• Journal of Korean Neurosurgical Society
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• v.40 no.3
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• pp.175-179
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• 2006

Objective : The surgical outcome of anterior lumbar interbody fusion[ALlF] with pedicle screw fixation for elderly isthmic spondylolisthesis was analyzed. Methods : Consecutive nineteen elderly patients [aged 65 years or more] with isthmic spondylolisthesis [Grade I or II] who underwent single level ALIF with pedicle screw fixation in 2002 were analyzed. Using clinical chart and mailed questionnaires, preoperative and postoperative Visual Analogue Scale[VAS] of back and leg pain and postopertive Macnab criteria were evaluated. Results : The mean age at the time of operation was 68.4 years [range 65 to 78 years]. Twelve patients underwent ALIF with percutaneous pedicle screw fixation. Seven patients underwent ALIF followed by posterior decompression and pedicle screw fixation. The postoperative complication rate was 10.5% [wound dehiscence in 1 patient and incisional hernia in 1 patient]. There was no postoperative major morbidity or mortality. At a mean follow-up duration of 30.7 months [range 25 to 35 months], 93.3% [14/15] of the patients showed excellent or good outcomes in terms of Macnab criteria. The mean VAS scores of back pain and leg pain significantly decreased after surgery. Conclusion : ALIF with pedicle screw fixation yielded favorable results for elderly isthmic spondylolisthesis in selected cases.

• Journal of Korean Neurosurgical Society
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• v.38 no.5
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• pp.399-402
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• 2005

Direct anterior approach for lesions located anterior to the thecal sac is definitely superior to lateral or posterior approach in many respects. However, various anatomical obstacles and technical difficulties often hinder direct anterior approach. Thanks to ripe experience of retroperitoneal approach to the lumbar spine for anterior lumbar interbody fusion and total disc replacement, the authors could perform lumbar corpectomy and reconstruction by using midline retroperitoneal approach recently. During this approach, we repaired anterior longitudinal ligament also to reduce the risk of graft extrusion and to prevent erosion of vascular wall due to direct contact between metallic hardware, which was used for reconstruction of vertebral body, and major vessels.

• Journal of Korean Neurosurgical Society
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• v.53 no.3
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• pp.174-179
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• 2013

Objective : Many studies have investigated paraspinal muscle changes after posterior lumbar surgery, including lumbar fusion. However, no study has been performed to investigate back muscle changes after pedicle based dynamic stabilization in patients with degenerative lumbar spinal diseases. In this study, the authors compared back muscle cross sectional area (MCSA) changes after non-fusion pedicle based dynamic stabilization. Methods : Thirty-two consecutive patients who underwent non-fusion pedicle based dynamic stabilization (PDS) at the L4-L5 level between February 2005 and January 2008 were included in this retrospective study. In addition, 11 patients who underwent traditional lumbar fusion (LF) during the same period were enrolled for comparative purposes. Preoperative and postoperative MCSAs of the paraspinal (multifidus+longissimus), psoas, and multifidus muscles were measured using computed tomographic axial sections taken at the L4 lower vertebral body level, which best visualize the paraspinal and psoas muscles. Measurements were made preoperatively and at more than 6 months after surgery. Results : Overall, back muscles showed decreases in MCSAs in the PDS and LF groups, and the multifidus was most affected in both groups, but more so in the LF group. The PDS group showed better back muscle preservation than the LF group for all measured muscles. The multifidus MCSA was significantly more preserved when the PDS-paraspinal-Wiltse approach was used. Conclusion : Pedicle based dynamic stabilization shows better preservation of paraspinal muscles than posterior lumbar fusion. Furthermore, the minimally invasive paraspinal Wiltse approach was found to preserve multifidus muscles better than the conventional posterior midline approach in PDS group.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2012.10a
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• pp.907-908
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• 2012

• Journal of Korean Neurosurgical Society
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• v.51 no.1
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• pp.20-23
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• 2012

Objective : To compare radiographic analysis on the sagittal lumbar curve when standing, sitting on a chair, and sitting on the floor. Methods : Thirty asymptomatic volunteers without a history of spinal pathology were recruited. The study population comprised 11 women and 19 men with a mean age of 29.8 years. An independent observer assessed whole lumbar lordosis (WL) and segmental lordosis (SL) between L1 and S1 using the Cobb's angle on lateral radiographs of the lumbar spine obtained from normal individuals when standing, sitting on a chair, and sitting on the floor. WL and SL at each segment were compared for each position. Results : WL when sitting on the floor was reduced by 72.9% than the average of that in the standing position. Of the total decrease in WL, 78% occurred between L4 to S1. There were significant decreases in SL at all lumbar spinal levels, except L1-2, when sitting on the floor as compared to when standing and sitting on a chair. Changes in WL between the positions when sitting on a chair and when sitting on the floor were mostly contributed by the loss of SL at the L4-5 and L5-S1 levels. Conclusion : When sitting on the floor, WL is relatively low; this is mostly because of decreasing lordosis at the L4-5 and L5-S1 levels. In the case of lower lumbar fusion, hyperflexion is expected at the adjacent segment when sitting on the floor. To avoid this, sitting with a lordotic lumbar curve is important. Surgeons should remember to create sufficient lordosis when performing lower lumbar fusion surgery in patients with an oriental life style.

• Journal of Yeungnam Medical Science
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• v.20 no.2
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• pp.160-168
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• 2003

Background: Confirm the stability of intervertebral disc sustaining each fused lumbar spine cases, comparing vertical compression, A-P shear force and rotational moment on intervertebral disc of instrumented lumbar spine with simple vertical compression load and follower load using finite element analysis. Materials and Methods: We analyze the stability of intervertebral disc L4-5 supporting fused lumbar spine segments. After performing finite element modelling about L1-L5 lumbar vertebral column and L1-L4 each fusion level pedicle screw system for fused lumbar spine fine element model. Intervertebral discs with complex structure and mechanical properties was modeled using spring element that compensate stiffness and tube-to-tube contact element was employed to give follower load. Performing geometrical non-linear analysis. Results: The differences of intervertebral disc L4-5 behavior under the follower compression load in comparision with vertical compression load are as follows. Conclusion: As a result of finite element interpretation of instrumented lumbar spine, the stability of L4-5 sustaining fused lumbar segment, the long level fused lumbar spine observed hing stability under follower load. This research method can be the basis tool of effects prediction for instrumentation, a invention of a more precious finite element interpretation model which consider the role of muscle around the spine is loaded.

• Journal of Korean Neurosurgical Society
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• v.29 no.8
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• pp.1055-1062
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• 2000

Objectives : Burst fracture of the lower lumbar spine(L3-L5) is rare and has some different features compare to that of thoracolumbar junction. Lower lumbar spine is flexible segments located deeply, and has physiologic lordosis. All of these contribute to making surgical approach difficult. Generally, lower lumbar burst fracture is managed either anteriorly or posteriorly with various fixation and fusion methods. But there is no general guideline or consensus regarding the proper approach for such lesion. We have tried to find out the influencing factors for selecting the surgical approach through the analysis of lower lumbar burst fractures treated for last 4 years(1994.3-1998.3). Method : This study includes 15 patients(male : 10, female : 5, age range 20-59 years with mean age of 36.7 years, L3 : 8 cases, L4 : 5 cases, L5 : 2 cases). Patients were classified into anterior(AO) and posterior operated(PO) groups. We investigated clinical findings, injured column, operation methods, and changes in follow-up radiologic study (kyphotic angle) to determine the considerable factors in selecting the surgical approaches. Results : There were 5 AO and 10 PO patients. Anterior operation were performed with AIF with Kaneda or Z-plate and posterior operation were done with pedicle screw fixation with PLIF with cages or posterolateral fusion. Canal compression was 46.6% in AO and 38.8% in PO. The degree of kyphotic angle correction were 10.7 degree(AO) and 8.5 degree(PO), respectively. There was no statistical difference between anterior and posterior operation group. All patients showed good surgical outcome without complications. Conclusion : Anterior operation provided good in kyphotic angle correction and firm anterior strut graft, but it difficulty arose in accessing the lesions below L4 vertebra. While posterior approach showed less correction of kyphotic angle, it required less time and provided better results for accompanied adjacent lesion and pathology such as epidural hematoma. The level of injury, canal compression, biomechanics, multiplicity, and pathology are considered to be important factors in selection of the surgical approach.

• Journal of Korean Neurosurgical Society
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• v.59 no.2
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• pp.91-97
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• 2016

Objective : To investigate the biomechanical effects of a newly proposed Interspinous Process Compressor (IPC) and compare with pedicle screw fixation at surgical and adjacent levels of lumbar spine. Methods : A three dimensional finite element model of intact lumbar spine was constructed and two spinal fusion models using pedicle screw fixation system and a new type of interspinous devices, IPC, were developed. The biomechanical effects such as range of motion (ROM) and facet contact force were analyzed at surgical level (L3/4) and adjacent levels (L2/3, L4/5). In addition, the stress in adjacent intervertebral discs (D2, D4) was investigated. Results : The entire results show biomechanical parameters such as ROM, facet contact force, and stress in adjacent intervertebral discs were similar between PLIF and IPC models in all motions based on the assumption that the implants were perfectly fused with the spine. Conclusion : The newly proposed fusion device, IPC, had similar fusion effect at surgical level, and biomechanical effects at adjacent levels were also similar with those of pedicle screw fixation system. However, for clinical applications, real fusion effect between spinous process and hooks, duration of fusion, and influence on spinous process need to be investigated through clinical study.

• Journal of Korean Neurosurgical Society
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• v.56 no.1
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• pp.66-70
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• 2014

Sympathetic dysfunction is one of the possible complications of anterior spine surgery; however, it has been underestimated as a cause of complications. We report two successful experiences of treating severe dysesthetic pain occurring after anterior spine surgery, by performing a sympathetic block. The first patient experienced a burning and stabbing pain in the contralateral upper extremity of approach side used in anterior cervical discectomy and fusion, and underwent a stellate ganglion block with a significant relief of his pain. The second patient complained of a cold sensation and severe unexpected pain in the lower extremity of the contralateral side after anterior lumbar interbody fusion and was treated with lumbar sympathetic block. We aimed to describe sympathetically maintained pain as one of the important causes of early postoperative pain and the treatment option chosen for these cases in detail.

• Journal of Korean Neurosurgical Society
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• v.47 no.5
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• pp.370-376
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• 2010

Objective : Although unilateral transforaminal lumbar interbody fusion (TLIF) is widely used because of its benefits, it does have some technical limitations. Removal of disk material and endplate cartilage is difficult, but essential, for proper fusion in unilateral surgery, leading to debate regarding the surgery's limitations in removing the disk material on the contralateral side. Therefore, authors have conducted a randomized, comparative cadaver study in order to evaluate the efficiency of the surgery when using conventional instruments in the preparation of the disk space and when using the recently developed high-pressure water jet system, SpineJet$^{TM}$ XL. Methods : Two spine surgeons performed diskectomies and disk preparations for TLIF in 20 lumbar disks. All cadaver/surgeon/level allocations for preparation using the SpineJet$^{TM}$ XL (HydroCision Inc., Boston, MA, USA) or conventional tools were randomized. All assessments were performed by an independent spine surgeon who was unaware of the randomizations. The authors measured the areas (cm2) and calculated the proportion (%) of the disk surfaces. The duration of the disk preparation and number of instrument insertions and withdrawals required to complete the disk preparation were recorded for all procedures. Results : The proportion of the area of removed disk tissue versus that of potentially removable disk tissue, the proportion of the area of removed endplate cartilage, and the area of removed disk tissue in the contralateral posterior portion showed 74.5 ${\pm}$ 17.2%, 18.5 ${\pm}$ 12.03%, and 67.55 ${\pm}$ 16.10%, respectively, when the SpineJet$^{TM}$ XL was used, and 52.6 ${\pm}$ 16.9%, 22.8 ${\pm}$ 17.84%, and 51.64 ${\pm}$ 19.63%, respectively, when conventional instrumentations were used. The results also showed that when the SpineJet$^{TM}$ XL was used, the proportion of the area of removed disk tissue versus that of potentially removable disk tissue and the area of removed disk tissue in the contralateral posterior portion were statistically significantly high (p < 0.001, p < 0.05, respectively). Also, compared to conventional instrumentations, the duration required to complete disk space preparation was shorter, and the frequency of instrument use and the numbers of insertions/withdrawals were lower when the SpineJet$^{TM}$ XL was used. Conclusion : The present study demonstrates that hydrosurgery using the SpineJet$^{TM}$ XL unit allows for the preparation of a greater portion of disk space and that it is less traumatic and allows for more precise endplate preparation without damage to the bony endplate. Furthermore, the SpineJet$^{TM}$ XL appears to provide tangible benefits in terms of disk space preparation for graft placement, particularly when using the unilateral TLIF approach.