The effect of large channel-based foraminoplasty on lumbar biomechanics in percutaneous endoscopic discectomy: a finite element analysis

The effect of large channel-based foraminoplasty on lumbar biomechanics in percutaneous endoscopic discectomy: a finite element analysis | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Research Article The effect of large channel-based foraminoplasty on lumbar biomechanics in percutaneous endoscopic discectomy: a finite element analysis Wei Sun, Duohua Li, Feng Zhang, Jiayu Tian, Hao Fu, Sicong Zhao, and 2 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-4201856/v1 This work is licensed under a CC BY 4.0 License Status: Under Review Version 1 posted 12 You are reading this latest preprint version Abstract Background: The aim of this study was to evaluate the effect of arthroplasty using large-channel endoscopy during TESSYS on the biomechanics of the lumbar spine in patients. Methods: A complete lumbar spine model,M1, was built using 3D finite elements, and models M2 and M3 were built by simulating the intraoperative removal of the supra-articular synchondrosis of L5 using a Trephine saw withdiametersof 5 mm and 8.5 mm,respectively, and applying normal physiological loads on the different models to simulate six working conditions—lumbaranterior flexion, posterior extension, left-right lateral flexion, and left-right rotation—toobserve the stress distributions of the vertebral body, the discs, and the articular synchondrosis. Results: Compared with the M1 model, theM2 and M3 models showed a decrease in stress at the L4-5 left synaptic joint and a significant increase in stress at the right synaptic joint in forward flexion. In the M2 and M3 models, the L4-5 articular synaptic joint stresses were significantly greater in left lateral flexion or left rotation than in right lateral flexion or right rotation. The right synaptic joint stress in M3 was greater duringleft rotation than that in M2, and that in M2 was greater than that in M1. The L4-5 disc stress in the M3 model was greater duringposterior extension than that in the M1 and M2 models. The L4-5 disc stress in the M3 model was greater in the right rotation than in the M2 model, and that in the M2 model was greater than that in the M1 model. Conclusion: Arthroplasty using large-channel endoscopy increases the stress on articular synovial joints and segmental discs under certain working conditions but does not cause degeneration of the discs in adjacent segments. Finite element analysis Biomechanical Range of motion Superior facet Figures Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Figure 7 Figure 8 Figure 9 1. Introduction Lumbar disc herniation (LDH) is a common and frequent disease in spinal surgery that seriously affects patients' quality of life and imposes a heavy economic burden on their families and society [ 1 , 2 ] . Patients with LDH who fail to respond to strict conservative treatment require surgical treatment. Traditional open surgery requires extensive incisions of the lumbar muscles and vertebral plate, and postoperative epidural scar formation is prone to cause adhesions between the dura and nerve roots, resulting in renewed compression of the dural sac, restricted nerve root movement, and possible recurrence of clinical symptoms or even surgical failure. A study by Ross [ 3 ] et al. revealed a significant correlation between postoperative radicular symptoms and epidural scar formation, with as many as 24% of patients suffering from scar formation resulting in prolonged postoperative pain in the lumbar spine. The emergence of intervertebral foraminal endoscopic techniques is epoch-making, and these techniques have become widely popular worldwide in the last decade [ 4 – 6 ] . Depending on the size of the patient's intervertebral foramen and the location of the herniated disc, intraoperative arthroplasty is often required in the transforaminal endoscopic spine system (TESSYS) [ 7 – 9 ] . During the process of arthroplasty, the superior synchondrosis and synchondral ligaments are damaged to varying degrees. The lumbar facet joint (FJ) is a synovial joint that consists of a synovial membrane, joint capsule, joint fluid, and articular cartilage structures [ 10 ] . FJs play a role in restricting and guiding the movement of the spine and effectively prevent discs from being damaged by excessive shear and torsional tension. Therefore, angular changes, intraoperative injuries or even resection of the lumbar articular process may accelerate the degeneration of the responsible interspace or even lead to degenerative spinal disease. The finite element analysis (FEA) method can overcome the defects of obtaining specimens and can accurately and effectively simulate a variety of loads to determine the change in stress distribution within the tissue structure under different mechanical conditions. On the basis of CT, MRI and other imaging data, the human tissue structure is imaged, and values are assigned to the target tissue structure so that various models can simulate mechanical changes according to various surgical situations, thus providing a theoretical basis for clinical treatment based on changes in the corresponding parameters [ 11 – 13 ] . In recent years, large-channel endoscopes have become increasingly widely used in clinical practice [ 14 – 15 ] . Large-channel endoscopes (10 mm) have a wider working channel than ordinary endoscopes (7 mm) and can use larger surgical instruments, which are minimally invasive and efficient. Large-channel endoscopes are usually combined with the use of an 8.5-mm-diameter Trephine, which can cause more damage to the articular eminence than ordinary endoscopes. Therefore, it is important to explore the long-term effects of applying large-channel endoscopy for arthroplasty on the biomechanics of the lumbar spine of patients during TESSYS to understand patient prognosis. The aim of this paper was to establish a three-dimensional finite element model to simulate the postoperative lumbar spine motion of patients to further understand the effect of arthroplasty on lumbar spine biomechanics during TESSYS to better guide clinical practice. 2. Materials and methods 2.1 Experimental materials 2.1.1 Experimental subjects One healthy male adult volunteer (35 years old, height 178 cm, weight 75 kg, no history of previous spinal diseases or spinal trauma) was selected for physical examination. Lumbar spine positive and lateral, hyperextension and hyperflexion films were used to exclude spinal pelvic deformity and other spinal diseases. Informed consent was signed, discussed and approved by the Ethics Committee of the Affiliated Hospital of Xuzhou Medical University. 2.1.2 Computer software for imaging equipment A Siemens 64-slice spiral CT scanner (Siemens Sensation Open CT scanner, Siemens, Erlangen, Germany) provided by the Department of Imaging of the Affiliated Hospital of Xuzhou Medical University was used. Computer software included 21.0 (professional medical image application software), Geomagic Studio (3D modeling reverse engineering software), Ansys 18.0 (finite element analysis software), and SPSS (computer software). analysis software) and SPSS (data analysis software). 2.2 Establishment of the normal L1-S1 3D finite element model 2.2.1 CT image processing and 3D image reconstruction of the L1-S1 vertebrae The DICOM format of the patient's whole lumbar spine CT data was first imported via Mimics, and then the 3D data of the lumbar spine of L1-S1 were extracted (Fig. 1 ). Using the Draw and Erase functions in Edit Masks, the tomographic images could be erased and repaired, and the CT images of each level of the L1-S1 vertebrae were obtained after processing, which provided a good foundation for the next step of building a 3D model of L1-S1 (Fig. 2 ). The Calculate 3D function of Mimics software was used to generate the L1-S1 3D geometric model. When generating the 3D geometric model, the “high” quality level was selected to generate a smooth model with a highly approximate geometric form, which is conducive to making a mesh with a better quantity and quality and provides a basis for optimizing the image in the next step (Fig. 3 ). 2.2.2 Mesh the 3D solid model of the L1-S1 vertebrae The generated L1-S1 solid 3D model was imported into Mimics software, and the remesh module was used to perform mesh faceting and optimize the quality and quantity of the triangular mesh to meet the requirements of the finite element calculations (Fig. 4 ). 2.2.3 Modeling process of each intervertebral disc, articular cartilage, ligament and joint capsule in the model The anterior longitudinal ligament, posterior longitudinal ligament, supraspinous ligament, interspinous ligament, articular capsule ligament, and intertransverse ligament were constructed in the model using three-dimensional rod units. According to the literature [ 12 ] , the upper and lower endplates were constructed with a thickness of 1.0 mm, and the intervertebral discs were established between the upper and lower endplates; the intervertebral discs consisted of the annulus fibrosus and the nucleus pulposus, which accounted for 44% of the intervertebral discs, and its center was offset by 3.5 mm from the center of the discs. The boundary of the intervertebral discs was offset inward for 12 mm, the of the intervertebral discs was displaced backward by 3.5 mm, and the boundary of the intervertebral discs was the boundary of the nucleus pulposus. The boundary is the boundary of the nucleus pulposus (Fig. 5 ). The articular cartilage is created between the upper and lower articular processes. 2.2.4 Optimization of the model Through the smooth and wrap functions in Mimics software, the finite element model was preliminarily processed, and the surface of the model was simplified by increasing the quality of the bone and introducing some irregular structures on the surface. The model was subsequently input into Geomagic Studio software to minimize the noise points of the point cloud, fill the ineffective cavities on the surface of the finite element model, remove the characteristic burrs and dents, smooth and relax the surface (Fig. 6 ), and finally obtain the geometric model of the L1-S1 segment for this experiment. The surface was smoothed and relaxed (Fig. 6 ) to obtain the L1-S1 segment geometry model for this experiment. 2.2.5 Segmenting the finite element model and assigning material properties to each tissue A finite element model of the L1-S1 segment was generated, and the structures of cancellous bone, cortical bone and the posterior part of the vertebral body were established. The complete 3D model was imported into Ansys 18.0 computing software for finite element analysis, and the material properties were added to the material library according to the literature [ 16 – 18 ] . Then, the values were assigned to each structure, and the material parameters are shown in Table 1 – 2 . Table 1 Assignment properties of the constituent structures of the L1-S1 sections anatomical structure modulus of elasticity/MPa Poisson's ratio cortical bone 12000 0.3 cancellous bone 100 0.2 cartilaginous endplate 3500 0.25 normal annulus fibrosus 2.6 0.4 degenerated annulus fibrosus 12.3 0.35 normal nucleus pulposus 1.0 0.49 degenerating nucleus pulposus 1.7 0.4 Table 2 Properties of the major ligaments of the L1-S1 segments ligaments modulus of elasticity (MPa) cross-section (mm 2 ) average length (mm) anterior longitudinal ligament (ALL) 7.8 22.4 20 posterior longitudinal ligament (PLL) 10 7.0 12 ligamentum flavum (LF) 17 14.1 15 intertransverse ligament (ITL) 10 0.6 32 capsular ligament (CL) 7.5 10.5 5 interspinous ligament (ISL) 10 14.1 13 supraspinous ligament (SSL) 8 10.5 22 2.3 Establishment of a three-dimensional finite element model for arthroplasty of the left side of L4-5 through the intervertebral foraminal approach On the basis of the normal L1-S1 3D finite element model, the following 3D finite element model was established based on the intraoperative situation by simulating the surgical procedure using Mimics software. 1. Simple L4-5 disc herniation without surgical treatment model (Model 1, M1): Approximately 1/4 of the left posterior part of the L4-5 disc was defined as the material property of the degenerated disc, and other tissues such as the L3-4 and L5-S1 discs were defined as normal properties. 2. 5 mm arthroplasty model (Model 2, M2): The fibrous annulus and nucleus pulposus of the left posterior 1/4 of the L4-5 intervertebral disc were removed to simulate resection of the protruding disc and replaced with scar tissue. The tip of the left superior articular process of L5 was used as the puncture point, 5 mm of bone was removed from the tip of the arthroplasty site at an angle of approximately 30 degrees from the coronal plane to simulate the removal of part of the bone of the superior articular process, the foramen was enlarged, and arthroplasty was performed. This model simulates the intraoperative removal of the L5 superior articular process using a conventional 5-mm-diameter Trephine under normal intervertebral foramenoscopy. 3. 8.5 mm arthroplasty model (Model 3, M3): The fibrous annulus and nucleus pulposus of the left posterior 1/4 of the L4-5 intervertebral disc were removed to simulate resection of the herniated disc and replaced with scar tissue. The apical part of the left upper arthroplasty of L5 was used as the puncture point, 8.5 mm of bone in the apical part of the left arthroplasty was resected at an angle of approximately 30 degrees from the coronal plane to simulate the removal of part of the bone of the upper arthroplasty, and an enlargement of the arthroplasty was performed. This model simulates the intraoperative removal of the L5 superior articular process using a large-channel intervertebral foramen with a trephine 8.5 mm in diameter. Definition of contact surfaces and interactions: After the model was assembled, the contact surfaces were defined according to the anatomical situation. For the relative sliding between the lumbar disc surfaces and the upper and lower endplates of each vertebral body, contact was defined as a "tie" pattern, with the upper and lower endplates of each vertebral body serving as the master surfaces and the upper and lower surfaces of the disc serving as the follower surfaces. The FJ was set as a micromanipulation joint, and contact was defined as limited sliding contact with a friction coefficient of 0.1, with the next vertebral body's upper articular process serving as the master surface. 2.4 Loading conditions and observables When the model was set in the neutral position, the bottom of S1 was fixed, and a pressure of 500 N was applied axially to the upper surface of the L1 vertebra to simulate the stress on the lumbar vertebra caused by the weight of the human body in the static state so that the loads were uniformly transmitted to the nodes of the surface. A torque of 10 N·m was applied to the sagittal, coronal and transverse surfaces to simulate the lumbar spine under six working conditions, including forward flexion, backward extension, left and right lateral flexion and left and right rotation. Changes in the range of motion of the L4-5 segment under forward flexion, backward extension, left and right lateral flexion and left and right rotation were observed in the three groups of models. Changes in the intravertebral disc pressure in the L3-4, L4-5 and L5-S1 segments of the three groups of models under different stresses were observed. Changes in the L4-5 FJs under stress were observed in the three groups of models. For the recording of the simulation results, according to previous methods reported in the literature, data were collected in the region of maximum stress or displacement, and five points in the collection region were randomly selected and represented by the mean. 2.5 Statistical analyses Statistical processing was carried out using SPSS 23.0 software, and measurement data are presented as the means ± standard deviations (‾ x ± s). Comparisons of data between multiple groups were performed using one-way analysis of variance (ANOVA), and if the results of the analyses were overall different, then two-by-two comparisons were performed using the least significant difference (LSD) method. P < 0.05 was considered to indicate statistical significance. 3. Results 3.1 Normal 3D finite element modeling and validation We successfully established a finite element model of the normal L1-S1 segment, including the L1-S1 vertebral body, the L1-2 to L5-S1 intervertebral discs, the anterior and posterior longitudinal ligaments, the supraspinous interspinous ligament, the ligamentum flavum, and the articular capsule ligaments, and endowed them with different material properties (Tables 1 – 2 ). The L4-5 intervertebral disc herniation model (M1), the 5 mm arthroplasty model (M2) and the 8.5 mm arthroplasty model (M3) were established on the basis of the finite element model of the normal L1-S1 segment (Fig. 7 ). The mechanical results were calculated after loading the established finite element model with the aforementioned boundary conditions, and some of the results were extracted and compared with those of Shim [ 19 ] (Table 3). The results show that the joint mobility (range of motion, ROM) of the L3-4 and L4-5 segments of the present study model under the same boundary conditions is within a reasonable range, which proves the validity of the present finite element model. 3.2 Mechanical changes after stress loading in the three models 3.2.1 Displacement analysis of the three models under six operating conditions The values and distribution areas of lumbar displacement can be observed in Fig. 8 , and we analyzed the lumbar displacement cloud to evaluate the stability of the lumbar spine. After comparison, we found that L4 vertebral displacement was greater in the M2 and M3 models than in the M1 model under the six working conditions, but the difference was not statistically significant ( P > 0.05). The difference in the degree of L4 vertebral displacement between the M2 and M3 models was not statistically significant ( P > 0.05). Table 4 Activity range of the normal L1-S1 finite element model L3-4 and L4-5 segments under different working conditions (‾ x ± s). Working condition Sections L3- 4 Section L4-5 this study Shim's research this study Shim's research Forward flexion 3.346 4.2 ± 0.8 5.873 5.4 ± 0.9 Backward extension 2.636 2.9 ± 0.5 3.203 2.9 ± 0.5 Left rotation 2.727 2.8 ± 0.6 3.890 3.8 ± 1.0 Right rotation 2.900 2.8 ± 0.6 4.023 3.8 ± 1.0 Left flexion 4.154 3.5 ± 1.0 3.842 4.4 ± 1.1 Right flexion 4.301 3.5 ± 1.0 3.625 4.4 ± 1.1 3.2.2 Stress analysis of three models of L4-5 articular synapse joints under various working conditions Stress distribution in the left FJ of L4-5 (Fig. 9 a). Compared with those in the M1 model, the stresses in the left FJ of L4-5 decreased under forward flexure conditions for the M2 and M3 models ( P 0.05). There was no significant difference between the M2 and M3 models for the left lateral flexion condition, but both were greater than that of the M1 model ( P 0.05). In the M2 and M3 models, the stress of the L4-5 left FJ was significantly greater in model left lateral flexion or left rotation than in right lateral flexion or right rotation, and the magnitude of increase was greater than that in the M1 model. The stress distribution of the right FJ of L4-5 under various working conditions was as follows (Fig. 9 b): under forward flexion conditions, the stress of the right FJ of L4-5 increased significantly in the M2 and M3 models compared with that of the M1 model ( P 0.05). The differences in FJ stress between the three models in the posterior extension, right and left lateral flexion and right rotation working conditions were not statistically significant ( P > 0.05). In the left rotation treatment, the M3 FJ stress was greater than the M2, and the M2 FJ stress was greater than the M1 stress, and the differences were statistically significant ( P < 0.05). In the M2 and M3 models, the stress in the right FJ of L4-5 was significantly greater than that in right lateral flexion or right rotation in the left lateral flexion or left rotation of the model, and the increase in magnitude was greater than that in the M1 model. 3.2.3 Stress analysis of L4-5 discs under six operating conditions for three models The stress distributions of the L4-5 disc stresses of the three models under various working conditions were as follows (Fig. 9 c): The L4-5 disc stresses of the M2 and M3 models were greater than those of the M1 model under forward flexion, levokinetic rotation, and right and left lateral flexion conditions, but the differences were not statistically significant ( P > 0.05). L4-5 interdisc stress was greater in the M3 model than in the M1 and M2 models in the posterior extension condition ( P 0.05). In the right-handed condition, the stress was greater in the M3 model than in the M2 model and in the M2 model than in the M1 model, and the differences were statistically significant ( P < 0.05). 3.2.4 Stress analyses of the adjacent segmental intervertebral discs (L3-4 and L5-S1) for the three models under six working conditions In spinal surgery, most studies have shown that surgical segments accelerate the degeneration of discs in neighboring segments, especially the degeneration of discs in the previous segment. One of the advantages of FEA is that it is easy to observe the stress distributions of various established tissues and structures under different working conditions after the model is completed, so we analyzed the changes in the stresses in the L3-4 and L5-S1 intervertebral discs after the FJ shaping of the left side of L5. Our study revealed that there was no significant difference in the stress distribution of the L3-4 and L5-S1 interdiscs among the three models under various working conditions (Fig. 9 d and e). 4. Discussion The FEA method can simulate the human body and analyze the biomechanical changes associated with different surgical methods on various parts of the spine and is widely used in the field of spinal surgery [ 20 – 23 ] . The L4-5 segment is the segment with the highest incidence of LDH, so in the present study, the L4-5 segment was used as the target segment, and the FEA method was used to establish a normal three-dimensional finite element model of the L1-S1 segment. Based on this model, an intraoperative arthroplasty model was established to investigate the effects of intraoperative arthroplasty on lumbar spine biomechanics. An arthroplasty model was established on the basis of this model to investigate the effect of intervertebral foramenoscopy on the biomechanics of the lumbar spine in patients after arthroplasty. The analysis of the effect of surgery on the biomechanics of the lumbar spine and the acquisition of the mechanical information of the corresponding motion segments are conducive to tracing the causes of postoperative lumbar pain and can provide a theoretical basis for guiding the design of intraoperative surgical protocols and the formulation of individualized treatment plans. The first step after establishing a 3D finite element model is to verify the validity of the model, which is usually performed by comparing the experimental results with similar 3D finite element models from previous literature [ 24 – 26 ] . A comparison of our established finite element model with the results of Shim et al. [ 19 ] shows that the ROM of our model is within the error range reported in the literature and is comparable, indicating the validity of the finite element modeling method and material assignment in this paper, which can be used for biomechanical analysis. The modeling methods and loading constraints used in this study are basically the same as those used in previous studies, with only the individual samples differing, and the results are plausible from the point of view of a qualitative comparative study. The diversity of the individual morphology and material properties of human spinal segments means that finite element models do not exactly match the results of computer simulations with those of in vivo experiments. The reason for this difference is the inconsistency in the sources used to construct the finite element models, and although the ideal approach would be to use the same in vitro experimental subject and finite element model object, this approach is essentially impossible for any experiment due to ethical issues. The advantage of using cadaveric samples for modeling is that the samples can be dissected and directly validated for each tissue, and the disadvantage is that the metrics in the physiological state are not available. Although the reconstruction of the human spine model can be achieved using cadaveric samples, it cannot be validated against homologous cadaveric samples, so the method of validating the finite element model is mainly to compare it with the test data of previous cadaveric specimens. During TESSYS, depending on the size of the intervertebral foramen and the location of the herniated disc, arthroplasty on one side is usually required to enlarge the foramen, a procedure that can injure the FJ to varying degrees. Previous studies have reported on the effect of conventional open surgery on FJs. Shah et al. [ 27 ] reported that 33–35% of FJs are injured during lumbar nailing via the transosseous interspace approach, whereas Monshirfar et al. [ 28 ] analyzed the probability of injury to the FJ during pedicle screw placement via the posterior median approach, and the presence of an injury to the FJ was detected on postoperative radiographs in approximately 15% of the patients. Because the TESSYS technique has not matured for a long time in China, no study has systematically analyzed its effect on lumbar spine biomechanics after performing arthroplasty during TESSYS. After we established a finite element model of TESSYS intraoperative arthroplasty, we analyzed the degree of displacement of the L4 vertebral body under different working conditions and found that there was no significant difference in L4 vertebral body displacement among the three groups of models, which suggests that TESSYS intraoperative arthroplasty is relatively safe and generally does not cause lumbar spine slippage in the postoperative period. Stress analyses of the L4-5 FJ in the three models revealed that after arthroplasty, the stresses in the L4-5 bilateral FJ in the left lateral flexion condition increased compared with those in the preoperative condition in all patients and that the 8.5 mm arthroplasty had a greater effect on the right synchondrosis than did the 5 mm arthroplasty. In both arthroplasty models, the stress in the bilateral FJ of L4-5 was significantly greater in left lateral flexion or left rotation than in right lateral flexion or right rotation, and the magnitude of the increase was greater than that in the unoperated model, which suggests that arthroplasty of one side of arthroplasty with an ipsilateral disc injury will lead to increased stress in the contralateral FJ and that the larger the amplitude of arthroplasty is, the greater the increase in the stress in the contralateral FJ, which suggests that arthroplasty is best performed by tightly applying media. This finding suggests that it is better to keep the synchondrosis as close to the medial side as possible when performing synchondroplasty and to minimize the removal of the synchondrosis under the premise of adequate decompression. Stress analysis of the L4-5 intervertebral discs of the three models showed that L4-5 intervertebral disc stress was greater in the M3 model than in the M2 model under conditions of posterior extension and rightward rotation, which indicated that a large range of arthroplasty might aggravate the degeneration of the intervertebral discs of the segments compared with a small range of arthroplasty. In contrast, there was no significant difference in the distribution of L3-4 or L5-S1 interbody disc stresses among the three models under various working conditions, suggesting that arthroplasty had no significant effect on disc degeneration in adjacent segments. This is an advantage of nonfusion surgery over fusion surgery, as lumbar fusion surgery mostly accelerates the degeneration of neighboring segments [ 29 – 32 ] . This study also has the following shortcomings. First, the finite element models established in this study are similar to those that have been well validated in previous studies, but they all simplify the physiological contraction force of the lumbar spine to varying degrees, especially simplifying the muscles connected to the lumbar spine and the weight of the upper body, which is still somewhat different from that of a real human body. Second, this FEA is a one-time loading study, which cannot systematically analyze the effect of fatigue loading on the biomechanics of the lumbar spine. The actual clinical situation is complex and variable, and the repeated accumulation of stress in the lumbar spine after disc removal and arthroplasty may accelerate the degeneration of the injured area. Overall, in this study, a normal L1-S1 segmental finite element model was developed, on the basis of which an L4-5 disc herniation model, a 5 mm arthroplasty model, and an 8.5 mm arthroplasty model were developed. The model was successfully validated, and the predicted results are credible and can be used for biomechanical analyses and simulation of surgical situations. Compared with 5 mm arthroplasty, 8.5 mm arthroplasty on the left side increases the stress on the FJ and segmental discs under certain working conditions, but it does not cause degeneration of the discs of the adjacent segments. Abbreviations FJ facet joint LDH lumbar disc herniation FSU functional spinal unit FEA finite element analysis PLIF posterior lumbar interbody fusion Declarations Ethics approval and consent to participate Approval was obtained from the Ethics Committee of the Second Affiliated Hospital of Xuzhou Medical University No. [2022] 080,701). Informed consent was obtained from the participants. Consent for publication We obtained informed consent from all participants and received their consent for publication of the study. Availability of data and materials The datasets used and/or analyzed during the current study are available from the corresponding author upon reasonable request. Competing interests The authors declare that they have no competing interests. Funding This study received support from the Xuzhou City Science and Technology Project (KC21210), Xuzhou City Science and Technology Project (KC23261), and Youth Reserve Talent Training Project of Xuzhou Medical University (XWRCHT20220038). Authors' contributions Wei Sun was responsible for writing the original draft, writing-review & editing, software, data compilation, and obtaining funding and was the main contributor to writing the manuscript. Duohua Li was responsible for processing the model and data compilation. Feng Zhang analyzed the data. Jiayu Tian was responsible for data compilation and table creation. Hao Fu was responsible for creating the images. Sicong Zhao was responsible for the software and validation. Dongying Wu was responsible for the writing of the original draft and concept development. Hu Feng is responsible for writing-review & editing, concept development, and supervision. All authors reviewed the final manuscript. Acknowledgments Not applicable Authors' information 1 Xuzhou Medical University affiliated Hospital, No. 99 Huaihai West Road, Xuzhou City, Jiangsu Province, People's Republic of China. 2 Xuzhou Medical University, No. 209 Tongshan Road, Xuzhou City, Jiangsu Province, People's Republic of China References Lucas CCosta J, Paixão J, Silva F, et al. Low Back Pain: A Pain That May Not Be Harmless. Eur J Case Rep Intern Med. 2018 Mar 21;5(3):000834. Higgins DM, LaChappelle KM, Serowik KL, et al. Predictors of Participation in a Nonpharmacological Intervention for Chronic Back Pain. Pain Med. 2018 Sep 1;19(suppl_1): S76-S83. Ross JS, Robertson JT, Frederickson RC, et al. 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Influence of different frequencies of axial cyclic loading on time-domain vibration response of the lumbar spine: A finite element study. Comput Biol Med. 2017 Jul 1; 86:75-81. Srinivas GR, Kumar MN, Deb A. Adjacent Disc Stress Following Floating Lumbar Spine Fusion: A Finite Element Study. Asian Spine J. 2017 Aug;11(4):538-547. Choi HW, Kim YE. Effect of lumbar fasciae on the stability of the lower lumbar spine. Comput Methods Biomech Biomed Engin. 2017 Oct;20(13):1431-1437. Shim CS, Park SW, Lee SH, et al. Biomechanical evaluation of an interspinous stabilizing device, Locker. Spine (Phila Pa 1976). 2008 Oct 15;33(22): E820-7. Lee JH, Park WM, Kim YH, et al. A Biomechanical Analysis of an Artificial Disc with a Shock-absorbing Core Property by Using Whole-cervical Spine Finite Element Analysis. Spine (Phila Pa 1976). 2016 Aug 1;41(15): E893-E901. Pyles CO, Zhang J, Demetropoulos CK, et al. Material Parameter Determination of an L4-L5 Motion Segment Finite Element Model Under High Loading Rates. Biomed Sci Instrum. 2015;51: 206-213. Davidson Jebaseelan D, Jebaraj C, Yoganandan N, et al. Biomechanical responses due to discitis infection of a juvenile thoracolumbar spine using finite element modeling. Med Eng Phys. 2014 Jul;36(7):938-943. DeVries Watson NA, Gandhi AA, Fredericks DC, et al. Sheep cervical spine biomechanics: a finite element study. Iowa Orthop J. 2014;34: 137-143. Sairyo K, Goel VK, Masuda A, et al. Three-dimensional finite element analysis of the pediatric lumbar spine. Part I: pathomechanism of apophyseal bony ring fracture. Eur Spine J. 2006 Jun;15(6):923-929. Wheeldon JA, Pintar FA, Knowles S, et al. Experimental flexion/extension data corridors for validation of finite element models of the young, normal cervical spine. J Biomech. 2006;39(2):375-380. Templeton A, Liebschner M. A hierarchical approach to finite element modeling of the human spine. Crit Rev Eukaryot Gene Expr. 2004;14(4):317-328. Shah RR, Mohammed S, Saifuddin A, et al. Radiologic evaluation of adjacent superior segment facet joint violation following transpedicular instrumentation of the lumbar spine. Spine (Phila Pa 1976). 2003 Feb 1;28(3):272-275. Moshirfar A, Jenis LG, Spector LR, et al. Computed tomography evaluation of superior-segment facet-joint violation after pedicle instrumentation of the lumbar spine with a midline surgical approach. Spine (Phila Pa 1976). 2006 Oct 15;31(22):2624-2629. Li XC, Huang CM, Zhong CF, et al. Minimally invasive procedure reduces adjacent segment degeneration and disease: New benefit-based global meta-analysis. PLoS One. 2017 Feb 16;12(2): e0171546. Maruenda JI, Barrios C, Garibo F, et al. Adjacent segment degeneration and revision surgery after circumferential lumbar fusion: outcomes throughout 15 years of follow-up. Eur Spine J. 2016 May;25(5):1550-1557. Lee CH, Jahng TA, Hyun SJ, et al. Dynamic stabilization using the Dynesys system versus posterior lumbar interbody fusion for the treatment of degenerative lumbar spinal disease: a clinical and radiological outcomes-based meta-analysis. Neurosurg Focus. 2016 Jan;40(1): E7. Yue ZJ, Liu RY, Lu Y, et al. Middle-period curative effect of posterior lumbar intervertebral fusion (PLIF) and interspinous dynamic fixation (Wallis) for treatment of L45 degenerative disease and its influence on adjacent segment degeneration. Eur Rev Med Pharmacol Sci. 2015 Dec;19(23):4481-4487. Additional Declarations No competing interests reported. Cite Share Download PDF Status: Under Review Version 1 posted Editorial decision: Revision requested 15 Apr, 2024 Reviews received at journal 09 Apr, 2024 Reviews received at journal 08 Apr, 2024 Reviews received at journal 08 Apr, 2024 Reviewers agreed at journal 08 Apr, 2024 Reviewers agreed at journal 08 Apr, 2024 Reviewers agreed at journal 03 Apr, 2024 Reviewers agreed at journal 03 Apr, 2024 Reviewers invited by journal 03 Apr, 2024 Editor assigned by journal 02 Apr, 2024 Submission checks completed at journal 02 Apr, 2024 First submitted to journal 01 Apr, 2024 You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. 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Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-4201856","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":287308447,"identity":"3f04204a-dcd4-409b-8bbe-dc97219a402f","order_by":0,"name":"Wei Sun","email":"","orcid":"","institution":"Affiliated Hospital of Xuzhou Medical University","correspondingAuthor":false,"prefix":"","firstName":"Wei","middleName":"","lastName":"Sun","suffix":""},{"id":287308448,"identity":"1083c763-7f33-4fc5-b809-b292f0c5c238","order_by":1,"name":"Duohua Li","email":"","orcid":"","institution":"Xuzhou Medical College","correspondingAuthor":false,"prefix":"","firstName":"Duohua","middleName":"","lastName":"Li","suffix":""},{"id":287308449,"identity":"57eba48a-2c38-4330-ade1-0eb27ccd06c4","order_by":2,"name":"Feng Zhang","email":"","orcid":"","institution":"Xuzhou Medical College","correspondingAuthor":false,"prefix":"","firstName":"Feng","middleName":"","lastName":"Zhang","suffix":""},{"id":287308450,"identity":"7385e6e4-9fae-4c72-bbca-baf5d383264d","order_by":3,"name":"Jiayu Tian","email":"","orcid":"","institution":"Xuzhou Medical College","correspondingAuthor":false,"prefix":"","firstName":"Jiayu","middleName":"","lastName":"Tian","suffix":""},{"id":287308451,"identity":"f4836c9c-c72e-49c2-bd84-08ce2e4bda13","order_by":4,"name":"Hao Fu","email":"","orcid":"","institution":"Xuzhou Medical College","correspondingAuthor":false,"prefix":"","firstName":"Hao","middleName":"","lastName":"Fu","suffix":""},{"id":287308452,"identity":"9ffa3031-80f9-415d-9522-14116264982a","order_by":5,"name":"Sicong Zhao","email":"","orcid":"","institution":"Xuzhou Medical College","correspondingAuthor":false,"prefix":"","firstName":"Sicong","middleName":"","lastName":"Zhao","suffix":""},{"id":287308453,"identity":"52e130f0-1bea-4a3f-a88c-00c63fcf3e88","order_by":6,"name":"Hu Feng","email":"","orcid":"","institution":"Affiliated Hospital of Xuzhou Medical University","correspondingAuthor":false,"prefix":"","firstName":"Hu","middleName":"","lastName":"Feng","suffix":""},{"id":287308454,"identity":"efa751c3-b420-472a-a271-4bcb09ee84df","order_by":7,"name":"Dongying Wu","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAAsElEQVRIiWNgGAWjYDCCAzCSvbHxwQfitSQASZ7DzYYzSNMikd4mzUGMDr7jzQ8fV/64I2c+82GDNAODnZxuAwEtkmeOGRueSXhmLHM7scG4gCHZ2OwAAS0GN3LYJBsSDifOkE5sSJ7BcCBxG/FaJA82HOYhTYsEY2MzUVrAfmlIO2wswZPYzDjDgAi/gELsYYPNYTkJ9uPPf3yosJMjqAXdnaQpHwWjYBSMglGAAwAA+hJH3ZQnBsIAAAAASUVORK5CYII=","orcid":"","institution":"Affiliated Hospital of Xuzhou Medical University","correspondingAuthor":true,"prefix":"","firstName":"Dongying","middleName":"","lastName":"Wu","suffix":""}],"badges":[],"createdAt":"2024-04-01 16:32:12","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-4201856/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-4201856/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":54180307,"identity":"041ccdca-d7dd-41f6-8110-83485b54d014","added_by":"auto","created_at":"2024-04-05 16:29:47","extension":"png","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":139180,"visible":true,"origin":"","legend":"\u003cp\u003ePatient CT data were imported into Mimics software.\u003c/p\u003e","description":"","filename":"1.png","url":"https://assets-eu.researchsquare.com/files/rs-4201856/v1/8ff63cd4cf9e150abb6e35a7.png"},{"id":54180309,"identity":"377d8034-ce4f-4eab-b62b-4a8a5925d14c","added_by":"auto","created_at":"2024-04-05 16:29:47","extension":"png","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":119152,"visible":true,"origin":"","legend":"\u003cp\u003e2D mask editing of individual vertebrae in Mimics.\u003c/p\u003e","description":"","filename":"2.png","url":"https://assets-eu.researchsquare.com/files/rs-4201856/v1/063866b1a649c3beac202612.png"},{"id":54181761,"identity":"bf0888f3-849d-417f-b58d-e778b5ccd25c","added_by":"auto","created_at":"2024-04-05 16:37:47","extension":"png","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":107397,"visible":true,"origin":"","legend":"\u003cp\u003e3D reconstruction model of the L1-S1 segment. a: lateral view; b: posterior view\u003c/p\u003e","description":"","filename":"3.png","url":"https://assets-eu.researchsquare.com/files/rs-4201856/v1/14310163483057bbca16ba61.png"},{"id":54180313,"identity":"b1b78996-bc2a-4fcb-96bf-134bc63a3ac7","added_by":"auto","created_at":"2024-04-05 16:29:47","extension":"png","order_by":4,"title":"Figure 4","display":"","copyAsset":false,"role":"figure","size":180443,"visible":true,"origin":"","legend":"\u003cp\u003eMeshing of the 3D finite element model. a: side view; b: front view; c: back view.\u003c/p\u003e","description":"","filename":"4.png","url":"https://assets-eu.researchsquare.com/files/rs-4201856/v1/c534e71f12442159f5e1925e.png"},{"id":54180308,"identity":"23dd3e3a-548e-45ac-aa7d-3d194ef0618a","added_by":"auto","created_at":"2024-04-05 16:29:47","extension":"png","order_by":5,"title":"Figure 5","display":"","copyAsset":false,"role":"figure","size":61104,"visible":true,"origin":"","legend":"\u003cp\u003eSimulation of a herniated disc. a: normal disc; b: herniated disc\u003c/p\u003e","description":"","filename":"5.png","url":"https://assets-eu.researchsquare.com/files/rs-4201856/v1/e6b2202b3742b67beda80391.png"},{"id":54180315,"identity":"ae7e7cb2-225c-455e-ac46-f58a4b514d39","added_by":"auto","created_at":"2024-04-05 16:29:48","extension":"png","order_by":6,"title":"Figure 6","display":"","copyAsset":false,"role":"figure","size":127839,"visible":true,"origin":"","legend":"\u003cp\u003eSmoothing of the established L1-S1 3D model. a: vertebrae before smoothing; b: vertebrae after smoothing.\u003c/p\u003e","description":"","filename":"6.png","url":"https://assets-eu.researchsquare.com/files/rs-4201856/v1/7d788262154392a1e93db9a5.png"},{"id":54180312,"identity":"ae8e0cc1-8138-44b1-9388-9b0aa45b6b2c","added_by":"auto","created_at":"2024-04-05 16:29:47","extension":"png","order_by":7,"title":"Figure 7","display":"","copyAsset":false,"role":"figure","size":172126,"visible":true,"origin":"","legend":"\u003cp\u003eTreatment of the L5 superior articular process in the arthroplasty model. a: Lateral view of the L5 vertebral body in the 5 mm arthroplasty(M2) model.b: Lateral view of the L5 vertebral body in the 8.5 mm arthroplasty (M3) model.\u003c/p\u003e","description":"","filename":"7.png","url":"https://assets-eu.researchsquare.com/files/rs-4201856/v1/7b556b42bddff4bf845433bb.png"},{"id":54180314,"identity":"4659c0da-f46d-4a82-b4ef-72abeb1f340d","added_by":"auto","created_at":"2024-04-05 16:29:47","extension":"png","order_by":8,"title":"Figure 8","display":"","copyAsset":false,"role":"figure","size":152349,"visible":true,"origin":"","legend":"\u003cp\u003eDisplacement clouds of the three models under vertical stress. a: Displacement cloud of the L4-5 disc herniation model (M1); b: displacement cloud of the 5 mm arthroplasty model (M2); c: displacement cloud of the 8.5 mm arthroplasty model (M3); d: bar graphs of the degree of L4 vertebral body displacement of the three models under anterior flexion, posterior extension, left lateral flexion, right lateral flexion, levokinetic rotation, and right hand rotation conditions.\u003c/p\u003e","description":"","filename":"8.png","url":"https://assets-eu.researchsquare.com/files/rs-4201856/v1/e3da222b3a317a85dad66840.png"},{"id":54180310,"identity":"4460df3b-9d4d-4f10-ae59-694820c5afa3","added_by":"auto","created_at":"2024-04-05 16:29:47","extension":"png","order_by":9,"title":"Figure 9","display":"","copyAsset":false,"role":"figure","size":88496,"visible":true,"origin":"","legend":"\u003cp\u003eHistograms of the stress distribution in the articular synapse joints and intervertebral discs undereach working condition for the three models. a: Histograms of stress distribution inthe left articular synapse joints of L4-5 under each working condition; b: Histograms of stress distribution inthe right articular synapse joints of L4-5 under each working condition; c: Histograms of stress distribution inthe intervertebral discs of L4-5 under each working condition; d: Histograms of stress distribution inthe intervertebral discs of L5-S1 under each working condition; e: Histograms of the intervertebral discs of L3-4 under each working condition; f: Histograms of the intervertebral discs of L3-4 under each working condition; g: Histograms of the intervertebral discs of L3-4 under each working condition. Histogram; e: histogram of the stress distribution in the L3-4 intervertebral disc under each working condition.\u003c/p\u003e","description":"","filename":"9.png","url":"https://assets-eu.researchsquare.com/files/rs-4201856/v1/ae587a746586f30b9d917db5.png"},{"id":54182370,"identity":"799d00e6-2f6e-4a62-9368-414b7b5883ab","added_by":"auto","created_at":"2024-04-05 16:45:47","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":1758526,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-4201856/v1/0f815dc2-cddd-4f0d-b0c2-0fd06b83c36b.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"The effect of large channel-based foraminoplasty on lumbar biomechanics in percutaneous endoscopic discectomy: a finite element analysis","fulltext":[{"header":"1. Introduction","content":"\u003cp\u003eLumbar disc herniation (LDH) is a common and frequent disease in spinal surgery that seriously affects patients' quality of life and imposes a heavy economic burden on their families and society \u003csup\u003e[\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e, \u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e]\u003c/sup\u003e. Patients with LDH who fail to respond to strict conservative treatment require surgical treatment. Traditional open surgery requires extensive incisions of the lumbar muscles and vertebral plate, and postoperative epidural scar formation is prone to cause adhesions between the dura and nerve roots, resulting in renewed compression of the dural sac, restricted nerve root movement, and possible recurrence of clinical symptoms or even surgical failure. A study by Ross \u003csup\u003e[\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e]\u003c/sup\u003e et al. revealed a significant correlation between postoperative radicular symptoms and epidural scar formation, with as many as 24% of patients suffering from scar formation resulting in prolonged postoperative pain in the lumbar spine.\u003c/p\u003e \u003cp\u003eThe emergence of intervertebral foraminal endoscopic techniques is epoch-making, and these techniques have become widely popular worldwide in the last decade \u003csup\u003e[\u003cspan additionalcitationids=\"CR5\" citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e]\u003c/sup\u003e. Depending on the size of the patient's intervertebral foramen and the location of the herniated disc, intraoperative arthroplasty is often required in the transforaminal endoscopic spine system (TESSYS) \u003csup\u003e[\u003cspan additionalcitationids=\"CR8\" citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e]\u003c/sup\u003e. During the process of arthroplasty, the superior synchondrosis and synchondral ligaments are damaged to varying degrees. The lumbar facet joint (FJ) is a synovial joint that consists of a synovial membrane, joint capsule, joint fluid, and articular cartilage structures \u003csup\u003e[\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e]\u003c/sup\u003e. FJs play a role in restricting and guiding the movement of the spine and effectively prevent discs from being damaged by excessive shear and torsional tension. Therefore, angular changes, intraoperative injuries or even resection of the lumbar articular process may accelerate the degeneration of the responsible interspace or even lead to degenerative spinal disease.\u003c/p\u003e \u003cp\u003eThe finite element analysis (FEA) method can overcome the defects of obtaining specimens and can accurately and effectively simulate a variety of loads to determine the change in stress distribution within the tissue structure under different mechanical conditions. On the basis of CT, MRI and other imaging data, the human tissue structure is imaged, and values are assigned to the target tissue structure so that various models can simulate mechanical changes according to various surgical situations, thus providing a theoretical basis for clinical treatment based on changes in the corresponding parameters \u003csup\u003e[\u003cspan additionalcitationids=\"CR12\" citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e]\u003c/sup\u003e.\u003c/p\u003e \u003cp\u003eIn recent years, large-channel endoscopes have become increasingly widely used in clinical practice \u003csup\u003e[\u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e]\u003c/sup\u003e. Large-channel endoscopes (10 mm) have a wider working channel than ordinary endoscopes (7 mm) and can use larger surgical instruments, which are minimally invasive and efficient. Large-channel endoscopes are usually combined with the use of an 8.5-mm-diameter Trephine, which can cause more damage to the articular eminence than ordinary endoscopes. Therefore, it is important to explore the long-term effects of applying large-channel endoscopy for arthroplasty on the biomechanics of the lumbar spine of patients during TESSYS to understand patient prognosis. The aim of this paper was to establish a three-dimensional finite element model to simulate the postoperative lumbar spine motion of patients to further understand the effect of arthroplasty on lumbar spine biomechanics during TESSYS to better guide clinical practice.\u003c/p\u003e"},{"header":"2. Materials and methods","content":"\u003cdiv id=\"Sec3\" class=\"Section2\"\u003e\n \u003ch2\u003e2.1 Experimental materials\u003c/h2\u003e\n \u003cdiv id=\"Sec4\" class=\"Section3\"\u003e\n \u003ch2\u003e2.1.1 Experimental subjects\u003c/h2\u003e\n \u003cp\u003eOne healthy male adult volunteer (35 years old, height 178 cm, weight 75 kg, no history of previous spinal diseases or spinal trauma) was selected for physical examination. Lumbar spine positive and lateral, hyperextension and hyperflexion films were used to exclude spinal pelvic deformity and other spinal diseases. Informed consent was signed, discussed and approved by the Ethics Committee of the Affiliated Hospital of Xuzhou Medical University.\u003c/p\u003e\n \u003c/div\u003e\n \u003cdiv id=\"Sec5\" class=\"Section3\"\u003e\n \u003ch2\u003e2.1.2 Computer software for imaging equipment\u003c/h2\u003e\n \u003cp\u003eA Siemens 64-slice spiral CT scanner (Siemens Sensation Open CT scanner, Siemens, Erlangen, Germany) provided by the Department of Imaging of the Affiliated Hospital of Xuzhou Medical University was used. Computer software included 21.0 (professional medical image application software), Geomagic Studio (3D modeling reverse engineering software), Ansys 18.0 (finite element analysis software), and SPSS (computer software). analysis software) and SPSS (data analysis software).\u003c/p\u003e\n \u003c/div\u003e\n\u003c/div\u003e\n\u003cdiv id=\"Sec6\" class=\"Section2\"\u003e\n \u003ch2\u003e2.2 Establishment of the normal L1-S1 3D finite element model\u003c/h2\u003e\n \u003cdiv id=\"Sec7\" class=\"Section3\"\u003e\n \u003ch2\u003e2.2.1 CT image processing and 3D image reconstruction of the L1-S1 vertebrae\u003c/h2\u003e\n \u003cp\u003eThe DICOM format of the patient\u0026apos;s whole lumbar spine CT data was first imported via Mimics, and then the 3D data of the lumbar spine of L1-S1 were extracted (Fig. \u003cspan class=\"InternalRef\"\u003e1\u003c/span\u003e). Using the Draw and Erase functions in Edit Masks, the tomographic images could be erased and repaired, and the CT images of each level of the L1-S1 vertebrae were obtained after processing, which provided a good foundation for the next step of building a 3D model of L1-S1 (Fig. \u003cspan class=\"InternalRef\"\u003e2\u003c/span\u003e). The Calculate 3D function of Mimics software was used to generate the L1-S1 3D geometric model. When generating the 3D geometric model, the \u0026ldquo;high\u0026rdquo; quality level was selected to generate a smooth model with a highly approximate geometric form, which is conducive to making a mesh with a better quantity and quality and provides a basis for optimizing the image in the next step (Fig. \u003cspan class=\"InternalRef\"\u003e3\u003c/span\u003e).\u003c/p\u003e\n \u003c/div\u003e\n \u003cdiv id=\"Sec8\" class=\"Section3\"\u003e\n \u003ch2\u003e2.2.2 Mesh the 3D solid model of the L1-S1 vertebrae\u003c/h2\u003e\n \u003cp\u003eThe generated L1-S1 solid 3D model was imported into Mimics software, and the remesh module was used to perform mesh faceting and optimize the quality and quantity of the triangular mesh to meet the requirements of the finite element calculations (Fig. \u003cspan class=\"InternalRef\"\u003e4\u003c/span\u003e).\u003c/p\u003e\n \u003c/div\u003e\n \u003cdiv id=\"Sec9\" class=\"Section3\"\u003e\n \u003ch2\u003e2.2.3 Modeling process of each intervertebral disc, articular cartilage, ligament and joint capsule in the model\u003c/h2\u003e\n \u003cp\u003eThe anterior longitudinal ligament, posterior longitudinal ligament, supraspinous ligament, interspinous ligament, articular capsule ligament, and intertransverse ligament were constructed in the model using three-dimensional rod units. According to the literature \u003csup\u003e[\u003cspan class=\"CitationRef\"\u003e12\u003c/span\u003e]\u003c/sup\u003e, the upper and lower endplates were constructed with a thickness of 1.0 mm, and the intervertebral discs were established between the upper and lower endplates; the intervertebral discs consisted of the annulus fibrosus and the nucleus pulposus, which accounted for 44% of the intervertebral discs, and its center was offset by 3.5 mm from the center of the discs. The boundary of the intervertebral discs was offset inward for 12 mm, the of the intervertebral discs was displaced backward by 3.5 mm, and the boundary of the intervertebral discs was the boundary of the nucleus pulposus. The boundary is the boundary of the nucleus pulposus (Fig. \u003cspan class=\"InternalRef\"\u003e5\u003c/span\u003e). The articular cartilage is created between the upper and lower articular processes.\u003c/p\u003e\n \u003c/div\u003e\n \u003cdiv id=\"Sec10\" class=\"Section3\"\u003e\n \u003ch2\u003e2.2.4 Optimization of the model\u003c/h2\u003e\n \u003cp\u003eThrough the smooth and wrap functions in Mimics software, the finite element model was preliminarily processed, and the surface of the model was simplified by increasing the quality of the bone and introducing some irregular structures on the surface. The model was subsequently input into Geomagic Studio software to minimize the noise points of the point cloud, fill the ineffective cavities on the surface of the finite element model, remove the characteristic burrs and dents, smooth and relax the surface (Fig.\u0026nbsp;\u003cspan class=\"InternalRef\"\u003e6\u003c/span\u003e), and finally obtain the geometric model of the L1-S1 segment for this experiment. The surface was smoothed and relaxed (Fig.\u0026nbsp;\u003cspan class=\"InternalRef\"\u003e6\u003c/span\u003e) to obtain the L1-S1 segment geometry model for this experiment.\u003c/p\u003e\n \u003c/div\u003e\n \u003cdiv id=\"Sec11\" class=\"Section3\"\u003e\n \u003ch2\u003e2.2.5 Segmenting the finite element model and assigning material properties to each tissue\u003c/h2\u003e\n \u003cp\u003eA finite element model of the L1-S1 segment was generated, and the structures of cancellous bone, cortical bone and the posterior part of the vertebral body were established. The complete 3D model was imported into Ansys 18.0 computing software for finite element analysis, and the material properties were added to the material library according to the literature \u003csup\u003e[\u003cspan class=\"CitationRef\"\u003e16\u003c/span\u003e\u0026ndash;\u003cspan class=\"CitationRef\"\u003e18\u003c/span\u003e]\u003c/sup\u003e. Then, the values were assigned to each structure, and the material parameters are shown in Table \u003cspan class=\"InternalRef\"\u003e1\u003c/span\u003e\u0026ndash;\u003cspan class=\"InternalRef\"\u003e2\u003c/span\u003e.\u003c/p\u003e\n \u003cdiv class=\"gridtable\"\u003e\u0026nbsp;\u003ctable id=\"Tab1\" border=\"1\"\u003e\n \u003ccaption language=\"En\"\u003e\n \u003cdiv class=\"CaptionNumber\"\u003eTable 1\u003c/div\u003e\n \u003cdiv class=\"CaptionContent\"\u003e\n \u003cp\u003eAssignment properties of the constituent structures of the L1-S1 sections\u003c/p\u003e\n \u003c/div\u003e\n \u003c/caption\u003e\n \u003ccolgroup cols=\"3\"\u003e\u003c/colgroup\u003e\n \u003cthead\u003e\n \u003ctr\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eanatomical structure\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003emodulus of elasticity/MPa\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003ePoisson\u0026apos;s ratio\u003c/p\u003e\n \u003c/th\u003e\n \u003c/tr\u003e\n \u003c/thead\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003ecortical bone\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e12000\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0.3\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003ecancellous bone\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e100\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0.2\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003ecartilaginous endplate\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e3500\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0.25\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003enormal annulus fibrosus\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e2.6\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0.4\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003edegenerated annulus fibrosus\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e12.3\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0.35\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003enormal nucleus pulposus\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e1.0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0.49\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003edegenerating nucleus pulposus\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e1.7\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\"\u003e\n \u003cp\u003e0.4\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n \u003c/table\u003e\n \u003c/div\u003e\n \u003cdiv class=\"gridtable\"\u003e\n \u003cdiv align=\"left\" class=\"colspec\"\u003e\u003cbr\u003e\u003c/div\u003e\u0026nbsp;\u003ctable id=\"Tab2\" border=\"1\"\u003e\n \u003ccaption language=\"En\"\u003e\n \u003cdiv class=\"CaptionNumber\"\u003eTable 2\u003c/div\u003e\n \u003cdiv class=\"CaptionContent\"\u003e\n \u003cp\u003eProperties of the major ligaments of the L1-S1 segments\u003c/p\u003e\n \u003c/div\u003e\n \u003c/caption\u003e\n \u003ccolgroup cols=\"5\"\u003e\u003c/colgroup\u003e\n \u003cthead\u003e\n \u003ctr\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eligaments\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\" colspan=\"2\"\u003e\n \u003cp\u003emodulus of elasticity (MPa)\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003ecross-section (mm\u003csup\u003e2\u003c/sup\u003e)\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eaverage length (mm)\u003c/p\u003e\n \u003c/th\u003e\n \u003c/tr\u003e\n \u003c/thead\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eanterior longitudinal ligament (ALL)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e7.8\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\" colspan=\"2\"\u003e\n \u003cp\u003e22.4\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e20\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eposterior longitudinal ligament (PLL)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e10\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\" colspan=\"2\"\u003e\n \u003cp\u003e7.0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e12\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eligamentum flavum (LF)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e17\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\" colspan=\"2\"\u003e\n \u003cp\u003e14.1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e15\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eintertransverse ligament (ITL)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e10\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\" colspan=\"2\"\u003e\n \u003cp\u003e0.6\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e32\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003ecapsular ligament (CL)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e7.5\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\" colspan=\"2\"\u003e\n \u003cp\u003e10.5\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e5\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003einterspinous ligament (ISL)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e10\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\" colspan=\"2\"\u003e\n \u003cp\u003e14.1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e13\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003esupraspinous ligament (SSL)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e8\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\" colspan=\"2\"\u003e\n \u003cp\u003e10.5\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e22\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n \u003c/table\u003e\n \u003c/div\u003e\n \u003cp\u003e\u003cstrong\u003e2.3 Establishment of a three-dimensional finite element model for arthroplasty of the left side of L4-5 through the intervertebral foraminal approach\u003c/strong\u003e\u003c/p\u003e\n \u003cp\u003eOn the basis of the normal L1-S1 3D finite element model, the following 3D finite element model was established based on the intraoperative situation by simulating the surgical procedure using Mimics software.\u003c/p\u003e\n \u003cp\u003e1. Simple L4-5 disc herniation without surgical treatment model (Model 1, M1): Approximately 1/4 of the left posterior part of the L4-5 disc was defined as the material property of the degenerated disc, and other tissues such as the L3-4 and L5-S1 discs were defined as normal properties.\u003c/p\u003e\n \u003cp\u003e2. 5 mm arthroplasty model (Model 2, M2): The fibrous annulus and nucleus pulposus of the left posterior 1/4 of the L4-5 intervertebral disc were removed to simulate resection of the protruding disc and replaced with scar tissue. The tip of the left superior articular process of L5 was used as the puncture point, 5 mm of bone was removed from the tip of the arthroplasty site at an angle of approximately 30 degrees from the coronal plane to simulate the removal of part of the bone of the superior articular process, the foramen was enlarged, and arthroplasty was performed. This model simulates the intraoperative removal of the L5 superior articular process using a conventional 5-mm-diameter Trephine under normal intervertebral foramenoscopy.\u003c/p\u003e\n \u003cp\u003e3. 8.5 mm arthroplasty model (Model 3, M3): The fibrous annulus and nucleus pulposus of the left posterior 1/4 of the L4-5 intervertebral disc were removed to simulate resection of the herniated disc and replaced with scar tissue. The apical part of the left upper arthroplasty of L5 was used as the puncture point, 8.5 mm of bone in the apical part of the left arthroplasty was resected at an angle of approximately 30 degrees from the coronal plane to simulate the removal of part of the bone of the upper arthroplasty, and an enlargement of the arthroplasty was performed. This model simulates the intraoperative removal of the L5 superior articular process using a large-channel intervertebral foramen with a trephine 8.5 mm in diameter.\u003c/p\u003e\n \u003cp\u003eDefinition of contact surfaces and interactions: After the model was assembled, the contact surfaces were defined according to the anatomical situation. For the relative sliding between the lumbar disc surfaces and the upper and lower endplates of each vertebral body, contact was defined as a \u0026quot;tie\u0026quot; pattern, with the upper and lower endplates of each vertebral body serving as the master surfaces and the upper and lower surfaces of the disc serving as the follower surfaces. The FJ was set as a micromanipulation joint, and contact was defined as limited sliding contact with a friction coefficient of 0.1, with the next vertebral body\u0026apos;s upper articular process serving as the master surface.\u003c/p\u003e\n \u003c/div\u003e\n\u003c/div\u003e\n\u003cdiv id=\"Sec12\" class=\"Section2\"\u003e\n \u003ch2\u003e2.4 Loading conditions and observables\u003c/h2\u003e\n \u003cp\u003eWhen the model was set in the neutral position, the bottom of S1 was fixed, and a pressure of 500 N was applied axially to the upper surface of the L1 vertebra to simulate the stress on the lumbar vertebra caused by the weight of the human body in the static state so that the loads were uniformly transmitted to the nodes of the surface. A torque of 10 N\u0026middot;m was applied to the sagittal, coronal and transverse surfaces to simulate the lumbar spine under six working conditions, including forward flexion, backward extension, left and right lateral flexion and left and right rotation.\u003c/p\u003e\n \u003cp\u003eChanges in the range of motion of the L4-5 segment under forward flexion, backward extension, left and right lateral flexion and left and right rotation were observed in the three groups of models. Changes in the intravertebral disc pressure in the L3-4, L4-5 and L5-S1 segments of the three groups of models under different stresses were observed. Changes in the L4-5 FJs under stress were observed in the three groups of models. For the recording of the simulation results, according to previous methods reported in the literature, data were collected in the region of maximum stress or displacement, and five points in the collection region were randomly selected and represented by the mean.\u003c/p\u003e\n\u003c/div\u003e\n\u003cdiv id=\"Sec13\" class=\"Section2\"\u003e\n \u003ch2\u003e2.5 Statistical analyses\u003c/h2\u003e\n \u003cp\u003eStatistical processing was carried out using SPSS 23.0 software, and measurement data are presented as the means\u0026thinsp;\u0026plusmn;\u0026thinsp;standard deviations (\u0026oline;\u003cem\u003ex\u003c/em\u003e\u0026thinsp;\u0026plusmn;\u0026thinsp;s). Comparisons of data between multiple groups were performed using one-way analysis of variance (ANOVA), and if the results of the analyses were overall different, then two-by-two comparisons were performed using the least significant difference (LSD) method. \u003cem\u003eP\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.05 was considered to indicate statistical significance.\u003c/p\u003e\n\u003c/div\u003e"},{"header":"3. Results","content":"\u003cdiv id=\"Sec15\" class=\"Section2\"\u003e \u003ch2\u003e3.1 Normal 3D finite element modeling and validation\u003c/h2\u003e \u003cp\u003eWe successfully established a finite element model of the normal L1-S1 segment, including the L1-S1 vertebral body, the L1-2 to L5-S1 intervertebral discs, the anterior and posterior longitudinal ligaments, the supraspinous interspinous ligament, the ligamentum flavum, and the articular capsule ligaments, and endowed them with different material properties (Tables\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e\u0026ndash;\u003cspan refid=\"Tab2\" class=\"InternalRef\"\u003e2\u003c/span\u003e). The L4-5 intervertebral disc herniation model (M1), the 5 mm arthroplasty model (M2) and the 8.5 mm arthroplasty model (M3) were established on the basis of the finite element model of the normal L1-S1 segment (Fig.\u0026nbsp;\u003cspan refid=\"Fig7\" class=\"InternalRef\"\u003e7\u003c/span\u003e).\u003c/p\u003e \u003cp\u003eThe mechanical results were calculated after loading the established finite element model with the aforementioned boundary conditions, and some of the results were extracted and compared with those of Shim \u003csup\u003e[\u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e19\u003c/span\u003e]\u003c/sup\u003e (Table\u0026nbsp;3). The results show that the joint mobility (range of motion, ROM) of the L3-4 and L4-5 segments of the present study model under the same boundary conditions is within a reasonable range, which proves the validity of the present finite element model.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec16\" class=\"Section2\"\u003e \u003ch2\u003e3.2 Mechanical changes after stress loading in the three models\u003c/h2\u003e \u003cdiv id=\"Sec17\" class=\"Section3\"\u003e \u003ch2\u003e3.2.1 Displacement analysis of the three models under six operating conditions\u003c/h2\u003e \u003cp\u003eThe values and distribution areas of lumbar displacement can be observed in Fig.\u0026nbsp;\u003cspan refid=\"Fig8\" class=\"InternalRef\"\u003e8\u003c/span\u003e, and we analyzed the lumbar displacement cloud to evaluate the stability of the lumbar spine. After comparison, we found that L4 vertebral displacement was greater in the M2 and M3 models than in the M1 model under the six working conditions, but the difference was not statistically significant (\u003cem\u003eP\u003c/em\u003e\u0026thinsp;\u0026gt;\u0026thinsp;0.05). The difference in the degree of L4 vertebral displacement between the M2 and M3 models was not statistically significant (\u003cem\u003eP\u003c/em\u003e\u0026thinsp;\u0026gt;\u0026thinsp;0.05).\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab3\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 4\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eActivity range of the normal L1-S1 finite element model L3-4 and L4-5 segments under different working conditions (\u0026oline;\u003cem\u003ex\u003c/em\u003e\u0026thinsp;\u0026plusmn;\u0026thinsp;s).\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"5\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003eWorking condition\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colspan=\"2\" nameend=\"c3\" namest=\"c2\"\u003e \u003cp\u003eSections L3-\u003cspan refid=\"Sec20\" class=\"InternalRef\"\u003e4\u003c/span\u003e\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colspan=\"2\" nameend=\"c5\" namest=\"c4\"\u003e \u003cp\u003eSection L4-5\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003ethis study\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eShim's research\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003ethis study\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c5\"\u003e \u003cp\u003eShim's research\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eForward flexion\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e3.346\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e4.2\u0026thinsp;\u0026plusmn;\u0026thinsp;0.8\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e5.873\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e5.4\u0026thinsp;\u0026plusmn;\u0026thinsp;0.9\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eBackward extension\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e2.636\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e2.9\u0026thinsp;\u0026plusmn;\u0026thinsp;0.5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e3.203\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e2.9\u0026thinsp;\u0026plusmn;\u0026thinsp;0.5\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eLeft rotation\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e2.727\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e2.8\u0026thinsp;\u0026plusmn;\u0026thinsp;0.6\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e3.890\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e3.8\u0026thinsp;\u0026plusmn;\u0026thinsp;1.0\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eRight rotation\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e2.900\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e2.8\u0026thinsp;\u0026plusmn;\u0026thinsp;0.6\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e4.023\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e3.8\u0026thinsp;\u0026plusmn;\u0026thinsp;1.0\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eLeft flexion\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e4.154\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e3.5\u0026thinsp;\u0026plusmn;\u0026thinsp;1.0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e3.842\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e4.4\u0026thinsp;\u0026plusmn;\u0026thinsp;1.1\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eRight flexion\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e4.301\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e3.5\u0026thinsp;\u0026plusmn;\u0026thinsp;1.0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e3.625\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e4.4\u0026thinsp;\u0026plusmn;\u0026thinsp;1.1\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec18\" class=\"Section3\"\u003e \u003ch2\u003e3.2.2 Stress analysis of three models of L4-5 articular synapse joints under various working conditions\u003c/h2\u003e \u003cp\u003eStress distribution in the left FJ of L4-5 (Fig.\u0026nbsp;\u003cspan refid=\"Fig9\" class=\"InternalRef\"\u003e9\u003c/span\u003ea). Compared with those in the M1 model, the stresses in the left FJ of L4-5 decreased under forward flexure conditions for the M2 and M3 models (\u003cem\u003eP\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.05), but there was no significant difference between the M2 and M3 models (\u003cem\u003eP\u003c/em\u003e\u0026thinsp;\u0026gt;\u0026thinsp;0.05). There was no significant difference between the M2 and M3 models for the left lateral flexion condition, but both were greater than that of the M1 model (\u003cem\u003eP\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.05). In the posterior extension, right lateral flexion, left rotation and right rotation working conditions, there was no statistically significant difference in stress among the three models (\u003cem\u003eP\u003c/em\u003e\u0026thinsp;\u0026gt;\u0026thinsp;0.05). In the M2 and M3 models, the stress of the L4-5 left FJ was significantly greater in model left lateral flexion or left rotation than in right lateral flexion or right rotation, and the magnitude of increase was greater than that in the M1 model.\u003c/p\u003e \u003cp\u003eThe stress distribution of the right FJ of L4-5 under various working conditions was as follows (Fig.\u0026nbsp;\u003cspan refid=\"Fig9\" class=\"InternalRef\"\u003e9\u003c/span\u003eb): under forward flexion conditions, the stress of the right FJ of L4-5 increased significantly in the M2 and M3 models compared with that of the M1 model (\u003cem\u003eP\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.05), but there was no significant difference between the M2 and M3 models (\u003cem\u003eP\u003c/em\u003e\u0026thinsp;\u0026gt;\u0026thinsp;0.05). The differences in FJ stress between the three models in the posterior extension, right and left lateral flexion and right rotation working conditions were not statistically significant (\u003cem\u003eP\u003c/em\u003e\u0026thinsp;\u0026gt;\u0026thinsp;0.05). In the left rotation treatment, the M3 FJ stress was greater than the M2, and the M2 FJ stress was greater than the M1 stress, and the differences were statistically significant (\u003cem\u003eP\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.05). In the M2 and M3 models, the stress in the right FJ of L4-5 was significantly greater than that in right lateral flexion or right rotation in the left lateral flexion or left rotation of the model, and the increase in magnitude was greater than that in the M1 model.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec19\" class=\"Section3\"\u003e \u003ch2\u003e3.2.3 Stress analysis of L4-5 discs under six operating conditions for three models\u003c/h2\u003e \u003cp\u003eThe stress distributions of the L4-5 disc stresses of the three models under various working conditions were as follows (Fig.\u0026nbsp;\u003cspan refid=\"Fig9\" class=\"InternalRef\"\u003e9\u003c/span\u003ec): The L4-5 disc stresses of the M2 and M3 models were greater than those of the M1 model under forward flexion, levokinetic rotation, and right and left lateral flexion conditions, but the differences were not statistically significant (\u003cem\u003eP\u003c/em\u003e\u0026thinsp;\u0026gt;\u0026thinsp;0.05). L4-5 interdisc stress was greater in the M3 model than in the M1 and M2 models in the posterior extension condition (\u003cem\u003eP\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.05), whereas there was no significant difference between the M1 and M2 models (\u003cem\u003eP\u003c/em\u003e\u0026thinsp;\u0026gt;\u0026thinsp;0.05). In the right-handed condition, the stress was greater in the M3 model than in the M2 model and in the M2 model than in the M1 model, and the differences were statistically significant (\u003cem\u003eP\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.05).\u003c/p\u003e \u003cp\u003e \u003cb\u003e3.2.4 Stress analyses of the adjacent segmental intervertebral discs (L3-4 and L5-S1) for the three models under six working conditions\u003c/b\u003e \u003c/p\u003e \u003cp\u003eIn spinal surgery, most studies have shown that surgical segments accelerate the degeneration of discs in neighboring segments, especially the degeneration of discs in the previous segment. One of the advantages of FEA is that it is easy to observe the stress distributions of various established tissues and structures under different working conditions after the model is completed, so we analyzed the changes in the stresses in the L3-4 and L5-S1 intervertebral discs after the FJ shaping of the left side of L5. Our study revealed that there was no significant difference in the stress distribution of the L3-4 and L5-S1 interdiscs among the three models under various working conditions (Fig.\u0026nbsp;\u003cspan refid=\"Fig9\" class=\"InternalRef\"\u003e9\u003c/span\u003ed and e).\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003c/div\u003e \u003c/div\u003e"},{"header":"4. Discussion","content":"\u003cp\u003eThe FEA method can simulate the human body and analyze the biomechanical changes associated with different surgical methods on various parts of the spine and is widely used in the field of spinal surgery \u003csup\u003e[\u003cspan additionalcitationids=\"CR21 CR22\" citationid=\"CR20\" class=\"CitationRef\"\u003e20\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR23\" class=\"CitationRef\"\u003e23\u003c/span\u003e]\u003c/sup\u003e. The L4-5 segment is the segment with the highest incidence of LDH, so in the present study, the L4-5 segment was used as the target segment, and the FEA method was used to establish a normal three-dimensional finite element model of the L1-S1 segment. Based on this model, an intraoperative arthroplasty model was established to investigate the effects of intraoperative arthroplasty on lumbar spine biomechanics. An arthroplasty model was established on the basis of this model to investigate the effect of intervertebral foramenoscopy on the biomechanics of the lumbar spine in patients after arthroplasty. The analysis of the effect of surgery on the biomechanics of the lumbar spine and the acquisition of the mechanical information of the corresponding motion segments are conducive to tracing the causes of postoperative lumbar pain and can provide a theoretical basis for guiding the design of intraoperative surgical protocols and the formulation of individualized treatment plans.\u003c/p\u003e \u003cp\u003eThe first step after establishing a 3D finite element model is to verify the validity of the model, which is usually performed by comparing the experimental results with similar 3D finite element models from previous literature \u003csup\u003e[\u003cspan additionalcitationids=\"CR25\" citationid=\"CR24\" class=\"CitationRef\"\u003e24\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR26\" class=\"CitationRef\"\u003e26\u003c/span\u003e]\u003c/sup\u003e. A comparison of our established finite element model with the results of Shim et al. \u003csup\u003e[\u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e19\u003c/span\u003e]\u003c/sup\u003e shows that the ROM of our model is within the error range reported in the literature and is comparable, indicating the validity of the finite element modeling method and material assignment in this paper, which can be used for biomechanical analysis. The modeling methods and loading constraints used in this study are basically the same as those used in previous studies, with only the individual samples differing, and the results are plausible from the point of view of a qualitative comparative study. The diversity of the individual morphology and material properties of human spinal segments means that finite element models do not exactly match the results of computer simulations with those of in vivo experiments. The reason for this difference is the inconsistency in the sources used to construct the finite element models, and although the ideal approach would be to use the same in vitro experimental subject and finite element model object, this approach is essentially impossible for any experiment due to ethical issues. The advantage of using cadaveric samples for modeling is that the samples can be dissected and directly validated for each tissue, and the disadvantage is that the metrics in the physiological state are not available. Although the reconstruction of the human spine model can be achieved using cadaveric samples, it cannot be validated against homologous cadaveric samples, so the method of validating the finite element model is mainly to compare it with the test data of previous cadaveric specimens.\u003c/p\u003e \u003cp\u003eDuring TESSYS, depending on the size of the intervertebral foramen and the location of the herniated disc, arthroplasty on one side is usually required to enlarge the foramen, a procedure that can injure the FJ to varying degrees. Previous studies have reported on the effect of conventional open surgery on FJs. Shah et al. \u003csup\u003e[\u003cspan citationid=\"CR27\" class=\"CitationRef\"\u003e27\u003c/span\u003e]\u003c/sup\u003e reported that 33\u0026ndash;35% of FJs are injured during lumbar nailing via the transosseous interspace approach, whereas Monshirfar et al. \u003csup\u003e[\u003cspan citationid=\"CR28\" class=\"CitationRef\"\u003e28\u003c/span\u003e]\u003c/sup\u003e analyzed the probability of injury to the FJ during pedicle screw placement via the posterior median approach, and the presence of an injury to the FJ was detected on postoperative radiographs in approximately 15% of the patients. Because the TESSYS technique has not matured for a long time in China, no study has systematically analyzed its effect on lumbar spine biomechanics after performing arthroplasty during TESSYS. After we established a finite element model of TESSYS intraoperative arthroplasty, we analyzed the degree of displacement of the L4 vertebral body under different working conditions and found that there was no significant difference in L4 vertebral body displacement among the three groups of models, which suggests that TESSYS intraoperative arthroplasty is relatively safe and generally does not cause lumbar spine slippage in the postoperative period.\u003c/p\u003e \u003cp\u003eStress analyses of the L4-5 FJ in the three models revealed that after arthroplasty, the stresses in the L4-5 bilateral FJ in the left lateral flexion condition increased compared with those in the preoperative condition in all patients and that the 8.5 mm arthroplasty had a greater effect on the right synchondrosis than did the 5 mm arthroplasty. In both arthroplasty models, the stress in the bilateral FJ of L4-5 was significantly greater in left lateral flexion or left rotation than in right lateral flexion or right rotation, and the magnitude of the increase was greater than that in the unoperated model, which suggests that arthroplasty of one side of arthroplasty with an ipsilateral disc injury will lead to increased stress in the contralateral FJ and that the larger the amplitude of arthroplasty is, the greater the increase in the stress in the contralateral FJ, which suggests that arthroplasty is best performed by tightly applying media. This finding suggests that it is better to keep the synchondrosis as close to the medial side as possible when performing synchondroplasty and to minimize the removal of the synchondrosis under the premise of adequate decompression. Stress analysis of the L4-5 intervertebral discs of the three models showed that L4-5 intervertebral disc stress was greater in the M3 model than in the M2 model under conditions of posterior extension and rightward rotation, which indicated that a large range of arthroplasty might aggravate the degeneration of the intervertebral discs of the segments compared with a small range of arthroplasty. In contrast, there was no significant difference in the distribution of L3-4 or L5-S1 interbody disc stresses among the three models under various working conditions, suggesting that arthroplasty had no significant effect on disc degeneration in adjacent segments. This is an advantage of nonfusion surgery over fusion surgery, as lumbar fusion surgery mostly accelerates the degeneration of neighboring segments \u003csup\u003e[\u003cspan additionalcitationids=\"CR30 CR31\" citationid=\"CR29\" class=\"CitationRef\"\u003e29\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR32\" class=\"CitationRef\"\u003e32\u003c/span\u003e]\u003c/sup\u003e.\u003c/p\u003e \u003cp\u003eThis study also has the following shortcomings. First, the finite element models established in this study are similar to those that have been well validated in previous studies, but they all simplify the physiological contraction force of the lumbar spine to varying degrees, especially simplifying the muscles connected to the lumbar spine and the weight of the upper body, which is still somewhat different from that of a real human body. Second, this FEA is a one-time loading study, which cannot systematically analyze the effect of fatigue loading on the biomechanics of the lumbar spine. The actual clinical situation is complex and variable, and the repeated accumulation of stress in the lumbar spine after disc removal and arthroplasty may accelerate the degeneration of the injured area.\u003c/p\u003e \u003cp\u003eOverall, in this study, a normal L1-S1 segmental finite element model was developed, on the basis of which an L4-5 disc herniation model, a 5 mm arthroplasty model, and an 8.5 mm arthroplasty model were developed. The model was successfully validated, and the predicted results are credible and can be used for biomechanical analyses and simulation of surgical situations. Compared with 5 mm arthroplasty, 8.5 mm arthroplasty on the left side increases the stress on the FJ and segmental discs under certain working conditions, but it does not cause degeneration of the discs of the adjacent segments.\u003c/p\u003e"},{"header":"Abbreviations","content":"\u003cp\u003eFJ \u0026nbsp; facet joint\u003c/p\u003e\n\u003cp\u003eLDH \u0026nbsp; lumbar disc herniation\u003c/p\u003e\n\u003cp\u003eFSU \u0026nbsp; functional spinal unit\u003c/p\u003e\n\u003cp\u003eFEA \u0026nbsp; finite element analysis\u003c/p\u003e\n\u003cp\u003ePLIF \u0026nbsp; posterior lumbar interbody fusion\u003c/p\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003cstrong\u003eEthics approval and consent to participate\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eApproval\u0026nbsp;was obtained from the Ethics Committee of the Second Affiliated Hospital of Xuzhou Medical University\u0026nbsp;No. [2022] 080,701). Informed consent\u0026nbsp;was obtained\u0026nbsp;from the\u0026nbsp;participants.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConsent for publication\u003c/strong\u003e\u003c/p\u003e\n\u003cp skip=\"true\"\u003eWe obtained informed consent from all participants and received their consent for publication of the study.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAvailability of data and materials\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe datasets used and/or analyzed during the current study are available from the corresponding author\u0026nbsp;upon\u0026nbsp;reasonable request.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eCompeting interests\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe authors declare that they have no competing interests.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eFunding\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThis study received support from the Xuzhou City Science and Technology Project (KC21210), Xuzhou City Science and Technology Project (KC23261), and Youth Reserve Talent Training Project of Xuzhou Medical University (XWRCHT20220038).\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAuthors\u0026apos; contributions\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eWei Sun\u0026nbsp;was\u0026nbsp;responsible for writing\u0026nbsp;the\u0026nbsp;original draft, writing-review\u0026nbsp;\u0026amp;\u0026nbsp;editing, software, data compilation, and obtaining funding and\u0026nbsp;was\u0026nbsp;the main contributor to writing the manuscript. Duohua Li\u0026nbsp;was\u0026nbsp;responsible for processing the model and data compilation. Feng Zhang analyzed the data. Jiayu Tian\u0026nbsp;was\u0026nbsp;responsible for data compilation and table creation. Hao Fu\u0026nbsp;was\u0026nbsp;responsible for creating the images. Sicong Zhao\u0026nbsp;was\u0026nbsp;responsible for\u0026nbsp;the\u0026nbsp;software and validation. Dongying Wu\u0026nbsp;was\u0026nbsp;responsible for\u0026nbsp;the\u0026nbsp;writing\u0026nbsp;of the\u0026nbsp;original draft\u0026nbsp;and\u0026nbsp;concept development. Hu Feng is responsible for writing-review\u0026nbsp;\u0026amp;\u0026nbsp;editing, concept development, and supervision.\u0026nbsp;All authors reviewed the final manuscript.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAcknowledgments\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eNot applicable\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAuthors\u0026apos; information\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e\u003csup\u003e1\u003c/sup\u003eXuzhou Medical University affiliated Hospital, No. 99 Huaihai West Road, Xuzhou City, Jiangsu Province, People\u0026apos;s Republic of China.\u003csup\u003e2\u003c/sup\u003eXuzhou Medical University, No. 209 Tongshan Road, Xuzhou City, Jiangsu Province, People\u0026apos;s Republic of China\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\n \u003cli\u003eLucas CCosta J, Paix\u0026atilde;o J, Silva F, et al. Low Back Pain: A Pain That May Not Be Harmless. Eur J Case Rep Intern Med. 2018 Mar 21;5(3):000834.\u003c/li\u003e\n \u003cli\u003eHiggins DM,\u0026nbsp;LaChappelle KM,\u0026nbsp;Serowik KL,\u0026nbsp;et al. Predictors of Participation in a Nonpharmacological Intervention for Chronic Back Pain. Pain Med. 2018 Sep 1;19(suppl_1): S76-S83.\u003c/li\u003e\n \u003cli\u003eRoss JS,\u0026nbsp;Robertson JT,\u0026nbsp;Frederickson RC,\u0026nbsp;et al. Association between peridural scar and recurrent radicular pain after lumbar discectomy: magnetic resonance evaluation. ADCON-L European Study Group. Neurosurgery. 1996 Apr;38(4):855-861.\u003c/li\u003e\n \u003cli\u003eChoi SH,\u0026nbsp;Adsul NM,\u0026nbsp;Kim HS,\u0026nbsp;et al. Percutaneous Endoscopic Interlaminar Unilateral Ventral Dural Approach for Symptomatic Bilateral L5-S1 Herniated Nucleus Pulposus: Technical Note. J Neurol Surg A Cent Eur Neurosurg. 2018 Nov;79(6):518-523.\u003c/li\u003e\n \u003cli\u003eAo S,\u0026nbsp;Wu J,\u0026nbsp;Zheng W,\u0026nbsp;et al. A Novel Targeted Foraminoplasty Device Improves the Efficacy and Safety of Foraminoplasty in Percutaneous Endoscopic Lumbar Discectomy: Preliminary Clinical Application of 70 Cases. World Neurosurg. 2018 Jul;115: e263-e271.\u003c/li\u003e\n \u003cli\u003eTacconi L,\u0026nbsp;Baldo S,\u0026nbsp;Merci G,\u0026nbsp;et al. Transforaminal percutaneous endoscopic lumbar discectomy: outcome and complications in 270 cases. J Neurosurg Sci. 2020 Dec;64(6):531-536.\u003c/li\u003e\n \u003cli\u003eLee CW,\u0026nbsp;Yoon KJ,\u0026nbsp;Jun JH. Percutaneous Endoscopic Laminotomy with Flavectomy by Uniportal, Unilateral Approach for the Lumbar Canal or Lateral Recess Stenosis. World Neurosurg. 2018 May;113: e129-e137.\u003c/li\u003e\n \u003cli\u003eLiu X,\u0026nbsp;Yuan S,\u0026nbsp;Tian Y,\u0026nbsp;et al. Comparison of percutaneous endoscopic transforaminal discectomy, microendoscopic discectomy, and microdiscectomy for symptomatic lumbar disc herniation: minimum 2-year follow-up results. J Neurosurg Spine. 2018 Mar;28(3):317-325.\u003c/li\u003e\n \u003cli\u003eChen Z,\u0026nbsp;Zhang L,\u0026nbsp;Dong J,\u0026nbsp;et al. Percutaneous transforaminal endoscopic discectomy compared with microendoscopic discectomy for lumbar disc herniation: 1-year results of an ongoing randomized controlled trial. J Neurosurg Spine. 2018 Mar;28(3):300-310.\u003c/li\u003e\n \u003cli\u003eVan den Heuvel SAS,\u0026nbsp;Cohen SPC,\u0026nbsp;de Andr\u0026egrave;s Ares J.\u0026nbsp;Pain originating from the lumbar facet joints. Pain Pract. 2024 Jan;24(1):160-176.\u0026nbsp;\u003c/li\u003e\n \u003cli\u003eTeo JC,\u0026nbsp;Chui CK,\u0026nbsp;Wang ZL, et al. Heterogeneous meshing and biomechanical modeling of human spine. Med Eng Phys. 2007 Mar;29(2):277-290.\u003c/li\u003e\n \u003cli\u003eMasni-Azian,\u0026nbsp;Tanaka M. Biomechanical investigation on the influence of the regional material degeneration of an intervertebral disc in a lower lumbar spinal unit: A finite element study. Comput Biol Med. 2018 Jul 1;98: 26-38.\u003c/li\u003e\n \u003cli\u003eHuang L,\u0026nbsp;Xu J,\u0026nbsp;Guo H,\u0026nbsp;et al.\u0026nbsp;Quantitative study of the influence of swimming therapy on osteoporosis rat models based on synchrotron radiation computed tomogaphy. J Synchrotron Radiat. 2018 May 1;25(Pt 3):793-800.\u003c/li\u003e\n \u003cli\u003eZhang F, Ye D, Zhang W, Sun Y, Guo L, Li J. Efficacy of lumbar decompression under large-channel spinal endoscope in elderly patients with segmental lumbar spinal stenosis. J Orthop Surg Res. 2024 Jan 3;19(1):16.\u0026nbsp;\u003c/li\u003e\n \u003cli\u003eSheng Y, Li J, Chen L, Geng M, Fen J, Sun S, Sun J. Delta large-channel technique versus microscopy-assisted laminar fenestration decompression for lumbar spinal stenosis: a one-year prospective cohort study. BMC Musculoskelet Disord. 2023 Jan 19;24(1):43.\u003c/li\u003e\n \u003cli\u003eFan W,\u0026nbsp;Guo LX. Influence of different frequencies of axial cyclic loading on time-domain vibration response of the lumbar spine: A finite element study. Comput Biol Med. 2017 Jul 1; 86:75-81.\u003c/li\u003e\n \u003cli\u003eSrinivas GR,\u0026nbsp;Kumar MN,\u0026nbsp;Deb A. Adjacent Disc Stress Following Floating Lumbar Spine Fusion: A Finite Element Study. Asian Spine J. 2017 Aug;11(4):538-547.\u003c/li\u003e\n \u003cli\u003eChoi HW,\u0026nbsp;Kim YE. Effect of lumbar fasciae on the stability of the lower lumbar spine. Comput Methods Biomech Biomed Engin. 2017 Oct;20(13):1431-1437.\u003c/li\u003e\n \u003cli\u003eShim CS,\u0026nbsp;Park SW,\u0026nbsp;Lee SH,\u0026nbsp;et al. Biomechanical evaluation of an interspinous stabilizing device, Locker. Spine (Phila Pa 1976). 2008 Oct 15;33(22): E820-7.\u003c/li\u003e\n \u003cli\u003eLee JH,\u0026nbsp;Park WM,\u0026nbsp;Kim YH,\u0026nbsp;et al. A Biomechanical Analysis of an Artificial Disc with a Shock-absorbing Core Property by Using Whole-cervical Spine Finite Element Analysis. Spine (Phila Pa 1976). 2016 Aug 1;41(15): E893-E901.\u003c/li\u003e\n \u003cli\u003ePyles CO,\u0026nbsp;Zhang J,\u0026nbsp;Demetropoulos CK, et al. Material Parameter Determination of an L4-L5 Motion Segment Finite Element Model Under High Loading Rates. Biomed Sci Instrum. 2015;51: 206-213.\u003c/li\u003e\n \u003cli\u003eDavidson Jebaseelan D,\u0026nbsp;Jebaraj C,\u0026nbsp;Yoganandan N,\u0026nbsp;et al.\u0026nbsp;Biomechanical responses due to discitis infection of a juvenile thoracolumbar spine using finite element modeling. Med Eng Phys. 2014 Jul;36(7):938-943.\u003c/li\u003e\n \u003cli\u003eDeVries Watson NA,\u0026nbsp;Gandhi AA,\u0026nbsp;Fredericks DC,\u0026nbsp;et al. Sheep cervical spine biomechanics: a finite element study. Iowa Orthop J. 2014;34: 137-143.\u003c/li\u003e\n \u003cli\u003eSairyo K,\u0026nbsp;Goel VK,\u0026nbsp;Masuda A,\u0026nbsp;et al. Three-dimensional finite element analysis of the pediatric lumbar spine. Part I: pathomechanism of apophyseal bony ring fracture. Eur Spine J. 2006 Jun;15(6):923-929.\u003c/li\u003e\n \u003cli\u003eWheeldon JA,\u0026nbsp;Pintar FA,\u0026nbsp;Knowles S,\u0026nbsp;et al. Experimental flexion/extension data corridors for validation of finite element models of the young, normal cervical spine. J Biomech. 2006;39(2):375-380.\u003c/li\u003e\n \u003cli\u003eTempleton A,\u0026nbsp;Liebschner M. A hierarchical approach to finite element modeling of the human spine. Crit Rev Eukaryot Gene Expr. 2004;14(4):317-328.\u003c/li\u003e\n \u003cli\u003eShah RR,\u0026nbsp;Mohammed S,\u0026nbsp;Saifuddin A,\u0026nbsp;et al. Radiologic evaluation of adjacent superior segment facet joint violation following transpedicular instrumentation of the lumbar spine. Spine (Phila Pa 1976). 2003 Feb 1;28(3):272-275.\u003c/li\u003e\n \u003cli\u003eMoshirfar A,\u0026nbsp;Jenis LG,\u0026nbsp;Spector LR,\u0026nbsp;et al. Computed tomography evaluation of superior-segment facet-joint violation after pedicle instrumentation of the lumbar spine with a midline surgical approach. Spine (Phila Pa 1976). 2006 Oct 15;31(22):2624-2629.\u003c/li\u003e\n \u003cli\u003eLi XC,\u0026nbsp;Huang CM,\u0026nbsp;Zhong CF,\u0026nbsp;et al. Minimally invasive procedure reduces adjacent segment degeneration and disease: New benefit-based global meta-analysis. PLoS One. 2017 Feb 16;12(2): e0171546.\u003c/li\u003e\n \u003cli\u003eMaruenda JI,\u0026nbsp;Barrios C,\u0026nbsp;Garibo F,\u0026nbsp;et al.\u0026nbsp;Adjacent segment degeneration and revision surgery after circumferential lumbar fusion: outcomes throughout 15\u0026nbsp;years of follow-up. Eur Spine J. 2016 May;25(5):1550-1557.\u003c/li\u003e\n \u003cli\u003eLee CH,\u0026nbsp;Jahng TA,\u0026nbsp;Hyun SJ,\u0026nbsp;et al. Dynamic stabilization using the Dynesys system versus posterior lumbar interbody fusion for the treatment of degenerative lumbar spinal disease: a clinical and radiological outcomes-based meta-analysis. Neurosurg Focus. 2016 Jan;40(1): E7.\u003c/li\u003e\n \u003cli\u003eYue ZJ, Liu RY, Lu Y, et al. Middle-period curative effect of posterior lumbar intervertebral fusion (PLIF) and interspinous dynamic fixation (Wallis) for treatment of L45 degenerative disease and its influence on adjacent segment degeneration. Eur Rev Med Pharmacol Sci. 2015 Dec;19(23):4481-4487.\u003c/li\u003e\n\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":false,"highlight":"","institution":"","isAcceptedByJournal":true,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"journal-of-orthopaedic-surgery-and-research","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"josr","sideBox":"Learn more about [Journal of Orthopaedic Surgery and Research](http://josr-online.biomedcentral.com)","snPcode":"13018","submissionUrl":"https://submission.nature.com/new-submission/13018/3","title":"Journal of Orthopaedic Surgery and Research","twitterHandle":"@MSKmedBMC","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"em","reportingPortfolio":"BMC/SO AJ","inReviewEnabled":true,"inReviewRevisionsEnabled":true},"keywords":"Finite element analysis, Biomechanical, Range of motion, Superior facet","lastPublishedDoi":"10.21203/rs.3.rs-4201856/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-4201856/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003e\u003cstrong\u003eBackground:\u003c/strong\u003eThe aim of this study was to evaluate the effect of arthroplasty using large-channel endoscopy during TESSYS on the biomechanics of the lumbar spine in patients.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eMethods:\u003c/strong\u003eA complete lumbar spine model,M1, was built using 3D finite elements, and models M2 and M3 were built by simulating the intraoperative removal of the supra-articular synchondrosis of L5 using a Trephine saw withdiametersof 5 mm and 8.5 mm,respectively, and applying normal physiological loads on the different models to simulate six working conditions—lumbaranterior flexion, posterior extension, left-right lateral flexion, and left-right rotation—toobserve the stress distributions of the vertebral body, the discs, and the articular synchondrosis.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eResults:\u003c/strong\u003e Compared with the M1 model, theM2 and M3 models showed a decrease in stress at the L4-5 left synaptic joint and a significant increase in stress at the right synaptic joint in forward flexion. In the M2 and M3 models, the L4-5 articular synaptic joint stresses were significantly greater in left lateral flexion or left rotation than in right lateral flexion or right rotation. The right synaptic joint stress in M3 was greater duringleft rotation than that in M2, and that in M2 was greater than that in M1. The L4-5 disc stress in the M3 model was greater duringposterior extension than that in the M1 and M2 models. The L4-5 disc stress in the M3 model was greater in the right rotation than in the M2 model, and that in the M2 model was greater than that in the M1 model.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConclusion:\u003c/strong\u003eArthroplasty using large-channel endoscopy increases the stress on articular synovial joints and segmental discs under certain working conditions but does not cause degeneration of the discs in adjacent segments.\u003c/p\u003e","manuscriptTitle":"The effect of large channel-based foraminoplasty on lumbar biomechanics in percutaneous endoscopic discectomy: a finite element analysis","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2024-04-05 16:29:41","doi":"10.21203/rs.3.rs-4201856/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"decision","content":"Revision requested","date":"2024-04-15T09:56:22+00:00","index":"","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2024-04-09T21:55:34+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2024-04-09T01:27:48+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2024-04-08T15:33:40+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"210bf287-8404-4936-b824-9d0a9e107609","date":"2024-04-08T15:09:08+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"427f3641-5c3f-4a30-acb4-c900d515bf47","date":"2024-04-08T06:49:50+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"53323f06-659c-429c-a7d7-6d868f23127f","date":"2024-04-04T02:07:21+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"33bcedef-5ced-487a-9120-f7217a04caae","date":"2024-04-04T01:24:43+00:00","index":"hide","fulltext":""},{"type":"reviewersInvited","content":"","date":"2024-04-04T01:23:43+00:00","index":"","fulltext":""},{"type":"editorAssigned","content":"","date":"2024-04-02T05:34:11+00:00","index":"","fulltext":""},{"type":"checksComplete","content":"","date":"2024-04-02T04:08:26+00:00","index":"","fulltext":""},{"type":"submitted","content":"Journal of Orthopaedic Surgery and Research","date":"2024-04-01T16:30:51+00:00","index":"","fulltext":""}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"journal-of-orthopaedic-surgery-and-research","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"josr","sideBox":"Learn more about [Journal of Orthopaedic Surgery and Research](http://josr-online.biomedcentral.com)","snPcode":"13018","submissionUrl":"https://submission.nature.com/new-submission/13018/3","title":"Journal of Orthopaedic Surgery and Research","twitterHandle":"@MSKmedBMC","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"em","reportingPortfolio":"BMC/SO AJ","inReviewEnabled":true,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"9e5d57ab-5fcc-4f49-bda6-9b6cb151f2c6","owner":[],"postedDate":"April 5th, 2024","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"under-review","subjectAreas":[],"tags":[],"updatedAt":"2024-06-21T23:24:27+00:00","versionOfRecord":[],"versionCreatedAt":"2024-04-05 16:29:41","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-4201856","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-4201856","identity":"rs-4201856","version":["v1"]},"buildId":"8U1c8b4HqxoKbykW_rLl7","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}