슬관절 주위 글격의 기초과학 및 스포츠 손상

김희천,Kim Hee-Chun 대한정형외과스포츠의학회 2003 대한정형외과스포츠의학회지 Vol.2 No.2

Purpose: The biomechanics and kinematics of knee joint were reviewed in this article. And then the common sports injuries were presented. Anatomy and Kinetics: None of the pairs of bearing surfaces in the knee joint is exactly congruent This allows the knee six degrees of freedom of motion. Tibiofemoral Kinematics: In flexion and extension, the axis of motion is not perpendicular to the medial-lateral plane of the joint, nor is it perpendicular to the axis of longitudinal rotation. This results in coupled varus angulation and internal rotation with flexion and in valgus angulation and external rotation with extension. Patellofemoral Articulation: Loads across the patellofemoral joint are indirectly related to the angle of knee flexion and directly related to the force generated within the quadriceps mechanism. Fractures of the Patella: Nonoperative treatment is indicated if the extensor mechanism is intact and if displacement of fragment is minimal. The specific type of internal fixation depends on the fracture pattern. It is important to repair retinaculum. Acute and Recurrent Patellar Instability: The degree of dysplasia and the extent of the instability play a large part in determining the success of nonoperative treatment. Patients who experience recurrent dislocations and patients with major anatomic variations require surgery to minimize their instability. Sports Injuries in School-age Atheletes: Patellar pain in young athletes groups a number of conditions, including Idiopathic Adolescent Anterior Knee Pain, Osgood- Schlatter Disease, and Sinding-Larsen-Johansson Disease. 목적: 슬관절 주위 골격의 기초과학을 생체역학을 중심으로 설명하고 빈도가 높은 스포츠 손상들에 대해 기술하고자 한다. 해부 밀 운동학: 슬관절은 순수한 경첩 관절이 아니며 적합하지 않으므로 여섯 방향의 운동이 가능하다. 경골대퇴간 운동역학: 슬관절의 굴곡-신전 축은 시상면에 수직이 아닐 뿐 아니라, 관상면상 관절선과 평행하지 않으므로, 경골대퇴관절은 굴곡 시 내반과 내회전이 동반되고 신전 시에는 외반과 외회전이 동반된다. 슬개대퇴 관절: 슬개대퇴 관절 압박력은 슬관절의 굴곡 각도와 사두고근력에 비례한다 슬개골은 신전기전의 moment arm을 증가시켜 신전기전의 효율을 증대시키고 지렛대 역할을 한다. 슬개골 골절: 비전위성 골절이면서 하지 직거상 운동이 보존된 경우에 비수술적 치료의 적응증이 되며 수술적 치료 시 고정 방법의 선택은 골절 양상에 따라 결정되겠으나 어느 술식을 선택하여도 신전지대의 봉합은 필수적이며 중요하다 슬개골 불안정성: 선행 해부학적 이상을 조사해야 하며 급성 탈구에서도 골연골 골절편이 있거나 재발의 위험이 높은 운동선수에서 인대 봉합을 고려할 수 있다. 비수술적 치료 및 재활에도 불수하고 계속되는 재발성 아탈구나 탈구는 수술이 필요하다 학령기 스포츠 손상: Idiopathic Adolescent Anterior Knee Pain, Osgood-Schlatter Disease, Sinding-Larsen-Johansson Disease 등이 흔하다

슬관절 전치환술에서 외측 지지대 박피의 효과

김희천 ( Hee Chun Kim ),노재영 ( Jae Young Roh ),이철우 ( Churl Woo Lee ),이창욱 ( Chang Wook Lee ),탁효철 ( Hyo Chul Tak ) 대한슬관절학회 2006 대한슬관절학회지 Vol.18 No.1

다면적 선호체계 하에서의 반복 양면매칭 게임

김희천 ( Hee Chun Kim ) 한국산업조직학회 2019 産業組織硏究 Vol.27 No.4

본 논문은 선호의 불완전성이 양면매칭 게임의 결과에 어떠한 영향을 미칠 수 있는지에 대하여 고찰한다. 각 참가자가 매 라운드마다 자신의 선호를 제출하고 참가자의 수가 한정적인 반복적인 1대1 양면매칭 게임을 고려한다. 또한 각 참가자의 매칭상대에 대한 선호가 과거라운드의 매칭 결과에 따라 갱신될 수 있으며, 위 선호가 다면적인 형태로 이루어져 있을 경우를 가정한다. 본 논문은 이러한 환경 하에서 반복적 매칭 결과가 최적배분(the first-best allocation) 결과와 일치하도록 수렴하기 위해서는 특정한 두 가지 조건(자극에 대한 빠른 반응과 높은 예측도)을 만족하여야 함을 보였다. 또한 상기한 두 조건 중 어느 하나의 조건이라도 만족하지 않을 경우 게임이 무한히 반복된다고 할지라도 최적배분 결과와 일치하지 않는 결과가 도출될 수 있음을 보였다. This paper examines how incompleteness of preference can affect the matching result in the two-sided matching environment. I consider a repeated two-sided one-to-one matching game with a finite number of players on each side. In each round of the matching game, players submit their preference, which can be updated according to the result of the past matching(s), about potential partners on another side. I assumed that players have a multi-attribute preference and each attribute could be revealed only when they receive high enough stimulus. Under this environment, I show that the sequence of matching allocations converges to the first-best allocation only when players are equipped with a “good enough” prediction or “low enough” threshold for an unrevealed attribute. If not, converged matching allocation can be different from the first-best allocation and it may result in inefficiency even after infinitely repeated matchings.

슬관절 전치환술 후 심부 감염의 술전 위험 인자

김희천 ( Hee Chun Kim ),손훈상 ( Hoon Sang Sohn ),이상은 ( Sang Eun Lee ) 대한슬관절학회 2009 대한슬관절학회지 Vol.21 No.4

Purpose: The aim of this study was to investigate the overall rate of deep infection and the risk factors for infection after primary total knee arhroplasties. Materials and Methods: We conducted a retrospective case-control study of 229 patients (376 knees) who underwent total knee replacement (TKR) between January 2006 and June 2007 and who were followed up for more than one year. The risk factors for deep infection were determined via univariate analyses. Results: The overall rate for developing infection was 1.9% (7 of 376). The risk factors were an operating theatre other than the main room (odds ratio=33.2, 95% confidence interval=1.9, 583.6) and a preoperative hemoglobin level lower than 12 mg% (odds ratio=4.3, 95% confidence interval=1.9, 9.4). Conclusion: The deep infection rates after TKRs might vary depending on the preoperative level of hemoglobin and the operating-room environment. Successful strategies to overcome the host and environmental risk factors are needed with the goal of preventing infection of the prosthesis.

현역군인에서 발생한 중족골 행군골절의 양상과 의의

김희천(Hee-Chun Kim),김태훈(Tae-Hoon Kim),김정환(Chung-Hwan Kim),조덕연(Duck- Yun Cho) 대한정형외과학회 1996 대한정형외과학회지 Vol.31 No.5

Scorpio 인공 슬관절의 단기 추시 결과

김희천 ( Hee Chun Kim ),안종구 ( Jong Goo Ahn ) 대한슬관절학회 2003 대한슬관절학회지 Vol.15 No.2

5kW 용융탄산염 연료전지 이젝터 설계 및 시험

김범주(Kim, Beom-Joo),김도형(Kim, Do-Hyung),이정현(Lee, Jung-Hyun),정상천(Jung, Sang-Chun),이성윤(Lee, Sung-Yoon),강승원(Kang, Seung-Won),임희천(Lim, Hee-Chun) 한국신재생에너지학회 2008 한국신재생에너지학회 학술대회논문집 Vol.2008 No.05

An ejector is a fluid machinery to be utilized for mixing fluids, maintaining vacuum, and transporting them. The Ejector is applied for a variety of industrial fields such as refrigerators and power plants. It is adopted to recycle anode off gas safely in 5kW Molten Carbonate Fuel Cell system of KEPRI(Korea Electric Power Research Institute). The ejector is placed at mixing point between the anode off gas and the cathode off gas or the fresh air. In this study, the entrainment ratio is measured according to the diametrical ratio of nozzle to throat. In addition, the performance curve of the ejector and the differential pressure in diffuser is observed.

슬개골전 점액낭에 발생한 Tumoral Calcinosis - 증례보고 -

김희천,송광진,조덕연,Kim, Hee-Chun,Song, Kwang-Jin,Cho, Duck-Yun 대한근골격종양학회 1997 대한골관절종양학회지 Vol.3 No.2

1. 10세 남아 환자에서 슬개골전 점액낭에 발생한 드문 형태의 Tumoral Calcinosis를 치험하였다. 2. 이 환자에서도 고인산혈증을 보여 일부 외국 저자들이 주장한 인산대사 장애설을 시사하였다. 3. 본 증례는 수술적 치료만으로도 만족스럽게 치유되었다. Tumoral calcinosis is a rare disorder of unknown etiology, which is characterized by the developement of large calcified masses overlying the large joints in otherwise healthy subjects. If histologic tests are not confirmed, the condition may be treated erroneously as bursitis. This report describes the case of a 10-year-old man with tumoral calcinosis of the knee, a joint very rarely affected by this unusual disorder. Microscopically the tumor consists of a stroma of chronic inflammatory tissue surrounding cystic spaces containing calcium-rich material. We made excision alone, and the patient made an uneventful recovery with no evidence of recurrence up to 13 months postoperatively.

외측 반월상 연골 이식술 후 이식물 탈출의 관절경적 평가 -증례 보고-

김희천,김택선,김영배,양재혁,김진각,윤정로,Kim, Hee-Chun,Kim, Taik-Sun,Kim, Young-Bae,Yang, Jai-Hyuk,Kim, Jin-Kak,Yoon, Jung-Ro 대한관절경학회 2013 대한관절경학회지 Vol.17 No.1

The meniscus is considered "extruded" when it extends beyond the tibial margins more than 3 mm in a coronal view of magnetic resonance imaging (MRI). However, identifying the meniscal extrusion intraoperatively may be difficult because of the simple fact that most of the arthroscopic procedures are done in knee flexion position while follow up MRI studies area taken at knee extension position. Here, we demonstrate the arthroscopic technique for evaluating the meniscal extrusion. 반월상 연골의 탈출은 슬관절 반월상 연골이 자기공명영상(magnetic resonance imaging, MRI) 사진의 관상면상 경골외측연에 대해 3 mm 이상의 전위를 보이는 경우이다. 그러나 이 소견을 관절경 하에서는 관찰하기는 어려운데 외측 반월상 연골의 관찰이 관절경 검사 시 슬관절 굴곡 상태에서 관찰되는 반면 자기공명영상(MRI)은 슬관전 신전 상태에서 촬영되는 차이점이 이유 중 하나이다. 이에 저자들은 관절경을 이용한 반월상 연골 탈출의 확인하는 방법에 대해 기술하고자 한다.

75kW 용융탄산염 연료전지 시스템의 MBOP 개발

김범주(Kim, Beom-Joo),김도형(Kim, Do-Hyung),이정현(Lee, Jung-Hyun),강승원(Kang, Seung-Won),임희천(Lim, Hee-Chun) 한국신재생에너지학회 2009 한국신재생에너지학회 학술대회논문집 Vol.2009 No.06

A pivotal mechanical balance of plant for 75kW class molten carbonate fuel cells comprise of a catalytic burner and an ejector which has been designed and tested in KEPRI(Korea Electric Power Research Institute). The catalytic burner, which oxidizes residual fuel in the anode tail gas, was operated at several conditions. Some problems arose due to local overheating or auto-ignition, which could limit the catalyst life. The catalytic burner was designed by considering both gas mixing and gas velocity. Test results showed that the temperature distribution is very uniform. In addition, an ejector is a fluid machinery to be utilized for mixing fluids, maintaining vacuum, and transporting them. The ejector is placed at mixing point between the anode off gas and the cathode off gas or the fresh air Several ejectors were designed and tested to form a suction on the fuel tail gas and balance the differential pressures between anode and cathode over a range of operating conditions. The tests showed that the design of the nozzle and throat played an important role in balancing the anode tail and cathode inlet gas pressures. The 75kW MCFC system built in our ejector and catalytic burner was successfully operated from Novembe, 2008 to April, 2009. It recorded the voltage of 104V at the current of 754A and reached the maximum generating power of 78.5kW DC. The results for both stand-alone and integration into another balance of plant are discussed.