• Proceedings of the Computational Structural Engineering Institute Conference
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• 2009.04a
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• pp.283-286
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• 2009

척추경 나사못을 이용한 요추 유합술은 가장 보편적으로 사용되어지는 수술적 치료 방법이다. 과거 여러 연구들에서 이러한 척추 유합술의 임상적 우수성은 이미 입증 되었으며, 척추경 나사못은 시술 부위의 운동을 완전히 제한함으로써 높은 유합율을 얻을 수 있으나, 상대적으로 인접 분절의 조기 퇴행성 변화의 요인 중 하나로 보고되고 있다. 따라서 본 연구에서는 유한요소해석 방법을 이용하여 척추경 나사못 시술에 따른 척추체의 운동범위 및 인접 분절 추간판의 스트레스 증가량을 계산하였고, 척추경 나사못 모델과 유합 후 나사못 제거에 따른 모델 또 시술하기 전 정상모델과 비교하여 생체 역학적 측면에서 분석하여 척추경 나사못을 이용한 요추 유합술 후, 척추경 나사못의 제거의 임상적 효과와 그 이론적 근거를 제시하고자 한다.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2010.04a
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• pp.280-283
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• 2010

척추경 나사못을 이용한 요추 유합술은 가장 보편적으로 사용되는 수술 적 치료 방법이다. 과거 여러 연구들에서 이러한 척추 유합술의 임상적 우수성은 이미 입증 되었으며, 척추경 나사못은 시술 부위의 운동을 완전히 제한함으로써 높은 유합율을 얻을 수 있으나, 상대적으로 인접 분절의 조기 퇴행성 변화의 요인 중 하나로 보고되고 있다. 또한 유합술을 수행 할 때 후방조직의 절제 또한 인접 분절의 퇴행을 초래하는 원인으로 보고되고 있다. 따라서 본 연구에서는 유한요소해석 방법을 이용하여 척추경 나사못 과 후방조직을 절제하는 시술 방법을 비교하여 척추체의 운동범위의 증가량을 계산하였고, 척추경 나사못 모델과 후방조직을 제거한 모델을 개발하여 시술하기 전 정상모델과 비교하였다. 개발된 모델과 정상 모델을 생체 역학적 측면에서 분석하여 인접분절의 조기 퇴행성 변화를 일으키는 가장 큰 원인이 무엇인지 정량적으로 분석하였고, 이를 근거 하여 임상적 효과와 그 이론적 근거를 제시하고자 한다.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.33 no.3
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• pp.145-152
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• 2020

In this study, we evaluated spinal stability based on the change in the thoracolumbar fixation segment using finite element analysis (FEA). To accomplish this, a finite element (FE) model of a normal thoracolumbar spine (T10-L4), including intervertebral discs (IVD), ligaments, and facet joints, was constructed, and the material properties reported in previous studies were implemented. However, L1 was assumed as the lesion site, and three types of posterior fixation, namely, L1-L2, T12-L2, and T12-L1-L2, were implemented in the thoracolumbar FE model. In addition, the loading conditions for flexion, extension, lateral bending, and axial rotation were adopted. Through the series FEA, the deformation, equivalent stress, range of motion, and moment on the pedicle screws, vertebrae, and IVD were calculated, and the spinal stability was evaluated based on the FEA results.

• Journal of Biomedical Engineering Research
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• v.23 no.1
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• pp.17-26
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• 2002

The purpose of this study was to investigate the important Parameters of the Pedicle screw by estimating the mechanical characteristics of screws under static and dynamic loads. Methodology for estimating Parameters under static load was proposed. It was also shown that the fatigue life of the one-level system could be increased by changing the shape of screws. Load parameters of the single pedicle screw were friction force. bending moment. and holding force. The test results of the one-level system could be inferred from teat results of the sin91e screw under bending force Fatigue life of the one-level system with flexible rod was longer than that of the upper Part test without rod . Considering the drop of flexibility of the rod due to muscles and ligament, fatigue life of the one-level system could be estimated b? that of the single screw.

• Composites Research
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• v.34 no.3
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• pp.186-191
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• 2021

The lumbar spinal fusion is a treatment performed to restore the stability of the degenerated lumbar. In this study, the intervertebral discs between two or more segments are removed and a bone graft is inserted to harden the segments. The pedicle screw system is inserted to vertebral bodies to fix two or more segments so that they can be firmly fused. In this study, a total of 7 patient-specific lumbar finite element models were created and pedicle screw systems were installed. The connecting rods made of titanium and CFR-PEEK was inserted to the generated models. Finite element analysis was conducted for four representative spine behaviors and statistical analysis was performed to investigate the biomechanical effects by the material properties of connecting rods. The intradiscal pressure of adjacent segments and the range of motion of the joints of each segment were investigated. In the subjects who used CFR-PEEK instead of Ti for connecting rods, the intradiscal pressure of adjacent segments tend to decrease and the range of motion of each segment tend to increase. However, no statistically significant difference in tendency was observed under all loading conditions.

• Journal of the Korean Society of Radiology
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• v.16 no.7
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• pp.879-887
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• 2022

In this study, we tried to confirm whether the mechanical sequential elevation method of the body pressure measuring bed actually induces segmental motion for each part of the spine. To this end, a lateral X-ray examination was performed, and it was confirmed that the sequential pressure device induces a step-wise segmentation of the spine by mechanically lifting each part of the spine vertically. Then, pain, walking ability, and depression scale were measured and analyzed in subjects who were aware of back pain. VAS(p<0.05) and ODI(p<0.05) for 10 days tended to decrease in average after bed use. In the gait ability test(p<0.05), as the number of times of bed use increased, the moving time in the test decreased and the moving distance increased. In addition, GSDDF(p<0.05) decreased after bed use. As a result, it was confirmed that the spinal segmentation caused by the heat and acupressure provided by the bed affected gait and depression as well as pain relief.

• Proceedings of the Korea Contents Association Conference
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• 2011.05a
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• pp.267-268
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• 2011

본 연구에서는 유한요소 해석 방법을 이용하여 경추 유한요소 모델을 개발하고, 척추 인공디스크 수술 후 경추 분절의 생체역학적 특성을 평가하였다. 반구속 및 비구속 개념의 인공디스크가 삽입된 경추 유한요소 모델의 제 7 경추체를 완전히 고정시키고 추적 경로 방향의 50 N의 압축력을 가한 상태에서 1 Nm의 굴곡과 신전, 측면 굴곡, 비틀림 모멘트를 가하였다. 모든 방향의 하중 조건에서 인공디스크가 삽입된 경추 모델들의 회전량이 정상 경추 모델의 회전량에 비하여 크게 나타났다. 또한 인공디스크를 삽입한 운동 분절에서 정상에 비하여 후관절의 접촉력과 여섯 가지 주요 인대에 걸리는 응력이 높게 나타났다. 본 연구의 결과는 척추 인공디스크 수술 시 수술 방법의 선택뿐만 아니라 새로운 경추 수술용 임플란트 개발을 위한 인체정보 콘텐츠를 구축하는데 유용하게 활용될 수 있을 것으로 기대된다.

• Korean Journal of Acupuncture
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• v.23 no.2
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• pp.79-88
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• 2006

Objectives : Yogaktong is the genernal term of lowback and sciatic pain. Simpley this is not for the syndrom or illiness but for the symptoms. In this study, the effect of Acupuncture and Moxibustion Treatment by Analysing Su-point(背兪穴) compared with X-ray measuring for three patients with Yogaktong(腰脚痛) were evaluated. Methods : After treatment with the Acupuncture and Moxibustion Treatment by Analysing Su-point(背兪穴) compared with X-ray measuring for one time, we evaluated the effect by the figure of x-ray measuring and complaints of patients. Results : In three cases, the change in the figure declined dramatically and symptoms of patients got better after one treatment. Conclusions : Acupuncture and Moxibustion Treatment by Analysing Su-point(背兪穴) compared with X-ray measuring was effective. It will be attempted to the patients with it.

• Journal of Biomedical Engineering Research
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• v.25 no.3
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• pp.171-182
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• 2004

This study investigates the biomechanical efficacies of vertebroplasty which is used to treat vertebral body fracture with bone cement augmentation for osteoporotic patients using image and finite element analysis. Simulated models were divided into two groups: (a) a vertebral body, (b) a functional spinal unit(FSU). For a vertebral body model, the maximum axial displacement was investigated under axial compression to evaluate the effect of structural integrity. The stiffness of each FE model simulated was normalized by the stiffness of intact model. In the case of FSU model, 3 types of compression fractures were formulated to assess the influence on spinal curvature changes. The FSU models were loaded under compressive pressure to calculate the change of spinal curvature. The results according to the various factors suggest that vertebroplasty has the biomechanical efficacy of the increment of structural reinforcement in a patient who has relatively high level of BMD and a patient with the amount of 15％, PMMA injection of the cancellous bone volume. The spinal curvatures after compression fracture simulation vary from 9$^{\circ}$ to 17$^{\circ}$ of kyphosis compared to that the spinal curvature of normal model was -2.8$^{\circ}$ of lordosis. These spinal curvature changes cause the severe spinal deformity under the same loading. As the degree of compressive fracture increases the spinal deformity also increases. The results indicate that vertebroplasty has the increasing effect of the structural integrity regardless of the amount of PMMA or BMD and the restoration of decreased vertebral body height may be an important factor when the compressive fracture caused the significant height loss of vertebral body.

• Journal of the Korean Orthopaedic Association
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• v.56 no.5
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• pp.419-426
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• 2021

Purpose: In the surgical treatment of pyogenic lumbar spondylodiscitis, screw insertion at the affected vertebra has been avoided because of biofilm formation, and the risk of infection recurrence. The authors analyzed the success rate of infection treatment while minimizing the number of instrumented segments by inserting pedicle screws into the affected vertebrae. Therefore, this study examined the usefulness of this technique. Materials and Methods: From January 2000 to June 2018, among patients with pyogenic lumbar spondylodiscitis treated surgically, group A consisted of patients with pedicle screws inserted directly at the affected vertebrae (28 cases), and group B underwent fusion by inserting screws at the adjacent normal vertebrae due to bone destruction of the affected vertebral pedicle (20 cases). The classified clinical results were analyzed retrospectively. All patients were treated via the posterior-only approach, so the affected disc and sequestrum were removed. Posterior interbody fusion was performed with an autogenous strut bone graft, and the segments were then stabilized with pedicle screw systems. The hospitalization period, operation time, amount of blood loss, EQ-5D index, duration of intravenous antibiotics, and the clinical and radiological results were analyzed. Results: In group A, the number of instrumented segments, operation time, blood loss, and EQ-5D index at one month postoperatively showed significant improvement compared to group B. There were no significant differences in the duration of antibiotic use, hospitalization, radiological bone union time, sagittal angle correction rate, and recurrence rate. Conclusion: Minimal segmental fixation, in which pedicle screws were inserted directly into the affected vertebrae through the posterior approach, reduced the surgery time and blood loss, preserved the lumbar motion by minimizing fixed segments and showed rapid recovery without spreading or recurrence of infection. Therefore, this procedure recommended for the surgical treatment of lumbar pyogenic spondyodiscitis.