• Title/Summary/Keyword: Introduction to Medicine

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On the Secret Scripture of Dragon and Tiger (Yong-Ho-Bi-Gyeol)-a Jungian Commentary (용호비결 연단술의 분석심리학적 의미)

  • Yong-Wook Shin
    • Sim-seong Yeon-gu
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    • v.33 no.2
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    • pp.141-194
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    • 2018
  • The article is about Yong-Ho-Bi-Gyeol(龍虎秘訣), which is one of the most important Taoist text in Korea written by Jeong-Ryum, a Taoist and alchemist in the Chosun Dynasty. The article deals with the alchemical and psychological meanings of Yong-Ho (龍虎, Dragon-Tiger), the way of nurturing cinnabar (修丹之道), the closing of the qi (閉氣), the method of alchemical breathing, the Dantian (丹田, cinnabar-field), and the Mysterious Female's One Opening (玄牝一竅), in addition to the brief introduction of the life of Jeong-Ryum and the bibliography of the book. The Yong-Ho (龍虎) meaning the dragon and tiger is the archetype of transformation in the form of their opposites, rooted in the psychoid system of the human psyche. The unified Yong-Ho makes Dan and the Dan, literally indicating cinnabar, has many alchemical connotations such as Mercurius, the rubedo state of the alchemical process, and the philosopher's stone. In the book, Jeong-Ryum emphasized the slow and subtle way of breathing in and out of Dantian to develop neidan (内丹, inner cinnabar or inner alchemy). The refining of neidan begins by the closing of the qi, which symbolizes the radical introversion and withdrawal of all the projections on the outer objects. The Dantian located at the lower part of the abdomen has been known to preserve jing (精), the vital essence of life, which can be refined into qi and spirit (神). In Jungian perspective, the Dantian is a mandala where an individual's mind can stay and focus at the center of psyche detached from ego and related to the Self. The long-nurtured introverted energy makes the Mysterious Female's One Opening (玄牝一竅), a pit or cavity in the transcendental space, through which the meditator can have a relationship with the great female principle of the universe. The current article has introduced the contents of the Yong-Ho-Bi-Gyeol in the perspective of analytical psychology. However, it has not dealth with the remaining topics including Taesik (胎息, embryonic breathing) and Juchenhwahu (周天火候, the great Celestial circuit firing), due to the lack of author's sufficient knowledge and experience. The unexplored areas of Yong-Ho-Bi-Gyeol will be studied in the future.

Legal Issues on the Collection and Utilization of Infectious Disease Data in the Infectious Disease Crisis (감염병 위기 상황에서 감염병 데이터의 수집 및 활용에 관한 법적 쟁점 -미국 감염병 데이터 수집 및 활용 절차를 참조 사례로 하여-)

  • Kim, Jae Sun
    • The Korean Society of Law and Medicine
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    • v.23 no.4
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    • pp.29-74
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    • 2022
  • As social disasters occur under the Disaster Management Act, which can damage the people's "life, body, and property" due to the rapid spread and spread of unexpected COVID-19 infectious diseases in 2020, information collected through inspection and reporting of infectious disease pathogens (Article 11), epidemiological investigation (Article 18), epidemiological investigation for vaccination (Article 29), artificial technology, and prevention policy Decision), (3) It was used as an important basis for decision-making in the context of an infectious disease crisis, such as promoting vaccination and understanding the current status of damage. In addition, medical policy decisions using infectious disease data contribute to quarantine policy decisions, information provision, drug development, and research technology development, and interest in the legal scope and limitations of using infectious disease data has increased worldwide. The use of infectious disease data can be classified for the purpose of spreading and blocking infectious diseases, prevention, management, and treatment of infectious diseases, and the use of information will be more widely made in the context of an infectious disease crisis. In particular, as the serious stage of the Disaster Management Act continues, the processing of personal identification information and sensitive information becomes an important issue. Information on "medical records, vaccination drugs, vaccination, underlying diseases, health rankings, long-term care recognition grades, pregnancy, etc." needs to be interpreted. In the case of "prevention, management, and treatment of infectious diseases", it is difficult to clearly define the concept of medical practicesThe types of actions are judged based on "legislative purposes, academic principles, expertise, and social norms," but the balance of legal interests should be based on the need for data use in quarantine policies and urgent judgment in public health crises. Specifically, the speed and degree of transmission of infectious diseases in a crisis, whether the purpose can be achieved without processing sensitive information, whether it unfairly violates the interests of third parties or information subjects, and the effectiveness of introducing quarantine policies through processing sensitive information can be used as major evaluation factors. On the other hand, the collection, provision, and use of infectious disease data for research purposes will be used through pseudonym processing under the Personal Information Protection Act, consent under the Bioethics Act and deliberation by the Institutional Bioethics Committee, and data provision deliberation committee. Therefore, the use of research purposes is recognized as long as procedural validity is secured as it is reviewed by the pseudonym processing and data review committee, the consent of the information subject, and the institutional bioethics review committee. However, the burden on research managers should be reduced by clarifying the pseudonymization or anonymization procedures, the introduction or consent procedures of the comprehensive consent system and the opt-out system should be clearly prepared, and the procedure for re-identifying or securing security that may arise from technological development should be clearly defined.

A Study of Mac(脈)-Theory and Change of Mac(脈)-Diagnosis in Whang Di Nei Qing(黃帝內經) (황제내경(黃帝內經)의 맥(脈) 이론(理論)과 진맥법(診脈法)의 변화(變化)에 관(關)한 연구(硏究))

  • Ra, Kyoung-Chan;Park, Hyun Kook
    • The Journal of Dong Guk Oriental Medicine
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    • v.2 no.1
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    • pp.73-105
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    • 1993
  • To say nothing of the orient and the west, the human beings discover the method of Jin Mac(診脈) by the way that observe disease. But oriental medicine devise special method of Jin Mac(診脈) in the study of Kyoung Mac(經脈). Although sip-ei Kyoung Mac Jin(十二經脈診), Sam Bu Gu Who Jin(三部九候診), In Young Mac Gu Jin(人迎脈口診), Chon Kwan Chuck Jin(寸關尺診) namely Yuk Bu Jung Wee Jin Mac (六部定位診脈) that is used today are devised, it has changed naturally by the changing treatment and the introduction of Yuin Yang(陰陽) and five element(五行). Many methods dg Jin Mac(診脈), it had not developped successing alternative, it had developped of declined by it's own way. 1. Results for the birth of Mac(脈) 1) Mac(脈), it means Kyoung Mac(經脈), at first entirelly Mac(脈), is seized a blood vessel that flows in the body. As presumed today, after finding many acupunture point, a general idea of Mac(脈) is not maked by the line that connect point and point, it connect between acupunture point and acupunture point. 2) Like blood flows in Hyul Mac(血脈), Gie(氣) flows in Kyoung Mac(經脈). The two things relate deeply each other. In a general idea or actrally Kyoung Rak(經洛), the two things sometimes accord, sometimes seperate, sometimes mix alternative. 3) Hyul Mac(血脈) and Kyoung Mac(經脈), we call it Mac(脈) entirely Kyoung Mac(經脈), is a way that manifest disease through Kyoung Mac(經脈) or a boundary that disease belongs to it method of Mac Jin(脈診) individual that disease of Kyoung Mac(經脈) is diagnosed by the jumping situation of Hyul Mac(血脈). 4) In method of Moxa, athough the pathology and the diagnostic of Mac(脈) are created by finding Mac(脈). Finding acupunture have opportunitty fot Mac Jin(脈診) and treatment. 2. Results of Kyoung Mac Mac Jin(經脈脈診) 1) In theory of kyoung Rak(經洛), disease are resumed for malfunction of Young Wee(榮衛) that flows in Kyung Rak(經洛). So to speak, in treatment of Kyoung Rak area, the purpose of diagnosis observe the situation of disease and cause. For fitting the purpose of diagnosis, the dead had esatablised four-diagnosis method mangMunMnnJeul(望聞問切), in four-diagnosis(四診法), the core is Mac Jin(脈診). 2) sip-ei Kyoung Mac Mac Jin(十二經脈診) had existed as Kyoung Mac Mac Jin(經脈脈診), it precedes Sam Bu Gu Who Jin(三部九候診). In Young Ki Gu Mac(人迎脈口診). 3) Although Bu Yang Mac(趺陽脈), So Um Mac(少陰脈) is a part of Sip-ei Kyoung Mac(十二經脈診), they developped especially because they located in the point of Won Hyul(原穴) and they are convenient for diagnose. 4) Sip-ei Kyoung Mac Mac Jin(十二經脈診), which belongs to Bu Yang Mac(趺陽脈) and So Urn Mac(少陰脈), is not important for the comming age medical books compared with Mac Kyoung(脈經). 3. Results gor Sam Bu Gu Who Jin(三部九候診) 1) Mac Jin(脈診) of Sam Bu Gu Who(三部九候), which is noted in the theory of Sam Bu Gu Who(三部九候診) of So Mun(素問), belongs to Kyoung Mac Mac Jin's(經脈脈診) geneology, Sip-ei Kyoung Mac Mac Jin(十二經脈診) is arranged, simplicated by the idealogy three talents(三才思想) in the heaven and the earth. 2) What Sam Bu Gu Jin(三部九候診) is regardded as very important in So Mun(素問), the editor of So Mun(素問) recognize the meaning that one discover disease early in this method of diagnosis. 3) After Young chu(靈樞), Nan Kyoung(難經) it is lacked the method of Sam Bu Gu Who Jin(三部九候診) in the books that treatment has changed. Sam Bu Gu Who Jin(三部九候診) based on actually clinic appropriate. 4. results for In Young Mac Gu Jin(人迎脈口診) 1) In Young Mac Gu Jin(人迎脈口診) is the method of comparative Mac Jin(脈診) according to the theory of Yin Yang(陰陽), it is presumed after Sam Bu Gu Who Jin(三部九候診), it had perished in parallel with the development of the theory of five elelment(五行). The development of the acupunture, the perishment of the treatment of negative(刺絡). 2) In Young Mac Gu Jin(人迎脈口診), Wang Suk Wha(王叔和) recreated that the left is In Young(人迎), the right is Kie Gu(氣口). In future generations by Jin Mu Taek(陳無擇) who is the writer of Sam In Bang(三因方). In Young Mac Gu Jin(人迎脈口診) is a measure for disease which classify it's inside and outside cause. 5. Results for Chon Gu Mac Jin(寸口脈診) 1) What we say Mac Jin(脈診) of Chon Gu(寸口) two means are used in commn. First case, we simply say the area of Chon Gu(寸口), second case, we say Chon Kwan Chuk Jin(寸口尺診) reducingly. Chon Gu(寸口) is the area which is the radial artery of wrist joint. What we attemp diagnose by only Chon Gu Mac(寸口脈), it is clearly shoued in the method of Nan Kyoung, five Nan(難經五難). 2) Because Jin Mac(診脈) is made in only Chon Gu(寸口), that is the area in which is concentated Kyoung Kee(經氣). That is the birth of Jin Kee(眞氣) and Jin Kee(眞氣) is related with disease. We can diagnose disease by taking Chon Gu(寸口). 3) Chuk Jin(尺診) in Nae Kyoung(難經) have two things. One is Il Chuk(一尺), the other is Chon Kwan Chu(寸關尺). 4) Chuk Chon Jin(尺寸診) is the method which diagnose the difference of point and the condition of Mac(脈) by dividing a part of Chuk(尺) in the area of Chon Gu(寸口). In Chon Gu Jin(寸口診), by introducing the theory of Yin Yang(陰陽), the method of Chon Gu Jin(寸口診) is developed by chon Gu Jin(寸口診). 5) What Chuk Kwan Chon Jin(寸關尺診) is that area of the Chon Gu(寸口) are divided fot three point, we can diagnose. By consulting Sam Bu Gu Who Jin(三部九候診), developping of the method of acupunture, utilzing the theory of five element(五行) it is devised by concentrating way of thinking of the method mac Jin(脈診) exiting. 6) Chon Kwan Chuk Jin MaC(寸關尺診脈) begin from Nae Kyoung(內徑) exiting. After Nan Kyoung(內徑), spread out widely from Mac Kyoung(脈診) of Wang Suk wha(王叔和), the future medicins followed it. Yang Hyun Jo(楊玄操) and established Chon Kwan Chuk Jin(寸關尺診) which is used widely today. This right and left Chon Kwan Chuk Jin(寸關尺診), we call it method of Yuk Bu Jung Wee Jin Mac(六部定位診脈). 7) We can think the base which presume the arrangement of the viscera for Chon Kwan Chuk(寸關尺) of the right and the left. 8) The origin, which seperate the right and the left of Mac(脈), is showed at the treory of Ji Jin Yo Dae(至眞要大論) in So Mun(素問) which Chon Chuk(寸尺) seperate the right and the left. But the method of diagnosis in Nan Kyoung(難經) have no seperation the fight and the left. Otherwise this. there is clearly writtened the seperation for the right origin of the method of Yuk Bu Jung Wee Jin Mac(六部定位診脈) seek for Cang Gong(倉公). 9) Yang Hyun Jo(楊玄操) notice that the Chuk(尺) is mentioned for Sam Cho(三焦) in the method of Mac Kyuong(脈經), Sim Po Kyung(心包經) which put together with Sam Cho(三焦) allot on this, he had established the method of Yuk Bu Jung Wee Jin Mac(六部定位診脈). 10) On the method of Paen Jak Yin Yang Mac(扁鵲陰陽脈) in Mac Kyoung(脈經), equal article exist with the theory of Pyung In Kee Sang(平人氣象論) in So Mun(素問). When Wang Suk Wha(王叔和) write Mac Kyung(脈經), we can presume that the book of Mac(脈) which Paen Jak(扁鵲) had experienced the origin have exited besides So Mun(素問), Young Chu(靈樞). If so he must be make Chon Kwan Chuk Jin(寸關尺診) very fairly standard. So Nae Kyoung(內經), which must be fllowed the method of Paen Jak Mac(扁鵲脈), do the method diagnosis of Chon Kwan Chuk(寸關尺), diagnise of disease and treat.

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Epidemiological Studies of Clonorchiasis. - I. Current Status and Natural Transition of the Endemicity of Clonorchis sinensis in Gimhae Gun and Delta, a High Endemic area in Korea (간흡충증(肝吸虫症)의 역학(疫學) - I. 고도유행지(高度流行地) 김해지방(金海地方)에 있어서의 간흡충감염(肝吸虫感染)의 현황(現況)과 자연추이(自然推移))

  • Kim, D.C.;Lee, O.Y.;Lee, J.S.;Ahn, J.S.;Chang, Y.M;Son, S.C.;Moon, I.S.
    • Journal of agricultural medicine and community health
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    • v.8 no.1
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    • pp.44-65
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    • 1983
  • As a part of the epidemiological studies of clonorchiasis, this study was conducted to evaluate the current endemicity and the natural transition of the Clonorchis infection in Gimhae Gun and delta area a high endemic area in Korea in recent years, prior to the introduction of praziquantel which will eventually influence the status of the prevalence. The data obtained in this study in 1983 were evaluated for natural transition of the infection in comparison with those obtained 16 years ago in 1967 by the author(Kim, 1974). The areas of investigation, villages and schools surveyed, methods and techniques used in this study were the same as in 1967, except for the contents of the questionnaire for raw freshwater fish consumption by the local inhabitants. 1) The prevalence rate of clonorchiasis in the general population of the villages was 48.1% on the average out of a total of 484 persons examined. The average of those of the riverside-delta area was 65.2% and 43.0% in the inland area. Among the schoolchildren, the prevalence rate was 8.2% on the average out of a total of 1,423 examined. By area, the prevalence rate was 10.8% in the riverside delta area and 2.8% in the inland area. By sex, difference in the prevalence was seen only in the inhabitants of the inland area showing 52.4% in the male and 33.5% in the female. 2) In the natural transition of the infection, the prevalence rate among the inhabitants has decreased from 68.8% in 1967 to 48.1% in 1983, and in the schoolchildren from 56.4% in 1967 to 8.2% in 1983. The reduction rate was higher in the riverside-delta area than in the inland area. 3) In the prevalence rate by age, 11.9% was first seen in the 5-9 age group and the rate gradually increased up to 75.0% in the 50-59 age group. By sex, the rate was higher in the male than in the female in the 20-29 age group and over. 4) In the natural transition of the prevalence rate by age, the reduction rate of the infection during the past 16 years was greater in the younger age groups up to the 40-49 age group and reached the same level in the age group 50-59. Reduction was seen again in the age group over 60s. By sex, the reduction rate was greater in the female than in the male in the 20-29 age group and over. By area, the reduction rate was greater in the riverside delta area than in the inland area, particularly in the young age groups. 5) In the intensity of the infection among the cases, the mean egg out-put per mg feces per infected cases(EPmg) in the inhabitants was 6.3. EPmg of those of the river-side-delta area was 15.4 and that of the in-land was 2.8. On the other hand, in the schoolchildren, EPmg was 3.2, and no difference was seen between the two areas, the river-side-delta area and the inland area. 6) In the transition of the intensity of the infection by area, EPmg among the inhabitants inexplically increased from 7.8 in 1967 to 15.4 in 1983. This was probably caused by uneven specimen collection in the process of sampling the population. EPmg of the inhabitants in the inland area and those of the schoolchildren of both riverside delta and inland areas showed a similar decrease in the past 16 years. 7) The intensity of the infection by age showed a relatively low level in the 20-29 age group and below, and EPmg 5.1-9.5 was seen in the 30-39 age group and over. Sex, Epmg was 5.8 in the male and 4.7 the female. By in 8) In the transition of the intensity of the infection, EPmg decreased from 6.2 in 1967 to 5.4 in 1983. By age, in contrast to the figures of 1967 in which EPmg gradually increased with some fluctuation from 1.1 in the 0-4 age group to peak 10.5 in the 50-59 age group, in 1983 lower intensity of the infection was seen in the age group from 10-14 to 20-29 with the EPmg range of 0.6-2.7. 9) In the distribution of the clonorchiasis cases by the range of EPmg value, 43.2% of the cases were in 0.1 0.9 and 34.6% in 1.0-4.9. As a whole by cumulative percent, 44.6% of them were under 0.9 as light infection and 86.1% of them under 9.9 up to moderate infection. By sex, no difference was seen in Epmg. 10) In the transition of the distribution by the range of Epmg, the cases were distributed up to the range 80.0-99.9 in 1967 and to 60.0-79.9 in 1983. By cumulative percent, in the range of 0.1-0.9 and less, light infection, 34.3% of them were distributed in 1967 and 44.6% in 1983 with about 10% increase. In the range of 5.0-9.9 and less, up to moderate infection, 83.2% in 1967 and 86.1% in 1983 of the cases were seen, respectively. 11) The practice of raw freshwater fish consumption among the inhabitants seems to have decreased in recent years. Those who admitted to raw freshwater fish consumption in the last two years among the infected inhabitants were 59.3%, although 86.8% of them professed to have experience with raw freshwater fish consumption. 31.7% of those who have had experience of the raw freshwater fish consumption denied any further consumption in recent years. From an interview of 543 school-children, 24.1% of them admitted to an experience of raw freshwater fish consumption. However, those who have practised in the past two years comprized 17.9%. Those who denied raw freshwater fish consumption in recent years among those who had such experience were 26.0% out of 131 interviewed. The rate of raw freshwater fish consumption in both inhabitants and schoolchildren were higher in the male than in the female. On the contrary, the rate of those who did not practise in recent years among those who had experience of raw freshwater fish consumption was higher in the female than in the male. 12) The major reason for the reduction of raw freshwater fish consumption among the local inhabitants was the risk of the fluke infection. However, it has become apparent that such change of taste has resulted from water pollution impact which has affected throughout the areas of the freshwater systems in this locality since last several years. 13) In animal survey, Clonorchis infection was seen in 14.8% of 88 dogs examined and 3.7% of 27 house rats examined. It was noted that populations of dogs and cats have increased in the villages surveyed. Although the prevalence rate was lower in the present survey than those of 1967, the significance of the animals as the reservoir host has not changed. 14) Prevalence rate of Clonorchis infection by cercariae in the first intermediate host, Parafossarulus manchouricus, was 0.6% out of 517 snails examined. The infection rate was lower in comparison with 2.3% out of 2,124 examined in 1967. Moreover, sharp decreases in number and distribution of the intermediate host snails in many watershed areas of the huge freshwater systems in this locality seemed to reduce transmission of Clonorchis in connection with the intermediate host stage of its life cycle. 15) Clonorchis infection in the second intermediate fish hosts was relatively low. The mean number of Clonorchis metacercaria per fish in Pseudorasbora parva was 517 in 1983, whereas it was 1943 in 1968 through 1969. Environmental water pollution has also caused the decreased fish population density in these areas, and this has also apparently affected to the practice of raw freshwater fish consumption among the local inhabitants. 16) In conclusion, endemicity of Clonorchis infection in Gimhae Gum and delta area of the Nagdong River has sharply decreased during the past 16 years. The major cause of the regressive transition of the infection was the water pollution of the land water systems of this locality. The pollution has upset the ecosystems comprizing of the intermediate hosts of Clonorchis in many areas, and also affected to a significant extent to the discontinuance of the local inhabitants for raw freshwater fish consumption.

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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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