• Annals of Clinical Neurophysiology
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• 제1권2호
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• pp.173-181
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• 1999

Eye movements serve vision by placing the image of an object on the fovea of each retina, and by preventing slippage of images on the retina. The brain employs two modes of ocular motor control, fast eye movements (saccades) and smooth eye movements. Saccades bring the fovea to a target, and smooth eye movements prevent retinal image slip. Smooth eye movements comprise smooth pursuit, the optokinetic reflex, the vestibulo-ocular reflex (VOR), vergence, and fixation. Saccades achieve rapid refixation of targets that fall on the extrafoveal retina by moving the eyes at peak velocities that can exceed $700^{\circ}/s$. Various brain lesions can affect saccadic latency, velocity, or accuracy. Smooth pursuit maintains fixation of a slowly moving target. The pursuit system responds to slippage of an image near the fovea in order to accelerate the eyes to a velocity that matches that of the target. When smooth eye movements velocity fails to match target velocity, catch-up saccades are used to compensate for limited smooth pursuit velocities. The VOR subserves vision by generating conjugate eye movements that are equal and opposite to head movements. If the VOR gain (the ratio of eye velocity to head velocity) is too high or too low, the target image is off the fovea, and head motion causes oscillopsia, an illusory to-and-fro movement of the environment.

• Journal of Korean Neurosurgical Society
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• 제47권3호
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• pp.221-223
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• 2010

C1 lateral mass and C2 pedicle (C1LM-C2P) fixation is a relatively new technique for atlantoaxial stabilization. Complications from C1LM-C2P fixation have been rarely reported. The authors report unilateral rod migration into the posterior fossa as a rare complication after this posterior C1-C2 stabilization technique. A 23-year-old man suffered severe head trauma and cervical spine injury after vehicle accident. He was unconscious for 2 months and regained consciousness. He underwent C1LM-C2P fixation for stabilization of type II odontoid process fracture described by Harms. The patient recovered without a major complication. Twenty months after operation, brain computed tomogram performed at psychology department for disability evaluation showed rod migration into the right cerebellar hemisphere. The patient had mild occipital headache and dizziness only regarding the misplaced rod. He refused further operation for rod removal. To our knowledge, this complication is the first report regarding rod migration after Harms method. We should be kept in mind the possibility of rod migration, and C1LM-C2P fixation should be performed with meticulous technique and long-term follow-up.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제37권1호
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• pp.62-66
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• 2011

Introduction: Endoscope-assisted open reduction and internal fixation (EAORIF) reduces the amount of facial scaring, but limitations, such as the possibility to convert to the open technique and the large learning curve, remain. Materials and Methods: The medical records of 19 patients diagnosed as lateral overridden subcondyle fractures and treated with endoscope-assisted open reduction and internal fixation at Yonsei University Health System from December 2006 to August 2010 were reviewed. Results: 11 patients underwent temporary discomfort or pain such as limitation of mouth opening, temporomandibular joint discomfort, lip paresthesia or facial weakness, but the symptoms disappeared within 3 months. There was no severe long-term complication except 2 patients with re-fractures of operated subcondyles. Conclusion: Subcondyle fracture with lateral overridden proximal segment is a better indication of endoscope-assisted open reduction and internal fixation than a condylar head/neck fracture, or medial overridden subcondyle fracture: allowing an anatomic reduction.

• 대한족부족관절학회지
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• 제7권2호
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• pp.151-156
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• 2003

Purpose: Proximal crescentic metatarsal osteotomy(PMO) is one of the most common procedures for correcting moderate to severe degree hallux valgus deformity. Although screw fixation is used for osteotomy site stability, loss of reduction can occur. The purpose of this study is to compare the sagittal plane stability of the conventional crescentic PMO fixed with a single screw with that of the crescentic PMO fixed with 1 screw and 2 supplemental K -wires. Material and Methods: Ten matched pairs of cadaveric foot specimens were used for the proximal crescentic metatarsal osteotomy. For one foot specimen of each pair, crescentic osteotomy was fixed with 4mm long threaded cannulated screw, while the matched pair was prepared by adding two axial 1.6mm K-wires to the conventionally fixed 4mm screw. The extensometer was used to measure the osteotomy gap as the metatarsal head was loaded continuously until failure using a servohydraulic MTS Mini Bionix test frame. The strength of fixation was normalized with the bone mineral density (BMD) of the paired specimen $(N{\times}cm^{2}/gm)$, Result: The average strength of the crescentic PMO with axial K-wire fixation ($458.8cm^{2}/gm$, S.D. 434.3) was significantly higher than the standard crescentic PMO ($367.5cm^{2}/gm$, S.D. 397,9) (p=0.05). Conclusion: Supplemental fixation with two axial K-wires can be added to the crescentic PMO to enhance the initial fixation stability to prevent the loss of reduction or dorsal malunion.

• Archives of Reconstructive Microsurgery
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• 제20권1호
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• pp.18-25
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• 2011

Purpose: In the process of replantation of the amputated fingertips, the primary concern was given to survival of the amputees, while the functional aspect of digits after the surgery has been easily neglected. Although an internal fixation with a K-wire is often a part of replantation of the amputated fingertips, little consideration had been given to the study of relationship between distal interphalangeal joint fixation and post operative range of motion. A comparative study in relation to post operative range of motion was done on two different groups, one group with K-wire insertion and the other group without a K-wire insertion at the distal interphalangeal joint. Materials and Methods: The study was done on the cases of a single digit amputation conducted at our institute (the age in the range of 10 to 60) in about four-year of time span from March of 2005 to March of 2009. The cases with a thumb replantation, osteomyelitis or articular surface injury have been excluded from this study. The cases of both head and shaft fracture, except the insertion site of tendon, of distal phalanx of internal fixation with a single K-wire were reviewed for this study. A group of 24 cases without distal interphalangeal joint fixation in comparison to a group of 22 cases with distal interphalangeal joint fixation was reviewed to assess the postoperative range of motion at distal interphalangeal joint on the 6th week after the surgery. And, on the 30th month after the surgery, a group of 10 cases without distal interphalangeal joint fixation in comparison to a group of 10 cases with joint fixation was reviewed. A K-wire was removed in about 5 weeks after the fracture was reunited under the radiographic image, immediately followed by a physical therapy. Result: The active range of motion for a group without interphalangeal joint fixation was measured $49.0^{\circ}$ on average, while $28.6^{\circ}$ was measured for a group with interphalengeal fixation on the 6th week after the surgery. On the 30th month after the surgery, the active range of motion was measured $52.0^{\circ}$ and $55.0^{\circ}$ on average for a group without and with interphalangeal fixation respectively. Conclusion: In the process of replantation of the amputated fingertips, short-term(on the 6th week) improvement of postoperative active motion of range can be expected in the cases without distal interphalangeal fixation in comparison to the cases of interphalangeal joint fixation with a K-wire. However, there seems to be no difference on motion of range in a long-term (on the 30th month) follow up period.

• Journal of Korean Neurosurgical Society
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• 제45권4호
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• pp.246-248
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• 2009

Atlantoaxial rotatory fixation (AARF) in adult is a rare disorder that occurs followed by a trauma. The patients were presented with painful torticollis and a typical 'cock robin' position of the head. The clinical diagnosis is generally difficult and often made in the late stage. In some cases, an irreducible or chronic fixation develops. We reported a case of AARF in adult patient which was treated by immobilization with conservative treatment. A 25-year-old female was presented with a posterior neck pain and limitation of motion of cervical spine after a traffic accident. She had no neurological deficit but suffered from severe defect on the scalp and multiple thoracic compression fractures. Plain radiographs demonstrated torticollis, lateral shift of odontoid process to one side and widening of one side of C1-C2 joint space. Immobilization with a Holter traction were performed and analgesics and muscle relaxants were given. Posterior neck pain and limitation of the cervical spine' motion were resolved. Plain cervical radiographs taken at one month after the injury showed that torticollis disappeared and the dens were in the midline position. The authors reported a case of type I post-traumatic AARF that was successfully treated by immobilization alone.

• 문화기술의 융합
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• 제6권3호
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• pp.443-448
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• 2020

본 연구에서는 영종대교를 구성하고 있는 교량형식(트러스교, 현수교)별 열차종류(AREX, AREX Express, KTX, KTX-Sancheon) 및 열차속도가 강직결 궤도구조의 동적거동에 미치는 영향을 분석하고자 현장측정을 수행하였다. 현장측정결과를 바탕으로 궤도충격계수 및 열차주행안정성(탈선계수, 윤중감소율, 레일두부횡변위)을 국내, 외 관련기준 및 법규와의 비교하여 영종대교 교량상 강직결 궤도구조의 동적거동에 영향을 미치는 열차하중 및 속도의 효과를 분석하였다. 연구결과, 영종대교 교량형식별 궤도의 동적거동의 차이는 뚜렷하지 않으나 열차하중의 크기에 보다 직접적인 영향을 받는 것으로 분석되었다. 따라서 향후 열차속도 증가에 따른 궤도충격계수의 증가와 이에 따른 궤도부담력의 증가수준을 감안한 영종대교 강직결 궤도구조의 보강방안 수립이 필요할 것으로 판단된다.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제30권4호
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• pp.359-369
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• 2008

Purpose: Fractures of the mandibular condyle accounts for 15% to 30% of all the mandibular fractures and lots of complications are reported. Among these complications, condylar resorption is the most important one to be taken into account. The purpose of this study is evaluating condylar resorption pattern in relation to extracorporeal fixation technique. Patients & methods: Thirty four patients with 42 mandibular condylar fractures were retrospectively examined with an average follow-up of 18.5 months (6-66 months). Male/female ratio is 27 males (7 bilateral cases) and 7 females (1 bilateral case). Applicated surgical techniques were extracorporeal fixation via submandibular approach and extracorporeal fixation via intraoral approach. We compared radiographic views of post-operative periods with that of most long term follow up in 34 operated sites respectively. Result: There were 2 generalized condylar resorption sites and 3 partial resorption sites with clinical implications. Others (29 joints) showed good healing or satisfactory adaptive state of temporomandibular joints clinically. Radiologically, signs of partial condylar resorption and/or osteoarthrosis were diagnosed in 11 patients. But, 8 out of the 11 patients didn't show significant clinical symptoms, which means successful adaptive remodeling of the surgically located condylar head. Conclusion: From the above results, intentional ramal osteotomy, temporary detachment of the fractured condyle and extracorporeal fixation technique seems to be effective and useful in those cases of condylar fractures in which reduction of the dislocated condyle is very difficult or virtually impossible.

• 대한족부족관절학회:학술대회논문집
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• 대한족부족관절학회 2009년도 춘계학술대회
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• pp.8-8
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• 2009

• Journal of Trauma and Injury
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• 제25권1호
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• pp.25-27
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• 2012

A 30-year-old, male truck driver had a traffic accident and visited a hospital due to left hip pain. The patient's femoral head was fractured, and he was treated conservatively. For 14 years afterwards, he walked without a limp, had no pain, and drove his truck. He was involved in another traffic accident and experienced a comminuted fracture of the left distal femur 14 years after the initial injury. Although he was symptom-free, while being treated by open reduction and internal fixation for the distal femur fracture, he was concerned about the status of his left femoral head. Pelvis radiographs and reconstructed CT images were done, and they showed a spur change around the femoral head which had a dense sclerotic band within and revealed a slight depression of subchondral bone of the medial portion of the femoral head. The diagnosis was a Pipkin type-II fracture of the femoral head.