• Journal of radiological science and technology
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• v.42 no.6
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• pp.423-428
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• 2019

The Precise measurement of the knee's Congruence angle is required for diagnosis of patella dislocation. The purpose of this study is to consider the distortion diagram and usefulness about the test of the bilateral side and one side through the evaluating congruence angle from Merchant view of patellofemoral joint to central X-ray. We've evaluated the sulcus angle and Congruence angle following central X-ray's changes when we took Merchant view of patellofemoral joint aimed to right lower limb from human whole body phantom. The subject of the evaluation was classified as normal group and varus group, and the varus group has experimented with External rotation of legs as 15° and 30°. When normal groups result as 0, 7.5, 15 cm, it was measured as 17.25 ± 1.34°, 19.60 ± 1.41°, 20.55 ± 1.77° each. The gap between minimal and maximum angle was 3.3°, and the value was shown as getting bigger when it further away from the centeral X-ray. When Congruence angle in 15° varus group was 0, 7.5, 15 cm, it was each 16.45 ± 1.34°, 17.10 ± 0.99°, 17.80 ± 1.13°. And when Congruence angle in 30° varus group was 0, 7.5, 15 cm, it was measured each 18.35 ± 1.63°, 18.95 ± 1.06°, 19.60 ± 1.41°. The difference between minimum and maximum of angle in 15° varus group and 30° varus group was each 1.35° and 1.25°, the angles have shown as increasing the further away from the center. The patellofemoral joint showed that the congruence angle increases as the further away from Central X-ray, and also it is judged that is possible to change the congruence angle by a degree of varus knee. Thus, accurate measurement of the congruence angle is shown to advantage that methods for examining by split each side at two times than methods for examining both sides at a time. Therefore, it is expected to helpful on the diagnostic side of patella dislocation and subluxation.

• Journal of the Korean Arthroscopy Society
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• v.10 no.1
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• pp.33-38
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• 2006

Purpose: This study seeks to address the results of percutaneous lateral release and medial reefing for patients with recurrent patellar dislocation. Materials and Methods: This paper focuses on 27 cases from 25 patients who had a surgical operation at our hospital in a span of eight years and six months from the time of December 1996 to May 2005. The subjects consist of 11 males and 14 females, and their average age was 22.2 years old. All the patients had their trauma history, and the average frequency of dislocation before surgery was 11.5 times. Results: The congruence angle before operation was 23.3 degree on the average, while the lateral patellofemoral angle was -5.7 degree on average. However, the congruence angle after surgery came to -2.4 degree, while the lateral patellofemoral angle recovered to the normal range of within 11.5 degrees. Four cases showed the recurrent dislocation, and two out of those four cases had -35, -12 degrees of their lateral patellofemoral angle respectively and 59, 14 degrees of their congruence angle respectively. Conclusion: Using percutaneous lateral release with medial reefing can be considered as an effective treatment for recurrent patellar dislocation

• Journal of the Korean Society of Radiology
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• v.15 no.6
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• pp.919-926
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• 2021

In this study, we wanted to find out the optimal angle as a modified tangential projection of the patella. In the experiment, we used Kyoto Kagaku's PBU-50 phantom. In the supine position, the F-T angle was set to 95°, 105°, 115°, 125°, 135°, 145°, and Patella tangential projection images were obtained by varying the X-ray tube angle by 5° so that the angle between the X-ray centerline and tibia at each angle was 5~20°. Image J was used for image analysis and the congruence angle, lateral patellofemoral angle, patellofemoral index and contrast to noise ratio(CNR) were also measured. SPSS 22 was used for statistical analysis, and the mean values of congruence angle, patellofemoral angle, patellofemoral index, and CNR were compared with Merchant method through one-way batch analysis and corresponding sample t-test. As a result of the study, in the case of congruence angle, the angle of incidence of the knee-angle X-ray centerline was 105°-72.5° (20° tangential irradiation), 115°-72.5°, 77.5° (15, 20° tangential irradiation), 125°-82.5° (20° tangential irradiation), lateral patellofemoral angle is 115°-72.5°, 77.5° (15, 20° tangential irradiation), 125°-72.5° (10° tangential irradiation), patellofemoral index is 115°-72.5° (15° tangential irradiation) and 125°-72.5° (10° tangential irradiation) were not significantly different from Merchant method (p> .05). In case of CNR, it is not different from Merchant method at 105°-67.5°, 72.5° (15, 20° tangential irradiation), 115°-67.5°, 72.5°, 77.5° (10, 15, 20° tangential irradiation). (P> .05). Based on the results of this study, high diagnostic value images can be obtained by setting the knee angle and the angle of incidence of the X-ray tube to 115°-72.5° (15° tangential irradiation) during the modified tangential examination of the knee bone. It was confirmed.

• Journal of Elementary Mathematics Education in Korea
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• v.18 no.3
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• pp.539-555
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• 2014

In this study, an implication has been drawn for the textbook development and teaching and learning process as a congruence of a figure is compared and analyzed between Korean elementary mathematics textbooks and American elementary math textbooks. Based on the result of comparison and analysis in congruence contents between Korean and EM textbooks, some applications for the development of figure and congruence chapters in Korean textbooks are as below. First of all, in term of congruence, activities related to congruence need to be introduced after the concept of congruence is defined either with illustrations of fundamental figures such as a segment and angle or with examples of polygon. Second, it is required to assist students to realize that compasses can be used to copy length. In Korean textbooks, compasses are being introduced as a tool to draw circles, which causes children to have difficulty in drawing triangles. Last, for the implication of congruence, tessellation suggested in American Everyday Mathematics textbooks is worth being applied to the development of Korean textbooks.

• Journal of the Korean Arthroscopy Society
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• v.4 no.2
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• pp.128-133
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• 2000

Purpose : To compare the changes of the patellar height, patellofemoral alignment and subjective symptom and to compare the effects of patellar tendon harvest after anterior cruciate ligament(ACL) reconstruction using autograft and allograft. Materials and Method : ACL reconstruction was performed on 87 patients who were followed up for minimum 1 year. The group I was 52 patients who were operated with bone-patellar tendon-bone autograft and the group II was 35 patients who were operated with bone-patellar tendon-bone allograft and achilles tendon allograft. At the time of follow-up, the authors evaluated the patellar height by Blackburne-Peel method, Merchant congruence angle, Lateral patellofemoral angle and subjective symptoms were assessed. Results : The patellar heights were significantly decreased from 0.86 preoperatively to 0.80 postoperatively in the group I and from 0.87 preoperatively to 0.83 postoperatively in the group II. There were no significant differences in the lateral patellofemoral angles between the both groups but in the Merchant congruence angle, significant differences were observed in the both groups, from$-1.43^{\circ}$ preoperatively to-$5.43^{\circ}$ postoperalively in the group I and from$-1.53^{\circ}$ preoperatively to$-3.65^{\circ}$ postoperatively in the group II. Conclusion : After ACL reconstruction, the patellofemoral alignment was changed and this kind of changes may be caused by multiple factorials such as harvest of autografts, ACL reconstruction itself, and quadriceps muscle atrophy.

• Journal of Korean Orthopaedic Sports Medicine
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• v.9 no.2
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• pp.98-103
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• 2010

Purpose: We reported the results of arthroscopically assisted lateral release and medial imbrication for the recurrent patella dislocation. Materials and Methods: Twenty patients (20 knees) underwent arthroscopically assisted surgery for the recurrent patella dislocation. There were 4 males and 16 female. The average age was 20.2 years. All patients had definite trauma history and average follow-up period was 19 months. The surgical results were evaluated according to the Lysholm knee score and the Kujala score. The congruence angle and lateral patellofemoral angle were measured on plain radiograph and the tibial tubercle-trochlear groove distance was calculated on computerized tomography. Results: The median value of preoperative congruence angle was $16.5^{\circ}$ (range, $0.0{\sim}+34^{\circ}$) and the average final follow-up was $-6.4^{\circ}$ (range, $-19{\sim}10^{\circ}$) with statistically significant improvement (p=0.025). The median value of preoperative Lysholm knee score was 70 (range, 63~81) and the final follow-up score had changed to 88 (range, 80~95) with statistically significant improvement (p=0.0341). The median value of preoperative Kujala score was 72 (range, 65~80) and the average final follow-up score showed 87 (range, 80~92) with statistically significant improvement (p=0.024). Recurrent dislocations after surgery occurred in 2 cases, one case which showed positive "thumb to forearm test" had been treated with medial patellofemoral ligament reconstruction. Conclusion: Arthroscopically assisted lateral release and medial imbrication for recurrent patella dislocation without bony malaligmenent showed the effective treatment, but would be inappropriate for the patients with the generalized joint laxity.

• School Mathematics
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• v.16 no.2
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• pp.219-236
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• 2014

We recognized that most teachers are having insufficient understanding or misunderstanding about congruent conditions of triangles. So the purpose of this study was to analyze teachers's understanding about congruent conditions of triangles and to find the causes of teachers's misunderstanding. Most teachers have been misunderstanding that triangle determining- conditions are only 3 ways(SSS, SAS, ASA). And they have wrong confidence that 2 sides and a non included angle(ASS) is not always able to make one triangle. This study found that these teachers's misconception was from the textbook using now. As the result of this study, we suggested 7 improvement ways about planning of curriculum, writing of textbook and teacher training course.

• The Mathematical Education
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• v.49 no.1
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• pp.53-65
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• 2010

The congruent conditions of triangles' plays an important role to connect intuitive geometry with deductive geometry in school mathematics. It is induced by 'three determining conditions of triangles' which is justified by classical geometric construction. In this paper, we analyze the essential meaning and geometric position of 'congruent conditions of triangles in Euclidean Geometry and investigate introducing processes for them in the Elements of Euclid, Hilbert congruent axioms, Russian textbook and Korean textbook, respectively. Also, we give justifications of construction methods for triangle having three segments with fixed lengths and angle equivalent to given angle suggested in Korean textbooks, are discussed, which can be directly applicable to teaching geometric construction meaningfully.

• Journal of Korean Orthopaedic Sports Medicine
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• v.9 no.2
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• pp.85-90
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• 2010

Purpose: To evaluate the results of percutaneous lateral release and arthroscopic medial plication for patients with recurrent patella dislocation. Materials and Methods: This study includes the thirty-one cases of patients who have had a surgical operation from March 2001 to March 2008. All the patients had recurrent patella dislocation after trauma history. The average age was 24.2 years old and the average follow up was 47.4 months (minimum 24 months). Results: The preoperative congruence angle, lateral patellofemoral angle, Lysholm score was $24.8^{\circ}$, $-6.2^{\circ}$, 75 points on average respectively. However, the postoperative congruence angle, lateral patellofemoral angle, Lysholm score was improved to normal range: $-2.8^{\circ}$, $10.2^{\circ}$, 95 points on average. Five cases showed the recurrent dislocation after operation. Among them, three cases showed femoral trochlear dysplasia. Conclusion: Percutaneous lateral release and arthroscopic medial plication showed satisfactory results for recurrent patella dislocation with low complication rate. However, in cases with femoral trochlear dysplasia, another surgical treatment may be considered.

• Korean Journal of Digital Imaging in Medicine
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• v.12 no.1
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• pp.43-50
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• 2010

The representative study of Patellofemoral Joint Merchant method can show the view for inspection of the sulcus angle, congruence angle and diagnose whether there are the vertical fractures and recognize the degree of dislocation and patella subluxation. However, anatomical correlation about the degree of knee joint curvature changes during position adjustment and distortion of the image reduces reproducibility. In order to resolve these problems, Merchant method needs to use assisting device which reduces the occurrence of repeat projection and effectively to increase unification of examination and the consistency of the image. However, there are disadvantages for patients who take other examinations. For example, they have to change the position for every examination and it might cause the patient's discomfort and increase of examination time. In this study, we newly devised commercial assisting device which improves the reproducibility of the images and reduces inconvenience of patients movement. Further research should be taken to obtain a image without patient's movement and to reduce the time of the examination than existing method.