• 대한토목학회논문집
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• 제8권3호
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• pp.1-10
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• 1988

본 연구에서는 고차 판 유한요소의 판의 기하학적 비선형 해석에의 적용성을 고찰한다. 고차판요소는 3 차원 연속체로부터 Total Lagrangian 형태로 나타낸 운동방정식을 이산화하고 고차 판이론을 도입하여 유도한다. 유한변형을 고려한 기하학적 비션형 방정식은 Newton-Raphson반복법으로 내력벡터를 선형화하여 강도매트릭스를 반복계산하여 푼다. 요소매트릭스는 shear locking 현상을 피하기 위하여 Gauss 적분법을 이용한 선택적 감차적분으로 계산한다. 여러가지 예제해석을 통하여 고차 판요소의 효율성과 정확도를 고찰하였다.

• 전산구조공학
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• 제10권2호
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• pp.179-188
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• 1997

본 논문에서는 평판 구조물의 효율적인 해석을 위한 4절점 평판휨 요소를 개발하였다. 이 요소는 전단변형을 고려하기 위해 Mindlin평판이론에 의하여 유도하였다. 평판휨 문제에서 4절점요소와 같은 저차의 등매개변수 Mindlin평판요소는 전단강성을 실제보다 강하게 평가하기 때문에 얇은 평판에서는 요소의 기능을 발휘하지 못한다. 이러한 문제점을 극복하기 위해 4절점 요소에 5개의 비적합변위모드를 추가함으로써 개선된 결과를 얻을 수 있었으며, 개발된 요소는 유사영에너지모드를 발생시키지 않는다. 아주 얇은 평판에서도 요소의 형상과 무관하게 전단구속현상을 극복하였으며, 예제 해석으로부터 변위의 신속한 수렴성과 단면력의 분포가 양호한 결과를 얻을 수 있었다. 또한 요소형상비가 매우 큰 경우에도 좋은 결과를 얻을 수 있었다.

• 대한정형외과스포츠의학회지
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• 제5권1호
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• pp.63-68
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• 2006

목적: 전위성 쇄골 간부 골절의 치료로 관혈적 정복술 후 LCP를 사용하여 내고정을 시행한 환자를 대상으로 방사선학적, 임상적 결과를 분석하여 전위성 쇄골 간부 골절의 치료에 있어서 LCP의 유용성을 알아보고자 하였다. 대상 및 방법: 2003년 5월부터 2004년 11월까지 본원에서 쇄골 간부 골절에 대해 LCP를 이용한 관혈적 정복, 금속내 고정술을 시행하고 6개월 이상 추시가 가능하였던 26례를 대상으로 하였다. 수술 후 최종 평가는 방사선 결과와 fang s criteria를 이용한 임상적 결과로 분석하였다. 결과: 수술 후 평균 9.3주에 모든 예에서 지연유합 없이 골유합 되었으며 임상적으로 Kangs criteria에 따라 구분한 결과, 우수 이 상이 22례로 나타났다. 특히, 견관절 운동은 상완골 골절이 동반된 두 경우를 제외한 24례에서 2.9주내에 정상 범위로 빠른 회복을 보였다. 합병증으로는 견관절 운동 장애 2례, 수술 절개 부위의 켈로이드 형성 1례였으며 그 이외에 다른 주요 합병증은 없었다. 결론: 전위성 쇄골 간부 골절에서 LCP를 이용한 관혈적 정복 및 금속내 고정술은 기존의 금속판에 비해 수술 후 합병증을 줄이고 효과적인 골유합과 조기 견관절 운동에 도움을 줄 수 있는 좋은 치료 방법 중 하나라고 사료된다.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제43권2호
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• pp.77-82
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• 2017

Objectives: The aim of this study was to compare the mechanical resistance of four different osteosyntheses modeled in two different sagittal split ramus osteotomy (SSRO) designs and to determine the linear loading in a universal testing machine. Materials and Methods: An in vitro experiment was conducted with 40 polyurethane hemimandibles. The samples were divided into two groups based on osteotomy design; Group I, right angles between osteotomies and Group II, no right angles between osteotomies. In each group, the hemimandibles were distributed into four subgroups according to the osteosynthesis method, using one 4-hole 2.0 mm conventional or locking plate, with or without one bicortical screw with a length of 12.0 mm (hybrid technique). Each subgroup contained five samples and was subjected to a linear loading test in a universal testing machine. Results: The peak load and peak displacement were compared for statistical significance using PASW Statistics 18.0 (IBM Co., USA). In general, there was no difference between the peak load and peak displacement related to osteotomy design. However, when the subgroups were compared, the osteotomy without right angles offered higher mechanical resistance when one conventional or locking 2.0 mm plate was used. One locking plate with one bicortical screw showed higher mechanical resistance ($162.72{\pm}42.55N$), and these results were statistically significantly compared to one conventional plate with monocortical screws (P=0.016) and one locking plate with monocortical screws (P=0.012). The difference in peak displacement was not statistically significant based on osteotomy design or internal fixation system configuration. Conclusion: The placement of one bicortical screw in the distal region promoted better stabilization of SSRO. The osteotomy design did not influence the mechanical behavior of SSRO when the hybrid technique was applied.

• 대한족부족관절학회지
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• 제17권2호
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• pp.130-135
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• 2013

Purpose: Preshaped Locking compression plate(LCP) has holes with fixed angle between screw and plate and have advantage firm fixation because it has stability of angular and axial deformity. We evaluated usefulness of LCP after open reduction and internal fixation in distal fibular fracture. Materials and Methods: Between December 2011 and May 2012, 23 patients with fracture of distal fibula were followed up at least 12 months underwent open reduction and internal fixation with LCP. There were 15 males and 8 females with a mean age 39.8(20~69) years. According to Danis-Weber classification, there were 20 cases of type B and 3 cases of type C. There were 13 cases of isolated lateral malleolus fractures, 1 case of bimalleolar fracture, 6 cases of trimalleolar fractures and 3 cases of distal tibia fractures with proximal fibula fracture. Intraoperatively, we assessed whether preshaped LCP fit lateral margin of distal fibula or not and evaluated quality of reduction and postoperative complications. The cases were analyzed by radiological bone union time and clinical results according to the criteria of Meyer Results: Of all cases, complete bone union was achieved and average radiological bone union time was 7.3(6~12) weeks. The clinical results were excellent in 18 cases(78%), good in 5 cases(22%). There were 5 cases of plate with 3 holes, 13 cases of plate with 4 holes, 2 cases of plate with 5 holes, 1 case of plate with 6 holes and 2 cases of plate with 7 holes. The average number of screws at proximal fragement was 2.5 and at distal fragment was 3.5. In 14 cases (60.8 %), we needed re-bending of plate because the distance between plate and lateral cortical margin of distal fibula was more than 5 mm at anteroposterior X-ray after reduction. All cases have anatomical reduction and there were no complications of wound infections. There were no complaint about hardware irritation. Conclusion: At fractures of distal fibula,preshaped LCP had a excellent stability although far cortex was not fixed with screw and bending of plate. And there are less complications of hardware irritation and wound problems. But, Some complement would be needed because there were no complete fitting between precontour of LCP and lateral cortical margin of distal fibula.

• Clinics in Shoulder and Elbow
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• 제15권2호
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• pp.123-129
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• 2012

목적: 견봉 쇄골 탈구의 수술적 치료에서 갈고리 금속판의 견봉측 고정장치 (acromial locking system)가 유용한지에 대한 조사를 위하여 견봉측 고정장치가 있는 Wolter 금속판과 그것이 없는 AO hook 금속판 두 가지 방법의 임상적 결과와 합병증을 비교하고자 하였다. 방법: Rockwood 분류 III-V형의 견봉 쇄골 관절 탈구로 수술한 환자 중 1년 이상 추시가 가능했던 71명을 대상으로 하였다. 이 중 Wolter 금속판을 이용하여 수술을 한 환자 39명, AO hook 금속판을 이용한 환자가 32명이었다. 술 후 평가는 Constant-Murley 평가 지표를 이용하여 수술 후 약 1개월, 3개월, 6개월, 12개월에 관절 기능을 점수화하고 운동범위를 측정하였으며 금속판과 골의 방사선적 합병증을 조사 하였다. 결과: 수술 후 1년 추시 Constant-Murley score는 Wolter 금속판 $85.2{\pm}5.3$점, AO Hook 금속판 $83.2{\pm}6.8$점으로 유의한 차이 없이 우수하였다. 운동범위는 수술 후 1개월 및 3개월에서 Wolter 금속판의 운동 범위가 유의하게 높게 호전 되었으나 6개월 이후에는 AO hook 금속판과 차이가 없었다. 수술 후 합병증으로 Wolter 금속판은 4예에서 방사선상 나사못의 이완 및 파열이 나타났으며, AO hook 금속판은 7예에서 견봉하 골용해 소견과 금속판 주위 골절이 나타났다. 결론: 견봉측 고정장치 유무에 상관없이 두 가지 수술 방법 모두 장기적인 임상 결과는 우수하며, 유용한 방법이라고 생각되나 견봉측 고정장치가 없는 AO hook 금속판이 수술 후 초기에 관절운동 제한이 더 많이 관찰 되었으며, 견봉의 골용해도 많았다. 그러나 Wolter 금속판은 큰 절개가 필요하다는 등의 단점이 있고 나사못의 이완 및 파열, 견봉 골절 등이 나타날 수 있어 두 방법 각각의 장단점이 있다고 판단되었다.

• Journal of Korean Neurosurgical Society
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• 제45권4호
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• pp.213-218
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• 2009

Objective : This study is a retrospective clinical study over more than 4 years of follow up to understand the mechanism of load sharing across the graft-bone interface in the static locking plate (SLP) fixation compared with non-locking plate (NLP). Methods : Orion locking plates and Top non-locking plates were used for SLP fixation in 29 patients and NLP fixation in 24 patients, respectively. Successful interbody fusion was estimated by dynamic X-ray films. The checking parameters were as follows : screw angle (SA) between upper and lower screw, anterior and posterior height of fusion segment between upper and lower endplate (AH & PH), and upper and lower distance from vertebral endplate to the end of plate (UD & LD). Each follow-up value of AH and PH were compared to initial values. Contributions of upper and lower collapse to whole segment collapse were estimated. Results : Successful intervertebral bone fusion rate was 100% in the SLP group and 92% in the NLP group. The follow-up mean value of SA in SLP group was not significantly changed compared with initial value, but follow-up mean value of SA in NLP group decreased more than those in SLP group (p=0.0067). Statistical analysis did not show a significant difference in the change in AH and PH between SLP and NLP groups (p>0.05). Follow-up AH of NLP group showed more collapse than PH of same group (p=0.04). The upper portion of the vertebral body collapsed more than the lower portion in the SLP fixation (p=0.00058). Conclusion : The fused segments with SLP had successful bone fusion without change in initial screw angle, which was not observed in NLP fixation. It suggests that there was enough load sharing across bone-graft interface in SLP fixation.

• 대한골관절종양학회지
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• 제16권2호
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• pp.80-86
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• 2010

목적: 골격계는 전이성 암에 의해 흔히 영향을 받는 부위이다. 본 연구를 통해 하지에서 발생한 전이성 병적 골절에 대한 치료로서 잠김 금속판을 이용한 치료 결과에 대해 알아보고자 한다. 대상 및 방법: 2004년부터 2010년까지 하지에 발생한 전이성 암에 의한 병적 골절에 대하여 잠김 금속판을 이용하여 치료받은 12명(13예)의 환자를 대상으로 평가를 시행하였다. 평균 환자 나이는 62.2세(50-81세)였으며, 골절은 각각 근위 대퇴골 2예, 대퇴골 간부 3예, 원위 대퇴골 3예, 근위 경골 4예, 원위 대퇴골 1예에서 발생하였다. 치료 결과로서 휠체어 보행 가능 시기, 통증 완화 정도 및 합병증을 평가하였으며, 또한 수술 시간 및 술 후 실혈량에 대하여 평가하였다. 결과: 수술 후부터 휠체어 보행까지는 평균 3.2일(1-6일)이 소요되었다. 평균 시각 통증 척도는 수술 전 8.1점(7-9점)에서 술 후 1주일째 2.7점(2-4점)으로 호전되었으며, 수술과 연관된 조기 합병증은 발생하지 않았다. 평균 수술 시간은 88.4분(70-105분)이었으며, 술후 평균 실혈량은 246.5 ml (130-320 ml)이었다. 결론: 하지의 전이성 병적 골절에 대한 치료로서, 잠김 금속판을 이용한 내고정술은 심한 골 파괴나 골 결손을 보이는 장골의 골간단부 혹은 골간부 병변에 효과적인 치료 방법이며, 또한 조기 보행을 가능하게 하고, 통증 및 술후 합병증 감소에 도움을 줄 수 있을 것이다.

• Clinics in Shoulder and Elbow
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• 제17권4호
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• pp.175-180
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• 2014

Background: For Neer type IIB fracture of distal clavicle with coracoclavicular ligament injury, various surgical treatments have been used in literatures. However, there was no consensus on the optimal treatment. The aim of this study is to report the clinical and radiological results of open reduction and internal fixation of unstable distal clavicle fracture and suture augmentation of disrupted coracoclavicular ligament. Methods: A prospective study was performed in 23 patients with Neer type IIB distal clavicle fracture in Seoul Medical Center, Eulji Hospital, and National Medical Center. Firstly, suture anchors are inserted in the base of coracoid process and preliminary reduction was achieved by tie-off of three suture limbs around the clavicle. Then, the final fixation was completed with anatomical locking plate. Bony union and the distance between coracoclavicular ligaments were evaluated. Clinical results and complications including stiffness and secondary procedures were evaluated. Results: Bony union was achieved in all cases except one (22 of 23). At mean 14.9 months, no significant difference in the mean coracoclavicular distance was observed compared to uninjured shoulder ($8.2{\pm}7.9mm$ versus $7.3{\pm}3.4mm$, p=0.14). Pain visual analogue scale, American Shoulder and Elbow Surgeons score, Constant score, and Disabilities of the Arm, Shoulder and Hand score were 0.5, 83.4, 78.5, and 6.2, respectively. Revision surgery was performed in one case of nonunion. Four patients who complained of skin irritation underwent implant removal. Conclusions: In cases of an unstable distal clavicle fracture with coracoclavicular ligament disruption, satisfactory clinical results were obtained by locking plate fixation and coracoclavicular ligament suture augmentation concurrently.

• Clinics in Shoulder and Elbow
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• 제21권4호
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• pp.220-226
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• 2018

Background: This study introduces a surgical technique with good clinical outcome useful in the treatment of osteoporotic displaced 3- or 4-part proximal humeral fractures. Methods: From May 2014 to February 2016, 16 patients with displaced 3- or 4-part proximal humeral fractures were treated by application of a locking plate with an endosteal strut allograft via a deltoid splitting approach with a minimum follow-up of 12 months. The allograft was inserted through a fractured gap of the greater tuberosity to support the humeral head and then fixed by a locking plate with meticulous soft tissue dissection to protect the axillary nerve. Surgical outcomes were evaluated by the American Shoulder and Elbow Surgeons (ASES) and visual analogue scale (VAS) scores, radiological imaging, and clinical examination. Fixation failure on radiographs was defined as a >$5^{\circ}$ loss of neck shaft angle (NSA) compared to that on an immediate postoperative radiograph. Avascular necrosis (AVN) of the humeral head was also evaluated. Results: In all cases, complete union was achieved. The ASES and VAS scores were improved to $85.4{\pm}2.1$ and $3.2{\pm}1.3$, respectively. Twelve patients (75.0%) had greater than a $5^{\circ}$ change in NSA; the average NSA change was $3.8^{\circ}$. Five patients (31.3%) had unsatisfactory ranges of motion exhibiting a <$100^{\circ}$ active forward flexion. No axillary nerve injuries or AVN were observed at the last follow-up. One patient was converted to reverse total arthroplasty due to severe pain and functional deficit. Conclusions: Minimally invasive fixation via a locking compression plate and an endosteal fibula strut allograft in Neer classification 3-or 4-part fractures with severe osteoporosis in elderly patients can achieve good clinical results.