• Journal of the Korean Society for Precision Engineering
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• v.20 no.10
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• pp.226-232
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• 2003

Difficulties in the finite element modeling of human spine are evaded by using a stiffness matrix element whose properties can be characterized from experimentally measured stiffness of functional spinal units. Relative easiness is in that inter-vertebral discs, ligaments, and soft tissues connecting vertebrae do not need to be modeled as they are. The remarkable coupling effect between distinct degrees of freedom induced by the geometric complexity can be accommodated without much effort. An idealized block model with simple geometry for vertebra is employed to assess the feasibility of this method. Analyses are performed in both levels of motion segment and spinal column, and the result is compared with that from detail model. As far as the global behavior of spine is concerned, the simplification is found not to aggravate inaccuracy only if sufficient experimental data is provided and interpreted properly.

• The Journal of Korean Academy of Orthopedic Manual Physical Therapy
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• v.11 no.1
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• pp.74-91
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• 2005

척추의 기본적인 생체 역학적 기능은 신체 부분간의 운동을 허용하고 척수와 신경근을 보호하는 것으로서 이러한 기능을 수행하기 위해서는 척추의 역학적 안정성이 필수적이다. 척추의 안정체계는 수동적 근 골격계, 능동적 근 골격계, 그리고 신경계의 세 가지 하부체계로 나누어지며 이들 하부체계는 각각 독립적으로 안정성에 관여하고 있다. 경추의 불안정성의 문제는 비정상적으로 증가된 추간관절의 운동에 의해 염증성의 신경을 압박 또는 신장하거나 또는 통증수용기가 많이 분포하는 인대, 관절낭, 섬유륜과 종판에 비정상적인 변형을 일으키는 것을 말한다. 안정성의 장애는 근육의 기능적 측면에서 국소적 안정체계와 포괄적 안정체계의 문제로 구분할 수 있다. 불안정한 경추 환자의 임상적 양상은 일반적으로 머리가 앞으로 나오고 전방 전위된 자세로 견갑대와 승모근 상부의 과활동성을 나타낸다. 또한 능동운동은 감소되지 않으나 수동운동에서 분절의 회전운동과 병진운동의 증가와 종말감의 변화가 있다. 경추의 불안정성을 관리하기 위한 실험적 연구로 전반적인 근육 훈련, 고유수용기 훈련, 그리고 도수치료의 세 가지 주된 접근법이 있고 실제적인 접근법으로는 고유수용성 재활프로그램, 칼텐본-에반스 접근법, 그리고, 슬링운동법 등이 있다. 각 방법들은 임상에서 나름대로의 이점이 있으며 환자의 상태에 따라 이들 방법을 단독으로 또는 병행해서 적용할 수 있을 것이다. 그러나 경추에서 이러한 방법들의 효과를 입증하는 증거는 부족하여 앞으로 이러한 방법에 대한 임상적 경험보다는 그 효과를 입증할 수 있는 연구가 필요하다고 본다.

• Journal of Biomedical Engineering Research
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• v.22 no.6
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• pp.551-557
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• 2001

Occlusion of the dural-sac in the lumbar spine was quantitatively analysed using a one motion segment finite element mode developed in this study. Occlusion was quantified by calculating the cross sectional area chance of the dural-sac. In static analysis. less than 2 kN of compressive load could Produced no dural-sac occlusion. whereas 6kN load reduced cross sectional area by 4%, and produced 7.4%, 10.5% occlusion for additional 8 Nm. 10 Nm extension moments. respectively. In creep analysis, 10 Nm extension reduced cross sectional area and volume of the dural-sac by 6.9% and 2.4%, respectively. However. flexion moment could not produce any occlusion. The results suggested that occlusions may result mainly from slackening of ligamentum flavum and disc budging.

• Journal of Yeungnam Medical Science
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• v.15 no.1
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• pp.164-172
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• 1998

The Graf stabilization has been introduced in treating lumbar spinal disorder associated with posterior instability. This study reviewed some problems of the Graf instrumentation as a soft stabilizer. The purpose of this study is to analyse the problems of the soft stabilization in spinal instability. We reviewed 145 cases which were operative treatment using the Graf instrument for lumbar spinal disorder associated with posterior instability at our department from May, 1991 to Dec, 1995. The mean follow up periods was 29 months ranging from 24 months to 6 years 8 months. Of the 145 cases, 22 cases were showed the problem. The diagnostic method were simple x-ray, flexion-extension lateral stress view and CT scan. Results were as follows: Adjacent segmental instability was 10 cases(6.9%), disc space narrowing was 8 cases(5.5%), screw loosening was 3 cases(2.1%) and breakage of the Graf band was 1 case(0.6%). The problems of the soft stabilization were adjacent segmental instability, disc space narrowing, screw loosening, and breakage of the Graf band. But the rate of adjacent segmental instability and disc space narrowing was lower than other lumbar spinal instrumentation.

• Journal of the Korean Orthopaedic Association
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• v.56 no.3
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• pp.208-214
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• 2021

Purpose: Verifying a reliable predictor of the progression of vertebral deformity in patients with acute osteoporotic fractures of the lumbar spine may be useful. A qualitative analysis of the muscle near the spine was performed using magnetic resonance imaging (MRI), and its correlation with a spinal deformity was determined under the hypothesis that the causes of the kyphotic deformity are associated with muscle reduction in the multifidus and erector spinae. Materials and Methods: The study was performed in a retrospective manner using the electronic medical records of patients who presented to the author's institution between January 2007 and March 2018, and were diagnosed with an acute lumbar fracture. The fat infiltration rates of the multifidus and erector spinae were measured using MRI taken at the time of injury, and the mean value was defined as the total fat infiltration rate (TFI). Based on lateral radiographs of the lumbar spine at the one-year follow-up, the loss of height of the vertebral body, the kyphotic angle and the wedge angle were measured. The statistical significance was confirmed by calculating the Pearson correlation coefficient. Results: One hundred twenty-nine patients, of which 30 were male and 99 were female, were examined. The mean age was 71.28 years. The mean T-score was -3.53±0.79 g/cm², and the mean fat infiltration was 15.20%±11.99%. TFI was positively correlated with age (R=0.373, p<0.001), compression rate (R=0.369, p<0.001), and Cobb's angle (R=0.386, p<0.001) after a one year follow-up, but negatively correlated with the BMD score (R=-0.252, p=0.004). As the fracture progressed to the lower lumbar level, the compression rate (R=-0191, p=0.030) and wedge angle (R=-0.428, p<0.001) at the time of injury tended to decrease. Conclusion: In patients with osteoporotic vertebral fractures, the fat infiltration rate may be an important predictor of conservative treatment. The prognosis of patients with a high-fat infiltration rate should be explained during patient education, and the patients must be monitored closely through short-term outpatient follow-up.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.3
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• pp.224-230
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• 2016

The purpose of this study was to examine the effects of height of the shoe heel in a one leg standing posture on the muscle activity of the rectus abdominis, erector spinae, hamstring, and rectus femoris. Twenty healthy female subjects were asked to perform a one leg standing posture with three types of shoes, which had different heights of shoe heel, 0cm, 3cm, and 7cm. Surface electromyography was used to evaluate the activities of the right rectus abdominis, erector spinae, hamstring, and rectus femoris muscles. The data was analyzed by repeated one-way ANOVA and the muscle activities among three heights of shoe heel were compared. The results showed that the muscle activities of the erector spinae and rectus femoris increased significantly according to increase height of shoe heel (p<0.05). The activity of the rectus abdominis and hamstring were not significantly different among the three height of shoe heel (p>0.05). These results suggest that the height of shoe heel affects the lumbo-pelvic alignment and center of mass; therefore, high-heeled shoes lead to musculoskeletal pain in the lumbopelvic, hip, and knee areas.

• Journal of the Korean Society of Radiology
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• v.85 no.1
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• pp.36-53
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• 2024

As the number of spinal surgeries being performed expands, the number of medical imaging procedures such as radiography, CT, and MRI is also increasing, and the importance of their interpretation is becoming more significant. Herein, we present the radiological findings of a variety of complications that can occur after spinal surgery and discuss how effectively and accurately they can be diagnosed through imaging. In particular, this study details the characteristic imaging findings specific to the early and long-term postoperative periods. Early complications of spinal surgery include improper placement of surgical instruments (instrument malpositioning), seromas, hematomas, pseudomeningoceles, and infections in the region surrounding the surgical site. Conversely, long-term complications may include osteolysis around surgical instruments, failure of fusion, adjacent segment disease, and the formation of epidural fibrosis or scar tissue. A precise understanding of the imaging assessments related to complications arising after spinal surgery is crucial to ensure timely and accurate diagnosis, which is necessary to achieve effective treatment.

• Journal of Chest Surgery
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• v.32 no.8
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• pp.768-771
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• 1999

A 45 year old man was admitted for further examination of an abnormal shadow of the right posterior mediastinum. The patient suffered from dysesthesia in the right thoracic wall of dermatome T7. CT scan and MRI revealed that two separate tumors had developed in the right paravertebral area linked to the vertebral canal via an intervertebral foramina. One-stage removal of the tumors were performed safely through the right posterolateral thoracotomy following the resection of the rib head and vertebral pedicle. The tumors were confirmed as histologically neurilemomas. The postoperative course was uneventful.

• Journal of the Korean Orthopaedic Association
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• v.55 no.4
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• pp.318-323
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• 2020

Purpose: To examine the relationship between total fat infiltration (TFI) rate, which quantifies the reduction of muscles around the spine and is an important factor for sarcopenia, and the factors affecting osteoporotic vertebral compression fracture. Materials and Methods: Patients treated for osteoporotic compression fractures of the lumber spine from January 2012 to December 2016 were analyzed retrospectively. Among them, this study included ninety-eight patients who were 1) diagnosed with osteoporosis with a bone mineral density (BMD) T score of less than 2.5 g/cm², 2) received vertebroplasty or kyphoplasty for lumbar fractures, 3) involved one segment of the lumbar spine, and 4) were followed-up for more than one year. The TFI rate confirmed by analyzing magnetic resonance imagings with the Image J program was studied. Based on this, the relationship between the TFI of the multifidus and erector spinae muscles and the factors of osteoporosis were analyzed. Results: The mean TFI of the multifidus and erector spinae was 14.66±10.16. The spine BMD showed a positive correlation with the hip BMD, but a negative correlation with the TFI. A positive correlation was observed between the hip BMD and body mass index. In addition, vitamin D was positively correlated with both the hip and spine BMD but negatively correlated with the TFI rate. Conclusion: Muscle growth helps treat osteoporosis, and can prevent fractures that occur frequently in osteoporosis patients. Increasing the vitamin intake can also slow the progression of muscle atrophy.

• Journal of the Korean Orthopaedic Association
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• v.54 no.2
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• pp.141-149
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• 2019

Purpose: To compare the results of two different instruments made of stainless steel and titanium alloy for correction of single thoracic adolescent idiopathic scoliosis (AIS) using pedicle screw instrumentation. Materials and Methods: A total of 141 patients with single thoracic AIS treated with pedicle screw instrumentation and selective thoracic fusion were retrospectively reviewed after a follow-up of 2 years. The patients had a main thoracic curve of 40° to 75° and were divided into two groups based on instrument materials; S group (stainless steel, n=90) and T group (titanium alloy, n=51). The diameter of the stainless steel rod used was 7.0 mm while that of the titanium alloy rod was 6.35 mm or 6.0 mm. Standing long-cassette radiographic measurements including various coronal and sagittal parameters for the preoperative, early postoperative and 2-year postoperative followup were analyzed. There were no significant differences in the preoperative curve characteristics between the two groups. Results: In the S group, the preoperative main thoracic curve of 51.3°±8.4° was improved to 19.0°±7.6° (63.1% correction) and the lumbar curve of 32.3°±8.4° spontaneously decreased to 12.7°±8.2° (62.9% correction) at 2 years postoperatively. In the T group, the preoperative main thoracic curve of 49.5°±8.4° and the lumbar curve of 30.3°±8.9° was improved to 18.8°±7.4° (62.2% correction) and 11.3°±5.4° (63.3% correction), respectively. The corrections of coronal curves were not statistically different between the two groups (p>0.05). The thoracic kyphosis was changed from 16.8°±8.5° to 24.3°±6.1° in the S group and from 19.6°±11.2° to 26.6°±8.5° in the T group. There were no significant differences in the changes of sagittal curves, coronal and sagittal balances at the 2-year follow-up and the number of fused segments and used screws between the two groups (p>0.05). Conclusion: When conducting surgery for single thoracic AIS using pedicles screw instrumentation, two different instruments made of stainless steel and titanium alloy showed similar corrections for coronal and sagittal curves.