• The Journal of the Korean bone and joint tumor society
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• v.11 no.1
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• pp.17-24
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• 2005

Local treatment for tumors has developed from extended radical surgery to function preserving surgery on the basis of modern biology. With the development of minimally invasive technique, it changed to be minimal-invasive surgery. And nowadays technical revolution made non-invasive surgery possible with appearance of several kinds of non-surgical knives such as gamma knife, cyber knife, and HIFU (high intensity focused ultrasound) knife. In this article, history, HIFU machine and treatment procedure, histological change and its mechanism, clinical applications, advantage, disadvantage, and future prospect of extracorporeal high intensity focused ultrasound therapy using HIFU knife will be reviewed.

• Journal of Korean Foot and Ankle Society
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• v.24 no.1
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• pp.19-24
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• 2020

Purpose: Anterolateral minimally invasive plate osteosynthesis (MIPO) was performed to treat patients with distal tibial fractures associated with open fractures or extensive soft tissue injuries, which is limited medial MIPO. The treatment results of the anterolateral MIPO technique were evaluated and analyzed. Materials and Methods: Seventeen patients with distal tibial fractures associated with an open fracture or large bullae formation on the distal tibia medial side were treated with anterolateral MIPO using anterolateral locking plates. Within 24 hours of visiting the emergency room, external fixation was applied, and the medial side wound was managed. After damage control, the anterolateral locking plate was applied using an anterolateral MIPO technique. The union time, nonunion, or malunion were evaluated with regular postoperative radiographs. The ankle range of motion, operative time, blood loss, Iowa score, and wound complications were investigated. Results: Radiological evidence of bony union was obtained in all cases. The mean time to union was 16.7 weeks (12~25 weeks). The mean operation time was 44.0 minutes. Regarding the ankle range of motion, the mean dorsiflexion was 15°, and the mean plantarflexion was 35°. Satisfactory results were obtained in 15 out of 17 cases; five results were classified as excellent, four were good, and six were fair. The mean blood loss was 125.2 mL. Two complications were recorded. Conclusion: In distal tibial fractures with severe medial soft tissue damage caused by high-energy trauma, the staged anterolateral MIPO technique using anterolateral locking plates is a useful alternative treatment to achieving optimal wound care, rapid union with biological fixation, and intra-articular reduction.

• Journal of Korean Neurosurgical Society
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• v.60 no.4
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• pp.433-440
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• 2017

Objective : Although minimally invasive posterior cervical foraminotomy (MI-PCF) is an established approach for motion preservation, the outcomes are variable among patients. The objective of this study was to identify significant factors that influence motion preservation after MI-PCF. Methods : Forty-eight patients who had undergone MI-PCF between 2004 and 2012 on a total of 70 levels were studied. Cervical parameters measured using plain radiography included C2-7 plumb line, C2-7 Cobb angle, T1 slope, thoracic outlet angle, neck tilt, and disc height before and 24 months after surgery. The ratios of the remaining facet joints after MI-PCF were calculated postoperatively using computed tomography. Changes in the distance between interspinous processes (DISP) and the segmental angle (SA) before and after surgery were also measured. We determined successful motion preservation with changes in DISP of ${\leq}3mm$ and in SA of ${\leq}2^{\circ}$. Results : The differences in preoperative and postoperative DISP and SA after MI-PCF were $0.03{\pm}3.95mm$ and $0.34{\pm}4.46^{\circ}$, respectively, fulfilling the criteria for successful motion preservation. However, the appropriate level of motion preservation is achieved in cases in which changes in preoperative and postoperative DISP and SA motions are 55.7 and 57.1%, respectively. Based on preoperative and postoperative DISP, patients were divided into three groups, and the characteristics of each group were compared. Among these, the only statistically significant factor in motion preservation was preoperative disc height (Pearson's correlation coefficient=0.658, p<0.001). The optimal disc height for motion preservation in regard to DISP ranges from 4.18 to 7.08 mm. Conclusion : MI-PCF is a widely accepted approach for motion preservation, although desirable radiographic outcomes were only achieved in approximately half of the patients who had undergone the procedure. Since disc height appears to be a significant factor in motion preservation, surgeons should consider disc height before performing MI-PCF.

• Journal of Korean Neurosurgical Society
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• v.61 no.6
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• pp.707-715
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• 2018

Objective : To investigate the potential risk of approach-related complications at different access angles in minimally invasive lateral lumbar interbody fusion. Methods : Eighty-six axial magnetic resonance images were obtained to analyze the risk of approach-related complications. The access corridor were simulated at different access angles and the potential risk of neurovascular structure injury was evaluated when the access corridor touching or overlapping the corresponding structures at each angle. Furthermore, the safe corridor length was measured when the corridor width was 18 and 22 mm. Results : When access angle was $0^{\circ}$, the potential risk of ipsilateral nerve roots injury was 54.7% at L4-L5. When access angle was $45^{\circ}$, the potential risk of abdominal aorta, contralateral nerve roots or central canal injury at L4-L5 was 79.1%, 74.4%, and 30.2%, respectively. The length of the 18 mm-wide access corridor was largest at $0^{\circ}$ and it could reach 44.5 mm at L3-L4 and 46.4 mm at L4-L5. While the length of the 22 mm-wide access corridor was 42.3 mm at L3-L4 and 44.1 mm at L4-L5 at $0^{\circ}$. Conclusion : Changes in the access angle would not only affect the ipsilateral neurovascular structures, but also might adversely influence the contralateral neural elements. It should be also noted to surgeons that alteration of the access angle changed the corridor length.

• Journal of Yeungnam Medical Science
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• v.41 no.3
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• pp.213-219
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• 2024

Background: Aortic valve replacement (AVR) has recently been performed at many centers using a minimally invasive approach to reduce postoperative mortality, morbidity, and pain. Most previous reports on minimally invasive AVR (MiAVR) have mainly focused on aortic stenosis, and those exclusively dealing with aortic regurgitation (AR) are few. The purpose of this study was to investigate early surgical results and review our experience with patients with chronic severe AR who underwent AVR via right anterior mini-thoracotomy (RAT). Methods: Data were retrospectively collected in this single-center study. Eight patients who underwent RAT AVR between January 2020 and January 2024 were enrolled. Short-term outcomes, including the length of hospital stay, in-hospital mortality, postoperative complications, and echocardiographic data, were analyzed. Results: No in-hospital mortalities were observed. Postoperative atrial fibrillation occurred temporarily in three patients (37.5%). However, none required permanent pacemaker implantation or renal replacement therapy. The median values of ventilator time, length of intensive care unit stay, and hospital stay were 17 hours, 34.5 hours, and 9 days, respectively. Preoperative and postoperative measurements of left ventricular ejection fraction were similar. However, the left ventricular end systolic and diastolic diameters significantly decreased postoperatively from 42 mm to 35.5 mm (p=0.018) and 63 mm to 51 mm (p=0.012), respectively. Conclusion: MiAVR via RAT is a safe and reproducible procedure with acceptable morbidity and complication rates in patients with chronic severe AR. Despite some limitations such as a narrow surgical field and demanding learning curve, MiAVR is a competent method for AR.

• Journal of Yeungnam Medical Science
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• v.22 no.1
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• pp.13-26
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• 2005

Atrial fibrillation (AF) is the most common cardiac rhythm disturbance, which carries significant cardiovascular morbidity and mortality. The medical treatment for AF is cumbersome and unsatisfactory, which has highlighted the need to develop alternative treatments for AF. The recent discovery that AF is often initiated by atrial ectopic beats has resulted in treatments designed to target the ectopic sources, particularly those within the pulmonary veins. Building on the pioneering work of Cox et al., a recent reported series demonstrated the feasibility of treating patients undergoing cardiac surgery for other structural heart diseases with limited, left-atrial ablation lesion sets using alternative energy sources. As less complex modifications of the Maze procedure have been developed, a number of energy sources have been introduced to create of electrically isolating lesions within the atria. These sources have been used both endocardially in arrest heart procedures as well as epicardially in a beating heart setting. This review summarizes the recent advances in surgery for AF that will aid in the development of an effective, minimally invasive surgical procedure to cure patients with AF.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.22 no.3
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• pp.284-290
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• 2012

In this research, a new type of haptic master device using electrorheological(ER) fluid for minimally invasive surgery(MIS) is devised and control performance of the proposed haptic master is evaluated. The proposed haptic master consists of ER bi-directional clutch/brake for 2 DOF rotational motion(X, Y) using gimbal structure and ER brake on the gripper for 1 DOF rotational motion (Z). Using Bingham characteristic of ER fluid and geometrical constraints, principal design variables of the haptic master are determined. Then, the generation of torque of the proposed master is experimentally evaluated as a function of applied field of voltage. A sliding mode controller which is robust to uncertainties is then designed and empirically realized. It has been demonstrated via experiment that the proposed haptic master associated with the controller can be effectively applied to MIS in real field conditions.

• Smart Structures and Systems
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• v.11 no.3
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• pp.283-297
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• 2013

An innovative cage for spinal fusion surgery is presented within this work. The cage utilizes shape memory alloy for its hinge actuation. Because of the use of SMA, a smaller incision is needed which makes the cage deployment minimally invasive. In the development of the cage, a model for predicting the torsional behavior of SMAs was developed and verified experimentally. The prototype design of the cage was developed and manufactured. The prototype was subjected to static tests per ASTM specifications. The cage survived all of the tests, alluding to its safety within the body.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2005.11a
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• pp.213-216
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• 2005

This paper presents force feedback control performance of a 3DOF haptic device that can be used for minimally invasive surgery (MIS). As a first step, a 3DOF electrorheological (ER) joint is designed using a spherical mechanism. And it is optimized based on the mathematical torque modeling. Subsequently, the master haptic device is manufactured by the spherical joint. In order to achieve desired force trajectories, model based compensation strategy is adopted for the ER master. Therefore, Preisach model fur the PMA-based ER fluid is identified using experimental first order descending (FOD) curves. A compensation strategy is then formulated through the model inversion to achieve desired force at the ER master. Tracking control performances for sinusoidal force trajectory are presented, and their tracking errors are evaluated.

• Archives of Craniofacial Surgery
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• v.23 no.5
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• pp.220-227
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• 2022

Background: Frontal sinus fractures are relatively rare. Their surgical management significantly differs depending on whether the posterior wall is invaded and the clinical features vary. A bicoronal incision or endoscopic approach can be used. However, the minimally invasive approach has been attracting attention, leading us to introduce a simple and effective surgical method using multiple-threaded Kirschner wires. Methods: All patients had isolated anterior wall fractures without nasofrontal duct impairment. The depth from the skin to the posterior wall was measured using computed tomography to prevent injury. The edge of the bone segment on the skin was marked, a threaded Kirschner wire was inserted into the center of the bone segment, and multiple Kirschner wires were gently reduced simultaneously. Results: Surgery was performed on 11 patients. Among them, seven patients required additional support for appropriate fracture reduction. Therefore, a periosteal elevator was used as an adjunct through a small sub-brow incision because the reduction was incomplete with the Kirschner wire alone. The reduction results were confirmed using facial bone computed tomography 1 to 3 days postoperatively. The follow-up period was 3 to 12 months. Conclusion: The patients had no complications and were satisfied with the surgical results. Here we demonstrated an easy and successful procedure to reduce a pure anterior wall frontal sinus fracture via non-invasive threaded Kirschner wire reduction.