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Duran, Semra, Mehtap Cavusoglu, Hatice Gul Hatipoglu, Deniz Sozmen Cılız i Bulent Sakman. "Association between Measures of Vertebral Endplate Morphology and Lumbar Intervertebral Disc Degeneration". Canadian Association of Radiologists Journal 68, nr 2 (maj 2017): 210–16. http://dx.doi.org/10.1016/j.carj.2016.11.002.
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Purpose The aim of this study was to evaluate the association between vertebral endplate morphology and the degree of lumbar intervertebral disc degeneration via magnetic resonance imaging (MRI). Methods In total, 150 patients who met the inclusion criteria and were 20–60 years of age were retrospectively evaluated. Patients were evaluated for the presence of intervertebral disc degeneration or herniation, and the degree of degeneration was assessed at all lumbar levels. Vertebral endplate morphology was evaluated based on the endplate sagittal diameter, endplate sagittal concave angle (ECA), and endplate sagittal concave depth (ECD) on sagittal MRI. The association between intervertebral disc degeneration or herniation and endplate morphological measurements was analysed. Results In MRI, superior endplates ( ie, inferior endplates of the superior vertebra) were concave and inferior endplates ( ie, superior endplates of the inferior vertebra) were flat at all disc levels. A decrease in ECD and an increase in ECA were detected at all lumbar levels as disc degeneration increased ( P < .05). At the L4-L5 and L5-S1 levels, a decrease in ECD and an increase in ECA were detected in the group with herniated lumbar discs ( P < .05). There was no association between lumbar disc degeneration or herniation and endplate sagittal diameter at lumbar intervertebral levels ( P > .05). At all levels, ECD of women was significantly lesser than that of men and ECA of women was significantly greater than that of men ( P < .05). Conclusions There is an association between vertebral endplate morphology and lumbar intervertebral disc degeneration. Vertebral endplates at the degenerated disc level become flat; the severity of this flattening is correlated with the degree of disc degeneration.
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Nagaraja, Srinidhi, Hassan K. Awada, Maureen L. Dreher, John T. Bouck i Shikha Gupta. "Effects of vertebroplasty on endplate subsidence in elderly female spines". Journal of Neurosurgery: Spine 22, nr 3 (marzec 2015): 273–82. http://dx.doi.org/10.3171/2014.10.spine14195.
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OBJECT The aim in this study was to quantify the effects of vertebroplasty on endplate subsidence in treated and adjacent vertebrae and their relationship to endplate thickness and underlying trabecular bone in elderly female spines. METHODS Vertebral compression fractures were created in female cadaveric (age range 51–88 years) thoracolumbar spine segments. Specimens were placed into either the control or vertebroplasty group (n = 9/group) such that bone mineral density, trabecular microarchitecture, and age were statistically similar between groups. For the vertebroplasty group, polymethylmethacrylate bone cement was injected into the fractured vertebral body under fluoroscopy. Cyclic compression (685–1370 N sinusoid) was performed on all spine segments for 115,000 cycles. Micro-CT scans were obtained before and after cyclic loading to quantify endplate subsidence. Maximum subsidence was compared between groups in the caudal endplate of the superior adjacent vertebra (SVcau); cranial (TVcra) and caudal (TVcau) endplates of the treated vertebra; and the cranial endplate of the inferior adjacent vertebra (IVcra). In addition, micro-CT images were used to quantify average endplate thickness and trabecular bone volume fraction. These parameters were then correlated with maximum endplate subsidence for each endplate. RESULTS The maximum subsidence in SVcau endplate for the vertebroplasty group (0.34 ± 0.58 mm) was significantly (p < 0.05) greater than for the control group (−0.13 ± 0.27 mm). Maximum subsidence in the TVcra, TVcau, and IVcra endplates were greater in the vertebroplasty group, but these differences were not significant (p > 0.16). Increased subsidence in the vertebroplasty group manifested locally in the anterior region of the SVcau endplate and in the posterior region of the TVcra and TVcau endplates (p < 0.10). Increased subsidence was observed in thinner endplates with lower trabecular bone volume fraction for both vertebroplasty and control groups (R2 correlation up to 62%). In the SVcau endplate specifically, these 2 covariates aided in understanding subsidence differences between vertebroplasty and control groups. CONCLUSIONS Bone cement injected during vertebroplasty alters local biomechanics in elderly female spines, resulting in increased endplate disruption in treated and superior adjacent vertebrae. More specifically, bone cement increases subsidence in the posterior regions of the treated endplates and the anterior region of the superior caudal endplate. This increased subsidence may be the initial mechanism leading to subsequent compression fractures after vertebroplasty, particularly in vertebrae superior to the treated level.
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Chen, Xiaofeng, Weijun Guo, Hao Li, Xi Li, Zhuangxun Han, Xueyuan Chu, Zehui Lao, Junxian Xie i Dongling Cai. "Evaluation of Cartilaginous Endplate Degeneration Based on Magnetic Resonance Imaging". Journal of Healthcare Engineering 2021 (23.03.2021): 1–12. http://dx.doi.org/10.1155/2021/5534227.
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In order to carry out the evaluation of cartilaginous endplate degeneration based on magnetic resonance imaging (MRI), this paper retrospectively analyzed the MRI data from 120 cases of patients who were diagnosed as lumbar intervertebral disc degeneration and underwent MRI examinations in the designated hospital of this study from June 2018 to June 2020. All cases underwent conventional sagittal and transverse T1WI and T2WI scans, and some cases were added with sagittal fat-suppression T2WI scans; then, the number of degenerative cartilaginous endplates and its ratio to degenerative lumbar intervertebral discs were counted and calculated, and the T1WI and T2WI signal characteristics of each degenerative cartilage endplate and its correlation with cartilaginous endplate degeneration were summarized, compared, and analyzed to evaluate the cartilaginous endplate degeneration by those magnetic resonance information. The study results show that there were 33 cases of cartilaginous endplate degeneration, accounting for 27.50% of all those 120 patients with lumbar intervertebral disc degeneration (54 degenerative endplates in total), including 9 cases with low T1WI and high T2WI signals, 5 cases with high T1WI and low T2WI signals, 12 cases with high and low mixed T1WI and high or mixed T2WI signals, and 4 cases with both low T1WI and T2WI signals. Therefore, MRI scanning can clearly present the abnormal signals of lumbar intervertebral disc and cartilaginous endplate degeneration, accurately identity their lesion locations, and type their degenerative characteristics, which may be best inspection method for the evaluation of cartilaginous endplate degeneration in the early diagnosis of intervertebral disc degeneration. The study results of this paper provide a reference for further researches on the evaluation of cartilaginous endplate degeneration based on magnetic resonance imaging.
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Liu, Sijing, Qiong Wang, Ziyi Li, Lei Ma, Ting Li, Yukun Li, Na Wang, Chang Liu, Peng Xue i Chuan Wang. "TRPV1 Channel Activated by the PGE2/EP4 Pathway Mediates Spinal Hypersensitivity in a Mouse Model of Vertebral Endplate Degeneration". Oxidative Medicine and Cellular Longevity 2021 (21.08.2021): 1–16. http://dx.doi.org/10.1155/2021/9965737.
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Low back pain (LBP) is the primary cause of disability globally. There is a close relationship between Modic changes or endplate defects and LBP. Endplates undergo ossification and become highly porous during intervertebral disc (IVD) degeneration. In our study, we used a mouse model of vertebral endplate degeneration by lumbar spine instability (LSI) surgery. Safranin O and fast green staining and μCT scan showed that LSI surgery led to endplate ossification and porosity, but the endplates in the sham group were cartilaginous and homogenous. Immunofluorescent staining demonstrated the innervation of calcitonin gene-related peptide- (CGRP-) positive nerve fibers in the porous endplate of LSI mice. Behavior test experiments showed an increased spinal hypersensitivity in LSI mice. Moreover, we found an increased cyclooxygenase 2 (COX2) expression and an elevated prostaglandin E2 (PGE2) concentration in the porous endplate of LSI mice. Immunofluorescent staining showed the colocalization of E-prostanoid 4 (EP4)/transient receptor potential vanilloid 1 (TRPV1) and CGRP in the nerve endings in the endplate and in the dorsal root ganglion (DRG) neurons, and western blotting analysis demonstrated that EP4 and TRPV1 expression significantly increased in the LSI group. Our patch clamp study further showed that LSI surgery significantly enhanced the current density of the TRPV1 channel in small-size DRG neurons. A selective EP4 receptor antagonist, L161982, reduced the spinal hypersensitivity of LSI mice by blocking the PGE2/EP4 pathway. In addition, TRPV1 current and neuronal excitability in DRG neurons were also significantly decreased by L161982 treatment. In summary, the PGE2/EP4 pathway in the porous endplate could activate the TRPV1 channel in DRG neurons to cause spinal hypersensitivity in LSI mice. L161982, a selective EP4 receptor antagonist, could turn down the TRPV1 current and decrease the neuronal excitability of DRG neurons to reduce spinal pain.
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Yao, Qi, Peng Yin, Kamran Khan, Tsung-Yuan Tsai, Jing-Sheng Li, Yong Hai, Peifu Tang i Guoan Li. "Differences of the Morphology of Subaxial Cervical Spine Endplates between Chinese and White Men and Women". BioMed Research International 2018 (2018): 1–8. http://dx.doi.org/10.1155/2018/2854175.
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Objective. The aim of this comparative anatomical study was to specifically investigate endplate morphology differences between Chinese and White men and women. Materials and Methods. Three-dimensional cervical endplate models were constructed using computed tomography imaging of 41 healthy Chinese and 24 White subjects. The morphologic measurements of cervical endplate included linear parameters (EPWu: upper endplate width; EPDu: upper endplate depth; EPWl: lower endplate width; and EPDl: lower endplate depth) and area parameters with a digital measuring system. Results. All linear parameters showed a constant increase from C3 to C7 except for EPDl in both the Chinese and the White subjects. An increase trend was observed on area parameters in both Chinese and White subjects. The ratio of EPWl/EPDl was smaller in Chinese females than in White females at C3, C4, and C6 levels (P<0.05). The ratio of EPWl/EPDl was significantly different between the Chinese and White men at C4-5 levels (P<0.05). Conclusions. Our data indicates that the morphology of subaxial cervical spine endplates between Chinese and White men and women is different in most of the linear and area parameters. This information could provide guidelines for the design of CDA implants and the improvement of surgical techniques.
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Herrero, Carlos Fernando P. S., Sergio Britto Garcia, Luis Vicente Garcia i Helton Luiz Aparecido Defino. "Endplates Changes Related to Age and Vertebral Segment". BioMed Research International 2014 (2014): 1–6. http://dx.doi.org/10.1155/2014/545017.
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Endplate separations are defined as the presence of a space between the hyaline cartilage and the cortical bone of the adjacent vertebral body. This study evaluates endplate separations from the vertebral body and intervertebral discs and verifies if endplate separation is related to age and the spinal level. Groups were formed based on age (20–40 and 41–85 years old) and the vertebral segment (T7-T8 and L4-L5 segments). Histological analysis included assessment of the length of the vertebral endplates, the number and dimensions of the separations, and orientation of the collagen fibers, in the mid-sagittal slice. Two indexes were created: the separation index (number of separations/vertebral length) and separation extension index (sum of all separations/vertebral length). The results of the study demonstrated a direct relationship between the density of separations in the endplate and two variables: age and spinal level.
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Chen, Shiming, Junming Jiang i Liangjiu Jia. "Numerical study on the performance of beam-to-concrete-filled steel tube column joint with adapter-bracket". Advances in Structural Engineering 21, nr 10 (27.12.2017): 1542–52. http://dx.doi.org/10.1177/1369433217746345.
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An innovative beam-to-column composite joint with adapter-bracket was proposed and its behavior was investigated through finite element analysis. The special adapter-bracket is to facilitate the assembly of the steel box beam and the concrete-filled steel tube column through high-strength blind bolts. In the adapter-bracket, two endplates are welded to the beam and bolted to the column, respectively. First, two finite element models of the bolted extended endplate joint were developed in ABAQUS and validated by available experimental results. Then, based on modified models, parametric analyses were conducted to evaluate the novel joint performance, in terms of the initial stiffness, rotation capacity, moment capacity, failure mode, and joint classification. The variables included flange thickness, endplate thickness, and bolt size. Results demonstrated that the joint behavior was significantly affected by the flange thickness, the endplate-A thickness, and bolt size while slightly influenced by the endplate-B thickness. Additionally, these joints had favorable rotation and moment capacity.
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Jensen, T. S., J. S. Sorensen i P. Kjaer. "Intra- and interobserver reproducibility of vertebral endplate signal (Modic) changes in the lumbar spine: the nordic modic consensus group classification". Acta Radiologica 48, nr 7 (wrzesień 2007): 748–54. http://dx.doi.org/10.1080/02841850701422112.
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Background: The lumbar vertebral endplate is considered a potential cause of specific low back pain. However, in relation to future research, there is need for a reliable and detailed magnetic resonance imaging (MRI) protocol to be used in the evaluation of vertebral endplate signal changes. Purpose: To assess the intra- and interobserver reliability of the “Nordic Modic classification” protocol. Material and Methods: MRI scans of 50 individuals representative of the general Danish population aged 40 were evaluated by two observers. Criteria for grading the changes were developed by the Nordic Modic Consensus Group. After consensus was established, all 50 MRI examinations were evaluated independently by each observer. Intraobserver reliability was assessed by re-evaluation of the 50 examinations by one of the observers. Kappa statistics were used to calculate agreement. Results: Intra- and interobserver agreement of the evaluation of variables describing vertebral signal changes, i.e. Modic type, location, volume, maximum height, and endplate area, were all found to have substantial to almost perfect agreement. The evaluation of osteophytes was found to be reliable, whereas the evaluation of localized endplate defects and irregular endplates had only moderate agreement. The evaluation of development over time was found to have substantial intraobserver agreement but only moderate interobserver agreement. As expected, intraobserver agreement was generally better than interobserver agreement. Conclusion: In this study, we found convincing reproducibility of a detailed evaluation protocol of vertebral endplate signal changes, the “Nordic Modic Classification.” The authors recommend that the evaluation protocol should be used in future studies investigating vertebral endplate signal changes.
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Desaulniers, Patrice, Pierre-André Lavoie i Phillip F. Gardiner. "Habitual exercise enhances neuromuscular transmission efficacy of rat soleus muscle in situ". Journal of Applied Physiology 90, nr 3 (1.03.2001): 1041–48. http://dx.doi.org/10.1152/jappl.2001.90.3.1041.
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Rat motor nerve terminals and the endplates they interact with exhibit changes to varying patterns of use, as when exposed to increased activation in the form of endurance exercise training. The extent to which these changes affect neuromuscular transmission efficacy is uncertain. In this study, the effects of habitual exercise on the electrophysiological properties of neuromuscular transmission in rat soleus muscle were investigated using a novel in situ approach. Consistent with previous reports, miniature endplate potential frequency was enhanced by habitual exercise. Other passive properties, such as resting membrane potential, miniature endplate potential amplitude, and “giant” miniature endplate potential characteristics were unaltered by the training program. Full-size endplate potentials were obtained by blocking soleus muscle action potentials with μ-conotoxin GIIIb. Quantal content values were 91.5 and 119.9 for control and active groups, respectively ( P < 0.01). We also measured the rate and extent of endplate potential amplitude rundown during 3-s trains of continuous stimulation at 25, 50, and 75 Hz; at 50 and 75 Hz, we found both the rate and extent of rundown to be significantly attenuated (10–20%) in a specific population of cells from active rats ( P < 0.05). The results establish the degree of activity-dependent plasticity as it pertains to neuromuscular transmission in a mammalian slow-twitch muscle.
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Fung, K., N. D. Hogikyan, S. B. Heavner, D. Ekbom i E. L. Feldman. "Development and characterisation of an experimental recurrent laryngeal nerve injury model for the study of viral gene therapy". Journal of Laryngology & Otology 122, nr 5 (25.06.2007): 500–505. http://dx.doi.org/10.1017/s0022215107009097.
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AbstractObjectives:To develop and characterise an experimental model of recurrent laryngeal nerve injury for the study of viral gene therapy.Methods:Twenty rats underwent unilateral recurrent laryngeal nerve injury. After vocal fold mobility was observed, larynges were serially sectioned, and immunohistochemical techniques were employed to stain for neurofilament and motor endplates in order for a blinded investigator to determine the percentage of nerve–endplate contact, as a histological indicator of an intact neuromuscular connection.Results:All animal procedures resulted in complete, ipsilateral vocal fold paralysis that recovered by three weeks. The mean nerve–endplate contact percentage was 11.6 per cent at one week, 53.9 per cent at two weeks, 88.6 per cent at three weeks, 81.7 per cent at four weeks and 86.6 per cent at five weeks. The differences between results at week one and week three were statistically significant (p < 0.01). The mean nerve–endplate contact percentage on the control side was 86.8 per cent.Conclusions:There was a dramatic, measurable decrease in nerve–endplate contact percentage following crush injury to the recurrent laryngeal nerve. Spontaneous recovery was observed by three weeks post-injury. This model will be used to investigate the potential therapeutic role of viral gene therapy for the treatment of recurrent laryngeal nerve injury.
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Simons, David G. "Do Endplate Noise and Spikes Arise from Normal Motor Endplates?" American Journal of Physical Medicine & Rehabilitation 80, nr 2 (luty 2001): 134–40. http://dx.doi.org/10.1097/00002060-200102000-00012.
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Yoganandan, N., S. Kumaresan, L. Voo i F. A. Pintar. "Finite Element Model of the Human Lower Cervical Spine: Parametric Analysis of the C4-C6 Unit". Journal of Biomechanical Engineering 119, nr 1 (1.02.1997): 87–92. http://dx.doi.org/10.1115/1.2796070.
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In this study, a three-dimensional finite element model of the human lower cervical spine (C4-C6) was constructed. The mathematical model was based on close-up CT scans from a young human cadaver. Cortical shell, cancellous core, endplates, and posterior elements including the lateral masses, pedicle, lamina, and transverse and spinous processes, and the intervertebral disks, were simulated. Using the material properties from literature, the 10,371-element model was exercised under an axial compressive mode of loading. The finite element model response agreed with literature. As a logical step, a parametric study was conducted by evaluating the biomechanical response secondary to changes in the elastic moduli of the intervertebral disk and the endplates. In the stress analysis, the minimum principal compressive stress was used for the cancellous core of the vertebral body and von Mises stress was used for the endplate component. The model output indicated that an increase in the elastic modulii of the disk resulted in an increase in the endplate stresses at all the three spinal levels. In addition, the inferior endplate of the middle vertebral body responded with the highest mean compressive stress followed by its superior counterpart. Furthermore, the middle vertebral body produced the highest compressive stresses compared to its counterparts. These findings appear to correlate with experimental results as well as common clinical experience wherein cervical fractures are induced due to external compressive forces. As a first step, this model will lead to more advanced simulations as additional data become available.
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Niiya, Tomohisa, Eichi Narimatsu i Akiyoshi Namiki. "Acute Late Sepsis Attenuates Effects of a Nondepolarizing Neuromuscular Blocker, Rocuronium, by Facilitation of Endplate Potential and Enhancement of Membrane Excitability In Vitro". Anesthesiology 105, nr 5 (1.11.2006): 968–75. http://dx.doi.org/10.1097/00000542-200611000-00018.
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Background Sepsis attenuates the muscle-relaxing effects of nondepolarizing neuromuscular blockers. The authors investigated the effects of acute late sepsis on neuromuscular transmission and neuromuscular actions of rocuronium to clarify the mechanisms by which sepsis attenuates the effects of nondepolarizing neuromuscular blockers. Methods Sepsis was induced by cecal ligation and puncture operation. Endplate potentials, acetylcholine potentials, and electrotonic potentials were recorded from the motor endplates of isolated diaphragms from acute late septic and nonseptic rats. Results (1) Sepsis did not influence the effect of rocuronium to decrease endplate potential amplitude, which was increased by sepsis itself; (2) sepsis facilitated the effect of rocuronium to decrease quantal acetylcholine release, which was increased by sepsis itself; (3) sepsis did not influence the effect of rocuronium to decrease acetylcholine sensitivity, which was decreased by sepsis itself; (4) sepsis decreased critical depolarization, and rocuronium did not influence critical depolarization. Conclusions These results indicate that acute late sepsis facilitates endplate potentials and enhances excitability of the muscle membrane, indicated by a decrease of critical depolarization. It is thought that these elicit the sepsis-induced attenuation of the muscle-relaxing effects of rocuronium.
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Zhou, Yuan-Li, Tian-Xia Qiu, Qing-Hang Zhang i Ee-Chon Teo. "THE RELATIONSHIP BETWEEN LOAD TRANSMISSION AND DISC DEGENERATION IN THE THORACOLUMBAR SPINE: A FINITE ELEMENT STUDY". Journal of Musculoskeletal Research 10, nr 03 (wrzesień 2006): 121–30. http://dx.doi.org/10.1142/s0218957706001789.
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Degenerative changes to the intervertebral disc structure appear gradually in the aging process, and are likely to affect the fracture patterns of the thoracolumbar vertebral body — a common site of spinal injuries — by changing the mechanical interaction within each motion segment. This study focused on the influence of disc degeneration on the mechanism of load transmission through the thoracolumbar vertebral body. Compressive stresses and ways of load transmission were examined in cases of normal and degenerated discs. The stress analysis was performed using the finite element (FE) method. For normal discs, the highest compressive stresses were found in the central region of the discs, corresponding to the anatomical nucleus. Such high stress made the endplates bulge towards the vertebral bodies. Hence, the fracture would most probably start in the center of the endplate. For degenerated discs, the peak stresses rose to high levels in the annuli. Thus, the annulus was mostly under compression, and so was the periphery of the endplate, with much less deflection at its center. The failure of the vertebra was due to the fracture of the periphery of the endplate. Ways of load transmission through the vertebral body were strongly affected by the disc condition.
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Wegner, Adam M., Yu-Hsuan Chou, Hsiao-Kang Chang i Tsung-Cheng Yin. "Transforaminal Interbody Impaction of Bone Graft to Treat Collapsed Nonhealed Vertebral Fractures with Endplate Destruction: A Report of Two Cases". Case Reports in Orthopedics 2020 (2.09.2020): 1–6. http://dx.doi.org/10.1155/2020/8873350.
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Background. A collapsed nonhealed vertebral fracture with endplate destruction is a challenging injury to address, as there is no single definitive treatment. We present two cases using an innovative transforaminal grafting technique to treat these patients. Case Presentation. Case 1: a 72-year-old woman had nonunion of an L1 compression fracture with destruction of both endplates. T12/L1 and L1/L2 transforaminal debridement and impaction of bone graft were performed followed by posterior instrumentation. At three years follow-up, the fusion mass between T12/L1 and L1/L2 was solid and the patient had minimal pain. Case 2: a 62-year-old woman had nonunion of an L1 burst fracture with destruction of the lower endplate. Hemilaminectomy and transforaminal interbody impaction of bone graft was performed. At three years follow-up, the patient had no back pain and a solid fusion. In both cases, local kyphosis was corrected and fusion obtained. Conclusions. Collapsed nonhealed vertebral body fractures combined with endplate destruction can be successfully treated with a one-step posterior surgery consisting of transforaminal debridement and impaction of bone graft in combination with posterior pedicle instrumentation.
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Antosh, Ivan J., John G. DeVine, Clyde T. Carpenter, Brian J. Woebkenberg i Stephen M. Yoest. "Magnetic resonance imaging evaluation of adjacent segments after cervical disc arthroplasty: magnet strength and its effect on image quality". Journal of Neurosurgery: Spine 13, nr 6 (grudzień 2010): 722–26. http://dx.doi.org/10.3171/2010.5.spine09721.
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Object Disc arthroplasty is an alternative to fusion following anterior discectomy when treating either cervical radiculopathy or myelopathy. Its theoretical benefits include preservation of the motion segment and the potential prevention of adjacent-segment degeneration. There is a paucity of data regarding the ability to use MR imaging to evaluate the adjacent segments. The purpose of this study was for the authors to introduce open MR imaging as an alternative method in imaging adjacent segments following cervical disc arthroplasty using a Co-Cr implant and to report their preliminary results using this technique. Methods Postoperative cervical MR images were obtained in the first 16 patients in whom the porous coated motion (PCM-V) cervical arthroplasty system was used to treat a single level between C-3 and C-7. Imaging was performed in all 16 patients with a closed 1.5-T unit, and in the final 6 patients it was also performed with an open 0.2-T unit. All images were evaluated by an independent radiologist observer for the ability to visualize the superior endplate, disc space, and inferior endplate at the superior and inferior adjacent levels. Results Utilizing the 1.5-T magnet to assess the superior adjacent level, the superior endplate, disc space, and inferior endplate could each be visualized less than 50% of the time on sagittal T1- and sagittal and axial T2-weighted images. Similarly, the inferior adjacent level structures were adequately visualized less than 50% of the time, with the exception of slightly improved visualization of the inferior endplate on T1-weighted images (56%). Axial images allowed worse visualization than sagittal images at both the superior and inferior adjacent levels. Utilizing the 0.2-T magnet to assess the superior and inferior adjacent levels, the superior endplate, disc space, and inferior endplate were adequately visualized in 100% of images. Conclusions Based on the results of this case series, it appears that the strength of the magnet affects the artifact from the Co-Cr endplates. The open 0.2-T MR imaging unit reduces artifact at adjacent levels after cervical disc arthroplasty without a significant reduction in the image quality. Magnetic resonance imaging can be used to evaluate the adjacent segments after disc arthroplasty if magnet strength is addressed, providing another means to assess the long-term efficacy of this novel treatment.
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Oshina, Masahito, Yasushi Oshima, Sakae Tanaka i K. Daniel Riew. "Radiological Fusion Criteria of Postoperative Anterior Cervical Discectomy and Fusion: A Systematic Review". Global Spine Journal 8, nr 7 (11.02.2018): 739–50. http://dx.doi.org/10.1177/2192568218755141.
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Study Design: Systematic review. Objectives: Diagnosis of pseudarthrosis after anterior cervical fusion is difficult, and often depends on the surgeon’s subjective assessment because recommended radiographic criteria are lacking. This review evaluated the available evidence for confirming fusion after anterior cervical surgery. Methods: Articles describing assessment of anterior cervical fusion were retrieved from MEDLINE and SCOPUS. The assessment methods and fusion rates at 1 and 2 years were evaluated to identify reliable radiographical criteria. Results: Ten fusion criteria were described. The 4 most common were presence of bridging trabecular bone between the endplates, absence of a radiolucent gap between the graft and endplate, absence of or minimal motion between adjacent vertebral bodies on flexion-extension radiographs, and absence of or minimal motion between the spinous processes on flexion-extension radiographs. The mean fusion rates were 90.2% at 1 year and 94.7% at 2 years. The fusion rate at 2 years had significant independence ( P = .048). Conclusions: The most common fusion criteria, bridging trabecular bone between the endplates and absence of a radiolucent gap between the graft and endplate, are subjective. We recommend using <1 mm of motion between spinous processes on extension and flexion to confirm fusion.
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Malham, Gregory M., Rhiannon M. Parker, Carl M. Blecher i Kevin A. Seex. "Assessment and classification of subsidence after lateral interbody fusion using serial computed tomography". Journal of Neurosurgery: Spine 23, nr 5 (listopad 2015): 589–97. http://dx.doi.org/10.3171/2015.1.spine14566.
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OBJECT Intervertebral cage settling during bone remodeling after lumbar lateral interbody fusion (LIF) is a common occurrence during the normal healing process. Progression of this settling with endplate collapse is defined as subsidence. The purposes of this study were to 1) assess the rate of subsidence after minimally invasive (MIS) LIF by CT, 2) distinguish between early cage subsidence (ECS) and delayed cage subsidence (DCS), 3) propose a descriptive method for classifying the types of subsidence, and 4) discuss techniques for mitigating the risk of subsidence after MIS LIF. METHODS A total of 128 consecutive patients (with 178 treated levels in total) underwent MIS LIF performed by a single surgeon. The subsidence was deemed to be ECS if it was evident on postoperative Day 2 CT images and was therefore the result of an intraoperative vertebral endplate injury and deemed DCS if it was detected on subsequent CT scans (≥ 6 months postoperatively). Endplate breaches were categorized as caudal (superior endplate) and/or cranial (inferior endplate), and as ipsilateral, contralateral, or bilateral with respect to the side of cage insertion. Subsidence seen in CT images (radiographic subsidence) was measured from the vertebral endplate to the caudal or cranial margin of the cage (in millimeters). Patient-reported outcome measures included visual analog scale, Oswestry Disability Index, and 36-Item Short Form Health Survey physical and mental component summary scores. RESULTS Four patients had ECS in a total of 4 levels. The radiographic subsidence (DCS) rates were 10% (13 of 128 patients) and 8% (14 of 178 levels), with 3% of patients (4 of 128) exhibiting clinical subsidence. In the DCS levels, 3 types of subsidence were evident on coronal and sagittal CT scans: Type 1, caudal contralateral, in 14% (2 of 14), Type 2, caudal bilateral with anterior cage tilt, in 64% (9 of 14), and Type 3, both endplates bilaterally, in 21% (3 of 14). The mean subsidence in the DCS levels was 3.2 mm. There was no significant difference between the numbers of patients in the subsidence (DCS) and no-subsidence groups who received clinical benefit from the surgical procedure, based on the minimum clinically important difference (p > 0.05). There was a significant difference between the fusion rates at 6 months (p = 0.0195); however, by 12 months, the difference was not significant (p = 0.2049). CONCLUSIONS The authors distinguished between ECS and DCS. Radiographic subsidence (DCS) was categorized using descriptors for the location and severity of the subsidence. Neither interbody fusion rates nor clinical outcomes were affected by radiographic subsidence. To protect patients from subsidence after MIS LIF, the surgeon needs to take care with the caudal endplate during cage insertion. If a caudal bilateral (Type 2) endplate breach is detected, supplemental posterior fixation to arrest progression and facilitate fusion is recommended.
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Agarwal, Nitin, Michael D. White, Xiaoran Zhang, Nima Alan, Alp Ozpinar, David J. Salvetti, Zachary J. Tempel, David O. Okonkwo, Adam S. Kanter i D. Kojo Hamilton. "Impact of endplate-implant area mismatch on rates and grades of subsidence following stand-alone lateral lumbar interbody fusion: an analysis of 623 levels". Journal of Neurosurgery: Spine 33, nr 1 (lipiec 2020): 12–16. http://dx.doi.org/10.3171/2020.1.spine19776.
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OBJECTIVEStand-alone lateral lumbar interbody fusion (LLIF) is a useful minimally invasive approach for select spinal disorders, but implant subsidence may occur in up to 30% of patients. Previous studies have suggested that wider implants reduce the subsidence rate. This study aimed to evaluate whether a mismatch of the endplate and implant area can predict the rate and grade of implant subsidence.METHODSThe authors conducted a retrospective review of prospectively collected data on consecutive patients who underwent stand-alone LLIF between July 2008 and June 2015; 297 patients (623 surgical levels) met inclusion criteria. Imaging studies were examined to grade graft subsidence according to Marchi criteria. Thirty patients had radiographic evidence of implant subsidence. The endplates above and below the implant were measured.RESULTSA total of 30 patients with implant subsidence were identified. Of these patients, 6 had Marchi grade 0, 4 had grade I, 12 had grade II, and 8 had grade III implant subsidence. There was no statistically significant correlation between the endplate-implant area mismatch and subsidence grade or incidence. There was also no correlation between endplate-implant width and length mismatch and subsidence grade or incidence. However, there was a strong correlation between the usage of the 18-mm-wide implants and the development of higher-grade subsidence (p = 0.002) necessitating surgery. There was no significant association between the degree of mismatch or Marchi subsidence grade and the presence of postoperative radiculopathy. Of the 8 patients with 18-mm implants demonstrating radiographic subsidence, 5 (62.5%) required reoperation. Of the 22 patients with 22-mm implants demonstrating radiographic subsidence, 13 (59.1%) required reoperation.CONCLUSIONSThere was no correlation between endplate-implant area, width, or length mismatch and Marchi subsidence grade for stand-alone LLIF. There was also no correlation between either endplate-implant mismatch or Marchi subsidence grade and postoperative radiculopathy. The data do suggest that the use of 18-mm-wide implants in stand-alone LLIF may increase the risk of developing high-grade subsidence necessitating reoperation compared to the use of 22-mm-wide implants.
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Hong, Chang-Zern. "Myofascial Trigger Points: Pathophysiology and Correlation with Acupuncture Points". Acupuncture in Medicine 18, nr 1 (czerwiec 2000): 41–47. http://dx.doi.org/10.1136/aim.18.1.41.
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A review is made of recent studies on myofascial trigger points (MTrP) and their mechanism is discussed. Clinical and basic science studies have shown that there are multiple MTrP loci in a MTrP region. A MTrP locus contains a sensory component (sensitive locus) and a motor component (active locus). A sensitive locus is a point from which tenderness or pain, referred pain, and local twitch response can be elicited by mechanical stimulation. Sensitive loci (probably sensitised nociceptors) are widely distributed in the whole muscle, but are concentrated in the endplate zone. An active locus is a site from which spontaneous electrical activity can be recorded. Active loci appear to be dysfunctional endplates since spontaneous electrical activity is essentially the same as the electrical activity reported by neurophysiologists as that recorded from an abnormal endplate. A MTrP is always found in a taut band which is histologically related to contraction knots caused by excessive release of acetylcholine in abnormal endplates. Both referred pain and local twitch response are mediated through spinal cord mechanisms, as demonstrated in both human and animal studies. The pathogenesis of MTrPs appears to be related to integration in the spinal cord of response to the disturbance of nerve endings and abnormal contractile mechanism at multiple dysfunctional endplates. There are many similarities between MTrPs and acupuncture points including their location and distribution, pain and referred pain patterns, local twitch responses (de qi), and possible spinal cord mechanism.
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Caldwell, J. H., D. T. Campbell i K. G. Beam. "Na channel distribution in vertebrate skeletal muscle." Journal of General Physiology 87, nr 6 (1.06.1986): 907–32. http://dx.doi.org/10.1085/jgp.87.6.907.
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The loose patch voltage clamp has been used to map Na current density along the length of snake and rat skeletal muscle fibers. Na currents have been recorded from (a) endplate membrane exposed by removal of the nerve terminal, (b) membrane near the endplate, (c) extrajunctional membrane far from both the endplate and the tendon, and (d) membrane near the tendon. Na current densities recorded directly on the endplate were extremely high, exceeding 400 mA/cm2 in some patches. The membrane adjacent to the endplate has a current density about fivefold lower than that of the endplate, but about fivefold higher than the membrane 100-200 micron from the endplate. Small local variations in Na current density are recorded in extrajunctional membrane. A sharp decrease in Na current density occurs over the last few hundred micrometers from the tendon. We tested the ability of tetrodotoxin to block Na current in regions close to and far from the endplate and found no evidence for toxin-resistant channels in either region. There was also no obvious difference in the kinetics of Na current in the two regions. On the basis of the Na current densities measured with the loose patch clamp, we conclude that Na channels are abundant in the endplate and near-endplate membrane and are sparse close to the tendon. The current density at the endplate is two to three orders of magnitude higher than at the tendon.
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Lateva, Zoia C., Kevin C. McGill i M. Elise Johanson. "The innervation and organization of motor units in a series-fibered human muscle: the brachioradialis". Journal of Applied Physiology 108, nr 6 (czerwiec 2010): 1530–41. http://dx.doi.org/10.1152/japplphysiol.01163.2009.
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We studied the innervation and organization of motor units in the brachioradialis muscle of 25 normal human subjects. We recorded intramuscular EMG signals at points separated by 15 mm along the proximodistal muscle axis during moderate isometric contractions, identified from 27 to 61 (mean 39) individual motor units per subject using EMG decomposition, and estimated the locations of the endplates and distal muscle/tendon junctions from the motor-unit action potential (MUAP) propagation patterns and terminal standing waves. In three subjects all the motor units were innervated in a single endplate zone. In the other 22 subjects, the motor units were innervated in 3–6 (mean 4) distinct endplate zones separated by 15–55 mm along the proximodistal axis. One-third of the motor units had fibers innervated in more than one zone. The more distally innervated motor units had distinct terminal waves indicating tendonous termination, while the more proximal motor units lacked terminal waves, indicating intrafascicular termination. Analysis of blocked MUAP components revealed that 19% of the motor units had at least one doubly innervated fiber, i.e., a fiber innervated in two different endplate zones by two different motoneurons, and thus belonging to two different motor units. These results are consistent with the brachioradialis muscle having a series-fibered architecture consisting of multiple, overlapping bands of muscle fibers in most individuals and a simple parallel-fibered architecture in some individuals.
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Qiang, Xuhong, Nianduo Wu, Xu Jiang, Frans Bijlaard i Henk Kolstein. "Performance assessment on high strength steel endplate connections after fire". Journal of Structural Fire Engineering 8, nr 2 (12.06.2017): 202–14. http://dx.doi.org/10.1108/jsfe-11-2016-0018.
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Purpose This study aims to reveal more information and understanding on performance and failure mechanisms of high strength steel endplate connections after fire. Design/methodology/approach An experimental and numerical study on seven endplate connections after cooling down from fire temperature of 550°C has been carried out and reported herein. Moreover, the provisions of European design standard for steel structures, Eurocode 3, were validated with test results of high strength steel endplate connections. Findings In endplate connections, a proper design using a thinner high strength steel endplate can achieve the same failure mode, similar residual load bearing capacity and comparable or even higher rotation capacity after cooling down from fire. It is found that high strength steel endplate connection can regain more than 90 per cent of its original load bearing capacity after cooling down from fire temperature of 550°C. Originality/value The post-fire performance of high strength steel endplate connection has been reported. The accuracy of Eurocode 3 for endplate connections is validated against test results.
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Qiang, Xuhong, Xu Jiang, Frans Bijlaard i Henk Kolstein. "Performance assessment on high strength steel endplate connections in fire". Journal of Structural Fire Engineering 7, nr 2 (13.06.2016): 168–78. http://dx.doi.org/10.1108/jsfe-06-2016-013.
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Purpose This paper aims to investigate and assess a perspective of combining high-strength-steel endplate with mild-steel beam and column in endplate connections. Design/methodology/approach First, experimental tests on high strength steel endplate connections were conducted at fire temperature 550°C and at an ambient temperature for reference. Findings The moment-rotation characteristic, rotation capacity and failure mode of high-strength-steel endplate connections in fire and at an ambient temperature were obtained through tests and compared with those of mild-steel endplate connections. Further, the provisions of Eurocode 3 were validated with test results. Moreover, the numerical study was carried out via ABAQUS and verified against the experimental results. Originality/value It is found that a thinner high-strength-steel endplate can enhance the connection’s rotation capacity both at an ambient temperature and in fire (which guarantees the safety of an entire structure) and simultaneously achieve almost the same moment resistance with a mild steel endplate connection.
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Barrantes, Francisco J. "Muscle endplate cholinoreceptors". Pharmacology & Therapeutics 38, nr 3 (styczeń 1988): 331–85. http://dx.doi.org/10.1016/0163-7258(88)90010-1.
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Zhang, Zhiming, Yapeng Shang i Tong Zhang. "An equivalent mechanical model investigating endplates deflection for PEM fuel cell stack". Advances in Mechanical Engineering 13, nr 7 (lipiec 2021): 168781402110300. http://dx.doi.org/10.1177/16878140211030039.
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The aim of this study is to obtain the deflection curve equations of endplates with one to five clamping belts which allows investigating endplates deflection for uniform contact pressure distribution. Based on an equivalent mechanical model for a large fuel cell stack, the effects of the thicknesses of endplates, numbers, and positions of clamping belts are discussed, and the optimal thickness of endplate with different clamping belts is obtained, and moreover the optimal position of intermediate and outer clamping belts on the endplates. Finally, a three-dimensional finite element analysis (FEA) of a fuel cell stack clamping with steel belts and nonlinear contact elements is compared to what the equivalent mechanical beam model predicts. The result of this study shows that the equivalent mechanical model gives good prediction accuracy for the deflection behavior of endplates and the clamping force of the fuel cell stack, which is effective and helpful for the design of a large fuel cell stack assembly.
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Chen, Ke, Xiaohua Lv, Wei Li, Fei Yu, Jianjing Lin, Junxuan Ma i Deming Xiao. "Autophagy Is a Protective Response to the Oxidative Damage to Endplate Chondrocytes in Intervertebral Disc: Implications for the Treatment of Degenerative Lumbar Disc". Oxidative Medicine and Cellular Longevity 2017 (2017): 1–9. http://dx.doi.org/10.1155/2017/4041768.
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Low back pain (LBP) is the leading cause of disability in the elderly. Intervertebral disc degeneration (IDD) was considered as the main cause for LBP. Degeneration of cartilaginous endplate was a crucial harmful factor during the initiation and development of IDD. Oxidative stress was implicated in IDD. However, the underlying molecular mechanism for the degeneration of cartilaginous endplate remains elusive. Herein, we found that oxidative stress could induce apoptosis and autophagy in endplate chondrocytes evidenced by western blot analysis, flow cytometry, immunofluorescence staining, GFP-LC3B transfection, and MDC staining. In addition, we also found that the apoptosis of endplate chondrocytes was significantly increased after the inhibition of autophagy by bafilomycin A1 shown by flow cytometry. Furthermore, mTOR pathway upstream autophagy was greatly suppressed suggested by western blot assay. In conclusion, our study strongly revealed that oxidative stress could increase autophagy and apoptosis of endplate chondrocytes in intervertebral disc. The increase of autophagy activity could prevent endplate chondrocytes from apoptosis. The autophagy in endplate chondrocytes induced by oxidative stress was mTOR dependent. These findings might shed some new lights on the mechanism for IDD and provide new strategies for the treatments of IDD.
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Covault, J., J. M. Cunningham i J. R. Sanes. "Neurite outgrowth on cryostat sections of innervated and denervated skeletal muscle." Journal of Cell Biology 105, nr 6 (1.12.1987): 2479–88. http://dx.doi.org/10.1083/jcb.105.6.2479.
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To localize factors that guide axons reinnervating skeletal muscle, we cultured ciliary ganglion neurons on cryostat sections of innervated and denervated adult muscle. Neurons extended neurites on sections of muscle (and several other tissues), generally in close apposition to sectioned cell surfaces. Average neurite length was greater on sections of denervated than on sections of innervated muscle, supporting the existence of functionally important differences between innervated and denervated muscle fiber surfaces. Furthermore, outgrowth was greater on sections of denervated muscle cut from endplate-rich regions than on sections from endplate-free regions, suggesting that a neurite outgrowth-promoting factor is concentrated near synapses. Finally, 80% of the neurites that contacted original synaptic sites (which are known to be preferentially reinnervated by regenerating axons in vivo) terminated precisely at those contacts, thereby demonstrating a specific response to components concentrated at endplates. Together, these results support the hypothesis that denervated muscles use cell surface (membrane and matrix) molecules to inform regenerating axons of their state of innervation and proximity to synaptic sites.
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Pekmezci, Murat, Jessica A. Tang, Liu Cheng, Ashin Modak, R. Trigg McClellan, Jenni M. Buckley i Christopher P. Ames. "Comparison of expandable and fixed interbody cages in a human cadaver corpectomy model, Part I: endplate force characteristics". Journal of Neurosurgery: Spine 17, nr 4 (październik 2012): 321–26. http://dx.doi.org/10.3171/2012.7.spine12171.
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Object Expandable cages are becoming more popular due in large part to their versatility, but subsidence and catastrophic failure remain a concern. One of the proposed reasons of failure is edge loading of the endplate caused by a mismatch between the sagittal alignment of the motion segment and cage. This in vitro analysis investigates the endplate forces characteristic of expandable and fixed interbody cages in a single-level human cadaver corpectomy model. Methods Ten human thoracolumbar spines (T10–L2, L3–5) were biomechanically evaluated following a single-level corpectomy that was reconstructed with an expandable or fixed cage. Fixed cages were deployed with the best-fitting end cap combination, whereas expandable cages were deployed in normal, hypolordotic, and hyperlordotic alignment scenarios. The endplate forces and contact area were measured with a pressure measurement system, and the expansion torque applied by the surgeon was measured with a custom-made insertion device. Results The contact areas of the expandable cages were, in general, higher than those of the fixed cages. The endplate forces of the expandable cages were similar to those of the fixed cages in the normal alignment scenario. Higher endplate forces were observed in the hyperlordotic scenario, whereas the endplate forces in the hypolordotic and normal alignment scenarios were similar. There was no correlation with the expansion torque and the final endplate forces. Conclusions Expandable cages resulted in consistently higher contact area and endplate forces when compared with the fixed cages. Because the expansion torque does not correlate with the final endplate forces, surgeons should not rely solely on tactile feedback during deployment of these cages.
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Gray, William P., Catherine Keohane i William O. Kirwan. "Motor nerve transplantation". Neurosurgical Focus 7, nr 3 (wrzesień 1999): E7. http://dx.doi.org/10.3171/foc.1999.7.3.8.
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The motor nerve transplantation (MNT) technique is used to transfer an intact nerve into a denervated muscle by harvesting a neurovascular pedicle of muscle containing motor endplates from the motor endplate zone of a donor muscle and implanting it into a denervated muscle. Thirty-six adult New Zealand White rabbits underwent reinnervation of the left long peroneal (LP) muscle (fast twitch) with a motor nerve graft from the soleus muscle (slow twitch). The right LP muscle served as a control. Reinnervation was assessed using microstimulatory single-fiber electromyography (SFEMG), alterations in muscle fiber typing and grouping, and isometric response curves. Neurofilament antibody was used for axon staining. The neurofilament studies provided direct evidence of nerve growth from the motor nerve graft into the adjacent denervated muscle. Median motor endplate jitter was 13 μsec preoperatively, and 26 μsec at 2 months, 29.5 μsec at 4 months, and 14 μsec at 6 months postoperatively (p < 0.001). Isometric tetanic tension studies showed a progressive functional recovery in the reinnervated muscle over 6 months. There was no histological evidence of aberrant reinnervation from any source outside the nerve pedicle. Isometric twitch responses and adenosine triphosphatase studies confirmed the conversion of the reinnervated LP muscle to a slow-type muscle. Acetylcholinesterase studies confirmed the presence of functioning motor endplates beneath the insertion of the motor nerve graft. It is concluded that the MNT technique achieves motor reinnervation by growth of new nerve fibers across the pedicle graft into the recipient muscle.
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Gray, William P., Catherine Keohane i William O. Kirwan. "Motor nerve transplantation". Journal of Neurosurgery 87, nr 4 (październik 1997): 615–24. http://dx.doi.org/10.3171/jns.1997.87.4.0615.
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✓ The motor nerve transplantation (MNT) technique is used to transfer an intact nerve into a denervated muscle by harvesting a neurovascular pedicle of muscle containing motor endplates from the motor endplate zone of a donor muscle and implanting it into a denervated muscle. Thirty-six adult New Zealand White rabbits underwent reinnervation of the left long peroneal (LP) muscle (fast twitch) with a motor nerve graft from the soleus muscle (slow twitch). The right LP muscle served as a control. Reinnervation was assessed using microstimulatory single-fiber electromyography (SFEMG), alterations in muscle fiber typing and grouping, and isometric response curves. Neurofilament antibody was used for axon staining. The neurofilament studies provided direct evidence of nerve growth from the motor nerve graft into the adjacent denervated muscle. Median motor endplate jitter was 13 µsec preoperatively, and 26 µsec at 2 months, 29.5 µsec at 4 months, and 14 µsec at 6 months postoperatively (p < 0.001). Isometric tetanic tension studies showed a progressive functional recovery in the reinnervated muscle over 6 months. There was no histological evidence of aberrant reinnervation from any source outside the nerve pedicle. Isometric twitch responses and adenosine triphosphatase studies confirmed the conversion of the reinnervated LP muscle to a slow-type muscle. Acetylcholinesterase studies confirmed the presence of functioning motor endplates beneath the insertion of the motor nerve graft. It is concluded that the MNT technique achieves motor reinnervation by growth of new nerve fibers across the pedicle graft into the recipient muscle.
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Chen, Jingming, Themba Nyirenda, Liancai Mu i Stanislaw Sobotka. "Intraoperative 1-Hour Electrical Nerve Stimulation Enhances Outcomes of Nerve–Muscle-Endplate Band Grafting Technique for Muscle Reinnervation". Journal of Reconstructive Microsurgery 33, nr 08 (2.06.2017): 533–43. http://dx.doi.org/10.1055/s-0037-1602824.
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Background Increasing evidence suggests that 1-hour electrical nerve stimulation during surgery improves nerve regeneration and functional recovery. However, it remains unknown if this approach has beneficial effects on the outcomes of our recently developed nerve–muscle-endplate band grafting-native motor zone (NMEG-NMZ) technique for muscle reinnervation. Methods In this study, NMEG-NMZ transplantation was performed in a rat model. The right sternomastoid muscle was experimentally denervated and immediately reinnervated by implanting a NMEG harvested from the ipsilateral sternohyoid (SH) muscle into the NMZ of the target muscle. Before implantation of the NMEG, the SH nerve branch innervating the NMEG was subjected to intraoperative 1-hour continuous electrical stimulation (20 Hz). Three months after surgery, the degree of functional recovery was evaluated with muscle force measurement and the extent of nerve regeneration and endplate reinnervation was examined using histological and immunohistochemical methods. Results A combination of NMEG-NMZ with electrical nerve stimulation resulted in a greater degree of functional recovery than the NMEG-NMZ alone. The mean muscle force of the treated muscles was 90% of the contralateral control. The muscle mass was recovered up to 90% of the control. The mean number and percentage of area of the regenerated axons in the treated muscles was computed to be 81 and 84% of the control muscles, respectively. On average, 83% of the denervated endplates in the treated muscles were reinnervated by regenerated axons. Conclusion Intraoperative brief nerve stimulation promotes nerve regeneration, endplate reinnervation, and functional recovery of the muscles reinnervated with NMEG-NMZ technique.
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Cohen-Gadol, Aaron A., Mark B. Dekutoski, Choll W. Kim, Lynn M. Quast i William E. Krauss. "Safety of supplemental endplate screws in thoracic pedicle hook fixation". Journal of Neurosurgery: Spine 98, nr 1 (styczeń 2003): 31–35. http://dx.doi.org/10.3171/spi.2003.98.1.0031.
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Object. The AO Universal Spine System thoracic pedicle hook design includes a fixation screw that passes obliquely through the inferior facet into the pedicle to engage in the posterior portion of the superior vertebral body endplate. This endplate screw provides additional purchase at the hook—bone interface. To determine the safety of this fixation system the authors reviewed the operative notes, radiographs, and outcomes of patients who underwent placement of endplate screws. Methods. Thirty-six patients (16 male and 20 female patients) who required posterior thoracic instrumentation for spinal deformity (11 cases), neoplasm (15 cases), and traumatic injury (10 cases) were included in this study. One hundred sixty-four endplate screws were placed (mean 4.3/patient) to augment pedicle hooks for posterior thoracic instrumentation. The number of instrumented levels ranged from seven to 16. The positions of the screws in relation to the pedicle, neural foramen, spinal canal, and endplate were evaluated by assessing plain radiographs and computerized tomography scans (10 cases). Eighty-two screws (56%) were in ideal position. Lateral pedicle wall perforation occurred with 51 screws (35%). Three screws violated the medial wall and nine screws violated the superior or inferior walls of the pedicle. There were no clinical sequelae associated with any of the malpositioned screws. Adequate follow-up radiographic data were not available in five patients. The mean follow-up duration was 19.8 months (range 3–61 months). Two patients required revision surgery at 3 months and 18 months, respectively, because of hook/endplate screw displacement. There was also one case of an endplate screw fracture without hook displacement that was discovered during subsequent revision surgery. The remainder of the endplate screws and associated pedicles hooks maintained their original positions. There was no case of spinal cord, nerve root, pulmonary, or vascular injury. Conclusions. The placement of supplemental endplate screws in conjunction with thoracic pedicle hooks can be conducted safely.
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Sahoo, Madan Mohan, Sudhir Kumar Mahapatra, Sheetal Kaur, Jitendra Sarangi i Manoranjan Mohapatra. "Significance of Vertebral Endplate Failure in Symptomatic Lumbar Disc Herniation". Global Spine Journal 7, nr 3 (20.04.2017): 230–38. http://dx.doi.org/10.1177/2192568217694142.
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Study Design: Prospective cohort study. Objective: Endplate lesions though have been implicated in the genesis of lumbar disc herniation (LDH), very little is known regarding their clinical course. Thus, the present study is aimed to investigate the incidence and types of endplate failure (EPF) in LDH and its correlation with the clinical symptoms and prognosis. Methods: Clinical and magnetic resonance imaging (MRI) features of 66 patients with isolated single level LDH were studied. Three-dimensional fast spoiled gradient (3D FSPGR) MRI and computed tomography scans were used to identify the bony and cartilaginous EPF. Twenty-five patients were operated on and 41 patients were treated conservatively. Changes in the pain score, function and neurology were noted at 3, 6, 12, 24, and 36 weeks. Results: Endplate lesions were observed in 64 patients (96.9%), including bony endplate failure (bony failure) in 47 patients (71.2%) and isolated cartilaginous endplate lesions in 17 patients (25.7%). Bony failure group had similar pain and functional scores but more severe neurological deficit at the initial evaluation. Clinical parameters improved in all groups, but the recovery was lesser in conservatively treated bony failure patients. Conclusion: Endplate lesions are commonly associated with symptomatic LDH. Presence of bony failure can increase neurological deficit and reduce the chance of recovery with conservative management. The 3D FSPGR sequence of MRI can be successfully used for detection of the endplate lesions in the herniated disc.
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Olsen, P. C. "Bolted endplate connections revisited". Journal of Constructional Steel Research 58, nr 9 (wrzesień 2002): 1265–80. http://dx.doi.org/10.1016/s0143-974x(01)00067-0.
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Hutchinson, David O., Timothy J. Walls, Satoshi Nakano, Shelley Camp, Palmer Taylor, C. Michel Harper, Robert V. Groover, Hamlet A. Peterson, Dara G. Jamieson i Andrew G. Engel. "Congential Endplate acetylocholinesterase deficiency". Brain 116, nr 3 (1993): 633–53. http://dx.doi.org/10.1093/brain/116.3.633.
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Wang, Yue, Tapio Videman i Michele C. Battié. "Lumbar Vertebral Endplate Lesions". Spine 37, nr 17 (sierpień 2012): 1432–39. http://dx.doi.org/10.1097/brs.0b013e31824dd20a.
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&NA;. "Mapping the Vertebral Endplate". Back Letter 15, nr 7 (lipiec 2000): 74–75. http://dx.doi.org/10.1097/00130561-200015070-00003.
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Antoniou, John, Nora M. Goudsouzian, Terrence F. Heathfield, Neil Winterbottom, Thomas Steffen, A. Robin Poole, Max Aebi i Mauro Alini. "The Human Lumbar Endplate". Spine 21, nr 10 (maj 1996): 1153–61. http://dx.doi.org/10.1097/00007632-199605150-00006.
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Johnson, Ernest W. "More on Endplate Noise". American Journal of Physical Medicine & Rehabilitation 81, nr 3 (marzec 2002): 161. http://dx.doi.org/10.1097/00002060-200203000-00001.
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Elfiky, Tarek Anwar, Nirmal Dhananjay Patil, Yasser Allam i Raafat Ragab. "Endplate Changes with Polyetheretherketone Cages in Posterior Lumbar Interbody Fusion". Asian Spine Journal 14, nr 2 (30.04.2020): 229–37. http://dx.doi.org/10.31616/asj.2019.0124.
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Study Design: A retrospective radiographic analysis.Purpose: The aim of the current study is to assess endplate changes after the use of polyetheretherketone (PEEK) cages in posterior lumbar interbody fusion (PLIF).Overview of Literature: A few recent reports had revealed endplate abnormalities due to PEEK cages, which may lead to nonunions.Methods: A retrospective computed tomography (CT)-based analysis of the endplate cavities and fusion status following PLIFs with PEEK cages was conducted by two independent observers. The term “cavity” was used to describe the endplate changes. The vertebral endplate cavities were assessed according to the size, multiplicity, location, and presence or absence of sclerosis.Results: There were 86 fixed levels in 65 consecutive patients, with a mean age of 35.44±19.60 years. The mean follow-up was 16.5±10.1 months (range, 6–57 months). Definite fusion was seen in 56 levels (65.12%) by observer 1 versus 44 levels (51.16) by observer 2. The strength of agreement was moderate. Endplate cavities were observed in 42 levels (48.84%) by observer 1 versus 47 levels (54.65%) by observer 2, with fair agreement. The strengths of agreement for the locations, multiplicity, and size were moderate, fair, and poor, respectively. Neither age, sex, etiology, levels, nor follow-up period was significantly associated with the presence of cavities. With regard to fusions, the nonunions detected by observer 1 were significantly associated with the presence of cavities (p<0.0001). However, those detected by observer 2 were nearly significant (p=0.05).Conclusions: There was a high rate of unfavorable radiographic findings in the form of endplate cavities in PLIF cases with PEEK cages. A more comprehensive classification for the assessment of fusions and endplate cavities should be formulated. We strongly recommend further CT-based studies with larger sample size and longer follow-up periods.
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Ye, Yi, Xucan Wang, Zhenqing Yang, Qian Xu i Bo Zhang. "Hsp22 Inhibits Oxidative Stress-Induced Endplate Chondrocyte Apoptosis by Regulating Mitochondrial Pathway". Journal of Biomaterials and Tissue Engineering 11, nr 10 (1.10.2021): 1947–54. http://dx.doi.org/10.1166/jbt.2021.2763.
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Background: Facet joint degeneration (FJD), which is also called facet joint syndrome (FJS), has become one of the most commonly seen etiological factors for lumbago. Cartilage lesion triggered by lumbar facet joint (LFJ) degeneration might be related to mitochondrial impairment, but the its underlying mechanism remains unclear. Materials and methods: The endplate chondrocytes were induced by hydrogen peroxide (H2O2) to mimic the pathological conditions of oxidative stress. Enzyme linked immunosorbent assay (ELISA) were used for the evaluation of reactive oxygen species (ROS). Adenosine-triphosphate (ATP) level was assessed using ATP detection, along with the detection the expression of cytochrome C in mitochondria (mito-cyt c) and in cell cytoplasm (cyto-cyt c) and cleaved caspase 3 by Western blot analysis. TUNEL assay was conducted for the measurement of cell apoptosis in endplate chondrocytes. Reverse transcription-polymerase chain reaction (RT-qPCR) was used to verify the expression of heat shock protein 22 (HSP22) and the transfection efficiency of HSP22 interference plasmid. Results: It was found that H2O2 promoted the mitochondrial dysfunction, ROS generation and cell apoptosis in endplate chondrocytes. Moreover, HSP22 was down-regulated in H2O2-induced endplate chondrocytes, and interference of HSP22 decreased the ROS production, increased the ATP level and promoted the cell apoptosis, resulting in the enhanced impairment of endplate chondrocytes. Additionally, mitochondrial ROS inhibitor (Mito-TEMPO) ameliorated the injury effects of HSP22 silencing in the H2O2-induced endplate chondrocytes. Conclusion: In conclusion, HSP22 inhibits oxidative stress-induced endplate chondrocyte apoptosis by regulating mitochondrial pathway, possibly providing novel guidance direction for the treatment of LFJ degeneration.
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Morimoto, Masatoshi, Kosaku Higashino, Shinsuke Katoh, Tezuka Fumitake, Kazuta Yamashita, Fumio Hayashi, Yoichiro Takata, Toshinori Sakai, Akihiro Nagamachi i Koichi Sairyo. "A Rare Case of Progressive Palsy of the Lower Leg Caused by a Huge Lumbar Posterior Endplate Lesion after Recurrent Disc Herniation". Case Reports in Orthopedics 2016 (2016): 1–4. http://dx.doi.org/10.1155/2016/5963924.
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A lesion of the lumbar posterior endplate is sometimes identified in the spinal canal of children and adolescents; it causes symptoms similar to those of a herniated disc. However, the pathology of the endplate lesion and the pathology of the herniated disc are different. We present a rare case of a 23-year-old woman who developed progressive palsy of the lower leg caused by huge lumbar posterior endplate lesion after recurrent disc herniation.
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Rothschild, Bruce M., Jonhan Ho i Yossef Masharawi. "Macroscopic anatomy of the vertebral endplate: Quid significat?" Anthropologischer Anzeiger 71, nr 3 (1.06.2014): 191–217. http://dx.doi.org/10.1127/0003-5548/2014/0365.
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Eijkelkamp, M. F., J. Hayen, A. G. Veldhuizen, J. R. Van Horn i G. J. Verkerke. "Improving the Fixation of an Artificial Intervertebral Disc". International Journal of Artificial Organs 25, nr 4 (kwiecień 2002): 327–33. http://dx.doi.org/10.1177/039139880202500412.
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The fixation of an artificial intervertebral disc has been studied especially with respect to the dimensions, the convexity of the endplates and the size of the fixation elements. From literature and cadaveric vertebrae, the dimensions and shape of the lumbar vertebral endplates were determined and the dimensions of fixation ribs for the artificial intervertebral disc were calculated. To withstand shear forces and prevent dislocation, two sagittal ribs, each 3.5 mm in height and at least 20 mm in length and four transversal ribs, each 1.5 mm in height and with a total length of 60 mm are sufficient. A range of five different sagittal diameters was selected as sufficient for all patients. At least 72.6 % of the endplate of the vertebrae is covered. A convexity with a radius of 140 mm limits the gap to 0.62 mm.
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Harada, Takashi, i Podi Liu. "Internal and External Forces Measurement of Planar 3-DOF Redundantly Actuated Parallel Mechanism by Axial Force Sensors". ISRN Robotics 2013 (9.10.2013): 1–8. http://dx.doi.org/10.5402/2013/593606.
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This paper proposes a method for measuring the internal and external forces of a planar 3-DOF (degree of freedom) redundantly actuated parallel mechanism. The internal forces, force acts inside the endplate and mechanism constraint force, and the external forces, forces act on the endplate and thrusts by actuators, were measured simultaneously using the axial forces of the rods. Kinetostatic equations of the parallel mechanism were used to derive algorithms for measuring the internal and external forces. A link axis force sensor was developed using a strain gauge sensor. To verify the actual internal force of the endplate, a force sensor was also installed on the endplate. A real-time system for measuring the forces of the parallel mechanism was developed using RT-Linux. The external and internal forces were measured accurately.
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Kotowski, S. E., K. G. Davis, R. J. Parkinson i J. P. Callaghan. "Taking an Acceleration Approach to Identifying Vertebral Endplate Failures". Proceedings of the Human Factors and Ergonomics Society Annual Meeting 51, nr 15 (październik 2007): 938–42. http://dx.doi.org/10.1177/154193120705101515.
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Identification of spine tolerances has typically involved the complete destruction of functional spinal units in order to confirm an endplate fracture. A new method of identifying endplate fractures utilizing the measurement of acceleration response through accelerometers mounted to the functional spinal unit was tested on porcine spines. Functional spinal units were mechanically tested to failure using a cyclic loading protocol modeled after the expected loading during a lifting task. Over 80% of the segments had visible endplate fractures upon dissection. Trends in acceleration profiles revealed increased accelerations when specimens failed, with more pronounced trends in the specimens that had visible cracks after dissection. While further analysis is necessary, the results do point to some level of shift in the biomechanical responses within the vertebral body meaning the methodology may have the potential to identify endplate structural breakdown prior to ultimate failure.
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Burges, Judith, Dennis W. Wray, Sergio Pizzighella, Zach Hall i Angela Vincent. "A myasthenia gravis plasma immunoglobulin reduces miniature endplate potentials at human endplates in vitro". Muscle & Nerve 13, nr 5 (maj 1990): 407–13. http://dx.doi.org/10.1002/mus.880130507.
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Ruff, R. L., i D. Whittlesey. "Comparison of Na+ currents from type IIa and IIb human intercostal muscle fibers". American Journal of Physiology-Cell Physiology 265, nr 1 (1.07.1993): C171—C177. http://dx.doi.org/10.1152/ajpcell.1993.265.1.c171.
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The voltage dependence and amplitude of Na+ currents (INa) were studied with the loose-patch voltage-clamp technique on 19 fast-twitch human intercostal skeletal muscle fibers at the endplate border and > 200 microns from the endplate (extrajunctional). The fibers were histochemically classified as fast-twitch oxidative-glycolytic (type IIa, n = 9) or fast-twitch glycolytic (type IIb, n = 10). The voltage dependence of activation and fast and slow inactivation of INa were similar for membrane patches recorded on the endplate border and on extrajunctional membrane for both fiber types. INa was about fivefold larger on the endplate border compared with extrajunctional membrane for both fiber types. Type IIb fibers had larger values of INa and manifest fast inactivation of INa at more negative potentials than type IIa fibers. The difference between type IIa and IIb fibers may enable IIb fibers to operate at higher firing frequencies for brief periods.
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Haastert, Kirsten, Maria Grosheva, Srebrina K. Angelova, Orlando Guntinas-Lichius, Emmanouil Skouras, Joern Michael, Claudia Grothe, Sarah A. Dunlop i Doychin N. Angelov. "Schwann Cells Overexpressing FGF-2 Alone or Combined with Manual Stimulation Do Not Promote Functional Recovery after Facial Nerve Injury". Journal of Biomedicine and Biotechnology 2009 (2009): 1–11. http://dx.doi.org/10.1155/2009/408794.
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Purpose. To determine whether transplantation of Schwann cells (SCs) overexpressing different isoforms of fibroblast growth factor 2 (FGF-2) combined with manual stimulation (MS) of vibrissal muscles improves recovery after facial nerve transection in adult rat.Procedures. Transected facial nerves were entubulated with collagen alone or collagen plus naïve SCs or transfected SCs. Half of the rats received daily MS. Collateral branching was quantified from motoneuron counts after retrograde labeling from 3 facial nerve branches. Quality assessment of endplate reinnervation was combined with video-based vibrissal function analysis.Results. There was no difference in the extent of collateral axonal branching. The proportion of polyinnervated motor endplates for either naïve SCs or FGF-2 over-expressing SCs was identical. Postoperative MS also failed to improve recovery.Conclusions. Neither FGF-2 isoform changed the extent of collateral branching or polyinnervation of motor endplates; furthermore, this motoneuron response could not be overridden by MS.