• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.9 no.3
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• pp.45-54
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• 2009

This study was developed the metallic plate for bone fixation in the neurosurgery and general surgery and plates has a finn place in bone operating and treatment. The plates can be realized to bending strength and stiffness for strength estimation. Maximum point of bending curves has a bending point(P) with maximum load which to applied nearly 0.2% offset displacement. The device's sizing has a ${\Phi}13$ and ${\Phi}18$, and algorithm of strength estimation compared a plate(${\Phi}13$, ${\Phi}18$, ${\Phi}13-{\Phi}18$). The bending strength of the curved metallic plate has to evaluate maximum of a 311N, 387N, 410N, 474N. When a displacement preserve with a load, tensile stress through to press a plate is 274N, 324N, 382N, 394N. The algorithm of strength estimation can be used to support estimation of bending strength and stiffness. Their tool bring to settlement in the new basic algorithm for evidence with varied adjustment.

• Archives of Craniofacial Surgery
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• v.25 no.4
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• pp.171-178
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• 2024

Background: We developed a novel interlocking three-dimensional (3D) miniplate design with an adjustable configuration. As this device is new, surgeons must become familiar with its application. This study evaluated the usability and learning curves associated with the novel interlocking 3D miniplate for mandibular fracture fixation. Methods: The study participants, nine plastic surgeons, were asked to apply an interlocking 3D miniplate and a standard miniplate to polyurethane mandible models. The participants had completed the Basic Craniomaxillofacial Osteosynthesis course during residency and had operated on craniomaxillofacial fractures within the past 5 years. They were instructed to place the interlocking 3D miniplate three times and the standard miniplate once. We assessed the time required for implant placement, the comfort level of the surgeons, and the biomechanical stability of the plates. Biomechanical testing was conducted by subjecting the mandible to forces ranging from 10 to 90 N and the displacement was measured. Results: The results indicate increasing comfort with each attempt at placing the interlocking 3D miniplate, with a significant difference between the first and third attempts. Additionally, a reduction in application time was noted with repeated attempts, suggesting improved efficiency. Biomechanical tests showed comparable stability between the tested plates. Conclusion: Multiple attempts at applying the interlocking 3D miniplate resulted in increased comfort and reduced application time. These findings indicate that, despite its novelty, the interlocking 3D miniplate is relatively straightforward to apply and has a short learning curve. However, surgeons must have specific qualifications to ensure proper training and minimize errors during placement.

• Journal of Korean Neurosurgical Society
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• v.63 no.2
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• pp.237-247
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• 2020

Objective : Fixation of the C1-2 segment is challenging because of the complex anatomy in the region and the need for a high degree of accuracy to avoid complications. Preoperative 3D-computed tomography (CT) scans can help reduce the risk of complications in the vertebral artery, spinal cord, and nerve roots. However, the patient may be susceptible to injury if the patient's anatomy does not match the preoperative CT scans. The intraoperative 3D image-based navigation systems have reduced complications in instrument-assisted techniques due to greater accuracy. This study aimed to compare the radiologic outcomes of C1-2 fusion surgery between intraoperative CT image-guided operation and fluoroscopy-guided operation. Methods : We retrospectively reviewed the radiologic images of 34 patients who underwent C1-2 fusion spine surgery from January 2009 to November 2018 at our hospital. We assessed 17 cases each of degenerative cervical disease and trauma in a study population of 18 males and 16 females. The mean age was 54.8 years. A total of 139 screws were used and the surgical procedures included 68 screws in the C1 lateral mass, 58 screws in C2 pedicle, nine screws in C2 lamina and C2 pars screws, four lateral mass screws in sub-axial level. Of the 34 patients, 19 patients underwent screw insertion using intraoperative mobile CT. Other patients underwent atlantoaxial fusion with a standard fluoroscopy-guided device. Results : A total of 139 screws were correctly positioned. We analyzed the positions of 135 screws except for the four screws that performed the lateral mass screws in C3 vertebra. Minor screw penetration was observed in seven cases (5.2%), and major pedicle screw penetration was observed in three cases (2.2%). In one case, the malposition of a C2 pedicle screw was confirmed, which was subsequently corrected. There were no complications regarding vertebral artery injury or onset of new neurologic deficits. The screw malposition rate was lower (5.3%) in patients who underwent intraoperative CT-based navigation than that for fluoroscopy-guided cases (10.2%). And we confirmed that the operation time can be significantly reduced by surgery using intraoperative O-arm device. Conclusion : Spinal navigation using intraoperative cone-beam CT scans is reliable for posterior fixation in unstable C1-2 pathologies and can be reduced the operative time.

• Journal of the Korean Arthroscopy Society
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• v.10 no.2
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• pp.141-147
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• 2006

Purpose: To compare the clinical and radiological results of anterior cruciate ligament(ACL) reconstruction using hamstring autograft and tibialis tendon allograft. Materials and Methods: Twenty four ACL reconstructions using hamstring autograft and 30 using tibialis anterior tendon altograft were followed up at least 1 year. We performed femoral tunnel fixation with Ligament Anchor(LA) screw and tibial tunnel fixation with biodegradable interference screw. Evaluations included Lysholm knee(LK) score, Tegner activity scale, Lachman test, Pivot-Shift test, Quardriceps atrophy, incision site numbness, anterior knee pain and instrumented anterior laxity with $Telos^{(R)}$ device. Results: Preoperativ mean LK score was $60.3(18{\sim}82)$ in autograft group and 61.2(25-80) in allograft group. Mean LK score improved to $91.6(68{\sim}100)\;and\;92.6(77{\sim}100)$ respectively. Activity level, using Tegner activity scale, slightly decreased compared with that of Preinjury state in both groups. Lachman test, pivot-shift test, Quadriceps atrophy, anterior knee pain, incision site numbness, and anterior drawer test using $Telos^{(R)}$ device showed no significant difference between two groups (p>0.05). Conclusion: In performing the ACL reconstruction, there was no statistically significant difference between hamstring autograft group and tibilis anterior allograft group in clinical or in radiological results.

• Clinics in Shoulder and Elbow
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• v.15 no.1
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• pp.32-36
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• 2012

Purpose: The purpose of this study was to evaluate the radiologic and clinical outcomes after intercalary tricortical iliac bone graft with plate fixation for the nonunion of midshaft clavicular fractures. Material and Methods: Between September 2007 and May 2011, 10 patients who were treated by the intercalary tricortical iliac bone graft, with plate fixation for clavicle nonunion, were studied. The mean follow-up period was 30.7 (12~57) months. After the sclerotic bone was excised to the bleeding cortical bone, we interposed the tricortical iliac bone to provide structural support and restore clavicle length, and then fixed the plate and screws. The radiologic outcomes on the serial plain radiographs and clinical outcomes, according to UCLA, ASES and Quick DASH scores, were analyzed. Results: Bony union was obtained in all cases (100%) and the average union time was 18.4 (14~24) weeks. The average respective UCLA and ASES scores improved from 16.7 and 52.1 preoperatively to 27.4 and 83.6 postoperatively (p<0.05). The average Quick DASH score was 40.5, at the final follow-up. Complications were 2 shoulder stiffness, and one case had removal of device and arthroscopic surgery at 11 months, postoperatively. There were no implant failure or infection. Conclusion: Intercalary tricortical iliac bone graft, with plate fixation for the nonunion of midshaft clavicular fractures, is a good option that can provide structural support and restore clavicle length, as well as high union rate.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.20 no.3
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• pp.250-255
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• 1998

The purpose of this study was to evaluate the histologic change of the inferior alveolar nerve according to distraction amount following mandibular lengthening. Seven rabbits weighing about 2 kg were used. Corticotomy was performed on the mandibular body anterior to the right first premolar region and unilateral external fixation device was placed. Every effort was made to preserve the inferior alveolar nerve during the corticotomy. The rabbits were then allowed to heal for 7 days without distraction of the device. The mandible was lengthened 0.36 mm/day, 0.76 mm/day, or 1.0 mm/day. Corticotomy and lengthening of mandible were not performed in control group. After the completion of the lengthening process, a 14-day-consolidation period was allowed. After consolidation, rabbits were sacrificed, and histologic examination of the inferior alveolar nerve was performed. The results obtained were as follows : 1. In the control group, normal trifascicular pattern of inferior alveolar nerve was observed. Epineurium, perineurium, endoneurium, and axon with myelin sheath were observed in normal appearance. 2. In 0.36 mm/day distraction group, the trifascicular pattern was normally shown, and there was no destruction in epineurium, perineurium, and endoneurium. The mild changes including myelin attenuation, axoplasmic swelling and darkening were observed. 3. In 0.72 mm/day distraction group, it was possible to differentiate the epineurium from the perineurium. Two normal fascicles and one injuried fascicle were observed with a partially destructed perineurium. Most of the axons had axoplasmic swelling and darkening. 4. In 1 mm/day distraction group, it was difficult to differentiate the nerve structures such as fascicles, epineurium, perineurium, and endoneurium. The axons were severely destroyed, except few which showed decreases in size and changes in shape. Some collagen matrices were observed around the axons. These results suggest that the higher the distraction amount, the more severe the injury to the inferior alveolar nerve, fascicles, axons. Although distraction osteogenesis may be useful, the amount of distraction should be carefully selected.

• Journal of Korean Neurosurgical Society
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• v.46 no.5
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• pp.425-430
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• 2009

Objective : The present study analyzed the risk factors, prevalence and clinical results following revision surgery for adjacent segment degeneration (ASD) in patients who had undergone lumbar fusion. Methods : Over an 8-year period, we performed posterior lumbar fusion in 81 patients. Patients were followed a minimum of 2 years (mean 5.5 years). During that time, 9 patients required revision surgery due to ASD development. Four patients underwent autogenous posterolateral arthrodesis and extended transpedicle screw fixation, 4 patients underwent decompressive laminectomy and interspinous device implantation, and 1 patient underwent simple decompression. Results : Of the 9 of patients with clinical ASD, 33.3% (3 of 9) of patients did not have radiographic ASD on plain radiographs. Following revision surgery, the clinical results were excellent or good in 8 patients (88.9%). Age > 50 years at primary surgery was a significant risk factor for ASD development, while number of fusion levels, initial diagnosis and type of fusion were not. Conclusion : The incidence of ASD development after lumbar surgery was 11.1% (9 of 81) in this study. Age greater than 50 was the statistically significant risk factor for ASD development. Similar successful clinical outcomes were observed after extended fusion with wide decompression or after interspinous device implantation. Given the latter procedure is less invasive, the findings suggest it may be considered a treatment alternative in selected cases but it needs further study.

• Journal of Biomedical Engineering Research
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• v.29 no.2
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• pp.132-138
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• 2008

We investigated the biomechanical properties of a newly designed self-expansion type anterior cruciate ligament (ACL) anchor. The ACL anchor consists of the ring section giving the elastic force, the wedge for maintaining in contact with the femur tunnel wall and the link suspending hamstring graft or artificial ligament. The main design parameters that determine the performance of this device were the expansion angle (${\theta}$) and the thickness ($t_R$). The Ti6Al4V anchors were heated after inserting in a jig for 1 hour at $800^{\circ}C$ in a protective argon gas atmosphere and allowed to cool to room temperature in the furnace. In order to investigate the influence of the expansion angle and the thickness of the ring on the biomechanical properties of the anchor, the maximum pull-out load, stiffness and slippage of the ACL anchor were measured using the pull-out tester, and statistical analyses were also executed. The present results showed that the design parameters gave a significant effect on the performance of the self- expansion type of anchor. The pull-out load of the ACL anchors significantly increased as the thickness of the ring section was increased, having a similar trend for both expansion angles. The ACL anchor showed about 2.5 times higher values of the pull-out load than that of the minimum load (500N)required for the "accelerated rehabilitation". The optimum ${\theta}$ and $t_R$ values of this ACL anchor were suggested to have sufficient resistance against the pull-out force, high stiffness and relatively low slippage after ACL reconstruction.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.29 no.2
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• pp.79-85
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• 2003

The purpose of this study is to observe histopathologic changes in the bilateral craniomandibular joints after allowing 6 weeks of consolidation by varying the amount of distraction in rabbit mandible. Eight rabbits weighing about 2 to 3 kg were used. After corticotomy was performed on the left mandibular body between the first premolar and the second premolar region, a unilateral fixation device was placed. Then, a 7-day period was allowed without distraction of the device. The mandible was lengthened 0.5 mm/day. Corticotomy and lengthening of mandible were not performed in control group. After the completion of the lengthening process, a 6-week-consolidation period was allowed. Then, the rabbits were sacrificed, and histologic examination of the craniomandibular joints was performed. Proliferative changes were observed in the craniomandibular joints in all groups. With the increasing amount of distraction, hypertrophy of the cartilage layer became more severe, bone formed was dense and enchondral ossification was clearly shown in subchondral bone. Hypertrophy of the cartilage layer was also seen in the non-distracted side as the distracted side in the experimental group. These results indicate that when physical force is applied constantly to joints, the proliferation of articular cartilage and bone formation are present. When more than 6 weeks of consolidation period is allowed at the time of performing distraction for more than 5 mm, articular changes, especially, in the contralateral side should also be noted.

• Journal of Dental Anesthesia and Pain Medicine
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• v.15 no.4
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• pp.235-239
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• 2015

The Combitube is an emergency airway-maintaining device, which can supply oxygen to dyspneic patients in emergency situations following two-jaw surgery. These patients experience difficulty in opening the mouth or have a partially obstructed airway caused by edema or hematoma in the oral cavity. As such, they cannot maintain the normal airway. The use of a Combitube may be favorable compared to the laryngeal mask airway because it is a thin and relatively resilient tube. A healthy 24-year-old man was dyspneic after extubation. Oxygen saturation fell below 90% despite untying the bimaxillary fixation and ambubagging. The opening of the mouth was narrow; thus, emergency airway maintenance was gained by insertion of a Combitube. The following day, a facial computer tomography revealed that the airway space narrowing was severe compared to its pre-operational state. After the swelling subsided, the patient was successfully extubated without complications.