. CONCLUSIONS The subsidence stiffness increased with anterior apophyseal cage placement. Periphery end plate cortical bone architecture may play a role in resisting the impact of cage subsidence. To fully understand the effect of cage placement on cage subsidence, future studies should investigate its implications on native and diseased spine.
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Affiliation(s)
| | - Matthew Rohde
- Donald and Barbara Zucker School of Medicine at Hofstra/Northwell, Hempstead, New York, USA.
| | - Pooja Swami
- Department of Orthopaedic Research Laboratory, Feinstein Institutes for Medical Research, Northwell Health, Manhasset, New York, USA
| | - Haixiang Liang
- Department of Orthopaedic Research Laboratory, Feinstein Institutes for Medical Research, Northwell Health, Manhasset, New York, USA
| | - Daniel Grande
- Department of Orthopaedic Research Laboratory, Feinstein Institutes for Medical Research, Northwell Health, Manhasset, New York, USA
| | - Sohrab Virk
- Department of Orthopaedic Surgery, Northwell Health Long Island Jewish Medical Center/North Shore University Hospital, Manhasset, New York, USA
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Zhang Y, Du S, Aiyiti W, Teng Y, Jia R, Jiang H. Customized design and biomechanical property analysis of 3D-printed tantalum intervertebral cages. Biomed Mater Eng 2024; 35:99-124. [PMID: 38217572 DOI: 10.3233/bme-230154] [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] [Indexed: 01/15/2024]
Abstract
BACKGROUND Intervertebral cages used in clinical applications were often general products with standard specifications, which were challenging to match with the cervical vertebra and prone to cause stress shielding and subsidence. OBJECTIVE To design and fabricate customized tantalum (Ta) intervertebral fusion cages that meets the biomechanical requirements of the cervical segment. METHODS The lattice intervertebral cages were customized designed and fabricated by the selective laser melting. The joint and muscle forces of the cervical segment under different movements were analyzed using reverse dynamics method. The stress characteristics of cage, plate, screws and vertebral endplate were analyzed by finite element analysis. The fluid flow behaviors and permeability of three lattice structures were simulated by computational fluid dynamics. Compression tests were executed to investigate the biomechanical properties of the cages. RESULTS Compared with the solid cages, the lattice-filled structures significantly reduced the stress of cages and anterior fixation system. In comparison to the octahedroid and quaddiametral lattice-filled cages, the bitriangle lattice-filled cage had a lower stress shielding rate, higher permeability, and superior subsidence resistance ability. CONCLUSION The inverse dynamics simulation combined with finite element analysis is an effective method to investigate the biomechanical properties of the cervical vertebra during movements.
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Affiliation(s)
- Yutao Zhang
- School of Mechanical Engineering, Xinjiang University, Urumqi, China
| | - Shu Du
- School of Mechanical Engineering, Xinjiang University, Urumqi, China
| | - Wurikaixi Aiyiti
- School of Mechanical Engineering, Xinjiang University, Urumqi, China
| | - Yong Teng
- Department of Orthopaedics, Hospital of Xinjiang Military Region PLA, Urumqi, China
| | - Ru Jia
- School of Mechanical Engineering, Xinjiang University, Urumqi, China
| | - Houfeng Jiang
- School of Mechanical Engineering, Xinjiang University, Urumqi, China
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Lin M, Doulgeris J, Dhar UK, O’Corner T, Papanastassiou ID, Tsai CT, Vrionis FD. Effect of graded posterior element and ligament removal on annulus stress and segmental stability in lumbar spine stenosis: a finite element analysis study. Front Bioeng Biotechnol 2023; 11:1237702. [PMID: 37790254 PMCID: PMC10543754 DOI: 10.3389/fbioe.2023.1237702] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2023] [Accepted: 08/30/2023] [Indexed: 10/05/2023] Open
Abstract
The study aimed to investigate the impact of posterior element and ligament removal on the maximum von Mises stress, and maximum shear stress of the eight-layer annulus for treating stenosis at the L3-L4 and L4-L5 levels in the lumbar spine. Previous studies have indicated that laminectomy alone can result in segmental instability unless fusion is performed. However, no direct correlations have been established regarding the impact of posterior and ligament removal. To address this gap, four models were developed: Model 1 represented the intact L2-L5 model, while model 2 involved a unilateral laminotomy involving the removal of a section of the L4 inferior lamina and 50% of the ligament flavum between L4 and L5. Model 3 consisted of a complete laminectomy, which included the removal of the spinous process and lamina of L4, as well as the relevant connecting ligaments between L3-L4 and L4-L5 (ligament flavum, interspinous ligament, supraspinous ligament). In the fourth model, a complete laminectomy with 50% facetectomy was conducted. This involved the same removals as in model 3, along with a 50% removal of the inferior/superior facets of L4 and a 50% removal of the facet capsular ligaments between L3-L4 and L4-L5. The results indicated a significant change in the range of motion (ROM) at the L3-L4 and L4-L5 levels during flexion and torque situations, but no significant change during extension and bending simulation. The ROM increased by 10% from model 1 and 2 to model 3, and by 20% to model 4 during flexion simulation. The maximum shear stress and maximum von-Mises stress of the annulus and nucleus at the L3-L4 levels exhibited the greatest increase during flexion. In all eight layers of the annulus, there was an observed increase in both the maximum shear stress and maximum von-Mises stress from model 1&2 to model 3 and model 4, with the highest rate of increase noted in layers 7&8. These findings suggest that graded posterior element and ligament removal have a notable impact on stress distribution and range of motion in the lumbar spine, particularly during flexion.
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Affiliation(s)
- Maohua Lin
- Department of Ocean and Mechanical Engineering, Florida Atlantic University, Boca Raton, FL, United States
| | - James Doulgeris
- Department of Ocean and Mechanical Engineering, Florida Atlantic University, Boca Raton, FL, United States
| | - Utpal Kanti Dhar
- Department of Ocean and Mechanical Engineering, Florida Atlantic University, Boca Raton, FL, United States
| | - Timothy O’Corner
- Department of Neurosurgery, Marcus Neuroscience Institute, Boca Raton Regional Hospital, Boca Raton, FL, United States
| | | | - Chi-Tay Tsai
- Department of Ocean and Mechanical Engineering, Florida Atlantic University, Boca Raton, FL, United States
| | - Frank D. Vrionis
- Department of Neurosurgery, Marcus Neuroscience Institute, Boca Raton Regional Hospital, Boca Raton, FL, United States
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Kiapour A, Massaad E, Kodigudla MK, Kelkar A, Begley MR, Goel VK, Block JE, Shin JH. Resisting subsidence with a truss Implant: Application of the "Snowshoe" principle for interbody fusion devices. J Biomech 2023; 155:111635. [PMID: 37216894 DOI: 10.1016/j.jbiomech.2023.111635] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2022] [Revised: 04/10/2023] [Accepted: 05/09/2023] [Indexed: 05/24/2023]
Abstract
The primary objective was to compare the subsidence resistance properties of a novel 3D-printed spinal interbody titanium implant versus a predicate polymeric annular cage. We evaluated a 3D-printed spinal interbody fusion device that employs truss-based bio-architectural features to apply the snowshoe principle of line length contact to provide efficient load distribution across the implant/endplate interface as means of resisting implant subsidence. Devices were tested mechanically using synthetic bone blocks of differing densities (osteoporotic to normal) to determine the corresponding resistance to subsidence under compressive load. Statistical analyses were performed to compare the subsidence loads and evaluate the effect of cage length on subsidence resistance. The truss implant demonstrated a marked rectilinear increase in resistance to subsidence associated with increase in the line length contact interface that corresponds with implant length irrespective of subsidence rate or bone density. In blocks simulating osteoporotic bone, comparing the shortest with the longest length truss cage (40 vs. 60 mm), the average compressive load necessary to induce subsidence of the implant increased by 46.4% (383.2 to 561.0 N) and 49.3% (567.4 to 847.2 N) for 1 and 2 mm of subsidence, respectively. In contrast, for annular cages, there was only a modest increase in compressive load when comparing the shortest with the longest length cage at a 1 mm subsidence rate. The Snowshoe truss cages demonstrated substantially more resistance to subsidence than corresponding annular cages. Clinical studies are required to support the biomechanical findings in this work.
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Affiliation(s)
- Ali Kiapour
- Department of Neurosurgery Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA.
| | - Elie Massaad
- Department of Neurosurgery Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
| | - Manoj K Kodigudla
- Engineering Center for Orthopedic Research Excellence, The University of Toledo, Toledo, OH, USA
| | - Amey Kelkar
- Engineering Center for Orthopedic Research Excellence, The University of Toledo, Toledo, OH, USA
| | - Matthew R Begley
- Department of Mechanical Engineering, University of California, Santa Barbara, CA, USA
| | - Vijay K Goel
- Engineering Center for Orthopedic Research Excellence, The University of Toledo, Toledo, OH, USA
| | | | - John H Shin
- Department of Neurosurgery Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
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Distefano F, Epasto G, Guglielmino E, Amata A, Mineo R. Subsidence of a partially porous titanium lumbar cage produced by electron beam melting technology. J Biomed Mater Res B Appl Biomater 2023; 111:590-598. [PMID: 36208414 PMCID: PMC10092161 DOI: 10.1002/jbm.b.35176] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2021] [Revised: 07/30/2022] [Accepted: 09/25/2022] [Indexed: 01/21/2023]
Abstract
The lumbar intervertebral devices are widely used in the surgical treatment of lumbar diseases. The subsidence represents a serious clinical issue during the healing process, mainly when the interfaces between the implant and the vertebral bodies are not well designed. The aim of this study is the evaluation of subsidence risk for two different devices. The devices have the same shape, but one of them includes a filling micro lattice structure. The effect of the micro lattice structure on the subsidence behavior of the implant was evaluated by means of both experimental tests and finite element analyses. Compressive tests were carried out by using blocks made of grade 15 polyurethane, which simulate the vertebral bone. Non-linear, quasi-static finite element analyses were performed to simulate experimental and physiologic conditions. The experimental tests and the FE analyses showed that the subsidence risk is higher for the device without micro lattice structure, due to the smaller contact surface. Moreover, an overload in the central zone of the contact surface was detected in the same device and it could cause the implant failure. Thus, the micro lattice structure allows a homogenous pressure distribution at the implant-bone interface.
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Affiliation(s)
- Fabio Distefano
- Department of Engineering, University of Messina, Messina, Italy
| | - Gabriella Epasto
- Department of Engineering, University of Messina, Messina, Italy
| | | | - Aurora Amata
- ABR Srl, Zona Industriale Dittaino, Assoro, Italy
| | - Rosalia Mineo
- Mt Ortho srl, via fossa lupo sn Aci Sant'Antonio, Catania, Italy
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Wang R, Wu Z. Recent advancement in finite element analysis of spinal interbody cages: A review. Front Bioeng Biotechnol 2023; 11:1041973. [PMID: 37034256 PMCID: PMC10076720 DOI: 10.3389/fbioe.2023.1041973] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2022] [Accepted: 03/13/2023] [Indexed: 04/11/2023] Open
Abstract
Finite element analysis (FEA) is a widely used tool in a variety of industries and research endeavors. With its application to spine biomechanics, FEA has contributed to a better understanding of the spine, its components, and its behavior in physiological and pathological conditions, as well as assisting in the design and application of spinal instrumentation, particularly spinal interbody cages (ICs). IC is a highly effective instrumentation for achieving spinal fusion that has been used to treat a variety of spinal disorders, including degenerative disc disease, trauma, tumor reconstruction, and scoliosis. The application of FEA lets new designs be thoroughly "tested" before a cage is even manufactured, allowing bio-mechanical responses and spinal fusion processes that cannot easily be experimented upon in vivo to be examined and "diagnosis" to be performed, which is an important addition to clinical and in vitro experimental studies. This paper reviews the recent progress of FEA in spinal ICs over the last six years. It demonstrates how modeling can aid in evaluating the biomechanical response of cage materials, cage design, and fixation devices, understanding bone formation mechanisms, comparing the benefits of various fusion techniques, and investigating the impact of pathological structures. It also summarizes the various limitations brought about by modeling simplification and looks forward to the significant advancement of spine FEA research as computing efficiency and software capabilities increase. In conclusion, in such a fast-paced field, the FEA is critical for spinal IC studies. It helps in quantitatively and visually demonstrating the cage characteristics after implanting, lowering surgeons' learning costs for new cage products, and probably assisting them in determining the best IC for patients.
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Affiliation(s)
- Ruofan Wang
- Guangzhou Key Laboratory of Spine Disease Prevention and Treatment, The Third Affiliated Hospital of Guangzhou Medical University, Guangzhou, China
- Department of Orthopaedic Surgery, The Third Affiliated Hospital of Guangzhou Medical University, Guangzhou, China
| | - Zenghui Wu
- Guangzhou Key Laboratory of Spine Disease Prevention and Treatment, The Third Affiliated Hospital of Guangzhou Medical University, Guangzhou, China
- Department of Orthopaedic Surgery, The Third Affiliated Hospital of Guangzhou Medical University, Guangzhou, China
- *Correspondence: Zenghui Wu,
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[Research progress of effect of cage height on outcomes of lumbar interbody fusion surgery]. ZHONGGUO XIU FU CHONG JIAN WAI KE ZA ZHI = ZHONGGUO XIUFU CHONGJIAN WAIKE ZAZHI = CHINESE JOURNAL OF REPARATIVE AND RECONSTRUCTIVE SURGERY 2022; 36:1440-1444. [PMID: 36382465 PMCID: PMC9681583 DOI: 10.7507/1002-1892.202205096] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
OBJECTIVE To summarize the effect of cage height on outcomes of lumbar interbody fusion surgery and the importance of the cage height selection. METHODS The related literature was widely reviewed to summarize the research progress on the complications caused by inappropriate height of the cage and the methods of selecting cage height. RESULTS Inappropriate height of the cage can lead to endplate injury, cage subsidence, internal fixation failure, adjacent segmental degeneration, over-distraction related pain, insufficient indirect decompression, instability of operation segment, poor interbody fusion, poor sequence of spine, and cage displacement. At present, the selection of the cage height is based on the results of the intraoperative model test, which is reliable but high requirements for surgical experience and hard to standardize. CONCLUSION The inappropriate height of the cage may have an adverse impact on the postoperative outcome of patients. It is important to develop a selection standard of the cage height by screening the related influential factors.
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Yee-Yanagishita C, Fogel G, Douglas B, Essayan G, Poojary B, Martin N, Williams GM, Peng Y, Jekir M. Biomechanical comparison of subsidence performance among three modern porous lateral cage designs. Clin Biomech (Bristol, Avon) 2022; 99:105764. [PMID: 36130418 DOI: 10.1016/j.clinbiomech.2022.105764] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/21/2022] [Revised: 09/06/2022] [Accepted: 09/12/2022] [Indexed: 02/07/2023]
Abstract
BACKGROUND Cage subsidence remains a major complication after spinal surgery. The goal of this study was to compare the subsidence performance of three modern porous cage designs. METHODS Three porous cages were evaluated: a porous titanium cage, a porous polyetheretherketone cage and a truss titanium cage. Mechanical testing was performed for each cage per the American Society for Testing and Materials F2077 and F2267 standards to evaluate cage stiffness and block stiffness, and per a novel clinically relevant dynamic subsidence testing method simulating cyclic spine loading during 3-months postoperatively to evaluate the subsidence displacement. FINDINGS The porous polyetheretherketone cage demonstrated the lowest cage stiffness (21.0 ± 1.1 kN/mm), less than half of both titanium cages (truss titanium cage, 49.1 kN/mm; porous titanium cage, 43.6 kN/mm). The block stiffness was greatest for the porous titanium cage (2867.7 ± 105.3 N/mm), followed by the porous polyetheretherketone (2563.4 ± 72.9 N/mm) and truss titanium cages (2213.7 ± 21.8 N/mm). The dynamic subsidence displacement was greatest for the truss titanium cage, which was 1.5 and 2.5 times the subsidence displacement as the porous polyetheretherketone and porous titanium cages respectively. INTERPRETATIONS Specific porous cage design plays a crucial role in the cage subsidence performance, to a greater degree than the selection of cage materials. A porous titanium cage with body lattice and microporous endplates significantly outperformed a truss titanium cage with a similar cage stiffness in subsidence performance, and a porous polyetheretherketone cage with half of its stiffness.
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Affiliation(s)
| | - Guy Fogel
- Spine Pain Begone Clinic, San Antonio, TX, United States
| | | | | | | | | | | | - Yun Peng
- NuVasive Inc., San Diego, CA, United States.
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Xie T, Pu L, Zhao L, Lu Y, Yang Z, Wang X, Song Y, Zeng J. Influence of coronal-morphology of endplate and intervertebral space to cage subsidence and fusion following oblique lumbar interbody fusion. BMC Musculoskelet Disord 2022; 23:633. [PMID: 35788206 PMCID: PMC9252057 DOI: 10.1186/s12891-022-05584-3] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/08/2022] [Accepted: 06/24/2022] [Indexed: 02/08/2023] Open
Abstract
Background Endplate morphology is considered to be one of the influencing factors of cage subsidence after lumbar interbody fusion (LIF). Previous radiographic evaluations on the endplate mostly used sagittal X-ray or MRI. However, there are few studies on the CT evaluation of the endplate and intervertebral space (IVS), especially the evaluation of coronal morphology and its influence on subsidence and fusion after LIF. We aimed to measure and classify the shapes of the endplate and IVS using coronal CT imaging and evaluate the radiographic and clinical outcomes of different shapes of the endplate/IVS following oblique lateral lumbar interbody fusion (OLIF). Methods A total of 137 patients (average age 59.1 years, including 75 males and 62 females) who underwent L4-5 OLIF combined with anterolateral fixation from June 2018 to June 2020 were included. The endplate concavity depth (ECD) was measured on the preoperative coronal CT image. According to ECD, the endplate was classified as flat (< 2 mm), shallow (2–4 mm), or deep (> 4 mm). The L4-5 IVS was further classified according to endplate type. The disc height (DH), DH changes, subsidence rate, fusion rate, and Oswestry Disability Index (ODI) in different endplate/IVS shapes were evaluated during 1-year follow up. Results The ECD of L4 inferior endplate (IEP) was significantly deeper than that of L5 superior endplate (SEP) (4.2 ± 1.1 vs 1.6 ± 0.8, P < 0.01). Four types of L4-5 IVS were identified: shallow-shallow (16, 11.7%), shallow-flat (45, 32.9%), deep-shallow (32, 23.4%), and deep-flat (44, 32.1%). A total of 45 (32.9%) cases of cage subsidence were observed. Only one (6.3%) subsidence event occurred in the shallow-shallow group, which was significantly lower than in the other three groups (19 shallow-flat, 6 deep-shallow, and 19 deep-flat) (P < 0.05). Meanwhile, the shallow-shallow group had the highest fusion rate (15, 93.8%) and the highest rate of reach minimal clinically important difference (MCID) ODI among the four types. For a single endplate, the shape of L4 IEP is the main influencing factor of the final interbody fusion rate, and the shallow shape L4 IEP facilitates fusion ( OR = 2.85, p = 0.03). On the other hand, the flat shape L5 SEP was the main risk factor to cage subsidence (OR = 4.36, p < 0.01). Conclusion The L4-5 IVS is asymmetrical on coronal CT view and tends to be fornix-above and flat-down. The shallow-shallow IVS has the lowest subsidence rate and best fusion result, which is possibly because it has a relatively good degree in matching either the upper or lower interface of the cage and endplates. These findings provide a basis for the further improvements in the design of OLIF cages. Supplementary Information The online version contains supplementary material available at 10.1186/s12891-022-05584-3.
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Affiliation(s)
- Tianhang Xie
- Department of Orthopedics, Orthopedic Research Institute, West China Hospital, Sichuan University, 37# Wuhou Guoxue road, Chengdu, 610041, China
| | - Liming Pu
- Department of Medical Statistics, School of Public Health, Sun Yat-Sen University, Guangzhou, China
| | - Long Zhao
- Department of Orthopedics, Orthopedic Research Institute, West China Hospital, Sichuan University, 37# Wuhou Guoxue road, Chengdu, 610041, China
| | - Yufei Lu
- Department of Orthopedics, Orthopedic Research Institute, West China Hospital, Sichuan University, 37# Wuhou Guoxue road, Chengdu, 610041, China
| | - Zhiqiang Yang
- Department of Orthopedics, Orthopedic Research Institute, West China Hospital, Sichuan University, 37# Wuhou Guoxue road, Chengdu, 610041, China
| | - Xiandi Wang
- Department of Orthopedics, Orthopedic Research Institute, West China Hospital, Sichuan University, 37# Wuhou Guoxue road, Chengdu, 610041, China
| | - Yueming Song
- Department of Orthopedics, Orthopedic Research Institute, West China Hospital, Sichuan University, 37# Wuhou Guoxue road, Chengdu, 610041, China
| | - Jiancheng Zeng
- Department of Orthopedics, Orthopedic Research Institute, West China Hospital, Sichuan University, 37# Wuhou Guoxue road, Chengdu, 610041, China.
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Huang S, Min S, Wang S, Jin A. Biomechanical effects of an oblique lumbar interbody fusion combined with posterior augmentation: a finite element analysis. BMC Musculoskelet Disord 2022; 23:611. [PMID: 35761228 PMCID: PMC9235194 DOI: 10.1186/s12891-022-05553-w] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/13/2021] [Accepted: 06/06/2022] [Indexed: 11/18/2022] Open
Abstract
Background Oblique lateral interbody fusion (OLIF) is widely used to treat lumbar degenerative disc disease. This study aimed to evaluate the biomechanical stability of OLIF, OLIF including posterior pedicle screw and rod (PSR), and OLIF including cortical screw and rod (CSR) instrumentation through finite element analysis. Methods A complete L2-L5 finite element model of the lumbar spine was constructed. Surgical models of OLIF, such as stand-alone, OLIF combined with PSR, and OLIF combined with CSR were created in the L3-L4 surgical segments. Range of motion (ROM), end plate stress, and internal fixation peak stress were compared between different models under the same loading conditions. Results Compared to the intact model, ROM was reduced in the OLIF model under all loading conditions. The surgical models in order of increasing ROM were PSR, CSR, and stand-alone; however, the difference in ROM between BPS and CSR was less than 0.4° and was not significant under any loading conditions. The stand-alone model had the highest stress on the superior L4 vertebral body endplate under all loading conditions, whereas the end plate stress was relatively low in the BPS and CSR models. The CSR model had the highest internal fixation stress, concentrated primarily at the end of the screw. Conclusions OLIF alone significantly reduces ROM but does not provide sufficient stability. Addition of posterior PSR or CSR internal fixation instrumentation to OLIF surgery can significantly improve biomechanical stability of the segment undergoing surgery.
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Yan Y, Li J, Yu J, Wang Y, Dong H, Sun Y, Wu X, He L, Chen W, Feng H. Biomechanical evaluation of two fusion techniques based on finite element analysis: percutaneous endoscopic and minimally invasive transforaminal lumbar interbody fusion. MEDICINE IN NOVEL TECHNOLOGY AND DEVICES 2022. [DOI: 10.1016/j.medntd.2022.100138] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
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Lin M, Paul R, Shapiro SZ, Doulgeris J, O'Connor TE, Tsai CT, Vrionis FD. Biomechanical Study of Cervical Endplate Removal on Subsidence and Migration in Multilevel Anterior Cervical Discectomy and Fusion. Asian Spine J 2022; 16:615-624. [PMID: 35263829 DOI: 10.31616/asj.2021.0424] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/18/2021] [Accepted: 11/14/2021] [Indexed: 11/23/2022] Open
Abstract
Study Design This study compares four cervical endplate removal procedures, validated by finite element models. Purpose To characterize the effect of biomechanical strength and increased contact area on the maximum von Mises stress, migration, and subsidence between the cancellous bone, endplate, and implanted cage. Overview of Literature Anterior cervical discectomy and fusion (ACDF) has been widely used for treating patients with degenerative spondylosis. However, no direct correlations have been drawn that incorporate the impact of the contact area between the cage and the vertebra/endplate. Methods Model 1 (M1) was an intact C2C6 model with a 0.5 mm endplate. In model 2 (M2), a cage was implanted after removal of the C4-C5 and C5-C6 discs with preservation of the osseous endplate. In model 3 (M3), 1 mm of the osseous endplate was removed at the upper endplate. Model 4 (M4) resembles M3, except that 3 mm of the osseous endplate was removed. Results The range of motion (ROM) at C2C6 in the M2-M4 models was reduced by at least 9º compared to the M1 model. The von Mises stress results in the C2C3 and C3C4 interbody discs were significantly smaller in the M1 model and slightly increased in the M2-M3 and M3-M4 models. Migration and subsidence decreased from the M2-M3 model, whereas further endplate removal increased the migration and subsidence as shown in the transition from M3 to M4. Conclusions The M3 model had the least subsidence and migration. The ROM was higher in the M3 model than the M2 and M4 models. Endplate preparation created small stress differences in the healthy intervertebral discs above the ACDF site. A 1 mm embedding depth created the best balance of mechanical strength and contact area, resulting in the most favorable stability of the construct.
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Affiliation(s)
- Maohua Lin
- Department of Ocean and Mechanical Engineering, Florida Atlantic University, Boca Raton, FL, USA
| | - Rudy Paul
- Department of Ocean and Mechanical Engineering, Florida Atlantic University, Boca Raton, FL, USA
| | - Stephen Z Shapiro
- Department of Neurosurgery, Marcus Neuroscience Institute, Boca Raton Regional Hospital, Boca Raton, FL, USA
| | - James Doulgeris
- Department of Neurosurgery, Marcus Neuroscience Institute, Boca Raton Regional Hospital, Boca Raton, FL, USA
| | - Timothy E O'Connor
- Department of Neurosurgery, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, Buffalo, NY, USA
| | - Chi-Tay Tsai
- Department of Ocean and Mechanical Engineering, Florida Atlantic University, Boca Raton, FL, USA
| | - Frank D Vrionis
- Department of Neurosurgery, Marcus Neuroscience Institute, Boca Raton Regional Hospital, Boca Raton, FL, USA
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Chen J, Li J, Sheng B, Li L, Wu S. Does preoperative morphology of multifidus influence the surgical outcomes of stand-alone lateral lumbar interbody fusion for lumbar spondylolisthesis? Clin Neurol Neurosurg 2022; 215:107177. [DOI: 10.1016/j.clineuro.2022.107177] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2021] [Revised: 02/10/2022] [Accepted: 02/11/2022] [Indexed: 11/29/2022]
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Finite Element Method for the Evaluation of the Human Spine: A Literature Overview. J Funct Biomater 2021; 12:jfb12030043. [PMID: 34449646 PMCID: PMC8395922 DOI: 10.3390/jfb12030043] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2021] [Revised: 07/23/2021] [Accepted: 07/29/2021] [Indexed: 02/07/2023] Open
Abstract
The finite element method (FEM) represents a computer simulation method, originally used in civil engineering, which dates back to the early 1940s. Applications of FEM have also been used in numerous medical areas and in orthopedic surgery. Computing technology has improved over the years and as a result, more complex problems, such as those involving the spine, can be analyzed. The spine is a complex anatomical structure that maintains the erect posture and supports considerable loads. Applications of FEM in the spine have contributed to the understanding of bone biomechanics, both in healthy and abnormal conditions, such as scoliosis, fractures (trauma), degenerative disc disease and osteoporosis. However, since FEM is only a digital simulation of the real condition, it will never exactly simulate in vivo results. In particular, when it concerns biomechanics, there are many features that are difficult to represent in a FEM. More FEM studies and spine research are required in order to examine interpersonal spine stiffness, young spine biomechanics and model accuracy. In the future, patient-specific models will be used for better patient evaluations as well as for better pre- and inter-operative planning.
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Cai K, Luo K, Zhu J, Zhang K, Yu S, Ye Y, Jiang G. Effect of pedicle-screw rod fixation on oblique lumbar interbody fusion in patients with osteoporosis: a retrospective cohort study. J Orthop Surg Res 2021; 16:429. [PMID: 34217340 PMCID: PMC8254285 DOI: 10.1186/s13018-021-02570-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/13/2021] [Accepted: 06/17/2021] [Indexed: 02/06/2023] Open
Abstract
STUDY DESIGN A retrospective cohort study. OBJECTIVE To investigate the radiological and clinical outcomes of patients with or without pedicle-screw rod fixation (PSRF) in OLIF surgery. METHODS Between June 2017 and December 2019, 66 consecutive patients who underwent OLIF surgery at two centers were divided into stand-alone and combined groups according to whether or not PSRF was used. Imaging and clinical data were collected preoperatively, postoperatively, 3 and 6 months postoperatively, and at the last follow-up. Related coefficient and multiple linear regression analysis was used to detect the influencing factors of cage subsidence (CS). RESULTS There was a lower baseline BMD in the combined group (p = 0.005). The combined group showed superior VAS score at 3 months postoperatively, although there was no difference in long-term VAS and ODI scores between the two groups. The foraminal height (FH) of the two groups was comparable at preoperatively, postoperatively, and 3 months postoperatively, but the combined group showed better maintenance of FH at 6 months postoperatively (p = 0.049) and last follow-up (p = 0.019). The total CS (tCS) of the combined group was lower than that of the stand-alone group during the whole follow-up period (all p ≤ 0.001). Multiple linear regression suggested that lower BMD was the risk factor for main CS, and PSRF could significantly reduce the BMD threshold for severe CS (-4.77 vs -1.38). CONCLUSIONS OLIF combined with PSRF can effectively avoid foraminal height loss and prevent severe CS, which may be more suitable for patients with osteoporosis or osteopenia and improve clinical outcomes.
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Affiliation(s)
- Kaiwen Cai
- Department of Orthopaedic, The Affiliated Hospital of Medical School of Ningbo University, No. 247, Renmin Road, Jiangbei District, Ningbo, Zhejiang, People's Republic of China.,Institute of Orthopaedics, Ningbo University, Ningbo, People's Republic of China
| | - Kefeng Luo
- Department of Orthopaedic, The Affiliated Hospital of Medical School of Ningbo University, No. 247, Renmin Road, Jiangbei District, Ningbo, Zhejiang, People's Republic of China.,Institute of Orthopaedics, Ningbo University, Ningbo, People's Republic of China
| | - Jinjin Zhu
- Department of Orthopaedic, Sir Run Run Shaw Hospital, School of Medicine, Zhejiang University, Hangzhou, People's Republic of China
| | - Kai Zhang
- Department of Orthopaedic, The Affiliated Hospital of Medical School of Ningbo University, No. 247, Renmin Road, Jiangbei District, Ningbo, Zhejiang, People's Republic of China.,Institute of Orthopaedics, Ningbo University, Ningbo, People's Republic of China
| | - Shengkai Yu
- The Medical School of Ningbo University, Ningbo, People's Republic of China
| | - Yi Ye
- Department of Orthopaedic, The Affiliated Hospital of Medical School of Ningbo University, No. 247, Renmin Road, Jiangbei District, Ningbo, Zhejiang, People's Republic of China.,Institute of Orthopaedics, Ningbo University, Ningbo, People's Republic of China
| | - Guoqiang Jiang
- Department of Orthopaedic, The Affiliated Hospital of Medical School of Ningbo University, No. 247, Renmin Road, Jiangbei District, Ningbo, Zhejiang, People's Republic of China. .,Institute of Orthopaedics, Ningbo University, Ningbo, People's Republic of China.
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He L, Xiang Q, Yang Y, Tsai TY, Yu Y, Cheng L. The anterior and traverse cage can provide optimal biomechanical performance for both traditional and percutaneous endoscopic transforaminal lumbar interbody fusion. Comput Biol Med 2021; 131:104291. [PMID: 33676337 DOI: 10.1016/j.compbiomed.2021.104291] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2020] [Revised: 02/13/2021] [Accepted: 02/13/2021] [Indexed: 11/16/2022]
Abstract
BACKGROUND Transforaminal lumbar interbody fusion (TLIF) is a well-established surgical treatment for patients with lumbar degenerative disc disease; however, the optimal position for the interbody fusion cage in TLIF procedures for reducing cage-related complications remains uncertain. The present study aims to compare the biomechanical effects between different cage positions in TLIF and percutaneous endoscopic-TLIF (PE-TLIF). METHOD An intact finite element model of L3-L5 from computed tomography images of a 25-year-old healthy male without any lumbar disease was reconstructed and validated. TLIF and PE-TLIF were performed on L4-L5 with bilateral pedicle screws fixation. Two surgical finite element models were subjected to loads with six degrees of freedom. The range of motion (ROM) and von Mises stress of the implantations and endplates were measured for the anterior, middle, and posterior district and the traverse or oblique direction of the cage respectively. RESULTS As the cage was implanted forward, the ROMs in the fused L4-L5 segments and the von Mises stress of the cage and endplates decreased while the von Mises stress of the screws increased; this was also shown in the traverse cage when compared with the oblique cage (A-90-compared with A-45- had a 31.3%, 1.7%, 12.6%, and 5.7% decrease in FL, EX, LB and AR). The ROMs (TLIF A-45 increase of 80.8%, 23.8%, and 12.2% in FL, EX, and LB when compared with PE-TLIF), cage stress, and endplate stress of PE-TLIF were lower than those of TLIF. CONCLUSIONS Considering the ROM of the fusion segments, implanting the cage in the anterior district in the traverse direction can effectively enhance the fusion segment stiffness, thus contributing to the stability of the lumbar spine after fusion. It can also cause less cage stress and endplate stress, which indicates its beneficial effect in avoiding cage injury or subsidence. However, the higher stress of the pedicle screws and rods indicates higher failure risk. PE-TLIF had better biomechanical performance than TLIF. Therefore, it is recommended that the surgeon implant the cage in the anterior district of the L5 vertebra's upper endplate in the traverse direction using the PE-TLIF technique.
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Affiliation(s)
- Lei He
- Department of Spine Surgery, Tongji Hospital, Tongji University School of Medicine, Shanghai, 200065, China; College of Civil Engineering, Tongji University, Shanghai, 200082, China; Key Laboratory of Spine and Spinal Cord Injury Repair and Regeneration (Tongji University), Ministry of Education, Tongji University School of Medicine, Shanghai, 200065, China
| | - Qingzhi Xiang
- Department of Spine Surgery, Tongji Hospital, Tongji University School of Medicine, Shanghai, 200065, China; Key Laboratory of Spine and Spinal Cord Injury Repair and Regeneration (Tongji University), Ministry of Education, Tongji University School of Medicine, Shanghai, 200065, China
| | - Yangyang Yang
- Shanghai Key Laboratory of Orthopaedic Implants, Department of Orthopaedic Surgery, Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, 200030, China; School of Biomedical Engineering & Med-X Research Institute, Shanghai Jiao Tong University, Shanghai, 200030, China
| | - Tsung-Yuan Tsai
- Shanghai Key Laboratory of Orthopaedic Implants, Department of Orthopaedic Surgery, Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, 200030, China; School of Biomedical Engineering & Med-X Research Institute, Shanghai Jiao Tong University, Shanghai, 200030, China
| | - Yan Yu
- Department of Spine Surgery, Tongji Hospital, Tongji University School of Medicine, Shanghai, 200065, China; Key Laboratory of Spine and Spinal Cord Injury Repair and Regeneration (Tongji University), Ministry of Education, Tongji University School of Medicine, Shanghai, 200065, China.
| | - Liming Cheng
- Department of Spine Surgery, Tongji Hospital, Tongji University School of Medicine, Shanghai, 200065, China; Key Laboratory of Spine and Spinal Cord Injury Repair and Regeneration (Tongji University), Ministry of Education, Tongji University School of Medicine, Shanghai, 200065, China
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Castro APG. Computational Challenges in Tissue Engineering for the Spine. Bioengineering (Basel) 2021; 8:25. [PMID: 33671854 PMCID: PMC7918040 DOI: 10.3390/bioengineering8020025] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2020] [Revised: 02/04/2021] [Accepted: 02/13/2021] [Indexed: 12/17/2022] Open
Abstract
This paper deals with a brief review of the recent developments in computational modelling applied to innovative treatments of spine diseases. Additionally, it provides a perspective on the research directions expected for the forthcoming years. The spine is composed of distinct and complex tissues that require specific modelling approaches. With the advent of additive manufacturing and increasing computational power, patient-specific treatments have moved from being a research trend to a reality in clinical practice, but there are many issues to be addressed before such approaches become universal. Here, it is identified that the major setback resides in validation of these computational techniques prior to approval by regulatory agencies. Nevertheless, there are very promising indicators in terms of optimised scaffold modelling for both disc arthroplasty and vertebroplasty, powered by a decisive contribution from imaging methods.
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Affiliation(s)
- André P G Castro
- IDMEC, Instituto Superior Técnico, Universidade de Lisboa, 1049-001 Lisboa, Portugal
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19
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Li H, Li J, Tao Y, Li F, Chen Q, Chen G. Is stand-alone lateral lumbar interbody fusion superior to instrumented lateral lumbar interbody fusion for the treatment of single-level, low-grade, lumbar spondylolisthesis? J Clin Neurosci 2021; 85:84-91. [PMID: 33581796 DOI: 10.1016/j.jocn.2020.11.040] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2020] [Revised: 08/26/2020] [Accepted: 11/23/2020] [Indexed: 12/13/2022]
Abstract
BACKGROUND The aim of this study was to compare surgical trauma and radiographic and clinical outcomes of stand-alone and instrumented lateral lumbar interbody fusion (LLIF) in the treatment of single-level low-grade lumbar spondylolisthesis. METHODS Ninety-five patients with single-level low-grade lumbar spondylolisthesis, who underwent stand-alone LLIF (stand-alone group, [n = 54]) or LLIF plus percutaneous posterior fixation (instrumented group, [n = 41]) were enrolled in this study. Operative time, intraoperative blood loss, serum C-reactive protein (CRP) and creatine kinase (CK) levels, the length of postoperative bed rest time, and hospital stay were compared between the 2 groups. Disc height, the percent of slip, segment lordosis, lumbar lordosis, the visual analog scale score, the Oswestry Disability Index and complications were also compared. RESULTS Operative and bed rest time were shorter, intraoperative blood loss was less, and postoperative CRP and CK levels were lower in the stand-alone group. During follow-up, 6 patients in stand-alone group underwent posterior fixation due to cage subsidence. Although satisfactory radiographic results were achieved in both groups, the maintenance of increased disc heights and segment lordosis was inferior in the stand-alone group at the final follow-up. Greater improvement in postoperative VAS scores and ODI were observed in the stand-alone group, although the rates of cage subsidence and revision were higher. CONCLUSION Stand-alone LLIF was superior to instrumented LLIF in terms of tissue trauma for the treatment of single-level low-grade lumbar spondylolisthesis. However, stand-alone LLIF was inferior in the maintenance of disc height and segment lordosis, and the occurrence of cage subsidence and revision.
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Affiliation(s)
- Hao Li
- Department of Orthopedics Surgery, Second Affiliated Hospital, School of Medicine, Zhejiang University, Jiefang Road 88, Hangzhou 310009, People's Republic of China
| | - Jun Li
- Department of Orthopedics Surgery, Second Affiliated Hospital, School of Medicine, Zhejiang University, Jiefang Road 88, Hangzhou 310009, People's Republic of China
| | - Yiqing Tao
- Department of Orthopedics Surgery, Second Affiliated Hospital, School of Medicine, Zhejiang University, Jiefang Road 88, Hangzhou 310009, People's Republic of China
| | - Fangcai Li
- Department of Orthopedics Surgery, Second Affiliated Hospital, School of Medicine, Zhejiang University, Jiefang Road 88, Hangzhou 310009, People's Republic of China
| | - Qixin Chen
- Department of Orthopedics Surgery, Second Affiliated Hospital, School of Medicine, Zhejiang University, Jiefang Road 88, Hangzhou 310009, People's Republic of China.
| | - Gang Chen
- Department of Orthopedics Surgery, Second Affiliated Hospital, School of Medicine, Zhejiang University, Jiefang Road 88, Hangzhou 310009, People's Republic of China.
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Cheng C, Wang K, Zhang C, Wu H, Jian F. Clinical results and complications associated with oblique lumbar interbody fusion technique. ANNALS OF TRANSLATIONAL MEDICINE 2021; 9:16. [PMID: 33553309 PMCID: PMC7859744 DOI: 10.21037/atm-20-2159] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Background Oblique lumbar interbody fusion (OLIF) is a minimally invasive technique performed through the antero-oblique trajectory to address a wide range of lumbar pathologies. However, it can lead to complications. We reviewed the results of OLIF and discussed the effective methods to avoid such complications. Methods Seventy-nine consecutive patients who underwent OLIF between May 2016 and July 2019 were retrospectively analyzed. They were divided into three groups: stand-alone, posterior, and lateral fixation, according to whether they were followed up with auxiliary internal fixation as well as the fixation methods. Preoperative and last follow-up visual analog scale (VAS) and Oswestry Disability Index (ODI) scores were used to assess the improvement in the lower back and leg pain as well as neurological conditions. We analyzed intervertebral disc height (DH), segmental lumbar lordotic angle (SLL), lumbar lordotic angle (LL), pelvic tilt (PT), pelvic incidence-lumbar lordosis (PI-LL) mismatch, and the cross-section area (CSA) on axial magnetic resonance imaging (MRI) image in different groups. Complications, including thigh symptoms, cage subsidence, neurological injury, and vascular injury, were also noted. Results Seventy-nine patients were followed up postoperatively for 23.2±11.5 (range, 12-48) months. Forty-eight (61%) patients underwent stand-alone surgery (without fixation), 15 (19%) patients underwent supplemental percutaneous pedicle screw fixation (posterior fixation), and 16 (20%) patients underwent lateral vertebral instrumentation (lateral fixation). In all three groups, the VAS score and the ODI score had significantly decreased at the final follow-up compared to pre-operation. The DH, SLL, LL, CSA, PT, and PI-LL mismatch had also improved by final follow-up. The most common approach-related complication was thigh symptoms. Of the 79 patients, ipsilateral transient psoas paresis occurred in 9 (11.4%), ipsilateral transient quadriceps weakness in 2 (2.5%), and groin/thigh numbness and pain in 17 (21.5%). Cage subsidence occurred in 8 (10.1%) patients, including five cases of grade 0, one of grade I, and two of grade II. Three (3.8%) patients in this study had a vascular injury. Conclusions OLIF is a minimally invasive and effective technique for dealing with degenerative lumbar diseases. However, it should also be noted that this approach carries risks of complications.
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Affiliation(s)
- Cheng Cheng
- Department of Neurosurgery, Xuanwu Hospital of Capital Medical University, Beijing, China.,Department of Neurosurgery, the Third Medical Centre, Chinese PLA (People's Liberation Army) General Hospital, Beijing, China
| | - Kai Wang
- Department of Neurosurgery, Xuanwu Hospital of Capital Medical University, Beijing, China
| | - Can Zhang
- Department of Neurosurgery, Xuanwu Hospital of Capital Medical University, Beijing, China
| | - Hao Wu
- Department of Neurosurgery, Xuanwu Hospital of Capital Medical University, Beijing, China
| | - Fengzeng Jian
- Department of Neurosurgery, Xuanwu Hospital of Capital Medical University, Beijing, China
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Yin JY, Guo LX. Biomechanical analysis of lumbar spine with interbody fusion surgery and U-shaped lumbar interspinous spacers. Comput Methods Biomech Biomed Engin 2020; 24:1-11. [PMID: 33241697 DOI: 10.1080/10255842.2020.1851368] [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: 08/01/2020] [Revised: 10/11/2020] [Accepted: 11/11/2020] [Indexed: 10/22/2022]
Abstract
Previous research indicates whole-body vibration may lead to low back pain. The aim of this study is assessing the dynamic characteristics of a lumbar spine with Coflex and Coflex-F (commercial implants used as lumbar interspinous spacers) and effect of lumbar interbody fusion surgery. A transient dynamic analysis is performed on three numerical lumbar spine models under the loading condition of a vertical sinusoidal force of ±40 N with a compressive follower preload of 400 N. Also, Coflex-F model with and without interbody fusion surgery is analyzed under the same loading condition. The results show that the maximum value and vibration amplitude of von Mises stress in annulus ground substance (AGS) and intradiscal pressure (IDP) at implanted segment decrease from healthy model to Coflex model, and Coflex-F model. By contrast, for adjacent segments the maximum value of implanted models are larger than that of healthy model. The maximum value of endplates with and without cage are 2.44 MPa and 1.73 MPa (L4 inferior endplate), 1.94 MPa and 1.42 MPa (L5 superior endplate), respectively. The vibration amplitude of Coflex-F model with fusion surgery is smaller than that without fusion surgery. Coflex and Coflex-F not only protect implanted segment but also have a negative effect on adjacent segments. Inserting cage for Coflex-F model can absorb vibration energy at adjacent segments.
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Affiliation(s)
- Jia-Yu Yin
- School of Mechanical Engineering and Automation, Northeastern University, Shenyang, China
| | - Li-Xin Guo
- School of Mechanical Engineering and Automation, Northeastern University, Shenyang, China
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22
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Biomechanical modelling of the facet joints: a review of methods and validation processes in finite element analysis. Biomech Model Mechanobiol 2020; 20:389-401. [PMID: 33221991 PMCID: PMC7979651 DOI: 10.1007/s10237-020-01403-7] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2020] [Accepted: 11/04/2020] [Indexed: 12/13/2022]
Abstract
There is an increased interest in studying the biomechanics of the facet joints. For in silico studies, it is therefore important to understand the level of reliability of models for outputs of interest related to the facet joints. In this work, a systematic review of finite element models of multi-level spinal section with facet joints output of interest was performed. The review focused on the methodology used to model the facet joints and its associated validation. From the 110 papers analysed, 18 presented some validation of the facet joints outputs. Validation was done by comparing outputs to literature data, either computational or experimental values; with the major drawback that, when comparing to computational values, the baseline data was rarely validated. Analysis of the modelling methodology showed that there seems to be a compromise made between accuracy of the geometry and nonlinearity of the cartilage behaviour in compression. Most models either used a soft contact representation of the cartilage layer at the joint or included a cartilage layer which was linear elastic. Most concerning, soft contact models usually did not contain much information on the pressure-overclosure law. This review shows that to increase the reliability of in silico model of the spine for facet joints outputs, more needs to be done regarding the description of the methods used to model the facet joints, and the validation for specific outputs of interest needs to be more thorough, with recommendation to systematically share input and output data of validation studies.
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Fan W, Guo LX. The effect of non-fusion dynamic stabilization on biomechanical responses of the implanted lumbar spine during whole-body vibration. COMPUTER METHODS AND PROGRAMS IN BIOMEDICINE 2020; 192:105441. [PMID: 32172078 DOI: 10.1016/j.cmpb.2020.105441] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/14/2020] [Accepted: 03/07/2020] [Indexed: 06/10/2023]
Abstract
BACKGROUND AND OBJECTIVE Non-fusion dynamic stabilization surgery is increasingly popular for treating degenerative lumbar disc disease. However, changes in spine biomechanics after application of posterior dynamic fixation devices during whole-body vibration (WBV) remain unclear. The study aimed to examine the effects of non-fusion dynamic stabilization on biomechanical responses of the implanted lumbar spine to vertical WBV. METHODS By modifying L4-L5 segment of the healthy human L1-sacrum finite element model, single-level disc degeneration, dynamic fixation using the BioFlex system and anterior lumbar interbody fusion (ALIF) with rigid fixation were simulated, respectively. Dynamic responses of stress and strain in the spinal levels for the healthy, degenerated, BioFlex and ALIF models under an axial cyclic loading were investigated and compared. RESULTS The results showed that endplate stress at implant level was lower in the BioFlex model than in the degenerated and ALIF models, but stress of the connecting rod in the BioFlex system was greater than that in the rigid fixation system used in the ALIF. Compared with the healthy model, stress and strain responses in terms of disc bulge, annulus stress and nucleus pressure at adjacent levels were decreased in the degenerated, BioFlex and ALIF models, but no obvious difference was observed in these responses among the three models. CONCLUSIONS This study may be helpful to understand variations in vibration characteristics of the lumbar spine after application of non-fusion dynamic stabilization system.
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Affiliation(s)
- Wei Fan
- School of Mechanical Engineering and Automation, Northeastern University, No. 3-11, Wenhua Road, Heping District, Shenyang, 110819, China.
| | - Li-Xin Guo
- School of Mechanical Engineering and Automation, Northeastern University, No. 3-11, Wenhua Road, Heping District, Shenyang, 110819, China
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Ramírez León JF, Ardila ÁS, Rugeles Ortíz JG, Martínez CR, Alonso Cuéllar GO, Infante J, Lewandrowski KU. Standalone lordotic endoscopic wedge lumbar interbody fusion (LEW-LIF™) with a threaded cylindrical peek cage: report of two cases. JOURNAL OF SPINE SURGERY 2020; 6:S275-S284. [PMID: 32195434 DOI: 10.21037/jss.2019.06.09] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
We report two cases of a standalone lordotic endoscopic wedge lumbar interbody fusion (LEW-LIF™) with a stress-neutral non-expandable cylindrical threaded polyether ether ketone (PEEK) interbody fusion implant. Patients underwent full-endoscopic transforaminal decompression and fusion for symptomatic lateral recess stenosis due to disc herniation, and hypertrophy of the facet joint complex and ligamentum flavum and no more than grade I spondylolisthesis. Lumbar interbody fusion with cages traditionally calls for posterior supplemental fixation with pedicle screws for added stability. A more simplified version of lumbar decompression and fusion without pedicle screws would allow treating patients suffering from stenosis and instability induced sciatica-type low back and leg pain in an outpatient ambulatory surgery center setting (ASC). This would realize a significant reduction in cost as well as the burden to the patient with decreased postoperative pain and earlier return to function. A 62-year-old female patient had surgery at L4/5 for a 6-year history of worsening right sided sciatica-type leg- and low back pain. Another 79-year-old female had the same surgical management at L4/5 for a 5-year history of unrelenting left-sided spondylolisthesis-related symptoms. Both patients had an uneventful postoperative course until the last available follow-up of 24 weeks with greater than 60% VAS and Oswestry disability index (ODI) reductions. There was no evidence of implant expulsion, subsidence, or postoperative instability. We concluded that standalone outpatient lumbar transforaminal endoscopic interbody fusion with a non-expandable threaded cylindrical cage is feasible, and favorable clinical outcomes provide proof of concept to study long-term clinical outcomes in larger groups of patients.
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Affiliation(s)
- Jorge Felipe Ramírez León
- Fundación Universitaria Sanitas, Bogotá, D.C., Colombia.,Research Team, Centro de Columna, Bogotá, Colombia.,Centro de Cirugía de Mínima Invasión, CECIMIN-Clínica Reina Sofía, Bogotá, Colombia
| | | | - José Gabriel Rugeles Ortíz
- Research Team, Centro de Columna, Bogotá, Colombia.,Centro de Cirugía de Mínima Invasión, CECIMIN-Clínica Reina Sofía, Bogotá, Colombia
| | - Carolina Ramírez Martínez
- Fundación Universitaria Sanitas, Bogotá, D.C., Colombia.,Research Team, Centro de Columna, Bogotá, Colombia.,Centro de Cirugía de Mínima Invasión, CECIMIN-Clínica Reina Sofía, Bogotá, Colombia
| | | | | | - Kai-Uwe Lewandrowski
- Fundación Universitaria Sanitas, Bogotá, D.C., Colombia.,Center for Advanced Spine Care of Southern Arizona, Surgical Institute of Tucson, Tucson, AZ, USA
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Nikkhoo M, Cheng CH, Wang JL, Khoz Z, El-Rich M, Hebela N, Khalaf K. Development and validation of a geometrically personalized finite element model of the lower ligamentous cervical spine for clinical applications. Comput Biol Med 2019; 109:22-32. [PMID: 31035068 DOI: 10.1016/j.compbiomed.2019.04.010] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2019] [Revised: 04/14/2019] [Accepted: 04/14/2019] [Indexed: 11/17/2022]
Abstract
Epidemiological and clinical studies show that the magnitude and scope of cervical disease are on the rise, along with the world's rising aging population. From a biomechanical perspective, the cervical spine presents a wide inter-individual variability, where its motion patterns and load sharing strongly depend on the anatomy. This study aimed to first develop and validate a geometrically patient-specific model of the lower cervical spine for clinical applications, and secondly to use the model to investigate the spinal biomechanics associated with typical cervical disorders. Based on measurements of 30 parameters from X-ray radiographs, the 3D geometry of the vertebrae and intervertebral discs (IVDs) were developed, and detailed finite element models (FEMs) of the lower ligamentous cervical spine for 6 subjects were constructed and simulated. The models were then used for the investigation of different grades of IVD alteration. The multi directional range of motion (ROM) results were in alignment with the in-vitro and in-Silico studies confirming the validity of the model. Severe disc alteration (Grade 3) presented a significant decrease in the ROM and intradiscal pressure (flexion, extension, and axial rotation) on the C5-C6 and slightly increase on the adjacent levels. Maximum stress in Annulus Fibrosus (AF) and facet joint forces increased for Grade 3 for both altered and adjacent levels. The novel validated geometrically-personalized FEM presented in this study potentially offers the clinical community a valuable quantitative tool for the noninvasive analyses of the biomechanical alterations associated with cervical spine disease towards improved surgical planning and enhanced clinical outcomes.
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Affiliation(s)
- Mohammad Nikkhoo
- Department of Biomedical Engineering, Science and Research Branch, Islamic Azad University, Tehran, Iran.
| | - Chih-Hsiu Cheng
- School of Physical Therapy and Graduate Institute of Rehabilitation Science, Chang Gung University, Taoyuan, Taiwan, ROC
| | - Jaw-Lin Wang
- Institute of Biomedical Engineering, College of Medicine and Engineering, National Taiwan University, Taipei, Taiwan, ROC
| | - Zahra Khoz
- Department of Biomedical Engineering, Science and Research Branch, Islamic Azad University, Tehran, Iran
| | - Marwan El-Rich
- Department of Mechanical Engineering, Khalifa University, Abu Dhabi, United Arab Emirates
| | - Nader Hebela
- Orthopaedic Spine Surgery, Neurological Institute, Cleveland Clinic Abu Dhabi, Abu Dhabi, United Arab Emirates
| | - Kinda Khalaf
- Department of Biomedical Engineering, Khalifa University of Science and Technology, Health Engineering Innovation Centre, Abu Dhabi, United Arab Emirates
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Wu AM, Li XL, Tian HJ, Zhang K, Zhao CQ, Sheng SR, Lin Y, Ni WF, Wang XY, Zhao J. Optimal medial transforaminal lumbar interbody fusion approach with five extensive options: A simulated study on three-dimensional digital reconstructed images. J Orthop Translat 2018; 15:1-8. [PMID: 30128289 PMCID: PMC6098232 DOI: 10.1016/j.jot.2018.07.004] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/27/2018] [Revised: 07/02/2018] [Accepted: 07/11/2018] [Indexed: 10/31/2022] Open
Abstract
Objective The objective of this study is to use 3D digital lumbar models to investigate and simulate the optimal posterior operative approach for safe decompression and insertion of an interbody cage. Methods Thirty lumbar spine (L3-S1) computed tomography data are collected for 3D reconstruction. We cut medial half part of the superior facet and define the distance between the margin of the operative side of the spinous process and the medial margin of the cut superior facet as "medial distance (MD)". Then, we cut the total superior facet and define the distance between the margin of the operative side of the spinous process and the lateral side of the junction of the pedicle and the vertebral body as "extend distance (ED)". The feasible insertion of the current standard width size (10 mm and 12 mm) interbody cages was assessed by the two aforementioned MD and ED approaches. Besides the ED, we also simulate four other extensive options of lateral upper, lateral lower, vertical upper and lower and transmedian contralateral decompression on 3D digital lumbar model. Results The MD increased from 13.48 ± 1.28 mm at L3/4 to 18.05 ± 1.43 mm at L5/S1, and the ED increased from 16.64 ± 1.34 mm at L3/4 to 21.12 ± 1.62 mm at L5/S1. To insert a 10-mm-wide cage, 16.7% (left) and 13.3% (right) of MD for L3/4 is not enough, 60.0% (left) and 46.7% (right) of MD for L3/4 is subsafe, 13.3% (left) and 16.7% (right) of MD for L4/5 is subsafe and all others are safe. To insert a 12-mm-wide cage, 76.7% (left) and 60.0% (right) of MD for L3/4 is not enough, 20.0% (left) and 30.0% (right) of MD for L3/4 is subsafe, 13.3%% (left) and 16.7% (right) of MD for L4/5 is not enough, 63.3% (left) and 56.7% (right) of MD for L4/5 is subsafe and 6.7% (left) and 10.0% (right) of MD for L5/S1 is subsafe, whereas 33.3%% (left) and 30.0% (right) of ED for L3/4 is subsafe, 3.3% (left) and 3.3% (right) of ED for L4/5 is subsafe and all others are safe. Besides the ED, on 3D models, four other extensive options could be simulated too and may need to be performed for different special individuals. Conclusion Our 3D digital image study provides a feasible optimal medial transforaminal lumbar interbody fusion approach with five extensive options on lower lumbar region. It can provide safe lumbar decompression and interbody fusion in most population. In addition, surgeons can choose the different extensive options for special individual conditions. The translational potential of this article Transforminal lumbar interbody fusion is very common used for lumbar degenerative diseases. The optimal medial transforminal lumbar interbody fusion with five options provide a safe and precise approach for surgeons in treatment of lumbar degenerative diseases.
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Affiliation(s)
- Ai-Min Wu
- Department of Orthopaedics, Ninth People's Hospital, Shanghai Jiaotong University School of Medicine, Shanghai Key Laboratory of Orthopaedic Implants, Shanghai 200011, China.,Department of Spine Surgery, Zhejiang Spine Surgery Centre, Orthopaedic Hospital, The Second Affiliated Hospital and Yuying Children's Hospital of the Wenzhou Medical University, The Second School of Medicine Wenzhou Medical University, The Key Orthopaedic Laboratory of Zhejiang Province, Wenzhou 325035, China
| | - Xun-Lin Li
- Department of Orthopaedics, Ninth People's Hospital, Shanghai Jiaotong University School of Medicine, Shanghai Key Laboratory of Orthopaedic Implants, Shanghai 200011, China
| | - Hai-Jun Tian
- Department of Orthopaedics, Ninth People's Hospital, Shanghai Jiaotong University School of Medicine, Shanghai Key Laboratory of Orthopaedic Implants, Shanghai 200011, China
| | - Kai Zhang
- Department of Orthopaedics, Ninth People's Hospital, Shanghai Jiaotong University School of Medicine, Shanghai Key Laboratory of Orthopaedic Implants, Shanghai 200011, China
| | - Chang-Qing Zhao
- Department of Orthopaedics, Ninth People's Hospital, Shanghai Jiaotong University School of Medicine, Shanghai Key Laboratory of Orthopaedic Implants, Shanghai 200011, China
| | - Sun-Ren Sheng
- Department of Spine Surgery, Zhejiang Spine Surgery Centre, Orthopaedic Hospital, The Second Affiliated Hospital and Yuying Children's Hospital of the Wenzhou Medical University, The Second School of Medicine Wenzhou Medical University, The Key Orthopaedic Laboratory of Zhejiang Province, Wenzhou 325035, China
| | - Yan Lin
- Department of Spine Surgery, Zhejiang Spine Surgery Centre, Orthopaedic Hospital, The Second Affiliated Hospital and Yuying Children's Hospital of the Wenzhou Medical University, The Second School of Medicine Wenzhou Medical University, The Key Orthopaedic Laboratory of Zhejiang Province, Wenzhou 325035, China
| | - Wen-Fei Ni
- Department of Spine Surgery, Zhejiang Spine Surgery Centre, Orthopaedic Hospital, The Second Affiliated Hospital and Yuying Children's Hospital of the Wenzhou Medical University, The Second School of Medicine Wenzhou Medical University, The Key Orthopaedic Laboratory of Zhejiang Province, Wenzhou 325035, China
| | - Xiang-Yang Wang
- Department of Spine Surgery, Zhejiang Spine Surgery Centre, Orthopaedic Hospital, The Second Affiliated Hospital and Yuying Children's Hospital of the Wenzhou Medical University, The Second School of Medicine Wenzhou Medical University, The Key Orthopaedic Laboratory of Zhejiang Province, Wenzhou 325035, China
| | - Jie Zhao
- Department of Orthopaedics, Ninth People's Hospital, Shanghai Jiaotong University School of Medicine, Shanghai Key Laboratory of Orthopaedic Implants, Shanghai 200011, China
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