• Title/Summary/Keyword: Vertebrae

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Biomechanical analysis of pullout strength of the pedicle screws in relation to change bone mineral density (반복 하중 후 골밀도 감소에 따른 척추경 나사못의 고정력(Pullout Strength)감소 형태 분석)

  • Jung, D.Y.;Lee, S.J.;Kim, D.S.;Shin, J.W.;Kim, W.J.;Suk, S.I.
    • Proceedings of the KOSOMBE Conference
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    • v.1998 no.11
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    • pp.155-156
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    • 1998
  • Screw loosening and subsequent pullout can be attributed to the reduction in bone mineral density in the vertebrae manifested by osteoporosis in which the decrease in fixation strength between the cancellous bone and screw threads are accelerated by repeated loads exerted by patients own weight and activities following the surgery. In this study, the change in pullout strength of the pedicle screws was investigated before and after repeated loads were imparted. For this purpose. Diapason pedicle screws $(6.7\times40mm)$ were inserted onto fresh porcine spine specimens (T1-L5) after bone mineral density was measured using a DEXA. With an MTS, an axial load was applied at a loading rate of 0.33mm/sec until failure to measure the maximum pullout strength. Flexion moment of 7.5N-m was then imparted at 0.5Hz for 2000 cycles. It was found that the maximum pullout strength was exponentially related to BMD regardless of load types ($107.71\;\times\;\exp^{(1.43{\times}BMD)}r^2=0.93$, P<0.0001 without repeated load; ($107.71\;\times\;\exp^{(2.19{\times}BMD)}r^2=0.78$, P<0.0001 with repeated load). The results suggest that the reduction in pullout strength for pedicle screws is far more prominent in osteoporotic spine than in normal spine especially as number of repeated load was increased. More importantly, it was demonstrated that the level of bone mineral density and the activity level of the patient should be evaluated in more detail for successful implementation of pedicle screw systems in spinal surgery.

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Regional variation in vertebral bone density and structure due to osteoporosis (골다공증에 따른 부위별 골 밀도와 구조의 변화)

  • Park, J.H.;Lee, S.J.;Chang, H.;Choi, W.S.;Kang, C.;Tack, G.R.
    • Proceedings of the KOSOMBE Conference
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    • v.1998 no.11
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    • pp.169-170
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    • 1998
  • In this study, regional variation in vertebral bone density due to osteoporosis were investigated using a method that employs images from QCT. QCT images(1mm thick slices) of the first lumbar vertebra from a normal person (23/M, BMD=139.8mg/ml) and from an osteoporotic patient (54/F, BMD=82.0mg/ml) were obtained. Uniform settings (140kVp, 204mA) were used and images of 300 Hounsfield Unit or greater were selectied to filler out soft tissue interference. To assess the regional variation of the area fraction the vertebral body was divided into 3 layers and each layer contained 9 regions. Area faction was calculated based on image analysis data. Our results showed that the area fraction at the middle of the vertebra was quite lower than the endplate and peripheral regions, but the area fraction values from the osteoporotic patient were uniform throughout the entire height of the vertebral body, which indicates the significant drop of BMD had occurred near both end-plates due to the osteoporosis, especially at the peripheral regions. Our results suggest the susceptability of the vertebrae to compression fracture types in osteoporotic spine.

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Evaluation of Hormone Deficiency in Vertebral Body: Analysis of Bone Structure and Quality (호르몬 결핍이 척추체에 미치는 영향 평가: 골의 구조학적 및 질적 요소 분석)

  • Kim, Chi-Hoon;Woo, Dae-Gon;Park, Ji-Hyung;Lee, Beob-Yi;Kim, Chi-Hyun;Kim, Han-Sung
    • Journal of the Korean Society for Precision Engineering
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    • v.27 no.5
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    • pp.92-101
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    • 2010
  • This study evaluated the structure and quality of osteoporotic vertebral bone. To induce osteoporosis, eight rats were ovariectomized (OVX). All rats were divided into two groups (Normal group: 4, OVX group: 4). Total lumbar vertebrae for each rat were scanned by in-vivo ${\mu}CT$ at 0, 4 and 8 weeks. Morphological characteristics (BV/TV, Tb.Th, Tb.N, Tb.Sp and SMI) were calculated by in-vivo ${\mu}CT$ image analyzer. Three dimensional finite element models were analyzed to investigate bone strength of OVX and Normal groups. Moreover, the elastic modulus was quantitatively analyzed to evaluate the quality changes of osteoporotic bone. In the OVX group, BV/TV, Tb.Th and Tb.N were significantly decreased at all the lumbar over time (p<0.05). We also investigated a contrary tendency in Tb.Sp and SMI, compared to the above results in each group. A degree of alteration of mechanical characteristics in OVX group was decreased over measuring time (p<0.05). Bone quality presented by distribution of elastic modulus was improved in the Normal group more than OVX group. The findings of the present study indicated that both bone structure and quality of whole lumbar could be tracked and detected by analyzing the morphological and biomechanical characteristics of bones, based on a nondestructive method.

The Influence of the Glenohumeral Rotation on the Scapulothoracic Motion (관절과 상완 관절의 회전운동이 견갑흉곽 운동에 미치는 영향)

  • Seo Joong-Bae;Choi Eui-Seong;Won Choong-Hee;Kim Yong-Min;Lee Ho-Seung;Kim Eung-Rok
    • Clinics in Shoulder and Elbow
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    • v.1 no.2
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    • pp.186-192
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    • 1998
  • This study was performed to evaluate the influences of the passive glenohumeral rotation on the scapulothoracic motion. We took anteroposterior radiograms of the right shoulders including the thoracic vertebrae with supine position in 10 normal male adults, at 0 degree abduction, 45 degrees abduction and 90 degrees abduction in scapular plane and in neutral rotation, maximal internal rotation and maximal external rotation in each abduction view. The scapulothoracic motion was measured as the distances between the vertical line drawn from the spinous process of the 7th cervical vertebra and the inferior and superior angles of the right scapula respectively. At 0 degree abduction, the distances were not changed in internal rotation relative to neutral rotation, but decreased significantly in external rotation, that is, the scapula shifts medially on external rotation. At 45 degrees abduction, the distances were increased significantly only in internal rotation, that is, the scapula shifts laterally on internal rotation. At 90 degrees abduction, the scapula rotated laterally on internal rotation and medially on external rotation. In conclusion, when a physician examines the rotation of the shoulder joint, he cannot exclude the scapulothoracic motion just by examining the patient with supine position. And we concluded that the rotatory movement of the shoulder is not solely contributed to the glenohumeral motion.

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The Adequacy of a Cross Table Lateral Cervical X-ray in Severely Traumatized Korean Patients (한국인 중증 외상 환자에서 촬영한 경추 외측면 단순 방사선 영상의 적절성)

  • Lee, Kyung-Hag;Kim, Yeong Cheol;Choi, Seok Ho;Han, Gook Nam;Lee, Soo Un;Lee, Jung Eun;Suh, Gil Joon;Yoon, Yeo-Kyu
    • Journal of Trauma and Injury
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    • v.25 no.4
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    • pp.241-246
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    • 2012
  • Purpose: The objective of this study was to investigate the appropriateness of the cross table lateral cervical X-ray used in the emergency department for severely traumatized Korean patients. Methods: Patients visiting our institution from May 2011 to May 2012, who had injury severity score (ISS) > 15 and who received a cervical X-ray in the emergency department, were included in this study. Data including demographics, ISS score, GCS score, and place where the x-ray was taken were collected to evaluate their relationship with appropriate coverage of the cervical X-ray. The appropriateness of a cervical cross lateral view X-ray was evaluated using exposure of the basion, and the opisthion, as well as the distal level of exposure. Results: Fifty-two patients were included in this study. The identification rate of the basion was 79.2%, and the identification rate of the opisthion was 88.7%. Complete exposure of C7/T1 was accomplished in 3.8% of the patients. The ISS was higher for X-ray taken in the trauma bay, but the range of exposure showed no difference between the places where the X-rays taken. Patients who had exposure of C 5/6 or more had lower body weight and body mass index (BMI) compared with unexposed patients. Conclusion: In severely traumatized Korean patients, the adequacy of the cross table lateral cervical X-ray was inappropriate in most cases. No difference was observed in the exposure range between the places where the X-rays were taken, and patients with less exposure showed higher body weight and higher BMI.

Predictive Factors for Cervical Spine Injury in Patients with Minor Head Injury (경증 두부 외상을 가진 환자의 경추 손상을 예측할 수 있는 관련 인자)

  • Park, Chul Woo;Sung, Ae Jin;Lee, Jun Ho;Hwang, Seong Youn
    • Journal of Trauma and Injury
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    • v.22 no.2
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    • pp.154-160
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    • 2009
  • Purpose: This study aimed to determine new criteria for detecting independent factors with high sensitivity in cases of cervical spine injury. We compared the sensitivity, the specificity, and the false negative predictive value (NPV) of plain radiographs with those of computed tomography for cervical spine injury in patients with minor head injury. Methods: We retrospectively reviewed the cases of 357 patients who underwent both cervical plain radiographs and computer tomography from January 2006, to September 2008. Patients were divided into two groups: the cervical spine injury group and the no cervical spine injury group. New criteria were organized based on variables that had significant differences in the logistic regression test. Results: Among the 357 patients, 78 patients had cervical spine injuries. The average age was $43.9{\pm}15.2$ yrs old, and the male-to-female ratio was 1.90. The most common mechanism of injury was motor vehicle accidents. There was a significant difference in loss of consciousness, Glasgow Coma Scale (GCS)=14, neurologic deficit, posterior neck tenderness, and abnormality of the cervical plain radiographs between the two groups on the logistic regression test. New criteria included the above five variables. If a patient has at least variable, the area under the ROC curve of the new criteria was 0.850, and the sensitivity and the false NPV were 87.2% and 5.2%, respectively. Conclusion: New criteria included loss of consciousness, GCS=14, neurologic deficit, posterior neck tenderness, and abnormality of the cervical plain radiographs. If the patient had at least 1 variable, he or she could have a of cervical spine injury with a sensitivity of 87.2% and a false NPV of 5.2%.

Neural Tube Defects with Abdominal Wall Defects in Sibling Dogs (복벽결손을 동반한 동복자견의 신경관결손)

  • Cho, Sung-Jin;Kim, Ok-Jin
    • Journal of Veterinary Clinics
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    • v.26 no.5
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    • pp.467-471
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    • 2009
  • This report describes Neural Tube Defects (NTDs) with Abdominal Wall Defects (AWDs) on the sibling of Yorkshire terriers. The NTDs and AWDs are rare serious congenital defects. The NTDs are neurulation abnormality that results from to failed transformation of the neurual tube by the incomplete closure of the embryonic neural plate. These dysraphic states range form mild to severe according to developmental malformation that include fusion defects of skull (crania bifida; CB) and fusion defects of vertebrae (spina bifida; SB). The AWDs are genetic defects that results from to failed formation of abdominal wall and cavity. These dysraphic states are omphalocele and gastroschisis. The 12-month dam was delivered by caesarian section and 4 littermate had obvious malformations. One male dead stillbirth fetus (L1) was revealed the extruded abdominal viscera, omphalocele. One female fetus (L2) was died within 1 hour after birth with defects of abdominal muscle upper umbilicus, gastroschisis. 3rd fetus (L3) was died within 36 hours after parturition and revealed a copious dermal and vertebral defects on the midline thorax, upper SB asperta. 4th fetus (L4) is still growing well now at 6 months but at the 2 week age, appears hairy nevus on the frontal cranium and dorsal thoracic portion. The radiograph of L1 and L2 are shown decrease bony density of calvarium and L3 was shown defect of spinose processes of the T9-T13. On our knowledge, this is first report of the SB and CB in Yorkshire terrier. And also sibling of NTDs with AWDs that has not previously been reported in the dog.

Effect of Diaphragmatic Breathing Exercise on Activation of Lumbar Paraspinal Muscles of Healthy people. (복식호흡 운동이 요부근육의 활성화에 미치는 영향)

  • Kim, Kyoung
    • Journal of the Korean Society of Physical Medicine
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    • v.1 no.1
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    • pp.59-66
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    • 2006
  • Purpose : The purpose of this study was to investigate the effects of diaphragmatic breathing on activation of lumbar paraspinal muscles of normal healthy people. Diaphragmatic breathing may affect activation of trunk muscles. The assumptions are as follows: the crural diaphragm attatches to the lumbar vertebrae from L1 to L3, the voluntary downward pressurization of the diaphragm increases intra-abdominal pressure, and this increases the stiffness of the spine. Methods : Sixty male college students ranging 19 to 34 years were screened and % maximal voluntary contraction(% MVC) of trunk muscles on the four positions of back extension exercise was compared during the pre and post of inspiration of diaphragmatic breathing. Results : 1. % MVC of right and left erector spinae had the statistically significant difference between pre and post inspiration of diaphragmatic breathing in the dynamic right arm and left leg extension position(p<0.05). 2. % MVC of right and left erector spinae had the statistically significant difference between pre and post inspiration of diaphragmatic breathing in the dynamic left arm and right leg extension position(p<0.05). 3. % MVC of right and left erector spinae had the statistically significant difference between pre and post inspiration of diaphragmatic breathing in the static lying prone extension position(p<0.05). 4. % MVC of right and left erector spinae had the statistically significant difference between pre and post inspiration of diaphragmatic breathing in the static lying on prone position(p<0.05). Conclusion : This study will be used as the purpose of data collection of lumbar paraspinal muscles on diaphragmatic breathing and be introduced as the new therapeutic intervention for management of patients with back pain.

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Effects of Self-stretching and Joint Mobilization to Upper Thoracic Vertebrae in Craniovertebral Angle and Autonomic System Function in Chronic Cervical Pain (만성 목통증에 대한 자가신장과 위등뼈 관절가동술이 머리척추각 및 자율신경계 기능에 미치는 효과)

  • Nam, Ki-Won;Kim, Se-Hun;Seo, Dong-Yel
    • Journal of the Korean Society of Physical Medicine
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    • v.13 no.2
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    • pp.61-68
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    • 2018
  • PURPOSE: This study aimed to examine the effects of self-stretching (SS) and joint mobilization (JM) on pain, craniovertebral angle (CVA), autonomic system function in chronic cervical pain patient with forward head posture (FHP). METHODS: A total of 30 male college students were selected as study subjects, and were divided into Group I (general physical therapy; GPT, n=10), Group II (GPT+SS, n=10), Group III (GPT+JM, n=10). All groups were evaluated three times a week for 4 weeks. Pain was measured by visual analogue scale (VAS), CVA was measured using digital goniometer and autonomic system function (heart rate; HR, skin conductivity; SC, LF norm, HF norm, LF/HF ratio) was measured by Biofeedback ProComp Infiniti. After 4 weeks, paired t-test was used to compare the changes within the group and one way ANOVA was used to compare those between the groups. RESULTS: In Group I, VAS was significantly decreased. In Group II and III was a significantly change in all items. In comparison between Group I and II was a difference in all items except HR. In comparison between Group I and III was a difference in all items. In comparison between Group II and III was a difference in VAS, LF norm and LF/HF ratio. CONCLUSION: This study showed that SS and JM can effectively reduce pain and normalize the autonomic system function.

Outbreaks of Akabane Diseasc of Cattle in Korea (한국(韓國)에서의 소의 Akabane병(病)의 발생(發生))

  • Bak, Ung-Bok;Lim, Chang Hyeong;Cheong, Chang Kook;Hwang, Woo Suk;Cho, Myung Rae
    • Korean Journal of Veterinary Research
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    • v.20 no.1
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    • pp.65-78
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    • 1980
  • From November 1978 to April 1979, there occurred among cows many cases of abortion, premature birth, stillbirth and congenital arthrogryposis or hydranencephaly in Kyongki-do province in Korea. Epizootics recurred between February and May, 1980 in the same area. Six calves born at 8 or 10 months of gestation were examined by means of pathology and one of the calves was examined by serological test. And a survey on local occurrence of the disease in other than Kyongki-do province, was conducted. 1. At necropsy, some calves showed distinct lesions such deformities of the limbs and the vertebrae as arthrogryposis or scoliosis. Other calves revealed arthrogryposis and partial or total deficience of the cerebral hemispheres with hydranencephaly. 2. In the calves with deformities the skeletal muscle showed histologically severe hypoplasia of the muscle fibers with cellular infiltration. In the central nervous system of the calves with hydranencephaly there were minute cystic cavitation and the decrease of ventral horn cells of the spinal cord in the number. 3. Similar epizootics were also observed in the same season in the other several provinces such as Chungoheongnam-do, Kangwon-do and Jeonrabuk-do. 4. Anti-Akabane virus antibody was detected in precolostral blood from the calf with arthroglposis and hydranencephaly syndrome. 5. On these findings of the disease it was diagnosed as Akabane disease presenting the first report on the epizootics in Korea.

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