• Clinics in Shoulder and Elbow
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• 제22권1호
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• pp.29-36
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• 2019

Background: The execution of fibular allograft augmentation in unstable proximal humerus fractures (PHFs) was technically demanding. In this study, the authors evaluated the clinical and radiographic outcomes after tricortical iliac allograft (TIA) augmentation in PHFs. Methods: We retrospectively assessed 38 PHF patients treated with locking-plate fixation and TIA augmentation. Insertion of a TIA was indicated when an unstable PHF showed a large cavitary defect and poor medial column support after open reduction, regardless of the presence of medial cortical comminution in preoperative images. Radiographic imaging parameters (humeral head height, HHH; humeral neck-shaft angle, HNSA; head mediolateral offset, HMLO; and status of the union), Constant score, and range of motion were evaluated. Patients were grouped according to whether the medial column support after open reduction was poor or not (groups A and B, respectively); clinical outcomes were compared for all parameters. Results: All fractures healed radiologically (average duration to complete union, 5.8 months). At final evaluation, the average Constant score was 73 points and the mean active forward flexion was $148^{\circ}$. Based on the Paavolainen assessment method, 33 patients had good results and 5 patients showed fair results. The mean loss of reduction was 1.32 mm in HHH and 5.02% in HMLO. None of the parameters evaluated showed a statistically significant difference between the two groups (poor and not poor medial column support). Conclusions: In unstable PHFs, TIA augmentation can provide good clinical and radiological results when there are poor medial column support and a large cavitary defect after open reduction.

• 대한정형외과학회지
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• 제54권3호
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• pp.281-286
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• 2019

무혈성 골괴사는 골조직 및 골수 조직의 허혈성 상태로 인한 괴사로 정의될 수 있으며, 외상성 및 비외상성으로 구분할 수 있다. 무혈성 골괴사는 대퇴골 골두, 상완골 골두와 같이 장골의 골단 부위에서 주로 발생한다. 기존의 무혈성 골괴사는 대부분 대퇴골 골두에 한정된 증례에 대한 보고 및 연구가 이루어져 왔다. 근위 대퇴골의 무혈성 괴사의 존재는 인공 고관절 전치환술 이후 생물학적 고정 실패의 원인이 된다. 본 저자들은 대퇴골 골두로부터 대퇴골 경부, 간단부 간부 및 원위부에 이르는 골수강내 부위의 대퇴골 전 영역의 무혈성 골괴사가 관찰된 56세 남자 환자에서 인공 고관절 전치환술을 시행하고 2년 추시 결과를 문헌 고찰과 함께 보고하고자 한다.

• 대한의용생체공학회:학술대회논문집
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• 대한의용생체공학회 1997년도 추계학술대회
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• pp.245-248
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• 1997

Operative interventions for the management of osteonecrosis of the femoral head (ONFH) include core drilling, with or without vascularized fibular bone grafting. Nevertheless, their clinical results have not been consistently satisfactory. Recently, a new surgical procedure that incorporates cementation with polymethylmethacrylate (PMMA) after core drilling has been tried clinically. In this study, a biomechanical analysis using a finite element method(FEM) was undertaken to evaluate surgical methods and their underlying surgical parameter. Our finite element models included five types. They were (1) normal model (Type I), (2) necrotic model (Type II), (3) core decompressed model (Type III). (4) fibular bone grafted model (Type IV), and (5) cemented with PMMA model (Type V). The geometric dimensions of the femur were based on digitized CT-scan data of a normal person. Various physiological loading conditions and surgical penetration depths by the core were used as mechanical variables to study their biomechanical contributions in stress transfer within the femoral head region. In addition. the peak von Mises stress(PVMS) within the necrotic cancellous bone of the femoral head was obtained. The fibular bone grafted method and cementation method provided optimal stress transfer behaviors. Here. substantial increase in the low stress level was observed when the penetration depth was extended to 0mm and 5mm from the subchondral region. Moreover, significant decrease in PVMS due to surgery was observed in the fibular bone grafted method and the cementation method when the penetration depths were extended up to 0 and 5mm from the subchondral region. The drop in PVMS was greater during toe-off than during heel-strike (57% vs. 28% in Type IV and 49% vs. 22% in Type V). Both the vascularized fibular bone grafting method (Type IV) and the new PMMA technique (Type V) appear to be very effective in providing good stress transfer and reducing the peak Von-Mises stress within the necrotic region. Overall results show that fibular bone grafting and cementation methods are quite similar. In light of above results, the new cementation method appears to be a promising surgical alternative or the treatment of ONFH. The use of PMMA for the core can be less prone to surgical complication as opposed to preparation of fibular bone graft and can achieve more immediate fixation between the core and the surrounding region.

• Clinics in Shoulder and Elbow
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• 제16권2호
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• pp.94-99
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• 2013

목적: 간섭나사(interference screw)를 이용한 관절경적 상완 이두건 대흉근 상부 건 고정술의 임상적 결과를 분석하고자 하였다. 대상 및 방법: 2008년 1월부터 2010년 1월까지 간섭나사를 이용한 관절경적 상완 이두건 장두의 대흉근 상부 건 고정술을 시행한 환자를 대상으로 하였고, 이 중 최소 1년 이상 추시 가능하였던 30예를 대상으로 하였다. 그 중 회전근 개 파열을 동반한 경우는 20예였다. 결과는 VAS, ASES, 상완 이두건 구의 통증, 고정실패 및 변형 정도로 판단하였다. 결과: 최종 추시에서 모든 환자에서 수술 전에 비해 VAS, ASES점수는 의미 있게 호전되었으나(p<0.05), 5예(17%)에서 견관절 전방 통증 및 상완 이두건 구의 압통이 존재하였고, 3예(10%)에서 고정실패로 인한 Popeye 변형이 존재하였다. 또한, 회전근 개 파열을 동반하지 않는 군에서 파열을 동반한 군보다 좋은 결과를 얻을 수 있었다(p<0.05). 결론: 상완 이두건 근위부 병변에 의한 통증이 있는 환자에서 간섭나사를 이용한 관절경적 상완 이두건 장두의 대흉근 상부 건 고정술은 좋은 결과를 얻을 수 있어 유용한 치료방법으로 사료되나, 17%에서 상완 이두건구에 압통이 존재해 이에 대한 추가적 연구가 필요할 것으로 사료된다.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제29권1호
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• pp.26-34
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• 2003

Intraoral Vertical Ramus Osteotomy,along with Sagittal Split Ramus Osteotomy,is an popular surgical technique performed on mandibular prognathism. However Intraoral Vertical Ramus Osteotomy has been suspected for an initial mobilization at the healing phase of segment because it does not employ the rigid fixation between segments. To execute a study on the healing phase of segment after Intraoral Vertical Ramus Osteotomy on the horizontal plane, 102 patients (204 parts) who were diagnosed mandibular prognathism and took Intraoral Vertical Ramus Osteotomy at the Yonsei University dental hospital were observed during the period of before operation, immediately postoperation, 1 month, 3 months, 6 months, and 12 months. The change in the width of segment and horizontal angle of proximal segment and condylar head on the Submentovertex Cephalogram taken from those patients represented following results. 1. The width of proximal and distal segment decreased with the lapse of time. It decreased into 84.5% between immediate postoperative and 6M and even continued to decrease till 12M. 2. The horizontal angle of the proximal segment did medial rotation according as the lapse of time and rigorously continued till 3M. The rotation angle of condylar head indicated its tendency of recurrence to the original position but the entire recurrence was not allowed. The bigger an initial angle was, the higher was the tendency of recurrence after the operation while the rotation angle remained still bigger. 3. After grouping into group 1, group 2,and group 3 based on the extent of the variation of rotation angle of condylar head at immediate postoperative, the variation of rotation angle was measures in each group. The result presented that the initial rotation angle of condylar head had correlation with that of proximal segment but had no relation with the extent of setback of the mandible. However a quantitative analysis alone is not a sufficient method for analyzing the healing phase of segment on the horizontal plane.Therefore a multilateral analysis using 3 dimensional data such as CT is recommendable for the future study.

• Animal Bioscience
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• 제35권9호
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• pp.1340-1350
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• 2022

Objective: Luxi Black Head sheep (LBH) is the first crossbreed specialized for meat production and was developed by crossbreeding Black Head Dorper sheep (DP) and Small Tailed Han sheep (STH) in the farming areas of northern China. Research on the genomic variations and selection signatures of LBH caused by continuous artificial selection is of great significance for identifying the genetic mechanisms of important traits of sheep and for the continuous breeding of LBH. Methods: We explored the genetic relationships of LBH, DP, and several Mongolian sheep breeds by constructing phylogenetic tree, principal component analysis and linkage disequilibrium analysis. In addition, we analysed 29 whole genomes of sheep. The genome-wide selection signatures have been scanned with four methods: heterozygosity (H_P), fixation index (F_ST), cross-population extended haplotype homozygosity (XP-EHH) and the nucleotide diversity (𝜃_π) ratio. Results: The genetic relationships analysis showed that LBH appeared to be an independent cluster closer to DP. The candidate signatures of positive selection in sheep genome revealed candidate genes for developmental process (HoxA gene cluster, BCL2L11, TSHR), immunity (CXCL6, CXCL1, SKAP2, PTK6, MST1R), growth (PDGFD, FGF18, SRF, SOCS2), and reproduction (BCAS3, TRIM24, ASTL, FNDC3A). Moreover, two signalling pathways closely related to reproduction, the thyroid hormone signalling pathway and the oxytocin signalling pathway, were detected. Conclusion: The selective sweep analysis of LBH genome revealed candidate genes and signalling pathways associated with developmental process, immunity, growth, and reproduction. Our findings provide a valuable resource for sheep breeding and insight into the mechanisms of artificial selection.

• 대한후두음성언어의학회지
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• 제8권1호
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• pp.75-81
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• 1997

The clinical investigation was done in the 42 patients with bilateral vocal cord palsy who visited the otorhinolaryngologic department of the Yongdong Severance Hospital during the 10-year period between August 1986 to August 1996. On the sex and age distribution, the ratio of male to female patients was 2.8 : 1 and the age was evenly distributed and average was 46 years old. Of their chief complaints, dyspnea was the most common symptom. Among the position of the paralyzed vocal cords, paramedian position was most common. The most common causes of the bilateral vocal cord palsy was idiopathic Other causes include iatrogenic, prolonged intubation, head ＆ neck trauma, brain tumor, Myasthenia Gravis, and mediastinitis. Our treament results were as follows. Recovery rate of idiopathic bilateral vocal cord palsy was 77.7% and recovery period after bilateral vocal cord palsy was shortened remarkedly after use with steroid. We performed laser arytenoidectomy in patients with irreversible idiopathic vocal cord palsy, neural injury, and cricoarytenoid joint fixation. Decannualtion was possible to be carried out in 86% of the patients and none of complication except for 1 case of aspiration developed. Thus we concluded that it was meaningful surgical treatment of bilateral vocal cord palsy.

• 대한족부족관절학회지
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• 제9권1호
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• pp.59-63
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• 2005

Purpose: To present the procedure and results of dorsal wedge osteotomy fixated by bioabsorbable polyglycolide pins for the treatment of symptomatic Freiberg's disease. Materials and Methods: From January 1997 to December 2002, six patients with Freiberg's disease underwent dorsal wedge osteotomy of the metatarsal neck to bring the healthy plantar part of the metatarsal head into articulation. Bioabsorbable polyglycolide pins were used for the fixation and short-leg walking cast was applied for 4 weeks. Results: All patients returned to full daily activities without pain in three months after the operation. Radiographically, solid healing of the osteotomy was observed at average ten weeks. The active range of motion of the metatarsophalangeal joint increased by a mean gain of 30 degrees, and no complication such as displacement, osteolysis or sinus formation was observed. Conclusion: Dorsal wedge osteotomy fixated by bioabsorbable pins for patients with symptomatic Freiberg's disease is effective procedure that provides relatively early range of motion exercise and avoids second procedure for implant removal.

• 한국정밀공학회지
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• 제28권10호
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• pp.1159-1165
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• 2011

The recording density of HDD is increasing in ratio of 100% each year. Because the increasing of recording density requires the feature of high rotation, fixation and low-noise, fluid hydrodynamic bearing(FDB) has been paid attention to overcome a limitation in ball bearing. Most of researches related to improving performance of FDB have been studied in Japan which has 80% more market share of HDD spindle motor assembly. Main subject of studies are about for the design of the groove shape, manufacturing process of fluid dynamic bearing, performance evaluation and measurement. In HDD, non-repeatable runout(NRRO) is most important parameter which determines the performance of HDD spindle system because NRRO is unpredictable that cannot be compensated in head/slider servo system. In this study, performance evaluation system can measure dynamic behaviors were designed and methodology for calculating imbalance, RRO, and NRRO were proposed.

• 한국응급구조학회지
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• 제23권1호
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• pp.7-17
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• 2019

Purpose: The aim of this study was to verify the necessity of endotracheal intubation through video laryngoscope and to provide basic data to inform the provision of video laryngoscope education. Methods: Eighty paramedic students participated in this study. A survey was conducted from November 5, 2018 to December 7, 2018. Data were analyzed with independent t-tests, and the chi-squared test. Results: The video laryngoscope is a highly usable instrument that can easily be applied during training. The instrument provides better visual evaluation of the normal airway (p=.004), the airway in case of cervical collar and head fixation (p=.000), and the airway in case of tongue edema (p=.000). The time of endotracheal intubation in the normal airway was significantly less with the video laryngoscope compared with the direct laryngoscope. The success rate of tracheal intubation was significantly higher in the video laryngoscope group than in the direct laryngoscope. Conclusion: This study suggests the necessity of education on endotracheal intubation through video laryngoscope in the professional airway maintenance training course of emergency department students. The video laryngoscope is easier to apply than the direct laryngoscope in cases of intubation in various clinical situations.