• Journal of Korean Neurosurgical Society
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• 제47권6호
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• pp.446-453
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• 2010

Objective : The purpose of this study was to analyze the biomechanical effects of three different constrained types of an artificial disc on the implanted and adjacent segments in the lumbar spine using a finite element model (FEM). Methods : The created intact model was validated by comparing the flexion-extension response without pre-load with the corresponding results obtained from the published experimental studies. The validated intact lumbar model was tested after implantation of three artificial discs at L4-5. Each implanted model was subjected to a combination of 400 N follower load and 5 Nm of flexion/extension moments. ABAQUS$^{TM}$ version 6.5 (ABAQUS Inc., Providence, RI, USA) and FEMAP version 8.20 (Electronic Data Systems Corp., Plano, TX, USA) were used for meshing and analysis of geometry of the intact and implanted models. Results : Under the flexion load, the intersegmental rotation angles of all the implanted models were similar to that of the intact model, but under the extension load, the values were greater than that of the intact model. The facet contact loads of three implanted models were greater than the loads observed with the intact model. Conclusion : Under the flexion load, three types of the implanted model at the L4-5 level showed the intersegmental rotation angle similar to the one measured with the intact model. Under the extension load, all of the artificial disc implanted models demonstrated an increased extension rotational angle at the operated level (L4-5), resulting in an increase under the facet contact load when compared with the adjacent segments. The increased facet load may lead to facet degeneration.

• 한방재활의학과학회지
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• 제19권4호
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• pp.151-163
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• 2009

Objectives : In the assessment of the lumbar spine by magnetic resonance imaging (hereinafter, "MRI"), changes in the paraspinal muscles are overlooked. The purpose of our study is to examine the correlation between the multifidus muscle atrophy on MRI findings and the clinical findings in low back pain (hereinafter, "LBP") patients. Methods : The retrospective study on 38 LBP patients, presenting either with or without associated leg pains, was undertaken. The MRI findings on the patients were visually analysed to find out a lumbar multifidus muscle atrophy, disc herniation, disc degeneration, spinal stenosis and nerve root compressions. The clinical history in each case was obtained from their case notes and pain drawing charts. Results : The lumbar multifidus muscle atrophy has occurred from more than 80% of the patients with LBP. Most of lumbar multifidus muscle atrophies have increased from lower level of lumbar spine. It was bilateral in the majority of the cases. In addition, multifidus muscle atrophy was correlated to the patient's age, disc degenerations and spinal stenosis. On the contrary, gender, the duration of LBP, referred leg pain, disc herniation and nerve root compressions had no relevance to multifidus muscle atrophies. Therefore, when assessing the MRIs of the lumbar spine, we should have more attetion on multifidus muscle, because it has lot's of information about spinal neuropathy problems. Conclusions : Therefore, the examination of multifidus muscle atrophies should be considered when assessing the MRIs of the lumbar spine. In addition, it helps to evaluate and plan the treatment modalities of LBP. Moreover, it prevents from LBP by discovering the importance between the multifidus muscle and the spine stabilization exercise.

• 대한치과교정학회지
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• 제23권4호
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• pp.503-527
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• 1993

This paper describes a new method to create an animal model for TMJ internal derangement in the New Zealand white rabbits and the light and electron microscopical changes of posterior attachment of them. Twenty six rabbits(2.5-3.0kg), four normal and twenty two experimental, were used. The right disc of experimental animal was displaced anteriorly without sectioning the posterior attachment and tied to the zygomatic arch with nylon not to be reduced to the original position. The left TMJ was sham-operated to be compared with its right experimental one. Normal animals were sacrificed one day and eight weeks after experiment. Experimental animals were sacrificed one day, ten days, three weeks, five weeks and eight weeks after surgery respectively. They were fixed intravenously with $2\%$ glutaldehyde under general anesthesia and the samples of them were processed for light and electron microscopic examination. The purpose of this experiment is to make a suitable animal model of disc displacement without reduction for studying and understanding the cellular and morphologic events in posterior attachment of TMJ including early changes which were difficult to be observed in human TMJs. The results of this investigation suggest the following conclusions : 1. Authors induced anterior disc displacement surgically in rabbits with new method to examine histologic changes of posterior attachment. Tissue reactions of this model seem to be similar to those observed in human disc displacement. We think this animal model for anterior disc displacement may be used to explore and evaluate objectively the effects of many treatment modalities in disc displacements. 2. The animal disease model showed inflammation at early stage(one and ten days). At this stage there were mild-to-severe mononuclear inflammatory cell infiltration, numerous newly formed vessels, vessel dilatation and engormement and many fibroblasts. 3. At middle stage(three weeks), fibrosis occurred, where fibroblasts decreased in number, but their cytoplasm was profuse indicating high activity. Collagen fibers increased in number and the tissue looked more dense. 4. At late stage(five weeks and eight weeks) showed degenerative changes including perforation of posterior attachment, disintegration of collagen fiber bundles, degeneration of fibroblasts, metastatic ossification, and dystrophic calcification.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제46권3호
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• pp.174-182
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• 2020

Objectives: Joint injuries frequently lead to progressive joint degeneration that causes articular disc derangement, joint inflammation, and osteoarthritis. Such arthropathies that arise after trauma are defined as post-traumatic arthritis (PTA). Although PTA is well recognized in knee and elbow joints, PTA in the temporomandibular joint (TMJ) has not been clearly defined. Interestingly, patients experiencing head and neck trauma without direct jaw fracture have displayed TMJ disease symptoms; however, definitive diagnosis and treatment options are not available. This study will analyze clinical aspects of PTA in TMJ and their treatment outcomes after joint arthrocentesis and lavage. Materials and Methods: Twenty patients with history of trauma to the head and neck especially without jaw fracture were retrospectively studied. Those patients developed TMJ disease symptoms and were diagnosed by computed tomography or magnetic resonance imaging. To decrease TMJ discomfort, arthrocentesis and lavage with or without conservative therapy were applied, and efficacy was evaluated by amount of mouth opening and pain scale. Statistical differences between pre- and post-treatment values were evaluated by Wilcoxon signed-rank test. Results: Patient age varied widely between 20 and 80 years, and causes of trauma were diverse. Duration of disease onset was measured as 508 post-trauma days, and 85% of the patients sought clinic visit within 2 years after trauma. In addition, 85% of the patients showed TMJ disc derangement without reduction, and osteoarthritis was accompanied at the traumatized side or at both sides in 40% of the patients. After arthrocentesis or lavage, maximal mouth opening was significantly increased (28-44 mm on average, P<0.001) and pain scale was dramatically decreased (7.8-3.5 of 10, P<0.001); however, concomitant conservative therapy showed no difference in treatment outcome. Conclusion: The results of this study clarify the disease identity of PTA in TMJ and suggest early diagnosis and treatment options to manage PTA in TMJ.

• Journal of Korean Neurosurgical Society
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• 제46권1호
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• pp.56-59
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• 2009

The lumbar intraspinal epidural ganglion cyst has been a rare cause of the low back pain or leg pain. Ganglion cysts and synovial cysts compose the juxtafacet cysts. Extensive studies have been performed about the synovial cysts, however, very little has been known about the ganglion cyst. Current report is about two ganglion cysts associated with implicative findings in young male patients. We discuss about the underlying pathology of the ganglion cyst based on intraoperative evidences, associated disc herniation at the same location or severe degeneration of the ligament flavum that the cyst originated from in young patients.

• Annals of Clinical Neurophysiology
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• 제11권2호
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• pp.41-47
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• 2009

Background: Discogenic pain can develop into chronic low back pain that is very difficult to treat effectively, because the pathogenesis of the disease still remains controversial. To clarify the pathogenesis, numerous animal models of intervertebral disc degeneration have been proposed in the literature, each with attendant advantages and disadvantages. The aim of this study was to determine the most efficacious method and dose of complete Freund's adjuvant (CFA) injection into intervertebral disc to develop a discogenic pain in a rat. Methods: CFA was injected into the L5-L6 or L4-L5 disc of male Sprague-Dawley rats in various conditions including a dose of CFA (10, 20, or 50 uL), drilling, injection site sealing using cyanoacrylate, and injection velocity. Sham animals were subjected to the same procedure, except for the CFA injection. Mechanical and heat allodynia were serially measured at both hindpaws until 8 weeks post-operatively. Serial MRI analyses were performed to observe degenerative changes of the discs. In addition, CGRP & Substance P-immunoreactivities (ir) in the superficial dorsal horn were evaluated at 4 weeks using immunohistochemistry. Results: Each condition provoked various problems such as development of hindpaw paralysis, CFA leakage, and no pain development. Mid-sagittal T2 MRI revealed no significant degenerative changes in the CFA injected disc. The CGRP-ir of the bilateral superficial dorsal horns at the level of L5-L6 was significantly increased in the CFA group. Conclusions: A total of 10 uL CFA injection into L5-L6 disc for a period of 10 minutes using a 26-gauge needle without drilling was the most efficacious way to develop discogenic pain animal model.

• Experimental and Molecular Medicine
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• 제50권11호
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• pp.5.1-5.14
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• 2018

Oxidative stress-induced mitochondrial dysfunction is implicated in the pathogenesis of intervertebral disc degeneration (IVDD). Sirtuin 3 (SIRT3), a sirtuin family protein located in mitochondria, is essential for mitochondrial homeostasis; however, the role of SIRT3 in the process of IVDD has remained elusive. Here, we explored the expression of SIRT3 in IVDD in vivo and in vitro; we also explored the role of SIRT3 in senescence, apoptosis, and mitochondrial homeostasis under oxidative stress. We subsequently activated SIRT3 using honokiol to evaluate its therapeutic potential for IVDD. We assessed SIRT3 expression in degenerative nucleus pulposus (NP) tissues and oxidative stress-induced nucleus pulposus cells (NPCs). SIRT3 was knocked down by lentivirus and activated by honokiol to determine its role in oxidative stress-induced NPCs. The mechanism by which honokiol affected SIRT3 regulation was investigated in vitro, and the therapeutic potential of honokiol was assessed in vitro and in vivo. We found that the expression of SIRT3 decreased with IVDD, and SIRT3 knockdown reduced the tolerance of NPCs to oxidative stress. Honokiol ($10{\mu}M$) improved the viability of NPCs under oxidative stress and promoted their properties of anti-oxidation, mitochondrial dynamics and mitophagy in a SIRT3-dependent manner. Furthermore, honokiol activated SIRT3 through the AMPK-PGC-$1{\alpha}$ signaling pathway. Moreover, honokiol treatment ameliorated IVDD in rats. Our study indicated that SIRT3 is involved in IVDD and showed the potential of the SIRT3 agonist honokiol for the treatment of IVDD.

• Asian Spine Journal
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• 제12권6호
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• pp.973-980
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• 2018

Study Design: Retrospective review. Purpose: To identify the trends in stimulator use, pair those trends with various grafting materials, and determine the influence of stimulators on the risk of revision surgery. Overview of Literature: A large number of studies has reported beneficial effects of electromagnetic energy in healing long bone fractures. However, there are few clinical studies regarding the use of electrical stimulators in spinal fusion. Methods: We used insurance billing codes to identify patients with lumbar disc degeneration who underwent anterior lumbar interbody fusion (ALIF). Comparisons between patients who did and did not receive electrical stimulators following surgery were performed using logistic regression analysis, chi-square test, and odds ratio (OR) analysis. Results: Approximately 19% of the patients (495/2,613) received external stimulators following ALIF surgery. There was a slight increase in stimulator use from 2008 to 2014 (multi-level $R^2=0.08$, single-level $R^2=0.05$). Patients who underwent multi-level procedures were more likely to receive stimulators than patients who underwent single-level procedures (p<0.05; OR, 3.72; 95% confidence interval, 3.02-4.57). Grafting options associated with most frequent stimulator use were bone marrow aspirates (BMA) plus autograft or allograft for single-level and allograft alone for multi-level procedures. In both cohorts, patients treated with bone morphogenetic proteins were least likely to receive electrical stimulators (p<0.05). Patients who received stimulation generally had higher reimbursements. Concurrent posterior lumbar fusion (PLF) (ALIF+PLF) increased the likelihood of receiving stimulators (p<0.05). Patients who received electrical stimulators had similar revision rates as those who did not receive stimulation (p>0.05), except those in the multilevel ALIF+PLF cohort, wherein the patients who underwent stimulation had higher rates of revision surgery. Conclusions: Concurrent PLF or multi-level procedures increased patients' likelihood of receiving stimulators, however, the presence of comorbidities did not. Patients who received BMA plus autograft or allograft were more likely to receive stimulation. Patients with and without bone stimulators had similar rates of revision surgery.

• 대한기계학회논문집B
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• 제36권11호
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• pp.1105-1110
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• 2012

척추는 인간의 근골격계 건강에 큰 영향을 미치는 신체 부위 중 하나이다. 최근에 고령화 사회에 진입하게 되면서 요통과 같은 척추 질환이 급속하게 증가하고 있다. 이러한 척추 질환의 요인에는 선천적인 척추 장애나 스포츠 및 교통사고의 부상뿐만 아니라 일상생활에서 반복적으로 취하는 나쁜 자세도 포함된다. 잘못된 척추 자세는 척추 디스크에 압력을 주어 퇴행성 변화를 가져옴으로써 척추를 변형시키고 척추질환을 일으킨다. 따라서 본 연구에서는 여러 나쁜 자세를 취했을 때 흉추와 요추 관절의 3 차원 관절 각도를 분석하였다. 그 결과로부터 일상생활에서의 나쁜 자세가 굽힘/신전, 측면 굽힘, 축 회전 방향으로 척추 관절에 각도 변형을 일으키고 정상범위에서 벗어날 수 있음을 알 수 있었다. 향후 연구로써 척추관절의 각도변화가 디스크와 인대 및 근육 등에 미치는 영향에 대한 연구가 필요하다 생각된다.

• 한국정밀공학회지
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• 제27권2호
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• pp.130-136
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• 2010

For stability analysis of the lumbar spine, the hypothesis presented is that the disc has stress sensors driving feedback mechanism, which could react to the imposed loads by adjusting the contraction of the muscles. Fusion in the motion segment of the lumbar spinal column is believed to alter the stability of the spinal column. To identify this effect finite element (FE) models combined with optimization technique was applied and quantify the role of each muscle and reaction forces in the spinal column with respect to the fusion level. The musculoskeletal FE model was consisted with detailed whole lumbar spine, pelvis, sacrum, coccyx and simplified trunk model. Vertebral body and pelvis were modeled as a rigid body and the rib cage was constructed with rigid truss element for the computational efficiency. Spinal fusion model was applied to L3-L4, L4-L5, L5-S1 (single level) and L3-L5 (two levels) segments. Muscle architecture with 46 local muscles was used as acting directions. Minimization of the nucleus pressure deviation and annulus fiber average axial stress deviation was selected for cost function. As a result, spinal fusion produced reaction changes at each motion segment as well as contribution of each muscle. Longissimus thoracis and psoas major muscle showed dramatic changes for the cases of L5-S1 and L3-L5 level fusion. Muscle force change at each muscle also generated relatively high nucleus pressure not only at the adjacent level but at another level, which can explain disc degeneration pattern observed in clinical study.