• Journal of Preventive Medicine and Public Health
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• v.30 no.4 s.59
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• pp.805-814
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• 1997

Injuries to the menisci occur in a variety of ways, most commonly with a twist, pivot, squat, or valgus stress to the knee. Tear patterns are classified to longitudinal, horizontal, or transverse features according to the mechanism of injury. Work-related meniscal tear usually occurs with a repetitive usage of the foot, hence it can be classified as a cumulative traumatic disorder. We found a 47 year-old female worker who had been taking charge of repetitive foot-switch stepping for 8 years. She suffered from pain in the right knee since 5 months ago. Tenderness along the medial joint line of the right knee was observed and pain was aggravated with full flexion of the right knee. On magnetic resonance imaging, high signal intensity was observed at the posterior horn of the medial meniscus of the right knee. Degenerative longitudinal and transverse complex tear in the medial meniscus was observed on arthroscopy. Arthroscopic partial meniscectomy was performed. We surveyed the work process and the health status of co-workers. It turned out that the work process was compatible to injure the meniscus and nine out of fourteen co-worker(64.3%) complained pain of the knee. No other factors related to her meniscal tear could be found except for the situation at her work. Therefore, we conclude that meniscal tear is related to the repetitive stepping of foot switch.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.34 no.5
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• pp.39-48
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• 2002

The water retention of coating colors can be accurately measured by devices such as an AA-GWR water retention meter whose principle of measurement Is based on pressure filtration of coatings under an externally applied air pressure over a certain period of time. It was hypothesized that such devices could be also used to determine the immobilization solids (IMS) of coating colors by determining a sudden drop in the rate of dewatering, that is, a sudden change in the drainage curves. To test this hypothesis, the immobilization solids of coating colors containing various thickeners and water retention additives at different levels were first accurately measured by a modified immobilization tester based on the well-known gloss drop method, and then their values were compared with those obtained by an AA-GWR water retention tester. They agreed very well and showed that the standard deviation is only 0.14% in the IMS points between both methods. This good agreement was not surprising because both test methods are based on the same end-point, that is, the immobilization solids point at which menisci begin to form at the coating surface. Theoretical considerations supporting this new method for measuring the immobilization solids of coating colors are presented and some recommendations for the test method are discussed. Also, the effect of various thickeners and water retention additives on the properties and printability of coated papers is discussed.

• Korean Journal of Veterinary Research
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• v.59 no.1
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• pp.17-24
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• 2019

Animal models of osteoarthritis (OA) have played a key role in understanding the etiology of OA and in the development of new therapeutic strategies. Although pigs have an advantage as an animal disease model due to their similarity to humans, there are few studies on the induction of OA in minipigs. Therefore, this study aimed to characterize disease progression of OA in total medial meniscectomy (TMM)-operated skeletally mature minipigs, up to day 180 postoperatively. There were no significant alterations in vital signs or hematological indices throughout the observation period. However, clinical manifestations of OA in the medial femoral condyles of TMM-operated minipigs were progressive, depending on postoperative duration, with respect to osteophytes formation and roughened surfaces on radiological observation, cartilage erosion under macroscopic examination, and severe cartilage defects including fibrillation, vertical fissures, and cartilage denuding on histopathological observation, with the highest score indicating late-stage OA on day 180 and without indicating apparent variation between subjects. In particular, the lateral femoral condyles were also degenerated, possibly due to localization of weight-bearing from both menisci to the lateral meniscus. Therefore, TMM in minipigs is suitable for reproducible induction of degenerative changes in the femorotibial joints that closely resemble late-stage OA, and is suitable for use in further research.

• Journal of the Korean Arthroscopy Society
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• v.12 no.2
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• pp.102-106
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• 2008

Purpose: To evaluate the anatomical localization of neurovascular bundle at the level of the korean knee joint using a magnetic resonance imaging study and minimize the risk of neurovascular injury from arthroscopy surgery. Materials and Methods: The transverse and central axes were described on axial MRI scans of 100 korean knee joints. The distance between the neurovascular bundle and central axis was measured. The differences in neurovascular bundle localization according to sex and side were analyzed. The results were evaluated with SPSS(ver. 10.1). The influence of sex was evaluated by t-test. The difference between right and left side was evaluated by paired t-test. Significance was considered as p<0.05. Results: Whereas neurovascular bundle localization was lateral to the central axis in 94 cases(94%), it was on central axis in 6 cases(6%). There was no statistically significant difference of sex and side(P>0.05). Conclusion: Preoperative evaluation of neurovascular bundle with MR axial scans may prevent neurovascular injury when performing arthroscopic posterior cruciate ligament reconstruction and interventions on the posterior horns of menisci.

• Investigative Magnetic Resonance Imaging
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• v.3 no.1
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• pp.73-77
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• 1999

Purpose : The purpose of the study was to evaluate the sensitivity and specificity of proton-weighted fast spin-echo MR imaging in diagnosing the meniscal tear of knee as an reasonable substitute for conventional spin-echo imaging. Materials and Methods : 102 consecutive patients, proved by surgery, proved by surgery, were participated in this study. All of them were suspected internal derangement of knee, examined by fast spin-echo MR imaging including sagittal and coronal images on a 1.5T MR imager and underwent arthroscopic or open surgery of knee joint within 2 months. These images were reviewed retrospectively by three radiologists. The sensitivity and specificity of meniscal tear were calculated. Results : The sensitivity and specificity of meniscal tear using proton-weighted fast spin-echo MR imaging were 94%, 93% inmedialmeniscus and 92%, 88% in lateral meniscus. Conclusion : The sensitivity and specificity of meniscal tear using proton weighted fast-spin echo MR images were as high as those using conventional spin-echo images. The proton-weighted fast-spin echo MR imaging can be an alternative to conventional spin-echo MR imaging in diagnosing meniscal tear of the knee.

• Journal of the Korean Arthroscopy Society
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• v.4 no.1
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• pp.32-37
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• 2000

Purpose : We performed routinely arthroscopy to diagnose and treat intra-articular soft tissue pathology and tibial condylar fractures. The purpose of this study was to evaluate clinical value of arthroscopy in the tibial condylar fractures. Materials and Methods : The 31 tibial condylar fractures was examed by routine arthroscopy, 9 treated by conservative method and 22 treated by surgery at least follow up of 12 months. The authors analysed to the cause, classification, soft tissue injuries such as ligaments and menisci, treatment and results. Results : The most common type was Schatzker classification type I in 15 cases$(18\%)$ and intra-articular lesions and associated ligament injury were in 21 cases$(67\%)$. Most common lesion was meniscal tear in 16 cases and most common type of meniscal lesions was peripheral detachment in 7 cases$(44\%)$. Schatzker I, II fracture patterns were associated with the highest frequency of soft tissue injuries, especially medial collateral ligament and meniscal injuries. Conclusion : Arthroscopic examination is useful method to evaluate the intra-articular pathology and to treat the tibial condylar fractures.

• Journal of the Korean Arthroscopy Society
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• v.3 no.1
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• pp.24-29
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• 1999

Purpose : The purpose of this paper is to analyze the clinical results after meniscal repair using meniscal arrow. Materials and Methods : Between May 1997 and Aug 1998, we repaired 22 tom menisci in 22 patients using meniscal arrows. There were nineteen males and three females with an average age of 27 years. There were longitudinal tear in 14 cases, Bucket-handle tear were 7 cases and horizontal tear was in 1 case. In 22 meniscus tears, 16 cases were associated with anterior cruciate ligament tear. Average number of meniscal arrow that was used were 2.5(ranged 1 to 4). Average follow-up period was 14.7 months(ranged 6 to 22 months). We evaluated the clinical results by the Tapper and Hoover's grading system. Results : There were excellent in 16 cases, good in 4 cases and fair in 2 cases on the clinical results. At the last follow up, the range of the motion of the knee joint were average 135 degrees(ranged 125 to 140 degrees). Mean time elapsed for meniscal repair were 25 minutes(ranged 15 to 40 minutes). Conclusion : Meniscal arrow has many advantages such as short operative time, easy fixation technique, and less neurovascular injury. We think that arthroscopic meniscal repair using meniscal arrow is effective treatment method in selected patient who have longitudinal, bucket-handle tear at the posterior hom associated with anterior cruciate ligament tear.

• Journal of Korean Orthopaedic Sports Medicine
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• v.6 no.1
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• pp.45-49
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• 2007

Purpose: We analyzed the location and type of meniscus tear associated with ACL rupture in order to estimate and prepare whether the meniscus tear is in a repairable location. Materials and Methods: We reviewed 78 cases who had ACL reconstructive surgery due to ACL rupture. We set the period of acute injury on the basis of under 12 months after trauma. The location and type of meniscus tear was analyzed in accordance with MRI findings and arthroscopic findings. Results: The 50 cases of meniscus tear were detected out of the 78 ACL rupture;32 cases were lateral meniscus tears, 24 were medial meniscus tears and 6 cases were both menisci tears. From a total of 56 meniscus tears, 30 cases were longitudinal tears, 22 cases were red-red zone tears and 35 cases(62%) were posterior horn tears. Conclusion: The most common type of meniscus tear associated with ACL rupture war longitudinal tear at the red-red zone or meniscosynovial junction. Majority of the tears located at that place can be healed with conservative treatment, arthroscopic meniscus suture.

• Journal of the Korean Arthroscopy Society
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• v.13 no.3
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• pp.280-284
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• 2009

Purpose: The authors introduce a new technique of arthroscopic reduction of subluxed medial meniscus using suture anchor for the restoration of hoop stress. Operative Technique: Anterolateral, anteromedial, and medial midpatellar arthroscopic portal are used. Arthroscope was inserted through anterolateral portal. Through the scope, we confirmed subluxation of medial meniscus. Transection of menisci including radial and root tear were excluded. We released the anterior horn of medial meniscus through anteromedial and burred the future insertion site of suture anchor. After inserting suture anchor through medial midpatellar portal, we used 90 degree suture hook and no.2 Nylon to retrieve the suture of inserted anchor. We tied the suture by sliding knot-tying method. Weight bearing was limited for 6 weeks postoperatively. Conclusion: Arthroscopic retightening of medial meniscus is less invasive, conserving and progressed method for subluxed meniscus.

• Investigative Magnetic Resonance Imaging
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• v.3 no.1
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• pp.66-72
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• 1999

Purpose : To evaluate the usefulness of Dual Echo in Steady State(DESS) image in the diagnosis of chondromalacia of the knee compared with turbo spin-echo MR images Materials and Methods : We included 26 patients with chondromalacia of the knee. MR imaging was obtained with a 1.5T imager. Sagittal and coronal double echo T2 weighted images(TR/TE 3000-4200/16-96msec, FOV $140-160{\times}140-160mm$, matrix size $180{\times}256$, slice thickness 4.0mm, interslice gap 0.5mm), and sagittal DESS image(TR/TE 25.4/9.0msec, flip angle $35-45^{\circ}$, FOV $150-160{\times}150-160mm,{\;}matrix{\;}size{\;}192{\times}256$, effective slice thickness 1.5mm) were obtained. Cartilage lesions were staged according to a modified scheme proposed by Outerbirdge: grade 0, normal; grade 1, softening or/and swelling; grade 2, mild surface fibrillation or/and less than 50% of cartilage thickness; grade 3, severe surface fibrillation or/and loss of more than 50% of cartilage thickness but without exposure of subchondral bone; and grade 4, complete loss of cartilage with subchondral bone exposure. Gradings were determined by two readers with consensus, and patellofemoral, medial and lateral tibiofemoral compartments were evaluated. Results : Arthroscopic findings revealed grade 1 in seven cases, grade 2 in 21 cases, grade 3 in six cases, and grade 4 in 18 cases. Sensitivity of turbo spin-echo MR image was as follows; 0%, 14%, 0%, 61% in each grade, and sensitivity of DESS image was as follows; 0%, 33%, 50%, 67%, in each grade(p=0.001). In the detection of chondromalacic lesions regardless of gradings, sensitivity, specificity and accuracy of conventional MR image were 59.6% 88.6% 78.8%, and of DESS image, 73.1% 88.4%, 82.2%(p=0.007). Conclusion : For chondromalacia of knee joints, DESS images showed higher sensitivity than turbo spin-echo MR images. Therefore, DESS images will be helpful for diagnosis of chondromalacia of knee joints.