• Proceedings of the KOSOMBE Conference
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• v.1995 no.05
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• pp.19-22
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• 1995

A biomechanical study was made to demonstrate the superior mechanical performance of the newly designed Miniplate staple to the conventional Coventry staple in high tibial osteotomy(HTO). Using twenty fresh porcine tibiae, the fixational strengh of the two different types of staple in HTO was compared. To minimize the error due to the specimen-to-specimen individuality, the bone mineral density of the tibiae was measured with a bone densitometry (Dual photon absorptionometer, Luner, USA) and those with $0.8\;{\sim}\;1.2\;gm/cm^2$ at the proximal tibia was used in the biomechanical test. Testing was performed on a material testing system (Autogram ET-5, Shimatzu, Japan) with aid of a commercial data processor (IBM 80386/ ASYST). Using two differant loading modes, 'pull-out' and 'push-out', the maximum resistant force required to release the staple from the substrate bone was recorded. In the pull-out test, ten non-osteotomized specimens were used and the staple was pullout by subjecting an axial tension on the head of the staple inserted. While in the pull-out test where ten tibiae osteotomized in the usual way of HTO were used, the staple was not directly loaded. In this testing, as a mimic condition of the natural knee, the distal part of the specimen tibia was pushed horizontally in order for the staple to be pulled out while the proximal tibia was fixed. The pull-out strength of Coventry staple and miniplate staple were found to be $27.88\;{\pm}\;5.12\;kgf$ and $182.47\;{\pm}\;32.75\;kgf$, respectively. The push-out strength of Coventry staple and miniplate staple were $18.40\;{\pm}\;4.47\;kgf$ and $119.95\;{\pm}\;19.06\;kgf$, respectively. The result revealed that miniplate staple had the pull-out/ push-out strength at least fivetimes higher than Coventry staple. Based on the measured data, it was believed that the newly designed miniplate staple could provide much better postoperative fixation in HTO. The postoerative application of long leg casting may not be needed after HTO surgery.

• Journal of Korean Foot and Ankle Society
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• v.16 no.4
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• pp.235-240
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• 2012

Purpose: The aim of this study was to evaluate the radiographic and clinical results of short scarf osteotomy that has minimized longitudinal cut for moderate hallux valgus. Materials and Methods: Total 12 patients (12 feet) were reviewed by medical records and radiographs. All patients were female and the mean age at the time of operation was 41.5 years. The mean followup time was 21.2 months. We modified original scarf osteotomy by shortening the longitudinal cut to 15~20 mm in length. Additionally, Akin osteotomy of the first proximal phalanx was done in 7 feet and Weil osteotomy of the second metatarsal was done in 4 feet. First-second intermetatarsal and hallux valgus angles were analyzed radiographically before and after the operation. And the clinical result was assessed by AOFAS (American Orthopaedic Foot and Ankle Society) hallux score. Results: First-second intermetatarsal and hallux valgus angles were reduced from the mean preoperative values of $14.6^{\circ}$ and $32.8^{\circ}$ to $6.5^{\circ}$ and $11.2^{\circ}$, respectively. The mean AOFAS hallux score was increased from 52.4 points preoperatively to 88.2 points at followup. Three complications were found: metatarsal fracture during the operation, painful scar around second metatarsal head after Weil osteotomy and postoperative neuralgia. There was no transfer metatarsalgia or recurrence of hallux valgus during followup. Conclusion: Short scarf osteotomy would be an effective surgical procedure for moderate hallux valgus with the benefits of minimized soft tissue dissection and stable fixation.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.45 no.5
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• pp.417-428
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• 2017

In this paper, we describe the architectural design, unit component hardware design and core software design(Helmet Pose Tracking Software and Terrain Elevation Data Correction Software) of IHDS(Intelligent Helmet Display System), and describe the results of unit test and integration test. According to the trend of the latest helmet display system, the specifications which includes 3D map display, FLIR(Forward Looking Infra-Red) display, hybrid helmet pose tracking, visor reflection type of binocular optical system, NVC(Night Vision Camera) display, lightweight composite helmet shell were applied to the design. Especially, we proposed unique design concepts such as the automatic correction of altitude error of 3D map data, high precision image registration, multi-color lighting optical system, transmissive image emitting surface using diffraction optical element, tracking camera minimizing latency time of helmet pose estimation and air pockets for helmet fixation on head. After completing the prototype of all system components, unit tests and system integration tests were performed to verify the functions and performance.

• Journal of Gastric Cancer
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• v.19 no.3
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• pp.290-300
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• 2019

Purpose: The optimal method for intracorporeal esophagojejunostomy remains unclear because a purse-string suture for fixing the anvil into the esophagus is difficult to perform with a laparoscopic approach. Therefore, this study aimed to evaluate our novel technique to fix the anvil into the esophagus. Materials and Methods: This retrospective study included 202 patients who were treated at our institution with an intracorporeal circular esophagojejunostomy in a laparoscopy-assisted total gastrectomy with a Roux-en-Y reconstruction (166 cases) or a laparoscopy-assisted proximal gastrectomy with jejunal interposition (36 cases). After incising 3/4 of the esophageal wall, a hand-sewn purse-string suture was placed on the esophagus. Next, the anvil head of a circular stapler was introduced into the esophagus. Finally, the circular esophagojejunostomy was performed laparoscopically. The clinical characteristics and surgical outcomes were evaluated and compared with those of other methods. Results: The average operation time was 200.3 minutes. The average hand-sewn purse-string suturing time was 6.4 minutes. The overall incidence of postoperative complications (Clavien-Dindo classification grade ${\geq}II$) was 26%. The number of patients with an anastomotic leakage and stenosis at the esophagojejunostomy site were 4 (2.0%) and 12 (6.0%), respectively. All patients with stenosis were successfully treated by endoscopic balloon dilatation. There was no mortality. Regarding the materials and devices for anvil fixation, only 1 absorbable thread was needed. Conclusions: Our procedure for hand-sewn purse-string suturing with the double ligation method is simple and safe.

• Journal of the Korean Orthopaedic Association
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• v.55 no.3
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• pp.193-199
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• 2020

A gamma nail has been used to treat intertrochanteric fractures since 1988. Although such cephalomedullary nails have mechanical advantages over extramedullary fixation devices, such as sliding hip screw, their beneficial effects on treating the Arbeitsgemeinschaft für Osteosynthesefragen/Orthopaedic Trauma Association (AO/OTA) 31-A1 and 31-A2 fractures are still controversial. During their 30-year history, many problems have been overcome, and new types of cephalomedullary nails have been introduced in clinical practice. New cephalomedullary nail systems facilitate nailing procedures and enhance the purchase capability of the femoral head by a lag screw. On the other hand, the failure rate still depends on the hands of the orthopedic surgeons. This review article focused on the basic principle of medial support and restoration of a medial buttress during the treatment of trochanteric fractures using a cephalomedullary nail.

• Archives of Craniofacial Surgery
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• v.24 no.4
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• pp.167-173
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• 2023

Background: Mandibular split fractures, in which the fracture occurs exclusively in the posterior wall, are uncommon. This study aimed to enhance clinicians' understanding of mandibular split fractures and offer insights for future research. Methods: This study included six patients who visited our hospital between January 2020 and June 2023 and were diagnosed with mandibular split fractures. We retrospectively collected data from patients' medical records on their age, sex, symptoms, mechanism, impact site, associated injuries, and treatment method, as well as the location, pattern, and number of fractures observed on computed tomography (CT) and panoramic images. The frequency of split fractures among all mandibular fractures was calculated. Results: The six patients included three men (50%) and three women (50%), ranging in age from 20 to 71 years (mean age, 49.8 years). The split fractures were located in the symphysis in one patient (16.7%), symphysis to parasymphysis in two patients (33.3%), parasymphysis in one patient (16.7%), and parasymphysis to the body in two patients (33.3%). Four patients (66.7%) had condylar head fractures, while two patients (33.3%) had single split fractures. The mechanism of trauma was a slip-down incident in four cases (66.7%), while two cases (33.3%) were caused by motorcycle traffic accidents. Four patients (67%) underwent intermaxillary fixation, while two patients (33%) improved with conservative treatment. Split fractures were diagnosed in all six patients on CT, whereas the fracture line was not clearly visible on panoramic images. Mandibular split fractures accounted for 5.6% of all mandibular fractures. Conclusion: This study provides insights into the clinical characteristics of rare mandibular split fractures and the diagnostic imaging findings. Furthermore, CT scans and three-dimensional image synthesis-instead of panoramic images-may be essential for accurately diagnosing mandibular fractures, including mandibular split fractures, in the future.

• Journal of Korean Neurosurgical Society
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• v.67 no.1
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• pp.6-13
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• 2024

The integrity of the high cervical spine, the transition zone from the brainstem to the spinal cord, is crucial for survival and daily life. The region protects the enclosed neurovascular structure and allows a substantial portion of the head motion. Injuries of the high cervical spine are frequent, and the fractures of the C2 vertebra account for approximately 17-25% of acute cervical fractures. We review the two major types of C2 vertebral fractures, odontoid fracture and Hangman's fracture. For both types of fractures, favorable outcomes could be obtained if the delicately selected conservative treatment is performed. In odontoid fractures, as the most common fracture on the C2 vertebrae, anterior screw fixation is considered first for type II fractures, and C1-2 fusion is suggested when nonunion is a concern or occurs. Hangman's fractures are the second most common fracture. Many stable extension type I and II fractures can be treated with external immobilization, whereas the predominant flexion type IIA and III fractures require surgical stabilization. No result proves that either anterior or posterior surgery is superior, and the surgeon should decide on the surgical method after careful consideration according to each clinical situation. This review will briefly describe the basic principles and current treatment concepts of C2 fractures.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.34 no.3
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• pp.388-397
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• 2008

The present study was performed to evaluate the function of the mandible according to the pattern of fracture and treatment methods of condylar fractures of the mandible and help operators in making a treatment plan. Sixty patients (average follow-up period was $7.8{\pm}9.4$ months) who were treated for condylar fracture from June, 2002 to May, 2006 at the Department of Oral and Maxillofacial surgery, Chonnam National University Hospital were reviewed. The common causes of the condylar fracture were traffic accident and fall-down (35.0%). In concomitant injuries, laceration was 46.7% and the fracture of the mandibular symphysis was highest incidence (60.0%). The common site of the fracture was the condylar head (47.8%), followed by subcondyle (36.2%) and condylar neck (15.9%). Under 15 years old patients, the closed reduction was performed in 87.5% out of the patients. All of the condylar fragments were fixed to the mandible with titanium miniplates in cases of open reduction. The mean period of intermaxillary fixation (IMF) was $14.2{\pm}6.5$ days in closed reduction and $10.0{\pm}4.2$ days in open reduction. The old patient with bilateral condylar head fractures, who were treated by closed reduction with IMF for 3 weeks, showed the limitation of mandibular movements. But, there was no significant different results between open reduction and closed reduction with the respect of the Helkimo's mandibular mobility index and clinical dysfunction index (DI). Complications, such as fibrous ankylosis and resorption of the mandibular condyle, were not observed in all patients. These results suggest that the good results can be obtained by closed reduction with proper IMF periods and functional exercise in most condylar fractures of the mandible except severely displaced extracapsular fractures.

• Journal of the Korean Arthroscopy Society
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• v.6 no.2
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• pp.156-160
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• 2002

Purpose : To evaluate the results and usefulness of meniscal repair using meniscal arrows with ACL reconstruction. Material and Methods : Among cases of the simultaneous meniscal arrow fixation and ACL recontruction performed between May, 1997 and September, 2000, 17 cases could be evaluated. The average follow-up were 18.5 months. Twelve cases were medial meniscus, 5 cases, lateral meniscus. All cases were longitudinal tear. Meniscal tear were seen at red-red zone in 13 cases, red-white zone in 5 cases. The results were analyzed by pain, joint line tenderness, locking, McMurray test, the Marshall knee scoring scale and complications. Results : Postoperatively two patients had mild joint line tenderness without pain on joint motion or weight bearing. No patient had locking or positive McMurray test. At last follow-up, 15 cases $(88\%)$ were 'excellent' or 'good' according to the Marshall knee score scale. There were two complications which are soft tissue irritation sign on active knee motion and a femoral chondral injury due to protruded T-shaped head of meniscus arrow. Conclusion : Meniscus arrow can be one of the options in repairing the associated meniscus tear, especially the posterior horn of medial meniscus, during ACL reconstruction. However, surgeons using meniscus arrow should be aware of its potential complications such as pain due to soft tissue irritation and chondral damage of the femoral condyle.

• Korean Journal of Cognitive Science
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• v.20 no.4
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• pp.507-533
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• 2009

This paper examines the time course and processing patterns of filler-gap dependencies in Korean relative clauses, using an eyetracking method. Participants listened to a short story while viewing four pictures of entities mentioned in the story. Each story is followed by an auditorily presented question involving a relative clause (subject relative or dative relative). Participants' eye movements in response to the question were recorded. Results showed that the proportion of looks to the picture corresponding to a filler noun significantly increased at the relative verb affixed with a relativizer, and was largest at the filler where the fixation duration on the filler picture significantly increased. These results suggest that online resolution of the filler-gap dependency only starts at the relative verb marked with a relativiser and is finally completed at the filler position. Accordingly, they partly support the filler-driven parsing strategy for Korean, as for head-initial languages. In addition, the different patterns of eye movements between subject relatives and dative relatives indicate the role of case markers in parsing Korean sentences.