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A Study of Masterplot of Disaster Narrative between Korea, the US and Japan (한·미·일 재난 서사의 마스터플롯 비교 연구)

  • Park, In-Seong
    • Journal of Popular Narrative
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    • v.26 no.2
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    • pp.39-85
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    • 2020
  • This paper examines the aspects of disaster narrative, which makes the most of the concept of 'masterplot' as a narrative simulation to solve problems. By analyzing and comparing the remnants of 'masterplots' operating in the disaster narratives of Korea, the United States, and Japan, the differences between each country and social community problem recognition and resolution will be discussed. Disaster narrative is the most suitable genre for applying the 'masterplot' toward community problem solving in today's global risk society, and the problem-solving method has cognitive differences for each community. First, in the case of American disaster narratives, civilian experts' response to natural disasters tracks the changes of heroes in today's 'Marvel Comic Universe' (MCU). Compared to the past, the close relationship between heroism and nationalism has been reduced, but the state remains functional even if it is bolstered by the heroes' voluntary cooperation and reflection ability. On the other hand, in Korea's disaster narratives, the disappearance of the country and paralysis of the function are foregrounded. In order to fill the void, a new family narrative occurs, consisting of a righteous army or people abandoned by the state. Korea's disaster narratives are sensitive to changes after the disaster, and the nation's recovery never returns to normal after the disaster. Finally, Japan's disaster narratives are defensive and neurotic. A fully state-led bureaucratic system depicts an obsessive nationalism that seeks to control all disasters, or even counteracts anti-heroic individuals who reject voluntary sacrifices and even abandon disaster conditions This paper was able to diagnose the impact and value of a 'masterplot' today by comparing a series of 'masterplots' and their variations and uses. In a time when the understanding and utilization of 'masterplots' are becoming more and more important in today's world where Over-the top(OTT) services are being provided worldwide, this paper attempt could be a fragmentary model for the distribution and sharing of global stories.

Seeking for a Curriculum of Dance Department in the University in the Age of the 4th Industrial Revolution (4차 산업혁명시대 대학무용학과 커리큘럼의 방향모색)

  • Baek, Hyun-Soon;Yoo, Ji-Young
    • Journal of Korea Entertainment Industry Association
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    • v.13 no.3
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    • pp.193-202
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    • 2019
  • This study focuses on what changes are required as to a curriculum of dance department in the university in the age of the 4th industrial revolution. By comparing and analyzing the curricula of dance department in the five universities in Seoul, five academic subjects as to curricula of dance department, which covers what to learn for dance education in the age of the 4th industrial revolution, are presented. First, dance integrative education, the integration of creativity and science education, can be referred to as a subject that stimulates ideas and creativity and raises artistic sensitivity based on STEAM. Second, the curriculum characterized by prediction of the future prospect through Big Data can be utilized well in dealing with dance performance, career path of dance-majoring people, and job creation by analyzing public opinion, evaluation, and feelings. Third, video education. Seeing the images as modern major media tends to occupy most of the expressive area of art, dance by dint of video enables existing dance work to be created as new form of art, expanding dance boundaries in academic and performing art viewpoint. Fourth, VR and AR are essential techniques in the era of smart media. Whether upcoming dance studies are in the form of performance or education or industry, for VR and AR to be digitally applied into every relevant field, keeping with the time, learning about VR and AR is indispensable. Last, the 4th industrial revolution and the curriculum of dance art are needed to foresee the changes in the 4th industrial revolution and to educate changes, development and seeking in dance curriculum.

A Reinterpretation of the Differences between the Tales of Jinmuk shown in The Investigation of Historical Remains of Patriarch Jinmuk and The Canonical Scripture: Highlighting Differences between Literary Transmission and Oral Transmission (『진묵조사유적고』와 『전경』에 나타난 진묵 설화의 차이에 대한 재해석 -문헌 전승과 구전 전승의 차이를 중심으로-)

  • Kim Tae-soo
    • Journal of the Daesoon Academy of Sciences
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    • v.41
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    • pp.179-217
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    • 2022
  • Concerning the differences in the tales between the Investigation of Historical Remains of Patriarch Jinmuk (hereafter, IHRPJ), as well as those which appear in Jeungsanist Thought and Daesoon Thought, previous studies view such differences as Jeungsan's intentional modification of the original intent of the narratives or as indicating differences in beliefs and values. This style of interpretation seeks to reconcile both Korean Buddhism and Jeungsanist and Daesoon Thought based on the premise that the former and the latter two exhibit differences in values. This study accepts the above view of the differences in description according to values. However, the differences between the tales of Jinmuk that appears in IHRPJ versus those in The Canonical Scripture can be approached from a new perspective, i.e., the differences that exist between literary and oral traditions; rather than only stemming from potential differences in the world views espoused by Buddhism and Daesoon Thought. These refer to the IHRPJ, which was constructed first as literary narratives in the 19th century; however, there was also folklore that had been handed down from the 18th century. As a result of examining the relationship between Jinmuk and Bonggok via this interpretive horizon, the contents of the IHRPJ are found to reflect the values and intentions of the intellectual class, such those held by Master Cho-ui and Kim Ki-jong, whereas oral traditions can be seen as a reflection of the hopes of the people of the late Joseon Dynasty. Jeungsan should also be interpreted as having utilized folklore in his teachings. Meanwhile, the circumstances and intentions behind publishing the IHRPJ are analyzed in the context of the text's historical background and the relationship between Confucianism and Buddhism during the 16th through 19th centuries. In particular, through the Compilations of Wandang and the collection of writings of Buddhist monastics, I have evaluated that Confucianism needed to purify and correct materials according to the ideology of the times in order to promote a spirit of morality and courtesy. Likewise, Buddhist Master Cho-Ui also embellished records to benefit Buddhism and deleted oral records that could harm the reputation of Buddhism. On the other hand, when viewing Records of Shrine Renovation and existing oral traditions, it can be shown that some Jinmuk tales existed in the 18 th century which were not included in the IHRPJ. Thereby, Jeungsan's description of Jinmuk tales can be reappraised as accepting the oral secular tradition that conveyed the wishes of the people. In other words, compared to the IHRPJ, which reflects only the harmonious content of Confucianism and Buddhism due to political and social factors, The Canonical Scripture reflects oral traditions that were widespread during the late Joseon Dynasty. As evidence, it can be suggested that there are many narratives about the relationship between Jinmuk and Bonggok that center on Bonggok's jealousy and the murder of Jinmuk. Jeungsan aimed to encompass people of all classes according to their minds and wills rather than their political positions or statuses. Therefore, Jeungsan did not need to rewrite the narrative content that had been passed down via oral tradition. Instead he embraced those narratives as a projection of the voices of the people.

Analysis of the Effect of Corner Points and Image Resolution in a Mechanical Test Combining Digital Image Processing and Mesh-free Method (디지털 이미지 처리와 강형식 기반의 무요소법을 융합한 시험법의 모서리 점과 이미지 해상도의 영향 분석)

  • Junwon Park;Yeon-Suk Jeong;Young-Cheol Yoon
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.37 no.1
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    • pp.67-76
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    • 2024
  • In this paper, we present a DIP-MLS testing method that combines digital image processing with a rigid body-based MLS differencing approach to measure mechanical variables and analyze the impact of target location and image resolution. This method assesses the displacement of the target attached to the sample through digital image processing and allocates this displacement to the node displacement of the MLS differencing method, which solely employs nodes to calculate mechanical variables such as stress and strain of the studied object. We propose an effective method to measure the displacement of the target's center of gravity using digital image processing. The calculation of mechanical variables through the MLS differencing method, incorporating image-based target displacement, facilitates easy computation of mechanical variables at arbitrary positions without constraints from meshes or grids. This is achieved by acquiring the accurate displacement history of the test specimen and utilizing the displacement of tracking points with low rigidity. The developed testing method was validated by comparing the measurement results of the sensor with those of the DIP-MLS testing method in a three-point bending test of a rubber beam. Additionally, numerical analysis results simulated only by the MLS differencing method were compared, confirming that the developed method accurately reproduces the actual test and shows good agreement with numerical analysis results before significant deformation. Furthermore, we analyzed the effects of boundary points by applying 46 tracking points, including corner points, to the DIP-MLS testing method. This was compared with using only the internal points of the target, determining the optimal image resolution for this testing method. Through this, we demonstrated that the developed method efficiently addresses the limitations of direct experiments or existing mesh-based simulations. It also suggests that digitalization of the experimental-simulation process is achievable to a considerable extent.

Usefulness of Abdominal Compressor Using Stereotactic Body Radiotherapy with Hepatocellular Carcinoma Patients (토모테라피를 이용한 간암환자의 정위적 방사선치료시 복부압박장치의 유용성 평가)

  • Woo, Joong-Yeol;Kim, Joo-Ho;Kim, Joon-Won;Baek, Jong-Geal;Park, Kwang-Soon;Lee, Jong-Min;Son, Dong-Min;Lee, Sang-Kyoo;Jeon, Byeong-Chul;Cho, Jeong-Hee
    • The Journal of Korean Society for Radiation Therapy
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    • v.24 no.2
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    • pp.157-165
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    • 2012
  • Purpose: We evaluated usefulness of abdominal compressor for stereotactic body radiotherapy (SBRT) with unresectable hepatocellular carcinoma (HCC) patients and hepato-biliary cancer and metastatic liver cancer patients. Materials and Methods: From November 2011 to March 2012, we selected HCC patients who gained reduction of diaphragm movement >1 cm through abdominal compressor (diaphragm control, elekta, sweden) for HT (Hi-Art Tomotherapy, USA). We got planning computed tomography (CT) images and 4 dimensional (4D) images through 4D CT (somatom sensation, siemens, germany). The gross tumor volume (GTV) included a gross tumor and margins considering tumor movement. The planning target volume (PTV) included a 5 to 7 mm safety margin around GTV. We classified patients into two groups according to distance between tumor and organs at risk (OAR, stomach, duodenum, bowel). Patients with the distance more than 1 cm are classified as the 1st group and they received SBRT of 4 or 5 fractions. Patients with the distance less than 1 cm are classified as the 2nd group and they received tomotherapy of 20 fractions. Megavoltage computed tomography (MVCT) were performed 4 or 10 fractions. When we verify a MVCT fusion considering priority to liver than bone-technique. We sent MVCT images to Mim_vista (Mimsoftware, ver .5.4. USA) and we re-delineated stomach, duodenum and bowel to bowel_organ and delineated liver. First, we analyzed MVCT images to check the setup variation. Second we compared dose difference between tumor and OAR based on adaptive dose through adaptive planning station and Mim_vista. Results: Average setup variation from MVCT was $-0.66{\pm}1.53$ mm (left-right) $0.39{\pm}4.17$ mm (superior-inferior), $0.71{\pm}1.74$ mm (anterior-posterior), $-0.18{\pm}0.30$ degrees (roll). 1st group ($d{\geq}1$) and 2nd group (d<1) were similar to setup variation. 1st group ($d{\geq}1$) of $V_{diff3%}$ (volume of 3% difference of dose) of GTV through adaptive planing station was $0.78{\pm}0.05%$, PTV was $9.97{\pm}3.62%$, $V_{diff5%}$ was GTV 0.0%, PTV was $2.9{\pm}0.95%$, maximum dose difference rate of bowel_organ was $-6.85{\pm}1.11%$. 2nd Group (d<1) GTV of $V_{diff3%}$ was $1.62{\pm}0.55%$, PTV was $8.61{\pm}2.01%$, $V_{diff5%}$ of GTV was 0.0%, PTV was $5.33{\pm}2.32%$, maximum dose difference rate of bowel_organ was $28.33{\pm}24.41%$. Conclusion: Despite we saw diaphragm movement more than 5 mm with flouroscopy after use an abdominal compressor, average setup_variation from MVCT was less than 5 mm. Therefore, we could estimate the range of setup_error within a 5 mm. Target's dose difference rate of 1st group ($d{\geq}1$) and 2nd group (d<1) were similar, while 1st group ($d{\geq}1$) and 2nd group (d<1)'s bowel_organ's maximum dose difference rate's maximum difference was more than 35%, 1st group ($d{\geq}1$)'s bowel_organ's maximum dose difference rate was smaller than 2nd group (d<1). When applicating SBRT to HCC, abdominal compressor is useful to control diaphragm movement in selected patients with more than 1 cm bowel_organ distance.

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Early and Mid-term Results of Operation for Infective Endocarditis on Mitral Valve (감염성 승모판 심내막염의 중단기 수술 성적)

  • Ahn, Byong-Hee;Chun, Joon-Kyung;Yu, Ung;Ryu, Sang-Wan;Choi, Yong-Sun;Kim, Byong-Pyo;Hong, Sung-Bum;Bum, Min-Sun;Na, Kook-Ju;Park, Jong-Chun;Kim, Sang-Hyung
    • Journal of Chest Surgery
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    • v.37 no.1
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    • pp.27-34
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    • 2004
  • Background: Infective endocarditis shows higher operative morbidity and mortality rates than other cardiac diseases. The vast majority of studies on infective endocarditis have been made on aortic endocarditis, with little attention having been paid to infective endocarditis on the mitral valve. This study attempts to investigate the clinical aspects and operative results of infective endocarditis on the mitral valve. Meterial and Method: The subjects of this study consist of 23 patients who underwent operations for infective endocariditis on the mitral valve from June 1995 to May 2003. Among them, 2 patients suffered from prosthetic valvular endocarditis and the other 21 from native valvular endocarditis. The subjects were evenly distributed age-wise with an average age of 44.8$\pm$15.7 (11∼66) years. Emergency operations were performed on seventeen patients (73.9%) due to large vegetation or instable hemodynamic status. In preoperative examinations, twelve patients exhibited congestive heart failure, four patients renal failure, two patients spleen and renal infarction, and two patients temporary neurological defects, while one patient had a brain abscess. Based on the NYHA functional classification, seven patients were determined to be at Grade II, 9 patients at Grade III, and 6 patients at Grade IV. Vegetations were detected in 20 patients while mitral regurgitation was dominant in 19 patients with 4 patients showing up as mitral stenosis dominant on the preoperative echocardiogram. Blood cultures for causative organisms were performed on all patients, and positive results were obtained from ten patients, with five cases of Streptococcus viridance, two cases of methicillin-sensitive Staphylococcus aureus, and one case each of Corynebacteriurn, Haemophillis, and Gernella. Operations were decided according to the AA/AHA guidelines (1988). The mean follow-up period was 27.6 $\pm$23.3 (1 ∼ 97) months. Result: Mitral valve replacements were performed on 43 patients, with mechanical valves being used on 9 patients and tissue valves on the other 4. Several kinds of mitral valve repair or mitral valvuloplasty were carried out on the remaining 10 patients. Associated procedures included six aortic valve replacements, two tricuspid annuloplasty, one modified Maze operation, and one direct closure of a ventricular septal defect. Postoperative complications included two cases of bleeding and one case each of mediastinitis, low cardiac output syndrome, and pneumonia. There were no cases of early deaths, or death within 30 days following the operation. No patient died in the hospital or experienced valve related complications. One patient, however, underwent mitral valvuloplasty 3 months after the operation. Another patient died from intra-cranial hemorrhage in the 31st month after the operation. Therefore, the valve-related death rate was 4.3%, and the valve-related complication rate 8.6% on mid-term follow-up. 1, 3-, and 5-year valve- related event free rates were 90.8%, 79.5%, and 79.5%, respectively, while 1, follow-up. 1, 3-, and 5-year valve- related event free rates were 90.8%, 79.5%, and 79.5%, respectively, while 1, 3-, and 5-year survival rates were 100%, 88.8%, and 88.8%, respectively. Conclusion: The findings suggest that a complete removal of infected tissues is essential in the operative treatment of infectious endocarditis of the mitral valve. It is also suggested that when infected tissues are completely removed, neither type of material nor method of operation has a significant effect on the operation result. The postoperative results also suggest the need for a close follow-up observation of the patients suspected of having brain damage, which is caused by preoperative blood contamination or emboli from vegetation, for a possible cerebral vascular injury such as mycotic aneurysm.

Effects of Rye Silage on Growth Performance, Blood Characteristics, and Carcass Quality in Finishing Pigs (호맥 사일리지의 급여기간이 비육돈의 생산성, 혈액 성상 및 도체특성에 미치는 영향)

  • Shin, Seung-Oh;Han, Young-Keun;Cho, Jin-Ho;Kim, Hae-Jin;Chen, Ying-Jie;Yoo, Jong-Sang;Whang, Kwang-Youn;Kim, Jung-Woo;Kim, In-Ho
    • Food Science of Animal Resources
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    • v.27 no.4
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    • pp.392-400
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    • 2007
  • This experiment was conducted to evaluate effects of various periods of rye silage feeding on the growth performance, blood characteristics, and carcass quality of finishing pigs. A total of sixteen [($Landrace{\times}Yorkshire{\times}Duroc$)] pigs (90.26 kg in average initial body weight) were tested in individual cages for a 30 day period. Dietary treatments included 1) CON (basal diet), 2) S10 (basal diet for 20 days and 3% rye silage for 10 days) 3) S20 (basal diet for 10 days and 3% rye silage for 20 days) and 4) S30 (3% rye silage for 30 days). There were no significant differences in the ADG and gain/feed ratio among the treatments(p>0.05), however the ADFI was higher in pigs fed the CON diet than with pigs fed diets with rye silage (p<0.05). The DM digestibility was higher with the S20 diet than with the S30 diet (p<0.05). With regard to blood characteristics, pigs fed rye silage had a significantly reduced cortisol concentration compared to pigs fed the CON diet (p<0.05). The backfat thickness was higher with the CON diet than with the S20 or S30 diets (p<0.05). Regarding the fatty acid contents of the leans, the C18:0 and total SFA were significantly higher with the CON diet than with the other diets (p<0.05). However, the C18:1n9, total MUFA and UFA/SFA levels were significantly lower with the CON diet than the other diets (p<0.05). Regarding the fatty acid contents of fat, the levels of C18:1n9 and MUFA were similar with the S20 and S30 diets, however, these levels were higher than with the CON or S10 diets (p<0.05). In conclusion, feed intake and DM digestibility were affected by rye silage, and the cortisol concentration, backfat thickness and fatty acid composition of pork were positively affected by feeding pigs rye silage.

The study on the cleft lip and/or palate patients who visited Dept. of Orthodontics, Seoul National University Dental Hospital during last 11 years (1988.3-1999.2) (최근 11년간 서울대학교병원 교정과에 내원한 순구개열 환자의 내원 현황에 관한 연구(1988.3 - 1999.2))

  • Yang, Won-Sik;Baek, Seung-Hak
    • The korean journal of orthodontics
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    • v.29 no.4 s.75
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    • pp.467-481
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    • 1999
  • Cleft lip and/or palate is one of the most common congenital craniofacial anomalies. According to previous epidemiologic studies, incidence of cleft lip and/or palate has been increasing nowadays. However, there is no report about epidemiologic study of cleft lip and/or palate patients who visited dept. of orthodontics in Korea. So the purpose of this study was to provide the epidemiological characteristics and important basic clinical data for the diagnosis and the treatment of the cleft lip and/or palate patients. With the orthodontic and cleft charts, diagnostic models and X-ray films from 250 patients with cleft lip and/or palate who visited Dept. of Orthodontics, Seoul National University Dental Hospital during the last 11 years, the authors investigated patient's visiting yew, types of cleft, patient's gender, and Angle's classification of malocclusion, and surgery timing. The results were as follows ; 1. The number of cleft patients who visited Dept. of Orthodontics, SNUDH increased during 1988-1990 and then it declined until 1992. From 1993 to 1996, it showed a stationary trend. After 1997 it showed an overwhelmingly increasing trend. 2. In the cleft type, the ratio of cleft lip cleft lip and alveolus cleft palate : cleft lip and palate was 7.6:19.2:9.6:63.6. In cleft position, unilateral clefts were more than bilateral ones (cleft lip 79:21, cleft lip and alveolus 77:23, cleft lip and palate 75.5:24.5). In cleft side, left clefts were mote than right clefts (cleft lip 53.3:46.7 cleft lip and alveolus 59.5:40.5, cleft lip and palate 59.2:40.8). 3. In gender ratio, males were more than females in cleft lip (57.9:42.1), cleft lip and alveolus (68.8:31.2) and cleft lip and palate (76.1:23.9). But in cleft Palate females were more than males as 41.7: 58.3. 4. In the age groups, 7-12 year group was the most abundant as $52\%$, and then 0-6 year group ($20.4\%$), 13-18 year group ($17.2\%$), more than 18 yew group ($10.4\%$) were followed as descending order. 5. Most of the cleft lip repair surgeries were operated in 0-3 month ($60.3\%$) and 4-6 month ($17.9\%$). 6. The cleft palate repair surgeries were done in 1-2 year ($31.7\%$), 0-1 year ($25.6\%$), 2-3 year ($12.1\%$), more than 5 year ($11.6\%$) as descending order. 7. The lip scar revision surgeries were done before admission at elementary school in $60\%$. (4-6 you ($27.5\%$), 6-8 year ($19.6\%$), more than 10 year ($19.6\%$), 2-4 year ($13.7\%$) as descending order) 8. The rhinoplasties were done before admission at elementary school in $51.7\%$. (0-2 year ($7.1\%$), 2-4 year ($14.3\%$), 4-6 year ($21.4\%$), 6-8 year ($14.3\%$)). 9. The pharyngeal flap were done at 6 Y (72.5 months) after birth on average and there was even distribution of surgery timing. 10. In relationship between Angle's classification of malocclusion and cleft types, Class I was most abundant and Class III, Class II were followed as descending order in cleft lip group. But Class III was most abundant and Class I, Class II were followed as descending order in cleft lip and alveolus group, cleft palate group, and cleft lip and Palate group. The percentage of frequency in Class III malocclusion was overwhelmingly higher in cleft lip and palate group than any other groups. 11. Because the frequency of class III malocclusion was most prevalent in all age groups, anterior crossbite was the most common chief complaint of cleft patients.

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Comparisons of Unicortical and Bicortical Lateral Mass Screws in the Cervical Spine : Safety vs Strength (경추부의 후관절 나사못 고정술에서 단피질삽입법과 양피질 삽입법 간의 특성에 관한 비교)

  • Park, Choon-Keun;Hwang, Jang-Hoe;Ji, Chul;Lee, Jae Un;Sung, Jae Hoon;Choi, Seung-Jin;Lee, Sang-Won;Seybold, Eric;Park, Sung-Chan;Cho, Kyung-Suok;Park, Chun-Kun;Kang, Joon-Ki
    • Journal of Korean Neurosurgical Society
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    • v.30 no.10
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    • pp.1210-1219
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    • 2001
  • Introduction : The purpose of this study was to analyze the safety, pullout strength and radiographic characteristics of unicortical and bicortical screws of cervical facet within cadaveric specimens and evaluate the influence of level of training on the positioning of these screws. Methods : Twenty-one cadavers, mean 78.9 years of age, underwent bilateral placement of 3.5mm AO lateral mass screw from C3-C6(n=168) using a slight variation of the Magerl technique. Intraoperative imaging was not used. The right side(unicortical) utilized only 14mm screws(effective length of 11mm) while on the left side to determine the length of the screw after the ventral cortex had been drilled. Three spine surgeons(attending, fellow, chief resident) with varying levels of spine training performed the procedure on seven cadavers each. All spines were harvested and lateral radiographs were taken. Individual cervical vertebrae were carefully dissected and then axial radiographs were taken. The screws were evaluated clinically and radiographically for their safety. Screws were graded clinically for their safety with respect to the spinal cord, facet joint, nerve root and vertebral artery. The grades consisted of the following categories : "satisfactory", "at risk" and "direct injury". Each screw was also graded according to its zone placement. Screw position was quantified by measuring a sagittal angle from the lateral radiograph and an axial angle from the axial radiograph. Pull-out force was determined for all screws using a material testing machine. Results : Dissection revealed that fifteen screws on the left side actually had only unicortical and not bicortical purchase as intended. The majority of screws(92.8%) were satisfactory in terms of safety. There were no injuries to the spinal cord. On the right side(unicortical), 98.9% of the screws were "satisfactory" and on the left side(bicortical) 68.1% were "satisfactory". There was a 5.8% incidence of direct arterial injury and a 17.4% incidence of direct nerve root injury with the bicortical screws. There were no "direct injuries" with the unicortical screws for the nerve root or vertebral artery. The unicortical screws had a 21.4% incidence of direct injury of the facet joint, while the bicortical screws had a 21.7% incidence. The majority of "direct injury" of bicortical screws were placed by the surgeon with the least experience. The performance of the resident surgeon was significantly different from the attending or fellow(p<0.05) in terms of safety of the nerve root and vertebral artery. The attending's performance was significantly better than the resident or fellow(p<0.05) in terms of safety of the facet joint. There was no relationship between the safety of a screw and its zone placement. The axial deviation angle measured $23.5{\pm}6.6$ degrees and $19.8{\pm}7.9$ degrees for the unicortical and bicortical screws, respectively. The resident surgeon had a significantly lower angle than the attending or fellow(p<0.05). The sagittal angle measured $66.3{\pm}7.0$ degrees and $62.3{\pm}7.9$ degrees for the unicortical and bicortical screws, respectively. The attending had a significantly lower sagittal angle than the fellow or resident(p<0.05). Thirty-three screws that entered the facet joint were tested for pull-out strength but excluded from the data because they were not lateral mass screws per-se and had deviated substantially from the intended final trajectory. The mean pull-out force for all screws was $542.9{\pm}296.6N$. There was no statistically significant difference between the pull-out force for unicortical($519.9{\pm}286.9N$) and bicortical($565.2{\pm}306N$) screws. There was no significant difference in pull-out strengths with respect to zone placement. Conclusion : It is our belief that the risk associated with bicortical purchase mandates formal spine training if it is to be done safely and accurately. Unicortical screws are safer regardless of level of training. It is apparent that 14mm lateral mass screws placed in a supero-lateral trajectory in the adult cervical spine provide an equivalent strength with a much lower risk of injury than the longer bicortical screws placed in a similar orientation.

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