The Feasibility of Translaminar Screws in the Subaxial Cervical Spine: Computed Tomography and Cadaveric Validation

Woojin Cho,Jason T. Le,Adam L. Shimer,Brian C. Werner,John A. Glaser,Francis H. Shen 대한정형외과학회 2022 Clinics in Orthopedic Surgery Vol.14 No.1

Background: The use of translaminar screws may serve as a viable salvage method for complicated cases. To our understanding, the study of the feasibility of translaminar screw insertion in the actual entire subaxial cervical spine has not been carried out yet. The purpose of this study was to report the feasibility of translaminar screw insertion in the entire subaxial cervical spine. Methods: Eighteen cadaveric spines were harvested from C3 to C7 and 1-mm computed tomography (CT) scans and three-dimensional reconstructions were created to exclude any bony anomaly. Thirty anatomically intact segments were collected (C3, 2; C4, 3; C5, 3; C6, 8; and C7, 14), and randomly arranged. Twenty-one segments were physically separated at each vertebral level (group S), while 9 segments were not separated from the vertebral column and left in situ (group N–S). CT measurement of lamina thickness was done for both group S and group N–S, and manual measurement of various length and angle was done for group S only. Using the trajectory proposed by the previous studies, translaminar screws were placed at each level. Screw diameter was the same or 0.5 mm larger than the proposed diameter based on CT measurement. Post-insertion CT was performed. Cortical breakage was checked either visually or by CT. Results: When 1° and 2° screws of the same size were used, medial cortex breakage was found 13% and 33% of the time, respectively. C7 was relatively safer than the other levels. With larger-sized screws, medial cortex breakage was found in 47% and 46% of 1° and 2° screws, respectively. There were no facet injuries due to the screws in group N–S. Conclusions: Translaminar screw insertion in the subaxial cervical spine is feasible only when the lamina is thick enough to avoid any breakage that could lead to further complications. The authors do not recommend inserting translaminar screws in the subaxial cervical spine except in some salvage cases in the presence of a thick lamina.

An In Vitro Biomechanical Analysis of Contralateral Sacroiliac Joint Motion Following Unilateral Sacroiliac Stabilization with and without Lumbosacral Fixation

Cho Woojin,Wang Wenhai,Lim Hyun Jin,Bucklen Brandon S. 대한척추외과학회 2023 Asian Spine Journal Vol.17 No.1

Study Design: Cadaveric biomechanics study.Purpose: This study investigated the effects of unilateral sacroiliac joint (SIJ) fixation for fusion with/without L5–S1 fixation on contralateral SIJ range of motion (ROM).Overview of Literature: SIJ fusion raises concerns that unilateral SIJ stabilization for fusion may increase contralateral SIJ mobility, leading to accelerated SIJ degeneration. Also, prior lumbosacral fixation may lead to accelerated SIJ degeneration, due to adjacent level effects. SIJ fixation biomechanics have been evaluated, showing a reduced-ROM, but SIJ fixation effects on contralateral nonfixated SIJ remain unknown.Methods: Seven human lumbopelvic spines were used, each affixed to six-degrees-of-freedom testing apparatus; 8.5-Nm pure unconstrained bending moments applied in flexion-extension, lateral bending, and axial rotation. The ROM of left and right SIJ was measured using a motion analysis system. Each specimen tested as (1) intact, (2) injury (left), (3) L5–S1 fixation, (4) unilateral stabilization (left), (5) unilateral stabilization+L5–S1 fixation, (6) bilateral stabilization, and (7) bilateral stabilization+L5–S1 fixation. Both left-sided iliosacral and posterior ligaments were cut for injury condition to model SIJ instability before surgery.Results: There were no statistical differences between fixated and contralateral nonfixated SIJ ROM following unilateral stabilization with/without L5–S1 fixation for all loading directions (<i>p</i>>0.930). Injured condition and L5–S1 fixation provided the largest motion increases across both joints; no significant differences were recorded between SIJs in any loading direction (<i>p</i>>0.850). Unilateral and bilateral stabilization with/without L5–S1 fixation reduced ROM compared with the injured condition for both SIJs, with bilateral stabilization providing maximum stability.Conclusions: In the cadaveric model, unilateral SIJ stabilization with/without lumbosacral fixation did not lead to significant contralateral SIJ hypermobility; long-term changes and <i>in vivo</i> response may differ.

MRI Measurement of Neuroforaminal Dimension at the Index and Supradjacent Levels after Anterior Lumbar Interbody Fusion: A Prospective Study

Woojin Cho,Mark J. Sokolowski,Amir A. Mehbod,Francis Denis,Timothy A. Garvey,John Perl,Ensor E. Transfeldt 대한정형외과학회 2013 Clinics in Orthopedic Surgery Vol.5 No.1

Background: Anterior interbody fusion has previously been demonstrated to increase neuroforaminal height in a cadaveric model using cages. No prior study has prospectively assessed the relative change in magnetic resonance imaging (MRI) demonstrated neuroforaminal dimensions at the index and supradjacent levels, after anterior interbody fusion with a corticocancellous allograft in a series of patients without posterior decompression. The objective of this study was to determine how much foraminal dimension can be increased with indirect foraminal decompression alone via anterior interbody fusion, and to determine the effect of anterior lumbar interbody fusion on the dimensions of the supradjacent neuroforamina. Methods: A prospective study comparing pre- and postoperative neuroforaminal dimensions on MRI scan among 26 consecutive patients undergoing anterior lumbar interbody fusion without posterior decompression was performed. We studies 26 consecutive patients (50 index levels) that had undergone anterior interbody fusion followed by posterior pedicle screw fixation without distraction or foraminotomy. We used preoperative and postoperative MRI imaging to assess the foraminal dimensions at each operated level on which the lumbar spine had been operated. The relative indirect foraminal decompression achieved was calculated. The foraminal dimension of the 26 supradjacent untreated levels was measured pre- and postoperatively to serve as a control and to determine any effects after anterior interbody fusion. Results: In this study, 8 patients underwent 1 level fusion (L5-S1), 12 patients had 2 levels (L4-S1) and 6 patients had 3 levels (L3-S1). The average increase in foraminal dimension was 43.3% (p < 0.05)−19.2% for L3-4, 57.1% for L4-5, and 40.1% for L5-S1. Mean pre- and postoperative supradjacent neuroforaminal dimension measurements were 125.84 mm2 and 124.89 mm2, respectively. No significant difference was noted (p > 0.05). Conclusions: Anterior interbody fusion with a coriticocancellous allograft can significantly increase neuroforaminal dimension even in the absence of formal posterior distraction or foraminotomy; anterior interbody fusion with a coriticocancellous allograft has little effect on supradjacent neuroforaminal dimensions.

한국어 형태소 분석기를 이용한 KoELECTRA 기반의 개체명 인식 기법

조우진(Woojin Cho),신규표(Gyupyo Shin),이원재(Wonjae Lee),손승현(Seunghyun Son),송현우(Hyunwoo Song ),이지훈(Jihoon Lee),이혁준(Hyukjoon Lee),조세현(Sehyeon Jo) 한국정보과학회 2021 한국정보과학회 학술발표논문집 Vol.2021 No.6

한글과 한자 획요소 간 매핑 조합 연구

조우진(WooJin Cho),조효동(Xiao-Tong Zhao),임순범(Soon-Bum Lim),송유정(Yoojeong Song) 한국콘텐츠학회 2023 한국콘텐츠학회논문지 Vol.23 No.1

사전학습 언어모델 기반의 한국어 질문-답변 데이터 증강 방법

조우진(Woojin Cho),이혁준(Hyukjoon Lee) 한국정보과학회 2021 정보과학회 컴퓨팅의 실제 논문지 Vol.27 No.12

자연어처리는 최근 인공지능이 각광을 받으며 비약적인 발전을 이루고 있다. 자연어처리의 여러 문제 중 질문-답변은 인공지능이 문단 내에서 질문에 맞는 답을 찾아주는 문제다. 인공지능 문제에서 우수한 성능을 달성하기 위해서는 인공지능 모델과 학습 데이터셋의 확보가 매우 중요하다. 특히 질문-답변 데이터셋은 질문-답변의 문법, 관계 등 인간의 직접적 개입이 많이 요구되어 데이터 구축이 쉽지 않다. 이런 문제점을 해결하기 위해 본 논문에서는 답변 생성, 질문 생성, 필터링의 3 단계로 구성된 질문-답변 데이터 증강 방법을 제안한다. 증강된 데이터를 이용하여 학습시킨 모델의 질의응답 성능이 KorQuAD 데이터만으로 학습시킨 모델에 비해 F1-score 기준 최대 1.13 증가한 결과를 얻을 수 있음을 실험을 통해 보인다. Natural language processing (NLP) has recently made rapid progress with artificial intelligence (AI) in the spotlight. Among the many problems of NLP, question-answer (QA) is a problem in which an AI algorithm finds the right answer to the question within a paragraph. Securing artificial intelligence models and training data are utmost important to achieve good performance of AI. In particular, QA data requires a lot of direct human intervention due to grammars and relationships between questions and answers, making it difficult to obtain a data set. To solve this problem, this paper proposes a QA data augmentation method consisting of four steps: answer generation, question generation, round-trip filter technique, and verification. Experiment results shows that the QA performance of the model trained using the augmented data could achieve up to 1.13-fold increase in terms of F1-score compared to the model learned by using KorQuAD data only.

LSTM을 이용한 하천수위 예측기법

조우진(Woojin Cho),강동수(Dongsu Kang) 한국정보과학회 2020 한국정보과학회 학술발표논문집 Vol.2020 No.12

임베디드 디바이스에서의 데이터베이스 활용 분석

조우진 ( Woojin Cho ),김동주 ( Dongju Kim ),구재회 ( Jae-hoi Gu ) 한국폐기물자원순환학회 2023 한국폐기물자원순환학회 추계학술발표논문집 Vol.2023 No.0

탄소세에 따른 대형트럭 비즈니스 패러다임 전략 연구 : 청정에너지 대형트럭 기술의 현주소와 과제

조우진(Woojin Cho),박종돈(Chongdon Park) 한국통상정보학회 2021 통상정보연구 Vol.23 No.3

환경오염에 대응할 목적으로, 우리나라는 수소전지에너지에 역점을 두고 있으나, 아직 기술적, 사회적, 경제적 한계에 따라 완전히 수소시대로 진입하는데 큰 리스크가 존재하는 실정이다. 하지만, 수소에너지가 갖는 청정성, 경제성 그리고 자원의 풍부함으로, 차후 반드시 활용해야 하는 미래의 신재생에너지 주 동력임이 자명한 바, 본 연구는 환경오염에 큰 책임이 있는 대형트럭과 탄소세에 역점을 두고 수소전지에너지를 대형트럭에 온전히 적용함에 있어 현 시점에서 대형트럭 메이커들이 취해야 할 효과적인 비즈니스 패러다임 전략을 제시하고자 했다. 이러한 연구목적을 위해 본 연구는 선행연구 고찰을 통한 질적연구를 통해, 수소에너지 활용 필요성과 현 시점에서 대형트럭에 적용시 문제점을 진단하였고, 이를 위한 대안으로 내연기관 즉, 액화천연가스(LNG) 기반의 내연기관의 사용 타당성을 도출했고, 수소에너지를 지속 개발하면서 현재 탄소세에 대응하기 위한 액화천연가스(LNG) 기반의 내연기관 활용 전략을 도출하고자 하였다. 연구를 진행한 결과, LNG가 갖는 오염도 최소화를 위한 기술적 대안 창출과 차후 주력 에너지가 될 수소전지에너지 완성도 고도화 방안 2가지 과제가 대형 트럭 메이커들이 해결해야 할 과제임을 도출했다. 이에 따라 본 연구는 정책적, 실무적, 학계 차원의 대응방안을 위한 시사점을 상호유기적으로 제시하여 차후 대형트럭 메이커가 온전히 수소전지에너지를 원활하게 활용하여 환경오염 최소화를 달성함에 있어 사회 전반의 노력이 함께 전개되어야 함을 강조했다. For the purpose of responding to environmental pollution, Korea is focusing on the hydrogen fuel-cell technology, but there is still a great risk in entering the hydrogen era completely due to technological, social, and economic limitations. However, due to the no emission of hydrogen fuel-cell, economy, and abundance of resources of hydrogen energy, it is clear that it is the main engine of new and renewable energy in the future that must be used in the future. It was intended to present an effective business paradigm strategy that heavy truck makers should take at this point in fully applying hydrogen cell energy to large trucks. For the purpose of this study, the study investigated the necessity of using hydrogen energy and the problems in applying it to large trucks at the present time through a qualitative research through the review of previous studies. The feasibility of using an internal combustion engine based on the internal combustion engine was drew, and a strategy for using a liquefied natural gas (LNG) based internal combustion engine was derived to respond to the current carbon tax while continuously developing hydrogen energy. As a result of this study, it was determined that the two tasks to be solved by heavy truck makers are the creation of technological alternatives to minimize the pollution of LNG and the improvement of the perfection of hydrogen fuel-cell, which will be the main energy in the future. Accordingly, this study organically suggests implications for policy, practical, and academia-level countermeasures, so that in the future, large truck makers can fully utilize hydrogen fuel cell to minimize environmental pollution, so emphasized the need to develop in the practical way.

에너지 관리 시스템의 데이터 수집 시스템접근을 위한 Rest API 성능 평가

조우진 ( Woojin Cho ),임채영 ( Chae-young Lim ),김동주 ( Dongju Kim ),이형아 ( Hyungah Lee ),여채은 ( Chae-eun Yeo ),구재회 ( Jae-hoi Gu ) 한국폐기물자원순환학회 2023 젊은 연구자 학술연구발표회 Vol.20 No.0