• Journal of the Korean Arthroscopy Society
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• v.17 no.1
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• pp.66-70
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• 2013

Flap tear is a type of displaced meniscal fragments that is often clinically significant lesions requiring surgical intervention. If the displaced tear is located inferomedial to the tibial plateau and incarcerated into the articular capsule, it can be overlooked from preoperative magnetic resonance imaging evaluation and escape detection during arthroscopic examination. In addition, the clinical feature and treatment result of incarcerated flap tear has not been reported. We present 2 cases of medial meniscus flap tear incarcerated into the articular capsule that showed specific clinical features, in order to emphasize the importance of clinical suspicion of such a lesion for accurate preoperative diagnosis.

• Journal of the Korean Arthroscopy Society
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• v.6 no.1
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• pp.14-20
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• 2002

Purpose : To analyze the clinical result of the arthroscopic decompression of meniscal cyst and meniscus resection or repair of meniscus tear. Materials and Methods : From April 1994 and October 2001, 19 patients with diagnosis of meniscal cyst associated with tears of the meniscus were treated by arthroscopic meniscal resection or repair with decompression of the cyst. The mean age was 39.8 years(range, 22-58years). The follow-up period ranged from 3 months to 36 months with an average of 18 months. Seven of 19 patients had tenderness over the joint line with palpable mass. Treatment consists of arthroscopic resection or repair of meniscal tear with decompression of the cyst through transmeniscal approach. Open excision of cyst was performed in one case. Clinical evaluation was performed using Lysholm knee score and Tegner activity. All cases were executed proper treatment using arthroscopy. Results : Twelve cysts involved the lateral meniscus$(64\%)$ and seven cysts were on medial cyst$(36\%)$. Most of lateral meniscal cysts were located in anterior one-third and medial meniscal cyst were on posterior one-third. Meniscal tear were observed in seventeen cases$(89.5\%)$ and most tears were horizontal$(79\%)$. Preoperative symptom disappeared and no cyst recurrences were observed at last follow-up(mean follow-up: 18 months). Conclusion : Meniscal cysts involved lateral side in $64\%$ and most of them were associated with meniscus tear$(89.5\%)$ which consists of mainly horizontal component$(79\%)$.

• Journal of the Korean Arthroscopy Society
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• v.16 no.2
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• pp.147-152
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• 2012

Purpose: The purpose of this study was to compare the preoperative magnetic resonance image (MRI) findings with postoperative arthroscopic findings on meniscus injury with anterior cruciate ligament (ACL) rupture. Materials and Methods: We reviewed MRI images and arthroscopic findings of 225 patients treated by ACL reconstruction due to rupture, from February 2001 to November 2010. There were 154 cases of meniscus tear in arthroscopic findings. We examined the sensitivity for detecting meniscal tears varied with the presence of a rupture of the ACL, with the location of the tear within the meniscus, and among configurations of meniscal tears. Results: In the presence of a rupture of the ACL, the sensitivity of MRI was 0.88 for medial meniscal tears and 0.69 for lateral meniscal tears. And sensitivity of MRI was lowest in posterior horn and peripheral portion tears in lateral meniscus injury accompanying ACL rupture, sensitivity was low in anterior horn and flap shape tears in medial meniscus injury accompanying ACL rupture. Conclusion: In Meniscus injury with ACL rupture, a special attention shoulder given to the posterior horn and peripheral portion injury in lateral meniscus during arthroscopic surgery due to difficulty in detecting on MRI.

• Journal of Korean Tunnelling and Underground Space Association
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• v.18 no.5
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• pp.469-485
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• 2016

The failure of rock mass around deep tunnel, different from shallow tunnel largely affected by discontinuities, is dominated by magnitudes and directions of stresses, and the failures dominated by stresses can be divided into ductile and brittle features according to the conditions of stresses and the characteristics of rock mass. It is important to know the range and the depth of the V-shaped notch type failure resulted from the brittle failure, such as spalling, slabbing and rock burst, because they are the main factors for the design of excavation and support of deep tunnels. The main features of brittle failure are that it consists of cohesion loss and friction mobilization according to the stress condition, and is progressive. In this paper, a three-dimensional numerical model has been developed in order to simulate the brittle behavior of rock mass around deep tunnel by introducing the bi-linear failure envelope cut off, elastic-elastoplastic coupling and gradual spread of elastoplastic regions. By performing a series of numerical analyses, it is shown that the depths of failure estimated by this model coincide with an empirical relation from a case study.