• The Journal of Korean Orthopaedic Ultrasound Society
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• v.6 no.1
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• pp.1-9
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• 2013

Purpose: The purpose is to perform objective evaluation for rotator cuff using ultrasonography and validate factors influencing cuff integrity as well as efficacy of follow-up ultrasonography after unreamed antegrade intramedullary nailing for humerus fracture. Materials and Methods: Seventeen patients with an average age of $55.7{\pm}18.6$ years underwent antegrade intramedullary nailing for humerus fracture and follow-up ultrasonography of shoulder joint. Mean follow-up period was $43.5{\pm}32.2$ months. Intraoperative evaluation for preoperative cuff tear was performed, of which four cuffs were repaired by single row repair technique. Clinical evaluation included visual analogue scale (VAS), range of motion, Korean Shoulder Scoring System (KSS) and American Shoulder and Elbow Society (ASES) score. Ultrasonographic evaluation was performed on cuff integrity and protrusion of proximal nail tip as well. Radiographic evaluation included time to union, protrusion of proximal nail tip and migration of proximal interlocking screw which could affect shoulder joint function. Results: Mean VAS at last follow-up was $1.65{\pm}1.84$ points. Range of motion showed forward flexion of $137.0{\pm}33.5^{\circ}$, external rotation of $43.5{\pm}12.7^{\circ}$ and internal rotation of $16.4{\pm}2.0^{\circ}$ while KSS score and ASES score were $79.6{\pm}20.7$ and $83.7{\pm}17.0$ points, respectively. Bone union was demonstrated in all cases and average time to union was $3.4{\pm}1.3$ months. Migration of proximal interlocking screw was shown in 6 cases (35%). On ultrasonographic evaluation, there were normal in 8 (47%), weaving in 4 (24%), partial tear in 5 cases (29%), but no complete tear. Protrusion of proximal nail tip was demonstrated in 8 cases (47%) on plain radiographs whereas in 11 cases (65%) on ultrasonography and was associated with increasing age (p=0.038). Ultrasonographic weaving and partial tear was associated with protrusion of proximal nail tip (p=006), but not with repair of preoperative tear (p>0.05). Conclusion: Because weaving and partial tear on ultrasonography originated from protrusion of proximal nail tip, careful insertion of nail and meticulous repair of cuff during operation lead to stable fixation with satisfactory recovery of shoulder function follow-up ultrasonography can be a useful tool for evaluating protrusion of nail tip and rotator cuff tear, of which diagnosis is difficult on plain X-ray after antegrade intramedullary nailing for humerus fracture.

• Nonlinear Functional Analysis and Applications
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• v.27 no.1
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• pp.23-44
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• 2022

In this paper, we consider and introduce some new concepts of the biconvex functions involving an arbitrary bifunction and function. Some new relationships among various concepts of biconvex functions have been established. We have shown that the optimality conditions for the general biconvex functions can be characterized by a class of bivariational-like inequalities. Auxiliary principle technique is used to propose proximal point methods for solving general bivariational-like inequalities. We also discussed the conversance criteria for the suggested methods under pseudo-monotonicity. Our method of proof is very simple compared with methods. Several special cases are discussed as applications of our main concepts and results. It is a challenging problem to explore the applications of the general bivariational-like inequalities in pure and applied sciences.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• v.6 no.1
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• pp.17-23
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• 2003

Purpose: The aim of this study was to determine clinical significance of dual-probe esophageal pH monitoring and to compare four pH monitoring parameters between proximal and distal esophagus in pathological gastroesophageal reflux disease with recurrent respiratory symptoms. Methods: Among the thirty-four patients who were performed 24 hr pH monitoring, seventeen patients with pathological distal reflux were classified into two groups: Group I (n:12) had recurrent respiratory symptoms and Group II (n:5) hadn't recurrent respiratory symptoms. The ambulatory dual-probe esophageal pH monitoring was performed for 18~24 hr. A pathologic GER was defined when reflux index (percent of the investigation time a pH<4) exceeded the 95th percentile of normal value. Results: Among the sixteen patients with recurrent respiratory symptoms, twelve patients (75%) have pathological distal reflux. Whereas among the eighteen patients without recurrent respiratory symptom, five patients (28%) have pathological distal reflux. In the Group I, the significant differences between proximal and distal esophageal pH recordings persisted for all parameters, but didn't persist in group II except for longest episode. Comparing esophageal pH four parameters between group I and group II at the proximal esophageal site, all parameters didn't show statistically significant differences. Conclusion: Regardless of respiratory symptoms, patients with pathological distal reflux didn't show statistically significant differences in the all parameters at the proximal esophageal site. Therefore we may reconsider usefulness of dual probe pH meter in patients with recurrent respiratory symptoms.

• Clinics in Shoulder and Elbow
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• v.3 no.2
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• pp.61-67
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• 2000

Purpose: Most proximal humeral fractures are minimally displaced and can be treated satisfactorily with a conservative method. But in many comminuted fractures, hemiarthroplasty is usually done as a primary treatment. The authors evaluated how much functional improvement was achieved after hemiarthroplasty and which factors influence on the final functional results. Materials and Methods: Eleven hemiarthroplasties were performed for three- and four-part fractures(including fracture-dislocation) between April 1992 and June 1999. There were eight women and three men, and the mean age was 65 years. According to Neer classification, six was three-part fracture and five was four-part fracture. Six patients were injured on their right shoulder and five on the left shoulder. Among the five four-part fractures, three had axillary nerve injury and among the six three-part fractures, only one patient had axillary nerve injury. The average follow-up period was 2.4 years(1 year-7 years) after operation. The functional results were evaluated with the UCLA scoring system(Modification for hemiarthroplasty). In addition to the overall results, we compared the results according to the classification of the fracture, the cause of injury, and whether the axillary nerve was injured. Results: At the last follow-up, average total UCLA score was 18.2. The mean score for pain was 7.0, mean muscle power and motion score was 5.5 and 5.7 respectively. The pain relief was more satisfactory than any other functional results. The average score for three-part fractures was 22, and the average for four-part fractures was 13.6. The average score for the patients fractured by vehicle accidents was 15.3, and 19.3 for the patients fractured by slip-down injury. In patients without axillary nerve injury, the average score was 20, and with axillary nerve injury, the score was 15. Conclusion: Shoulder hemiarthroplasty, for the treatment of proximal humeral fractures, cannot restore the shoulder function to normal, but can achieve the functional result to some degree, especially for the activity of daily living. And as for pain, we think that it is relatively effective measure. And we think that the severer the comminution, the more the chance of axillary nerve injury, and the poorer the functional results. In conclusion, the severity of initial injury seems to be the major prognostic factor.

• Archives of Reconstructive Microsurgery
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• v.16 no.1
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• pp.1-5
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• 2007

The purpose of this article to evaluate the availability of the rectus femoris flap in Korean subjects. Material and Methods is that Cadaveric dissections were done on 51 femoral triangles of 26 cadevers. We measured the length of the direct head of rectus femoris from anterior superior iliac spine to patella upper pole, ASIS to lateral border of femoral nerve, and entry point of femoral nerve and vessel branches to rectus. Usually, there were three terminal branches to rectus femoris from the femoral nerve. The entry point of the first branch was at the proximal $17.5{\sim}31.4%$ portion of the rectus femoris. The second and the third branch entered at the proximal $22.5{\sim}40.7%$ and $26.3{\sim}42.3%$, respectively. The vessel entry was at $20.2{\sim}37.3%$. The length from ASIS to femoral nerve was $3.5{\sim}8.5\;cm$. Among the 51 rectus femoris muscles, 44 had one nutrient artery, and 7 had 2 nutrient arteries. The nutrient artery originated from the descending branch of the lateral femoral circumflex artery in 18(40.9%) cases, directly from the lateral femoral circumflex artery in 8(18.0%) cases, and from proximal(6 cases, 13.6%) and distal(12 cases, 27.3%) portion of the deep femoral artery. The average length of the nutrient artery was 29.8 mm and the width was 2.14 mm. The point where it meets the main feeding artery of the rectus femoris was $9.0{\sim}15.0\;cm$ from the ASIS. In all cases, the main artery's entrance was proximal to the first nerve branch. Conclusion is that rectus femoris has available data for functional flap.

• Journal of the Korean Arthroscopy Society
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• v.9 no.2
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• pp.137-142
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• 2005

Purpose: The purpose of this study is to evaluate the results of arthroscopic anterior cruciate ligament(ACL) repair with minimal incision and to review prognostic factors according to ACL tear patterns and the presence of associated injury Materials and Methods: Thirty eight patients (thirty nine knees) with acute ACL tear were given arthroscopic ACL repair between January 2001 and December 2002 and were followed up at least over six months. Intraoperative findings such as ACL tear pattern and the presence of synovial or concomitant medial collateral ligament injuries were recorded. Each knee was then postoperatively re-evaluated with aid of KT-1000 arthrometer and Lachman test and Lysholm score. Results: Postoperative limitation of motion was significant when combined typed ACL tear was present with concurrent medial collateral ligament(MCL) injury. In contrast, in the case where there were sole proximal ACL tear or no evidence of synovial injury, the limitation of motion was not significant. Anterior laxity was significantly associated with the presence of combined typed ACL tear or concurrent synovial injury, but was not significant when there were sole proximal ACL tear. Conclusion: In the case where there is sole proximal ACL tear without concurrent synovial injury, arthroscopic ACL repair can be considered as a treatment modality for the treatment of acute ACL injury.

• Journal of Korean Foot and Ankle Society
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• v.12 no.1
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• pp.26-30
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• 2008

Purpose: The authors evaluated the differences between K-wires and Bold screw for fixing the proximal metatarsal chevron osteotomy of moderate and severe hallux valgus. Materials and Methods: There were 59 patients (81 feet) who were moderate and severe degree hallux valgus according to the classification of Mann. They all got the proximal chevron osteotomy when correcting the deformity. All patients were followed up at least 6 months. We divided the patients into 2 groups, K-wires fixed group as A, Bold screw fixed group as B. Group A were 42 patients (63 feet) and Group B were 18 patients (19 feet). Among the Group B, 2 feet who were failed to fix the oetotomy site with Bold screw, were fixed with K-wires during operation. We measured the AOFAS score preoperatively, postoperatively and at final follow-up, VAS score at 2 weeks after the operation. Also preoperative, postoperative and follow-up hallux valgus angle (HVA) and intermetatarsal angle (IMA) were measured for each patients. Results: Mean follow up period was 1.34 year (range: 6 months-6.16 years). Mean VAS score of group A was $3.21{\pm}1.7$ and group B $1.76{\pm}1.0$. Preoperative mean AOFAS score of group A was $45.61{\pm}8.3$, group B $44.41{\pm}8.9$, the final mean score of group A was $88.87{\pm}8.3$ and group B $92.47{\pm}4.4$. Preoperative mean HVA was $30.82{\pm}6.6$ degrees in group A and $32.88{\pm}14.5$ degrees in group B, the final mean angle of group A was $14.89{\pm}8.3$ degrees and group B $17{\pm}4.4$ degrees. The preoperative mean IMA of group A was $13.69{\pm}3.6 $degrees and group B $12.35{\pm}5.2$, the final mean angle of group A was $9.26{\pm}3.6$ degrees and group B $12.35{\pm}5.8$ degrees. Conclusion: There were no statistical differences in radiologic and clinical results (p>0.05) but, group B exceeded group A in VAS score (p=0.0007) and had no statistical significance in terms of reduction angle loss (p=0.06). Early returning to normal life activity may be possible for patients using Bold screws.

• The Journal of the Korean bone and joint tumor society
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• v.9 no.2
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• pp.200-205
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• 2003

Purpose: To report our experiences of clinical features, treatment method and results of giant cell tumor of 5 patients in proximal fibula. Materials and Methods: Five patients managed with an en bloc resection preserving common peroneal nerve and lateral collateral ligament reconstruction with biceps femoris tendon followed up between January 1997 and July 2001. Preoperative plain radiograph and MRI and bone scan were checked. The recurrence of the tumor was judged by plain radiograph and clinical signs. Lateral instability of knee joint was checked during the outpatient follow-up. Results: The mean age of the patients at the time of operation was twenty- three (21-29). There were one male and four female patients. Dull pain was main symptom and palpable mass was seen in two patients. Peroneal nerve palsy and local recurrence were not observed except one case of temporary peroneal nerve palsy. During the outpatient follow up, one among 5 patients showed slight lateral instability and the other 4 patients showed no instabililty. Conclusion: Giant cell tumor in proximal fibula managed with an en bloc resection preserving common peroneal nerve and lateral collateral ligament reconstruction with biceps femoris tendon showed favorable results.

• Journal of the Korean Data and Information Science Society
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• v.28 no.6
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• pp.1229-1244
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• 2017

In recent years, as demand for data-based analytical methodologies increases in various fields, optimization methods have been developed to handle them. In particular, various constraints required for problems in statistics and machine learning can be solved by convex optimization. Alternating direction method of multipliers (ADMM) can effectively deal with linear constraints, and it can be effectively used as a parallel optimization algorithm. ADMM is an approximation algorithm that solves complex original problems by dividing and combining the partial problems that are easier to optimize than original problems. It is useful for optimizing non-smooth or composite objective functions. It is widely used in statistical and machine learning because it can systematically construct algorithms based on dual theory and proximal operator. In this paper, we will examine applications of ADMM algorithm in various fields related to statistics, and focus on two major points: (1) splitting strategy of objective function, and (2) role of the proximal operator in explaining the Lagrangian method and its dual problem. In this case, we introduce methodologies that utilize regularization. Simulation results are presented to demonstrate effectiveness of the lasso.

• Journal of Korean Foot and Ankle Society
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• v.20 no.3
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• pp.112-115
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• 2016

Purpose: We aimed to investigate the safety zone for Achilles tendon insertion in the posterior aspect of the calcaneus via the use of magnetic resonance imaging (MRI) when planning for insertional Achilles tendinopathy. Materials and Methods: This study included 95 patients. The MRI of midsagittal plane of the ankle joint was used to measure the proximal and distal insertion point for the Achilles tendon in the posterior aspect of the calcaneus. Patients were divided into three groups according to the proportion of the distal insertion point out of the entire calcaneal length: the proximal, middle, and distal insertion groups. Results: The mean proximal and distal insertion points for the Achilles tendon were measured as 1.05 cm (0~2.11 cm) and 2.36 cm (1.60~2.93 cm), respectively. When the posterior aspect of the calcaneus was used as the reference plane, none of the patients was in the proximal insertion group, while 75 and 20 patients were in the middle and distal insertion groups, respectively. The insertion portion was longer in the distal insertion group ($1.47{\pm}0.25cm$) than in the middle insertion group ($1.27{\pm}0.35cm$). Statistically significant differences with respect to the length of the insertion portion were observed between the two groups (p=0.008). Conclusion: Removal of more than 1 cm below the superior margin of the posterior calcaneus may be dangerous. An MRI study on the Achilles tendon of patients without hindfoot deformity or tendinopathy revealed various insertional characteristics. Preoperative MRI evaluation is safer than relying solely on the simple radiological assessment when planning for insertional Achilles tendinopathy.