• Journal of Korean Ophthalmic Optics Society
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• v.13 no.4
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• pp.115-119
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• 2008

Purpose: To compare the tentative and final addition, a combination chart of cross-grid and red green with the final addition prescribed in presbyopia were used in this study. Methods: The study subjects were 60 persons with presbyopia who were 41 to 60 years (mean: 51.7 years). Tentative addition were determined using red green chart (RG), cross-grid chart (CG) and the combination chart (red green cross-grid chart, RGCG) of the above two. And the final addition for a 40 cm working distance was determined for each subject by adjusting the tentative addition. Results: It was found that there were statistically significant differences of the final addition and the tentative addition between the each different test method. This result indicated that using the red-green cross-grid chart is the higher repeatability. Conclusions: This study shows that red green cross-grid chart (RGCG) seems to be get proper data for determining addition in presbyopes, and this method would be helpful in the diagnostic evaluation of addition in binocular vision testing.

• Journal of Korean Orthopaedic Sports Medicine
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• v.8 no.1
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• pp.26-32
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• 2009

Purpose: This study was performed to compare the strength of ligamentous attached sites of cadaveric distal femur and to obtain reliable biomechanical data to use in ligamentous reconstruction or augmentation. Materials and Methods: Fifteen cadaveric distal femurs were used for this study. After measuring the bone density, 5.0 mm cannulated screw (Experiment 1) or reconstructed porcine ligament (Experiment 2) was inserted into the each ligamentous attached sites of anterior cruciate ligament (ACL), posterior cruciate ligament (PCL), medial collateral ligament (MCL) and lateral collateral ligament (LCL). In experiment 2, reconstructed porcine graft was fixed with bioabsorbable screw in ligamentous insertion sites. And we measured the maximal pullout force of each ligamentous attached sites of cadaveric distal femur. Results: Average bone mineral density was $1.205{\pm}0.137\;g/cm^2$ in experiment 1, $1.236{\pm}0.089\;g/cm^2$ in experiment 2, which showed no statistically significant differences. In experiment 1, average pull-out strength of ACL, PCL, MCL and LCL group were $519.1{\pm}111.7$ N, $638.9{\pm}144.4$ N, $169.7{\pm}56.0$ N, $225.6{\pm}61.5$ N respectively. In experiment 2, the average pull-out strength were $310.6{\pm}31.0$ N, $379.9{\pm}47.4$ N, $104.0{\pm}14.4$ N, $131.5{\pm}21.9$ N respectively. In experiment 1, there was no significant difference between ACL and PCL group and between MCL and LCL group. However, the maximal pullout strength of MCL and LCL group were significantly lower than that of ACL and PCL group (p<0.01). Experiment 2 showed the same results of experiment 1. Conclusion: Because stiffness of MCL and LCL attached sites are much lower than that of ACL and PCL attached sites, we may consider augmented fixation in ligamentous reconstructions of MCL and LCL.

• Journal of the Korean Arthroscopy Society
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• v.12 no.1
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• pp.32-39
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• 2008

Purpose: To evaluate the effectiveness of MRI after ACL reconstruction with femoral tunnel at 10 o'clock position. Materials and Methods: MRI findings of 29 patients after ACL reconstruction using hamstring tendon autograft were evaluated. The mean period from operation to MRI was 18.9 months($7{\sim}40$ months). Signal intensity, morphology and continuity of graft, femoral insertion, graft angle, roof impingement, cross pin breakage and position were evaluated. Those findings were compared with KT-2000, Lysholm knee score and pivot shift test. Results: There was no significant correlation between signal intensity of graft and the duration to MRI. Most common pattern of the morphology was straight, and the continuity was well-preserved. 13 cases of femoral tunnel insertion were zone 4 and 16 were zone 3. There were no roof impingement. 10 cases showed cross pin breakages, of which 5 were found at the outside of distal femoral posterior cortex. 9 showed cross pin directed posteriorly in axial view. There was no significant correlation between clinical results and cross pin breakage. Conclusion: MRI examinations after ACL reconstructions are useful to evaluate the graft status, position of the graft and cross pins. Since the direction of the cross pin is important especially in 10 o'clock femoral position, care should be taken to avoid cross pin breakage.

• Journal of the Korean Arthroscopy Society
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• v.1 no.1
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• pp.128-131
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• 1997

전방십자인대의 일차수복술이나 재건술후에 장기간의 비체중부하가 필요한지를 결정하기 위해서 일차수복술을 시행한 96례와 재건술을 시행한 82례등 총 178례를 대상으로 술후 체중부하시기에따라 두군으로 나누어 비교분석 하였다. 모든 례에서 술후 보조기를 착용하였고 120례에서는 술후 첫6주간 점차적으로 관절운동범위를 증가를 시키고 다음 6주간은 완전운동범위 회복상태에서 유지후 술후 12주에 체중부하를 허용하였으며 나머지 58례에서 술후 완전신전상태에서 즉시 체중부하를 시켜서 정기적으로 Lachman검사, KT 2000을 이용하여 불안정성여부를 관찰하였다. 평균 추시기간은 4.2년(2년$\~$6년)이었고 불안정성에 대한 평가는 AMA 분류에 따랐다. 최종추시상 모든환자에서 1+이상의 불안정성은 발견되지 않았으며 술후 12주에 체중부하를 한군에서 1a+가 104례$(86.7\%)$, 1b+군이 16례$(13.3\%)$로 관찰되고 즉시 체중부하를 한 군에서 1a+가 51례$(87.9\%)$, 1b+가 7례$(12.1\%)$에서 보였으나 통계적으로 의미있는 차이는 없었다(P>0.05). 본연구의 결과로 전방십자인대 일차수복술이나 재건술후 신전보조기를 착용시키고 즉시 보행을 시키는 것이 술후 슬관절의 불안정성에 영향을 주지 않으며 안전한 재활방법으로 생각된다.

• The Bulletin of The Korean Astronomical Society
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• v.41 no.2
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• pp.48.1-48.1
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• 2016

남십자자리(Crux)는 현재 북반구 중위도 지역에서는 관측할 수 없는 별자리지만 고대 중국의 전통 별자리 체계가 성립되던 시기인 춘추전국시대만 하더라도 지평선 부근에서 쉽게 관측할 수 있는 별자리였다. 우리는 세차운동 계산을 통해 남십자자리가 출몰성에서 전몰성으로 변했음을 확인하였고, 고대 중국의 문헌 기록과 성표, 성도의 별자리 그림 분석을 통해 남십자자리의 밝은 4개의 별이 중국의 전통 별자리인 고루성(庫褸星)과 일치함을 확인하였다. 또한 남십자자리가 관측되던 시기와 관측되지 않던 시기에 각각 작성되었던 성표와 성도 분석을 통해 고루성의 별자리 모양이 점차 변형되어 갔음을 제시하였다. 마지막으로 서양의 천문기술이 중국에 전해 진 이후 진행된 동서양의 별자리 상호 비교 및 동정 결과들을 분석하여 중국의 전통 별자리 체계에서 어떻게 고루성이 완전히 배제되게 되었는지에 대한 논의를 포함, 본 연구의 초기 결과들을 발표할 예정이다.

• Journal of the Korean Arthroscopy Society
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• v.8 no.1
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• pp.26-30
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• 2004

Purpose: We analyzed the clinical results of ACL(anterior cruciate ligament) reconstruction of chronic anterior cruciate ligament injuries with a fresh frozen Achilles allograft, retrospectively. Methods: Thirty-eight patients(average age 32.4 years) who had an chronic injury of ACL reconstructed with an Achilles allograft between January 1999 and February 2001 were included. The mean follow-up was 19.2(12-36) months. The clinical evaluation was done by range of motion, Lachman and pivot-shift test, KT-1000 arthrometer, Lysholm knee score, and the modified Feagin score. Results: All patients recovered full range of motion of affected knees. With use of Lachman and pivot-shift test data, thirty seven(97.4%) were functional. When comparing KT-1000, we found mean maximum side-to-side differences less than 2.1 mm. According to Lysholm knee score, mean postoperative score was 90.4. Thirty four(89.5%) had good to excellent results in modified Feagin score. Conclusion: Results of ACL reconstruction using fresh frozen Achilles allografts were comparable to autografts. ACL reconstruction with Achilles allograft could be a reasonable altemative to autografts.

• Journal of the Korean Arthroscopy Society
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• v.13 no.1
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• pp.1-7
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• 2009

Purpose: To evaluate the 2 to 4-year follow-up results after arthroscopic anterior cruciate ligament (ACL) reconstruction using transtibial femoral tunnel at 10 or 2 O'clock position. Materials and Methods: Eighty-six ACL reconstructions could be evaluated. Evaluations included 2000 International Knee Documentation Committee (IKDC) subjective knee score, Lachman test, Pivot-shift test, KT-1000 arthrometer measurement, 2000 IKDC knee examination and second-look arthroscopy. Results: Seventy-five patients (87.2%) had over 80 in 2000 IKDC subjective knee score. Eighty-three patients (96.5%) had 1+firm end or negative Lachmann test. Seventy-eight patients (90.7%) had a negative Pivot-shift test. Eighty-three patients (96.5%) had less than 5 mm difference by KT-1000 arthrometer. Eighty patients (93.0%) were normal or nearly normal by 2000 IKDC knee examination. Second-look arthroscopy was done in fifteen cases. Nine cases showed good synovialization, four cases showed partial synovialization, two cases showed poor synovialization and graft failure was noted in one case. Conclusion: ACL reconstruction using transtibial femoral tunnel at 10 or 2 O'clock position resulted in a good outcome in terms of rotatory stability as well as antero-posterior stability.

• Journal of the Korean Arthroscopy Society
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• v.5 no.1
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• pp.13-16
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• 2001

Purpose : To evaluate the types of the fibrous scar formation around graft after ACL reconstruction. Materials and Methods : Between Nov 1997 and Jun. 1999, the second look arthroscopy was performed on 15 knees of 14 patients. We evaluated the changes around graft and measured the tunnel position that the tibial tunnel position as a percentage along the length of the tibial plateau from the anterior-to-posterior as seen on a lateral radiograph and the femoral tunnel position as a percentage along Blumensaat's line from anterior-to-posterior as seen on a lateral radiograph. Results : The tibial tunnel position was from $27\%\;to\;58\%(mean\;41\%)$ and the femoral tunnel position was from $58\%\;to\;83\%(mean\;76\%)$, so the tunnel position was ideal in almost cases. By arthroscopic findings, the grafts were not impinged in all cases and tile fibrous scar was formed between intercondylar notch and graft in almost cases except 3 cases. The types of fibrous scar formation were 6 cases of fibrillated fiber and 5 cases of fibrous nodule and 1 case of fibrous band. Conclusion : There was no impingement on graft in all cases and various types of fibrous scars were formed around grafts.

• Proceedings of the Membrane Society of Korea Conference
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• 1991.04a
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• pp.13-14
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• 1991

본 연구에서는 Tobler[1]가 십자흐름여과 (crossflow filtration)의 개선책으로 제안한 동역학적 여과기를 제작하여 그 특성을 실험적으로 고찰하였다. 이 여과기는 두 개의 동심원통 사이를 유체가 흐를 때 내부원통의 회전속도가 외부원통의 회전속도보다 매우 빠를 경우 발생하는 Taylor 와류를 응용한 것이다.

• Journal of the Korean Arthroscopy Society
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• v.8 no.1
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• pp.14-18
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• 2004

Purpose: To compare the mid-term follow-up results of anterior cruciate ligament(ACL) reconstruction with the bone-patellar tendon- bone(BTB) autograft to those with the BTB allograft. Materials and Methods: Retrospective study was performed in 59 cases with BTB autograft and 42 cases with BTB allograft. Evaluations include Lysholm score, 2000 IKDC subjective knee score, Shelbourne patello-femoral pain score , Lachman test, pivot shift test, KT-1000 arthrometer test and 2000 IKDC knee examination. Results: There were no significant statistic differences between two groups in Lysholm score and 2000 IKDC subjective knee score of more than 70 (p<0.05). Five cases(8.5%) showed the patello-femoral pain score less than 80 according to Shelboume with autograft group and two cases(4.8%) with allograft group (p<0.05). Lachman test, pivot shift test and KT-1000 arthrometer test showed no significant statistic differences between two groups(P<0.05). Fifty-four cases(91.5%) were normal or nearly normal according to the 2000 IKDC knee examination with autograft group and thirty-eight cases(90.4%) with allograft group(p<0.05).Conclusion: BTB allograft as well as BTB autograft is considered to be an acceptable choice for ACL reconstruction.