• Archives of Reconstructive Microsurgery
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• v.8 no.2
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• pp.184-191
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• 1999

Reconstruction of soft tissue defect of the foot, ankle and distal tibial area has been and remains a challenging problem for reconstructive surgeons. We treated 19 patients who showed soft tissue defect in these area with distally based superficial sural artery flaps, including four adipofascial flaps, two sensate flaps. The size of the soft tissue defect was from $4{\times}5cm\;to\;8{\times}10cm$. In nine cases, we preserved sural nerve. Seventeen flaps survived completely, but one flap failed and another flap showed partial skin necrosis at the distal half. In failed cases, lesser saphenous vein was ruptured at initial injury. The advantage of this flap is a constant and reliable blood supply without sacrifice of major artery or sensory nerve. Elevation of the flap is technically easy and quick. The pedicle is long and the island flap can be transffered as far as to the instep area. It also has the potential for sensate flap, innervated by the lateral sural cutaneous nerve. But for appropriate venous drainage small saphenous vein must be preserved.

• Journal of Chest Surgery
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• v.31 no.9
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• pp.899-902
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• 1998

Recent advances in understanding the anatomy of complete atrioventricular septal defect have led to alternative methods of repairing these defects. Here we report two cases of complete atrioventricular septal defect repair by direct closure of the ventricular element of the defect. Follow-up for average of 3 months suggests that, when direct closure can be performed, the results can be comparable with those of the standard technique. Our initial success with this approach is encouraging; however, longer follow-up and more experiences are required to establish whether it will be broadly applicable.

• Clinics in Shoulder and Elbow
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• v.19 no.2
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• pp.78-83
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• 2016

Background: We investigated the risk factors for the recurrence of anterior shoulder instability after arthroscopic surgery with suture anchors and the clinical outcomes after reoperation. Methods: A total of 281 patients (February 2001 to December 2012) were enrolled into our study, and postoperative subluxation and dislocation were considered as recurrence of the condition. We analyzed radiologic results and functional outcome including the American Shoulder and Elbow Surgeons Evaluation Form, the Korean Shoulder Society Score, and the Rowe scores. Results: Of the 281 patients, instability recurred in 51 patients (18.1%). Sixteen out of 51 patients (31.4%) received a reoperation. In terms of the functional outcome, we found that the intact group, comprising patients without recurrence, had a significantly better functional outcome than those in the recurrent group. The size of glenoid defect at the time of initial surgery significantly differed between intact and recurrent group (p<0.05). We found that the number of dislocations, the time from the initial presentation of symptoms to surgery, and the number of anchor points significantly differed between initial operation and revision group (p<0.05). The functional outcome after revision surgery was comparable to intact group after initial operation. Conclusions: Eighteen percent of recurrence occurred after arthroscopic instability surgery, and 5.6% received reoperation surgery. Risk factors for recurrence was the initial size of glenoid defect. In cases of revision surgery, good clinical outcomes could be achieved using additional suture anchor.

• Journal of Periodontal and Implant Science
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• v.45 no.1
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• pp.30-35
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• 2015

Purpose: Implant beds with an insufficient amount of cortical bone or a loss of cortical bone can result in the initial instability of a dental implant. Thus, the objective of this study was to evaluate the effect of bone cement grafting on implant initial stability in areas with insufficient cortical bone. Methods: Two different circumferential defect depths (2.5 mm and 5 mm) and a control (no defect) were prepared in six bovine rib bones. Fourteen implants of the same type and size ($4mm{\pm}10mm$) were placed in each group. The thickness of the cortical bone was measured for each defect. After the implant stability quotient (ISQ) values were measured three times in four different directions, bone cement was grafted to increase the primary stability of the otherwise unstable implant. After grafting, the ISQ values were measured again. Results: As defect depth increased, the ISQ value decreased. In the controls, the ISQ value was $85.45{\pm}3.36$ ($mean{\pm}standard$ deviation). In circumferential 2.5-mm and 5-mm defect groups, the ISQ values were $69.42{\pm}7.06$ and $57.43{\pm}6.87$, respectively, before grafting. These three values were significantly different (P<0.001). After grafting the bone cement, the ISQ values significantly increased to $73.72{\pm}8.00$ and $67.88{\pm}10.09$ in the 2.5-mm and 5.0-mm defect groups, respectively (P<0.05 and P<0.001). The ISQ value increased to more than double that before grafting in the circumferential 5-mm defect group. The ISQ values did not significantly differ when measured in any of the four directions. Conclusions: The use of bone cement remarkably increased the stability of the implant that otherwise had an insufficient level of stability at placement, which was caused by insufficient cortical bone volume.

• Proceedings of the Korean Society For Composite Materials Conference
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• 2005.04a
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• pp.67-70
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• 2005

The carbon fiber reinforced/epoxy laminated composites were fabricated with initial fiber failures within the unidirectional fiber pre-pregnated ply. The fiber failures were made intentionally either parallel to and/or perpendicular to the unidirectional fibers within the ply. The pre-made clear-cut cracks were found to be healed partially after laminating process. The laminates were impacted with or without initial fiber failures within the laminates. The force versus deflection curves were compared. The partially healed laminates showed the reduced laminate stiffness as compared to those without any intentional fiber failures. The impact curves were compared with size and the location of the initial failures varied.

• Proceedings of the KWS Conference
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• 1995.10a
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• pp.214-217
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• 1995

In order to investigate characteristics of surface fatigue crack propagation from a pit shaped surface defect which frequently exists near weld joints, SS400 steel with thickness of 12mm, which generally used for structure members, was submerged-arc welded with butt type and machined for both surface. The weld joints were devided into 5 regions, weld metal, boundary between heat affected zone (HAZ), HAZ, boundary between HAZ and base metal, and base metal. Specimens from each region were machined for a pit shaped initial surface defect with aspect ratio of 2. characteristics of surface fatigue crack por pagation from the defect under the same loading condition were compared and discussed.

• Geomechanics and Engineering
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• v.22 no.5
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• pp.461-473
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• 2020

Natural rock mass contains defects of different shapes, usually filled with inclusions such as clay or gravel. The presence of inclusions affects the failure characteristics and mechanical properties of rock mass. In this study, the strength and failure characteristics of rock with inclusions were studied using the particle flow code under uniaxial compression. The results show that the presence of inclusions not only improves the mechanical properties of rock with defects but also increases the bearing capacity of rock. Circular inclusion has the most obvious effect on improving model strength. The inclusions affect the stress distribution, development of initial crack, change in crack propagation characteristics, and failure mode of rock. In defect models, concentration area of the maximum tensile stress is generated at the top and bottom of defect, and the maximum compressive stress is distributed on the left and right sides of defect. In filled models, the tensile stress and compressive stress are uniformly distributed. Failing mode of defect models is mainly tensile failure, while that of filled models is mainly shear failure.

• Clinical Endoscopy
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• v.56 no.6
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• pp.754-760
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• 2023

Background/Aims: Endoscopic vacuum therapy (EVT) can heal a variety of defects within the gastrointestinal (GI) tract via applying negative pressure, which reduces the defect size, aspirates the infected fluid, and promotes granulation tissue. Here we present our experience with EVT as it relates to both spontaneous and iatrogenic upper GI tract perforations, leaks, and fistulas. Methods: This retrospective study was conducted at four large hospital centers. All patients who underwent EVT between June 2018 and March 2021 were included. Data on multiple variables were collected, including demographics, defect size and location, number and intervals of EVT exchanges, technical success, and hospital length of stay. Student t-test and the chi-squared test were used to analyze the data. Results: Twenty patients underwent EVT. The most common defect cause was spontaneous esophageal perforation (50%). The most common defect location was the distal esophagus (55%). The success rate was 80%. Seven patients were treated with EVT as the primary closure method. The mean number of exchanges was five with a mean interval of 4.3 days between exchanges. The mean length of hospital stay was 55.8 days. Conclusions: EVT is a safe and effective initial management option for esophageal leaks and perforations.

• Proceedings of the Korean Nuclear Society Conference
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• 2001.05a
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• pp.327-327
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• 2001

• Transactions of the Korean Society of Mechanical Engineers A
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• v.20 no.11
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• pp.3387-3397
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• 1996

The Hub is an auto mobile component used as aircon clutch. The important aspects in cold forging of the Hub with complex geometry are the design of an initial shape of the workpiece, the possibility of the forming by one-stage operation and the determination of number of performs, etc. Based on the systematic procedure of process sequence design, in this paper, the forming operation of cold forged part of the Hub is designed by the rigid-plastic finite element method. The two design criterion of geometrical filling without defect and an even distribution of effective strain in final product are investigated in controlling the initial shape of the workpiece and preform configuration. It is noted that one preforming operation is required in order to obtain final product of the Hub.