1.Biomechanical Study of Rigidity in the External Fixators
Joo Chul IHN ; Myun Whan AHN ; Jae Sung SEO ; Jong Hyeung LEE ; Il Key LEE ; Jung Il SONG ; Young Hoon KANG
The Journal of the Korean Orthopaedic Association 1990;25(2):535-544
The finite element method was utilized to find the rigidity of the device in changing the parameters, such as geometrical configuration, material property, and loading condition in an external fixation. In the experimental analysis, a universal testing machine(UTM) was used to evaluate the rigidity of EBI, Monofixator and Hoffmann under the different type of lodings, such as axial compression, bending and torsion in changing the parameters. The result was compared with those of the experimental work. The results were as follows: 1) In standard condition, the yielding loads in axial compression were 85Kg in the EBI, 55Kg in the Hoffmann, and 100Kg in the Monofixator, The rigidity figures were 2930N/cm in the EBI, 764N/cm in the Hoffmann, and 2391M/cm in the Monofixator. Z) The experimental method was adapted to figure out the effect of parametric change on the stiffness of 3 different external fixation apparatus(Monofixator,EBI, Hoffmann). A Monofixator with a parametric change of pin diameter from 6mm to 5mm indicated 40% reduction of stiffness in axial compression and 60% reduction of stiffness in torsion. Also, in the case of the change of pin group separation from 20cm to 15cm it showed 64% increase of stiffness in, AP bending. EBI with the increase of the distance between pin and aluminum bar to 8cm showed 32% decrement of stiffness in axial compression and 38% decrement of stiffness in AP bending. The stiffness of the Hoffmann device was remarkable according to the number of the pin used and the distance between the pin and the aluminum bar. 3) Concerning the difference between the experimental analysis and finite element method in a Monofixator, the results of the experimental analysis were 10% to 37% lower than those of the finite element method. The reason is thought to be caused by complete binding. The obtained data shed light on the future guide-lines and future alterations of the design factors in external fixation device. Approprate use of the obtained information is desirable for the optimal,treatment of the fractured long bone.
Aluminum
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External Fixators
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Methods
2.Incidental Polyorchidism in Testicular Injury.
Hyeung Chul PARK ; Eun Suk KIM ; Eun Hong JUNG ; Keun Bai MUN ; Che Il KIM
Korean Journal of Andrology 2009;27(2):130-132
Polyorchidism is a very rare congenital anomaly and about 100 cases have been documented in the literature until today. Polyorchidism or supernumenary testis is defined as the presence of more than 2 histologically proven testes. In most case, polyorchidism have characteristics of unilateral involvement and three testis and mainly finding in left-side testis. And although patient age was various, average age was about 18-year-old in previous review of article. We report a rare case of polyorchidism that an old age patient had an incidentally found right accessory testis in operating a testicular injury.
Adolescent
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Humans
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Testis
3.Comparison of the Cobalt Alloy and Stainless Steel Core(r) Stent in a Porcine Coronary Restenosis Model.
Jang Young KIM ; Junghan YOON ; Il Hyeung JUNG ; Hee Sung WANG ; Min Soo AHN ; Kyung Hoon LEE ; Byung Soo YOO ; Seung Hwan LEE ; Kyung Hoon CHOE ; Yangsoo JANG ; Jea Mo AHN ; Yong Sun RYU
Korean Circulation Journal 2005;35(7):507-512
BACKGROUND AND OBJECTIVES: The stent material and thickness may influence the rate of restenosis following coronary artery stenting. A thin strut cobalt-alloy stent has been developed in an attempt to reduce the restenosis rate, while maintaining the radiopacity and radial strength. The purpose of this study was to compare a stainless steel Core(r) stent (thickness: 90 micrometer/HUMED Co. Ltd, Korea) with that of a cobalt alloy Core(r) stent (thickness: 60 micrometer/HUMED Co. Ltd, Korea) in a porcine coronary stent restenosis model. MATERIALS AND METHODS: The cobalt alloy (Co-alloy) and stainless steel (SS) stents were implanted in 24 porcine coronary arteries. Four weeks after stenting, the pigs were sacrificed after quantitative coronary angiography (QCA). The coronary arteries were perfusion-fixed and stained, and a pathological examination performed by computer-aided histomorphometry. RESULTS: The minimal luminal diameter at 4 weeks was larger in the Co-alloy than the SS group according to the QCA (1.8+/-0.8 mm vs. 2.7+/-0.8 mm, p=0.019). The neointimal area was significantly smaller in the Co-alloy than the SS group (1.96+/-0.68 mm2 vs. 0.89+/-0.27 mm2, p<0.001). The intima/media area ratio was significant lower in the Co-alloy than the SS group (1.33+/-0.46 vs. 0.69+/-0.21, p=0.003). CONCLUSION: The thin strut cobalt alloy Core(r) stent significantly reduces the neointimal formation compared to the stainless steel Core(r) stent in a porcine coronary stent injury model.
Alloys*
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Cobalt*
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Coronary Angiography
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Coronary Restenosis*
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Coronary Vessels
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Models, Animal
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Phenobarbital
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Stainless Steel*
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Stents*
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Swine
4.Colon cancer: the 2023 Korean clinical practice guidelines for diagnosis and treatment
Hyo Seon RYU ; Hyun Jung KIM ; Woong Bae JI ; Byung Chang KIM ; Ji Hun KIM ; Sung Kyung MOON ; Sung Il KANG ; Han Deok KWAK ; Eun Sun KIM ; Chang Hyun KIM ; Tae Hyung KIM ; Gyoung Tae NOH ; Byung-Soo PARK ; Hyeung-Min PARK ; Jeong Mo BAE ; Jung Hoon BAE ; Ni Eun SEO ; Chang Hoon SONG ; Mi Sun AHN ; Jae Seon EO ; Young Chul YOON ; Joon-Kee YOON ; Kyung Ha LEE ; Kyung Hee LEE ; Kil-Yong LEE ; Myung Su LEE ; Sung Hak LEE ; Jong Min LEE ; Ji Eun LEE ; Han Hee LEE ; Myong Hoon IHN ; Je-Ho JANG ; Sun Kyung JEON ; Kum Ju CHAE ; Jin-Ho CHOI ; Dae Hee PYO ; Gi Won HA ; Kyung Su HAN ; Young Ki HONG ; Chang Won HONG ; Jung-Myun KWAK ;
Annals of Coloproctology 2024;40(2):89-113
Colorectal cancer is the third most common cancer in Korea and the third leading cause of death from cancer. Treatment outcomes for colon cancer are steadily improving due to national health screening programs with advances in diagnostic methods, surgical techniques, and therapeutic agents.. The Korea Colon Cancer Multidisciplinary (KCCM) Committee intends to provide professionals who treat colon cancer with the most up-to-date, evidence-based practice guidelines to improve outcomes and help them make decisions that reflect their patients’ values and preferences. These guidelines have been established by consensus reached by the KCCM Guideline Committee based on a systematic literature review and evidence synthesis and by considering the national health insurance system in real clinical practice settings. Each recommendation is presented with a recommendation strength and level of evidence based on the consensus of the committee.