Hyung Joon Cho

Sungkyunkwan University, Sŏul, Seoul, South Korea

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Publications (14)29.25 Total impact

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    ABSTRACT: An 85 year male patient complaining epigastric discomfort was admitted. From the esophagogastroduodenoscopy, three early gastric cancer (EGCa) lesions had been identified and these were diagnosed as adenocarcinoma with poorly differentiated cell type. The patient underwent operation. From the post-operative mapping, however, additional 4 EGCa lesions were found, and the patient was diagnosed with 7 synchronous EGCa. Out of the 7 EGCa lesions, 6 had shown invasion only to the mucosal layer and one had shown invasion into the 1/3 layer of submucosa. In spite of such superficial invasions, 28 of 48 lymph nodes had been identified as metastases. The multiple lesions of EGCa do not increase the risk of lymph node metastasis, but if their differentiations are poor or if they have lympho-vascular invasion, multiple lymph node metastases could incur even if the depth of invasion is limited to the mucosal layer or the upper portion of the submucosal layer.
    World Journal of Gastroenterology 11/2013; 19(44):8141-5. DOI:10.3748/wjg.v19.i44.8141 · 2.43 Impact Factor
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    ABSTRACT: Uniform tunnel pits are fabricated with equally spaced intervals while avoiding excessive dissolution of an aluminum surface with a polyimide material as a mask layer. To increase the area S of capacitance C, uniform tunnel pits are made selectively to increase the aluminum surface area S into the vertical direction on Al foil. In this article, the relationship between the surface area and the etching tunnel is analyzed through selective electrochemical etching with patterning on aluminum foil, and the controllability of the etching tunnel is also studied. Copyright © 2012 John Wiley & Sons, Ltd.
    Surface and Interface Analysis 11/2012; 44(11-12). DOI:10.1002/sia.4961 · 1.39 Impact Factor
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    ABSTRACT: BACKGROUND: The use of total knee arthroplasty (TKA) has increased substantially in most Western countries. However, the trends in TKA use and changes in demographic characteristics of patients having TKA in Korea remain unclear. QUESTIONS/PURPOSES: We documented the trends in TKA use and in the demographics of patients undergoing TKA in Korea over the past decade and determined whether current TKA use in Korea corresponds to worldwide trends. METHODS: Using the Health Insurance Review and Assessment Service of Korea database, we analyzed TKA records (n = 398,218) from 2001 to 2010 in Korea. Trends in TKA use and demographics, including numbers and rates of primary and revision TKA, growth rate and the revision burden, and age- and sex-specific rates, were estimated. They were compared with nationwide TKA registry reports from other countries, and a systematic review was performed. RESULTS: Over the past decade, the primary and revision TKA rates increased by 407% and 267%, respectively. However, the revision burden remained 2%. The highest proportion was observed in 65 to 74 years old and the greatest increase in 75 to 84 years old, but a decrease was observed in those 55 to 64 years old. Women consistently had a ninefold higher TKA rate. The primary TKA rate was comparable with that of other countries, but the revision burden remained lower. In addition, old and female patients comprised considerably higher proportions in Korea. CONCLUSIONS: During the past decade, TKA use in Korea has markedly increased and caught up with the use levels of most developed Western countries. Trends toward consistent growth in elderly patients and higher rates in females were observed. Appropriate healthcare strategies reflecting these trends in demographics are urgently needed in Korea.
    Clinical Orthopaedics and Related Research 10/2012; 471(5). DOI:10.1007/s11999-012-2622-y · 2.88 Impact Factor
  • Arthroscopy The Journal of Arthroscopic and Related Surgery 09/2012; 28(9):e422-e423. DOI:10.1016/j.arthro.2012.05.630 · 3.19 Impact Factor
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    ABSTRACT: We undertook to document sex differences in the prevalence of knee osteoarthritis (OA) at different disease stages in an elderly Korean population. Prevalence of 3 stages of knee OA (radiographic OA, severe radiographic OA, and candidacy for total knee arthroplasty [TKA]) was investigated in 696 elderly (≥65 years old) Korean subjects. Multivariate logistic regression was performed to evaluate associations between the risk factors of OA at these 3 disease stages. The overall prevalence of knee OA was 38.1% for radiographic OA, 26.4% for severe radiographic OA, and 6.5% for advanced OA warranting TKA. Women had much higher prevalence for all 3 stages. Female sex was found to be the strongest predictor for all 3 disease stages, but this was most remarkable for TKA candidates. This study documents that knee OA is highly prevalent among Korean elderly and that elderly Korean women are at much greater risk of requiring TKA.
    The Journal of arthroplasty 03/2011; 26(7):994-9. DOI:10.1016/j.arth.2011.01.007 · 2.37 Impact Factor
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    ABSTRACT: This study was conducted to analyze the clinical and radiographic results of isolated acetabular revisions during which intact femoral stems were retained. Twenty-nine hips of 26 patients who were followed up for a minimum of 3 years were examined. The average time from primary operation to revision surgery was 9.2 years, and the average follow-up time after revision was 5 years. The average Harris hip scores improved from 56.4 to 89.8 points after revision surgery, and in all cases, the acetabular components and femoral stems were assessed as stable at the final follow-up. The average length of service of the femoral components was 14.2 years. In conclusion, we recommend that isolated acetabular revision be considered in cases with an acetabular component failure and a stable femoral component.
    The Journal of arthroplasty 03/2011; 26(8):1239-44. DOI:10.1016/j.arth.2011.02.015 · 2.37 Impact Factor
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    ABSTRACT: We sought to investigate the reported association between depression and severity of knee osteoarthritis symptoms stratified by radiographic severity of osteoarthritis and to quantify the contribution made by depression to symptom severity. Six hundred and sixty elderly Koreans (sixty-five years or older) were evaluated for radiographic severity of knee osteoarthritis on the basis of the Kellgren-Lawrence grading system and also for symptom severity on the basis of the Western Ontario and McMaster Universities Osteoarthritis Index scales. Patient interviews and a questionnaire that made use of a geriatric depression scale were conducted for the purpose of assessing depressive disorders. Regression analyses were performed to assess the relative contributions by radiographic severity and depression severity to Western Ontario and McMaster Universities Osteoarthritis Index scores and to explore any associations between radiographic severity and the presence of a depressive disorder with regard to the risk of symptomatic knee osteoarthritis. Symptomatic knee osteoarthritis was defined as a Western Ontario and McMaster Universities Osteoarthritis Index score of ≥39. The presence of a depressive disorder was found to be associated with an increased risk of symptomatic knee osteoarthritis (odds ratio = 5.87 [95% confidence interval, 3.01 to 11.44]). However, the influence of the presence of a depressive disorder was limited to subjects with a radiographic severity of minimal to moderate (Kellgren-Lawrence grade 0 to 3). The presence of a depressive disorder was not associated with the risk of symptomatic knee osteoarthritis in subjects with severe osteoarthritis (Kellgren-Lawrence grade 4). This study indicates that the assessment and management of coexisting depression should be integrated with the assessment and management of knee osteoarthritis, particularly when radiographic changes of osteoarthritis in the knee joint are not severe.
    The Journal of Bone and Joint Surgery 03/2011; 93(6):556-63. DOI:10.2106/JBJS.I.01344 · 4.31 Impact Factor
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    ABSTRACT: This study was conducted to longitudinally compare a new floating platform mobile-bearing (MB) prosthesis with an established fixed-bearing (FB) system with respect to early clinical outcomes in patients with bilateral TKAs using the MB prosthesis in one knee and the FB prosthesis in the other. Clinical outcomes (ROM, AKS and WOMAC scores, and side preference), evaluated at 6, 12 and 24months postoperatively, were compared between knees fitted with the MB prosthesis (e.motion-FP) or the FB prosthesis (Genesis II) in 66 patients who underwent bilateral TKA. In addition, the same comparisons between the knees fitted with the MB prosthesis and the knees with the FB prosthesis were made separately in the subgroup of 33 patients implanted with a cruciate retaining FB (FB-CR) prosthesis and the other subgroup of 33 patients with a posteriorly stabilized FB (FB-PS) prosthesis in a knee. The floating platform MB prosthesis achieved comparable clinical outcomes to the FB prosthesis. No significant differences were found between the FB- and MB-implanted sides at any time with respect to the outcome scales, and temporal patterns were similar. However, comparisons of FB-CR and FB-PS patient groups revealed different temporal patterns. In the FB-CR group, most outcome scales were improved at 6months, peaked at 12months and then remained at this level at 24months. In contrast, outcomes in the FB-PS group improved much faster to almost peak at 6months, and then remained at this level. In the FB-CR group, more patients preferred the knee with fitted with a MB prosthesis at 6months. In contrast, in the FB-PS group, no side preference for the MB prosthesis was observed, and more patients preferred knees implanted with the FB prosthesis at 12 and 24months. This study demonstrates that this new mobile-bearing prosthesis, designed as a floating platform, provides satisfactory clinical performances that are comparable to those achieved using the established fixed-bearing prosthesis in terms of clinical outcomes. KeywordsTotal knee arthroplasty-Mobile-bearing knee-Fixed-bearing knee-e.motion-FP-Genesis II
    Knee Surgery Sports Traumatology Arthroscopy 07/2010; 18(7):879-888. DOI:10.1007/s00167-009-0985-8 · 2.84 Impact Factor
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    ABSTRACT: The effects of gender on the relationship between symptom manifestations and radiographic grades of knee osteoarthritis are not well understood. We therefore determined the increments of symptom progression with regard to radiographic grades of knee osteoarthritis and asked if those increments differed by gender and whether symptom severity was differentially manifested by gender within the same grade. We recruited 660 community residents; 368 (56%) women and 292 (44%) men. The mean subject age was 71.5 years (range, 65-91 years). Severity of symptoms was measured using the WOMAC and SF-36 scales, and the radiographic severity using Kellgren-Lawrence grades. Incremental changes in WOMAC and SF-36 scores were compared between adjacent Kellgren-Lawrence grades separately in men and women, and in the overall population. We compared symptom severity between men and women with the same radiographic grade. For the entire cohort, the mean incremental change in symptom severity was not gradual between the adjacent radiographic grades but was greater between Kellgren-Lawrence Grades 1 and 2 and Grades 2 and 3 than between Grades 0 and 1 or Grades 3 and 4. The patterns of incremental changes in symptom severity differed between men and women: women had more severe symptom progression between Kellgren-Lawrence Grades 2 and 3 and Grades 3 and 4 than men. Furthermore, women had worse mean WOMAC and SF-36 scores than men with the same radiographic grade of knee osteoarthritis. These data suggest symptom progression is not gradual between adjacent radiographic grades, and for the same radiographic grade, symptoms are worse in women. Level III, diagnostic study. See Guidelines for Authors for a complete description of levels of evidence.
    Clinical Orthopaedics and Related Research 03/2010; 468(7):1749-58. DOI:10.1007/s11999-010-1282-z · 2.88 Impact Factor
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    ABSTRACT: While computer assisted total knee arthroplasty (TKA) has been documented to increase the surgical accuracy in the planning process, there is little information about the accuracy in execution processes. We aimed to determine the accuracy of execution processes for bone resections and implant fixation in TKAs performed with the techniques of computer assisted navigation and minimally invasive surgery. Execution deviations, defined as the differences between planned targets and executed results, were evaluated for bone resections and implant fixation in 107 TKAs. In tibia resection, the mean resection thickness, coronal alignment, and sagittal alignment were 0.2mm smaller, 0.3 degrees more valgus, 0.3 degrees less posterior slope than the planned, respectively. In femur resection, the mean resection thicknesses in the medial and lateral femoral condyles, coronal alignment, and sagittal alignment were 0.6mm smaller, 0.8mm smaller, 0.1 degrees more varus, and 0.7 degrees less posterior slope than the planned, respectively. In implant fixation, the mean coronal alignment and degree of extension was 0.7 degrees more valgus and 1.6 degrees decrease than the planned, respectively. Only the occurrence of unacceptable executions in implant fixation had significant effects on the final coronal alignment. The density of a bone and the quality of saw blade had significant effect on the accuracy of bone resections. Execution deviations from planned alignment commonly occur in computer-assisted minimally invasive TKA, resulting typically from the techniques of bone resections and implant fixation, and this information should be considered to improve the surgical accuracy of navigated TKAs.
    The Knee 08/2009; 17(1):23-8. DOI:10.1016/j.knee.2009.06.004 · 1.70 Impact Factor
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    ABSTRACT: The rotating-platform posterior-stabilized (RP/PS) prosthesis was developed to take advantage of the benefits of the traditional RP mobile-bearing system and the posterior-stabilized design. This nonconsecutive cohort study compared the clinical outcomes of TKAs performed using a RP/PS mobile system or a floating-platform (FP) system. The clinical outcomes of 93 TKAs with a RP/PS prosthesis were compared with the same number of TKAs with a FP mobile-bearing prosthesis at 6, 12, and 24 months after surgery. Clinical outcomes differed between the FP and RP/PS groups as a function of length of followup. In the FP group, most outcomes peaked at 12 months and then deteriorated, whereas in the RP/PS group, outcomes stabilized or continued to improve between 12 and 24 months. The RP/PS group had greater maximum flexion throughout followup and better clinical outcomes 24 months after surgery. Patient satisfaction was superior in the RP/RS group. This study suggests the RP/PS prosthesis provides better functional outcomes, including greater maximum flexion and better patient satisfaction. We propose the RP/PS mobile-bearing system is a more attractive option than the FP mobile-bearing system for patient populations of elderly women similar to patients enrolled in our study.
    Clinical Orthopaedics and Related Research 04/2009; DOI:10.1007/s11999-009-0787-9 · 2.88 Impact Factor
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    ABSTRACT: The basic discharge characteristics of the coplanar long gap electrodes in an AC PDP were investigated. The luminous efficiency of the 150μm gap coplanar discharge was 3.7 lm/W. The luminous efficiency was decreased drastically when the gap of the coplanar discharge was 500μm. The luminous efficiency of the 500μm gap coplanar discharge was about 4 lm/W when the high frequency pulses were applied to the auxiliary electrode located at the center of two sustain electrode.
    SID Symposium Digest of Technical Papers 01/2003; 34(1). DOI:10.1889/1.1832303
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    Jong C. Park, Hyung Joon Cho
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    ABSTRACT: Coordination in natural language hampers efficient parsing, especially due to the multiple and mostly unintended candidate conjuncts/disjuncts in a given sentence that shows structural ambiguity. The problem gets more serious in a combinatory categorial grammar framework, which is well known for its competent treatment of coordination, as the flexibility of syntactic analysis often strikes back as spurious ambiguity. We propose to address these ambiguities with predicate argument structures and semantic co-occurrence similarity information, and present encouraging results.
    COLING 2000, 18th International Conference on Computational Linguistics, Proceedings of the Conference, 2 Volumes, July 31 - August 4, 2000, Universität des Saarlandes, Saarbrücken, Germany; 01/2000
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    ABSTRACT: Purpose: This study was conducted to investigate the epidemiologic characteristics of knee osteoarthritis (OA) in elderly Koreans with respect to its detailed prevalence and association with demographic factors such as gender, age and body mass index (BMI). Materials and Methods: Six hundred and ninety six subjects (men 298 and women 398) aged 65 years or older were recruited from an urban population. Radiographic evaluations were conducted using three plain radiographs (weight bearing anteroposterior view, 45 degree of flexion posteroanterior view, and the Merchant view). Radiographic severity was determined using the Kellgren-Lawrence (K/L) grading scale and radiographic OA was defined as K/L grade 2 or higher. Overall prevalence of OA was analyzed with regard to gender, age and BMI using multivariate logistic regression. Results: The overall prevalence of knee OA in the study cohort was 38.1%. Women had the much higher prevalence of knee OA than men (53.8% vs. 17.1%). Female gender, obesity and ageing were associated with the risk of knee OA, but a female gender was found to be the strongest predictor for knee OA. Conclusion: This study documents that knee OA is highly prevalent among Korean elderly, and that elderly Korean women are at much greater risk of development of knee OA. It is hoped that our findings provide information that aids the creation of national health policies that better target the prevention and treatment of knee OA.

Publication Stats

122 Citations
29.25 Total Impact Points

Institutions

  • 2012
    • Sungkyunkwan University
      • Centre of Advanced Materials Technology Research
      Sŏul, Seoul, South Korea
  • 2011–2012
    • Pusan National University
      Tsau-liang-hai, Busan, South Korea
    • Seoul National University
      Sŏul, Seoul, South Korea
    • Korea University
      Sŏul, Seoul, South Korea
  • 2009–2010
    • Seoul National University Bundang Hospital
      • Joint Reconstruction Center
      Sŏul, Seoul, South Korea
  • 2003
    • LG Electronics
      Sŏul, Seoul, South Korea
  • 2000
    • Korea Advanced Institute of Science and Technology
      Sŏul, Seoul, South Korea