• Journal of the Korean Arthroscopy Society
• /
• v.16 no.2
• /
• pp.160-166
• /
• 2012

Purpose: The aim of this study was to determine the patterns of the stress distribution within the reconstructed anterior cruciate ligament (ACL) double bundles in response to an anterior tibial load and rotatory load at $45^{\circ}$ flexed knee model by use of a 3-dimensional finite element analysis (FEM). Materials and Methods: The $0^{\circ}$ and $45^{\circ}$ flexed 3-D knee model were reconstructed based on the high resolution computed tomography (CT) images from the right knee of a healthy male subject. To simulate double bundle ACL reconstruction, in $0^{\circ}$ analytic model, four 7 mm diameter tunnels were created at the center of each anteromedial (AM) and posterolateral (PL) footprints on the femur and tibia. The grafts were inserted into the corresponding bone tunnels and then reconstructed knee model was flexed to $45^{\circ}$. As a next step, the 5 mm anterior tibial load and internal rotational load of $10^{\circ}$ were applied on the final Computer aided design (CAD) model. And then stress patterns of each bundle were assessed using a finite element analysis. Results: In response to the 5 mm of anterior tibial load, the AM bundle showed increased stresses around the tibial and femoral attachment sites; especially in the anterior aspect of the bundle. In the PL bundle, the highest stress concentration was also noticed on the anterior aspect of the bundle. Under $10^{\circ}$ internal rotational load, the stress concentration was predominant around the anterior aspect of the tibial attachment site within the AM bundle. The PL bundle also showed highest stress concentration on the anterior aspect of the bundle. Conclusion: Although the stress patterns were not identical among the AM and PL bundle, there were common trends in the stress distribution. The stress concentration was predominant on the anterior aspect of both bundles in response to the anterior tibial load and rotatory load.

• Journal of the Korean Orthopaedic Association
• /
• v.56 no.3
• /
• pp.253-260
• /
• 2021

Purpose: The least constrained prosthesis is generally recommended in primary total knee arthroplasty (TKA). Nevertheless, a varus/valgus constrained (VVC) prosthesis should be implanted when a semi-constrained prosthesis is not good for adequate stability, especially in the coronal plane. In domestic situations, however, the VVC prosthesis could not always be prepared for every primary TKA case. Therefore, it is sometimes impractical to use a VVC prosthesis for unsual unstable situations. This study provides information for preparing VVC prostheses in the preoperative planning of primary TKA through an analysis of primary VVC TKA cases. Materials and Methods: This study reviewed 1,797 primary TKAs, performed between May 2003 and February 2016. The reasons for requiring VVC prosthesis and the preoperative conditions in 29 TKAs that underwent primary TKA with a VVC prosthesis were analyzed retrospectively. Results: In primary TKA, 29 cases (1.6%) in 27 patients (6 male and 21 female) used VVC prosthesis. Two patients underwent a VVC prosthesis on both knees. The mean age of the patients was 63.4 years old (34-79 years). The mean flexion contracture was 16.2° (-20°-90°), and the mean angle of great flexion was 111.7° (35°-145°). The situations requiring a VVC prosthesis were severe valgus deformity in 10 knees, knee stiffness requiring extensive soft tissue release in 10 knees, previously injured collateral ligaments in five knees, and distal femoral bone defect due to avascular necrosis in four knees. The mean tibiofemoral angle was 25.7° (21°-43°) in 10 cases with a valgus deformity. The mean flexion contracture was 37.5° (20°-90°), and the mean range of motion was 48.5° (10°-70°) in 10 cases with knee stiffness. Conclusion: The preparation of VVC prosthesis is recommended, even for primary TKA in cases of severe valgus deformity (tibiofemoral angle>20°), stiff knee (the range of motion: less than 70° with more than 20° flexion contracture), and the cases with a previous collateral ligament injury. This information will help in the preparation of adequate TKA prostheses for unusual unstable situations.

• The Journal of the Korean bone and joint tumor society
• /
• v.10 no.2
• /
• pp.147-151
• /
• 2004

Conventional osteochondroma is common bone lesion usually originated near the end of a long bone. But intra-articular osteochondromas are very rare and have been reported less than a dozen cases. The authors experienced two cases of intra-articular osteochondroma of the knee joint. Histology as well as gross finding were consistent with osteochondroma. The tumor was excised surgically, and symptoms were relieved.

• The Journal of Korean Orthopaedic Ultrasound Society
• /
• v.1 no.1
• /
• pp.58-63
• /
• 2008

Mechanism of the peroneal tendon dislocation is mainly the ankle trauma and commonly caused by severe peroneal tendon contraction at ankle dorsiflexion state. Peroneal tendon tears are frequently combined in recurrent dislocation. The peroneal tendon dislocation from the fibula groove can be confirmed with ultrasound scanning. Recurrent dislocation needs surgical treatment and usually gains good clinical outcome with fibula groove deepening procedure. Tibialis anterior tendon rupture is frequently found in old age but active patients who had tendency of tendon weakness due to chronic tendon attrition, repeated steroid injection, diabetic tendinopathy or inflammatory arthropathy.

• The Journal of the Korean bone and joint tumor society
• /
• v.16 no.1
• /
• pp.37-41
• /
• 2010

A hemangioma occurred in the bony epiphysis is extremly rare. A 5-year-old boy visited to our hospital with pain and flexion contracture on the right knee. MRI showed some lesions scattered in the epiphysis of the distal femur and the proximal tibia. Biopsy specimen from the distal femoral epiphysis revealed pathologic findings compatible with hemangioma. On 8 years follow-up, the lesion in the distal femoral epiphysis had been cured, and those in the proximal tibial epiphysis were spontaneously disappeared without surgery. The scanogram shows no leg length discrepancy and angular deformity. We reports a rare case of hemangioma occurred in the bony epiphysis with the results of 8 year follow-up with the review of literatures.

• Archives of Reconstructive Microsurgery
• /
• v.13 no.2
• /
• pp.117-122
• /
• 2004

Purpose : The aim of this study was to evaluate the efficacy of arterialized venous flap in finger flexion contracture correction. Materials and methods : From 2002 to 2004, we have performed 10 arteriaized venous flap for treatment of severe flexion contracture in digit. The duration of flexion contracture was from 1 year to 50 years. The cause of contracture were bum scar(7 cases), postoperative contracture(2 cases) and other(l case). We evaluated the survival of flap, flap size, recovery of flexion contracture and subjective satisfaction. Results : All arterialized venous flap survived. The marginal minimal skin necrosis developed in 2 cases. The flap size was average $5.2{\times}3.5cm$. The recovery of flexion contracture was 87% compared with non affected side. 9 patients(90%) satisfied the results of operation. Conclusion : Arterialized venous flap is one of the useful procedure in treatment of finger flexion contracture because it has many advantages such as thin and good quality, variable length of pedicle, preservation of major vascular pedicle, less operation time and in addition possibility of various modifications.

• Proceedings of the Korean Society of Broadcast Engineers Conference
• /
• 2004.11a
• /
• pp.31-35
• /
• 2004

정보통신 기술의 발달과 디지털 방송의 시작, 뉴미디어의 출현으로 인한 통신과 방송의 융합은 가속화되고 있다. 또한 2010년까지 광대역통신망 BcN과 홈네트워크 구축을 위한 정부정책이 실행 중에 있다. 100Mbps의 전송속도를 구현해야 하는 광대역 통신망(BcN)을 위해 기존 인터넷 백본 1)망은 잘 구축이 되어 있으나 가입자까지의 망 구조에 많은 문제점을 앉고 있다. 기존 전화국을 이용한 XDSL과 지역 SO를 활용한 Cable Modem의 경우 병목현상과 이론상 속도 또한 BcN과 통방통합이 요구하는 50-100Mhz의 전송속도를 만족하지 못한다. 새로운 망 구조를 구축하기 위해 많은 비용과 시간의 소요가 예상된다 가입자 망 구축에 따른 많은 방법과 이론이 제시되고 있다. 똔 논문에선 지역 SO를 활용하여 가입자까지 망을 통방통합과 BcN에 적합한 가입자 망을 새롭게 구성하는 것을 목표로 한다. 먼저 지역 50의 망을 활용하기 위해선 기존 KT와 파워콤의 COF(Glass Optical Fiber)망과 지역 케이블 SO의 HFC 망을 이용하기에는 동축케이블 망의 물리적 특성에 따른 한계로 통방통합과 BcN에 부적합하다. Tree And Branch 구조의 HFC망 대신 $SMF^{2)}$의 기존 SO의 자가망을 새롭게 설계하고 광분배망 기술인 $E-PON^{3)}$방식을 접목시켜 최대한 동축망을 사용하지 않고 굴곡 특성에 약한 $FOG^{4)}$의 특성을 극복하기 위해 $POF^{5)}$망을 이용하여 댁내 홈게이트웨이까지 연결하는 방식으로 지역 SO를 거점으로 활용하여 댁내까지 FHHT와 홈 네트워크까지의 가입자 망을 새롭게 구성하고자 한다. 저장의 효율성을 위해 이진 포멧인 IPMP화된 MP4 파일을 생성할 수 있다.으로써, 에러 이미지가 가지고 있는 엔트로피에 좀 근접하게 코딩을 할 수 있게 되었다. 이 방법은 실제로 Arithmetic Coder를 이용하는 다른 압축 방법에 그리고 적용할 수 있다. 실험 결과 압축효율은 JPEG-LS보다 약 $5\%$의 압축 성능 개선이 있었으며, CALIC과는 대등한 압축률을 보이며, 부호화/복호화 속도는 CALIC보다 우수한 것으로 나타났다.우 $23.87\%$($18.00\~30.91\%$), 갑폭 $23.99\%$($17.82\~30.48\%$), 체중 $91.51\%$($58.86\~129.14\%$)이였으며 성장율은 사육 온도구간별 차는 없었다.20 km 까지의 지점들(지점 2에서 지점 6)에서 매우 높은 값을 보이며 이는 조석작용으로 해수와 담수가 강제혼합되면서 표층퇴적물이 재부유하기 때문이라고 판단된다. 영양염류는 월별로 다소의 차이는 있으나, 대체적으로 지점 1과 2에서 가장 낮고, 상류로 갈수록 점차 증가하며 지점 7 상류역이 하류역에 비해 높은 농도이다. 월별로는 7월에 규산염, 용존무기태질소 및 암모니아의 농도가 가장 높은 반면에 용존산소포화도는 가장 낮다. 그러나 지점 14 상류역에서는 5월에 측정한 용존무기태질소, 암모니아, 인산염 및 COD 값이 7월보다 다소 높거나 비슷하다. 한편 영양염류와 COD값은 대체적으로 8월에 가장 낮으나 용존산소포화도는 가장 높다.출조건은 $100^{\circ}C$에서 1분간의 고온단시간 추출이 적합하였다. 증가를 나타내었는데

• Journal of the Korean earth science society
• /
• v.27 no.4
• /
• pp.416-424
• /
• 2006

Because there is no generally accepted definition of a geographic center and no completely satisfactory method to determine one, there may be as many geographic centers of a country as there are many definitions. The geographic center of an area may be defined as the center of gravity on a surface, or that point on which the surface of an area would balance if it were a plane of uniform thickness. This research uses geographic information system (GIS) analysis and there are places where it defines the geographical and the geological centers in the inland of South Korea. To compute the geo-centers in South Korea: 1) firstly, we collected existing reaserch data related to digital map data. 2)Secondly, we analyzed a geological center and data collection examples of Korea and other nations-the Europe and America. 3) Thirdly, we carried out numerous processes to build a geodatabase, short for geograhic database, so that GIS analysis and the constructed geodatabase is covered within the inland in South Korea. Where geodatabase is a kind of spatial database. 4) Fourthly, in order to determine the geographical center, we supposed that the condition of continental surface is the plane of homogeneous or irregular density. 5) Consequently, we chose a few resonable conditions and produced a variety of geographical centers that is geometric and gravitational in South Korea. As a result of the analysis, center points are massed to southern part of Chungbuk province, Korea.

• Journal of the Korean Arthroscopy Society
• /
• v.3 no.2
• /
• pp.102-108
• /
• 1999

Purpose : The purpose of this study was to evaluate the clinical results of bone-patellar tendon-bone(B-PTB) allograft for ACL reconstruction without mechanical tensioning device. Material and Method : Forty-six knees in 43 patients were reviewed and evaluated with subjective evaluation, objective evaluation, Telos stress arthrometer and modified Feagin Scoring System. The average age at the time of operation was 27 years(range, 18-42) and the average follow up period was 41 months(range, 22-79). Authors reconstructed ACL using B-PTB allograft which was prepared by rehydration preoperatively without tensioning by mechanical tensioning device. The tension for allograft was obtained by full flexion and extension intraoperatively. All operation were performed arthroscopically by two-tunnel method to avoid the mismatching of allograft tendon length. Result : The modified Feagin Scoring System revealed 39 cases(84.7%) with excellent or good results and 7 cases(15.3%) with fair or poor results. The mean follow-up Lysholm Knee Score was 84. Telos arthrometer revealed 41 cases had an injured-to-uninjured difference of 5 mm or less(mean 2.3mm). The range of motion of knee was nearly normal and there was no extension lag in any cases at last follow up. Conclusion : Clinical results using B-PTB allograft showed less morbidity than B-PTB autograft. The intraoperative tensioning method by full flexion and extension without mechanical tensioning device was not bad. Therefore, B-PTB allograft is a good substitute material in reconstruction of the ACL.

• Journal of Gastric Cancer
• /
• v.5 no.4 s.20
• /
• pp.288-294
• /
• 2005

Purpose: Superficially spreading (SS) early gastric cancer (EGC) is characterized by wide horizontal extension without deep vertical invasion. It is a relatively rare form of EGC, and it's clinicopathological (C-P) characteristics are not evident. This study aimed to clarify their C-P characteristics. Materials and Methods: We defined SS EGC as invading less than the submucosal layer that measured more than 60 mm in diameter or wider than $5{\times}5cm \;(25cm^2)$ in width. The C-P characteristics and prognosis were compared between 69 patients with SS EGC and 319 patients with the common type EGC (EGC except SS type). Results: For SS EGC lymph node metastases, Lauren's diffuse type, lymphatic invasion were significantly higher than in common type EGC. In patients with SS EGC, all of the metastatic lymph nodes were anatomically distributed within the paragastric region, with fewer along the left gastric artery and common hepatic artery. In 6 cases of SS EGC with resection marqins less than 10 mm, there was no death during the follow-up period (4 to 13 years after operation) if margins were not involved. Age (>58 yrs), tumor site (upper 1/3), lymph node metastasis, submucosal invasion were statistically significant poor prognostic factor in univariate survival analysis. In multivariate survival analysis, age and lymph node metastasis were independent prognostic factors. However, tumor diameter or width was not a significant prognostic factor. Conclusion: Although SS EGC has histologically distinct properties, gastrectomy with free surgical margins and appropriate lymph node dissection $(D1+{\beta})$ could be a suitable treatment.