• Journal of Korean Neurosurgical Society
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• v.59 no.2
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• pp.143-148
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• 2016

Objective : We evaluated postoperative outcomes in patients who have lumbar foraminal or extraforaminal disc herniation (FELDH) and suggested the risk factors for poor outcomes. Methods : A total of 234 patients were selected for this study. Pre- and post-operative Visual Analogue Scale (VAS) and Korean version Oswestry Disability Index (KODI) were evaluated and the changes of both score were calculated. Outcome was defined as excellent, good, fair, and poor based on Mcnab classification. The percentage of superior facetectomy was calculated by using the Maro-view 5.4 Picture Archiving Communication System (PACS). Results : Paramedian lumbar discectomy was performed in 180 patients and combined lumbar discectomy was performed in 54 patients. Paramedian lumbar discectomy group showed better outcome compared with combined discectomy group. p value of VAS change was 0.009 and KODI was 0.013. The average percentage of superior facetectomy was 33% (range, 0-79%) and it showed negative correlation with VAS and KODI changes (Pearson coefficient : -0.446 and -0.498, respectively). Excellent or good outcome cases (Group I) were 136 (58.1%) and fair or poor outcome cases (Group II) were 98 (41.9%). The percentage of superior facetectomy was 26.5% at Group I and 42.5% at Group II. There was significant difference in superior facetectomy percentage between Group I and II (p=0.000). Conclusion : This study demonstrated that paramedian lumbar discectomy with preservation of facet joints is an effective and good procedure for FELDH. At least 60% of facet should be preserved for excellent or good outcomes.

• Journal of Korean Neurosurgical Society
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• v.47 no.5
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• pp.358-364
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• 2010

Objective : Morphometric data on dorsal cervical anatomy were examined in an effort to protect the nerve root near the lateral mass during posterior foraminotomy. Methods : Using 25 adult formalin-fixed cadaveric cervical spines, measurements were taken at the lateral mass from C3 to C7 via a total laminectomy and a medial one-half facetectomy. The morphometric relationship between the nerve roots and structures of the lateral mass was investigated. Results from both genders were compared. Results : Following the total laminectomy, from C3 to C7, the mean of the vertical distance from the medial point of the facet (MPF) of the lateral mass to the axilla of the root origin was 3.2-4.7 mm. The whole length of the exposed root had a mean of 4.2-5.8 mm. Following a medial onehalf facetectomy, from C3 to C7, the mean of the vertical distance to the axilla of the root origin was 2.1-3.4 mm, based on the MPF. Mean vertical distances from the MPF to the medial point of the root that crossed the inferior margin of the intervertebral disc were 1.2-2.7 mm. The mean distance of the exposed root was 8.2-9.0 mm, and the mean angle between the dura and the nerve root was significantly different between males and females, at $53.4-68.4^{\circ}$. Conclusion : These data will aid in reducing root injuries during posterior cervical foraminotomy.

• Journal of Korean Neurosurgical Society
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• v.64 no.4
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• pp.552-561
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• 2021

Objective : To compare the anterior cervical discectomy and fusion (ACDF) and posterior cervical fusion (PCF) with wide facetectomy in the treatment of parallel-shaped bony foraminal stenosis (FS). Methods : Thirty-six patients underwent surgery due to one-or-two levels of parallel-shaped cervical FS. ACDF was performed in 16 patients, and PCF using CPS was performed in 20 patients. All patients were followed up at 1, 3, 6, and 12 months postoperatively. Standardized outcome measures such as Numeric rating scale (NRS) score for arm/neck pain and Neck disability index (NDI) were evaluated. Cervical radiographs were used to compare the C2-7 Cobb's angle, segmental angle, and fusion rates. Results : There was an improvement in NRS scores after both approaches for radicular arm pain (mean change -6.78 vs. -8.14, p=0.012), neck pain (mean change -1.67 vs. -4.36, p=0.038), and NDI score (-19.69 vs. -18.15, p=0.794). The segmental angle improvement was greater in the ACDF group than in the posterior group (9.4°±2.7° vs. 3.3°±5.1°, p=0.004). However, there was no significant difference in C2-7 Cobb angle between groups (16.2°±7.9° vs. 14.8°±8.5°, p=0.142). As a complication, dysphagia was observed in one case of the ACDF group. Conclusion : In the treatment of parallel-shaped bony FS up to two surgical levels, segmental angle improvement was more favorable in patients who underwent ACDF. However, PCF with wide facetectomy using CPS should be considered as an alternative treatment option in cases where the anterior approach is burdensome.

• Journal of Korean Neurosurgical Society
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• v.48 no.6
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• pp.496-500
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• 2010

Objective : Surgical treatment of lumbosacral foraminal stenosis requires an understanding of the anatomy of the lumbosacral area in individual patients. Unilateral facetectomy has been used to completely decompress entrapment of the L5 nerve root, followed in some patients by posterior lumbar interbody fusion (PLIF) with stand-alone cages Methods : We assessed 34 patients with lumbosacral foraminal stenosis who were treated with unilateral facetectomy and PLIF using stand-alone cages in our center from January 2004 to September 2007. All the patients underwent follow-up X-rays, including a dynamic view, at 3, 6, 12, 24 months, and computed tomography (CT) at 24 months postoperatively. Clinical outcomes were analyzed with the mean numeric rating scale (NRS), Oswestry Disability Index (ODI) and Odom's criteria. Radiological outcomes were assessed with change of disc height, defined as the average of anterior, middle, and posterior height in plain X-rays. In addition, lumbosacral fusion was also assessed with dynamic X-ray and CT. Results : Mean NRS score, which was 9.29 prior to surgery, was 1.5 at 18 months after surgery. The decrease in NRS was statistically significant. Excellent and good groups with regard to Odom's criteria were 31 cases (91%) and three cases (9%) were fair. Pre-operative mean ODI of 28.4 decreased to 14.2 at post-operative 24 months. In 30 patients, a bone bridge on CT scan was identified. The change in disc height was 8.11 mm, 10.02 mm and 9.63 mm preoperatively, immediate postoperatively and at 24 months after surgery, respectively. Conclusion : In the treatment of lumbosacral foraminal stenosis, unilateral facetectomy and interbody fusion using expandable stand-alone cages may be considered as one treatment option to maintain post-operative alignment and to obtain satisfactory clinical outcomes.

• Journal of Korean Neurosurgical Society
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• v.50 no.3
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• pp.224-230
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• 2011

Objective : This study aimed to show the possibility of neural canal enlargement and restoration of bony fragments through laminectomy and minimal facetectomy without pediculectomy or an anterior approach, and also to prove the adequacy of posterior stabilization of vertebral deformities after thoracolumbar bursting fracture. Methods : From January 2003 to June 2009, we experienced 45 patients with thoracolumbar burst fractures. All patients enrolled were presented with either a neural canal compromise of more than 40% with a Benzel-Larson Grade of VI, or more than 30% compromise with less than a Benzel-Larson Grade of V. Most important characteristic of our surgical procedure was repositioning retropulsed bone fragments using custom-designed instruments via laminectomy and minimal facetectomy without removing the fractured bone fragments. Beneath the dural sac, these custom-designed instruments could push the retropulsed bone fragments within the neural canal after the decompression and bone fragment repositioning. Results : The mean kyphotic deformities measured preoperatively and at follow-up within 12 months were 17.7 degrees (${\pm}6.4$ degrees) and 9.6 degrees (${\pm}5.2$ degrees), respectively. The mean midsagittal diameter improved from 8.8 mm (${\pm}2.8$ mm) before surgery to 14.2 mm (${\pm}1.6$ mm) at follow-up. The mean traumatic vertebral body height before surgery was 41.3% (${\pm}12.6%$). At follow-up assessment within 12 months, this score showed a statistically significant increase to 68.3% (${\pm}12.8%$). Neurological improvement occurred in all patients. Conclusion : Though controversy exists in the treatment of severe thoracolumbar burst fracture, we achieved effective radiological and clinical results in the cases of burst fractures causing severe canal compromise and spinal deformity by using this novel custom-designed instruments, via posterior approach alone.

• Journal of Korean Neurosurgical Society
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• v.41 no.3
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• pp.207-209
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• 2007

We present an elderly patient with unilateral foraminal stenosis treated by isthmus resection. An 83-year-old female could not walk due to severe leg pain along right L5 sensory dermatome. Despite the laminotomy for spinal stenosis on the right side at the L4-5 level, her leg pain did not improve. Careful review of computed tomography scans and coronal source images of magnetic resonance myelography revealed foraminal stenosis on the right side at the L5 vertebra. Because of medical problem, she underwent isthmus resection on the right side at the L5 level instead of total facetectomy and fusion. After surgery, her leg pain was markedly improved. Isthmus resection showed successful result for this medically compromised elderly patient with unilateral foraminal stenosis.

• Journal of Korean Neurosurgical Society
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• v.42 no.1
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• pp.11-15
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• 2007

Objective : Lumbar foraminal stenosis is an important etiology of lumbar radicular symptomatology and frequent causes of remained symptoms after decompressive surgery. This study was conducted to determine the precise clinical and radiologic diagnosis of lumbar foraminal stenosis, and to demonstrate thorough treatment by decompressive surgery using a minimally invasive technique. Methods : Seven patients with established unilateral lumbar foraminal stenosis according to clinical and radiologic diagnosis were retrospectively studied. All patients underwent combined interlaminar and paraisthmic procedure with partial facetectomy. The outcome of surgery was evaluated and classified into excellent, good, fair and poor. Results : The results were excellent in four patients, good in two, and fair in one during the follow-up. There were no surgery-related complications. Conclusion : Minimally invasive combined interlaminar and paraisthmic approach provides good outcome in carefully selected patients with symptomatic lumbar foraminal stenosis.

• Journal of Korean Neurosurgical Society
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• v.43 no.5
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• pp.239-241
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• 2008

Migration of a disc fragment to the posterior epidural space is rare, especially in the thoracic spine. Only four such cases of posterior epidural migration of thoracic disc fragments have been reported. The authors report a case of 66-year-old man who presented with back pain and right leg weakness due to posterior epidural migration of thoracic disc fragment. The patient was successfully treated by laminectomy and partial facetectomy with disc removal.

• Journal of Korean Neurosurgical Society
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• v.38 no.3
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• pp.196-201
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• 2005

Objective : Among upper lumbar disc herniations, L1-2 disc herniations are especially rare. We present the specific clinical features of L1-2 disc herniation and compared results of different surgical options. Methods : The authors undertook a retrospective single institution review of the patients who underwent surgery for L1-2 disc herniation. Thirty patients who underwent surgery for isolated L1-2 disc herniations were included. Results : Buttock pain was more frequent than anterior or anterolateral thigh pain. Standing and/or walking intolerance was more common than sitting intolerance. The straight leg raising test was positive only in 15 patients [50%]. Iliopsoas weakness was more frequent than quadriceps weakness. Percutaneous discectomy group demonstrated worse outcome than laminectomy group or lateral retroperitoneal approach group. Conclusion : Standing and/or walking intolerance, positive femoral nerve stretch test, and iliopsoas weakness can be useful clues to the diagnosis of L1-2 disc herniation. Posterior approach using partial laminectomy and medial facetectomy or minimally invasive lateral retroperitoneal approach seems like a better surgical option for L1-2 disc herniation than percutaneous endoscopic discectomy.

• Journal of Korean Neurosurgical Society
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• v.30 no.7
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• pp.883-890
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• 2001

Objectives : An in vitro biomechanical study of posterior lumbar interbody fusion(PLIF) with threaded cage using two different approaches was performed on eighteen functional spinal units of bovine lumbar spines. The purpose of this study was to compare the segmental stiffnesses among PLIF with one long posterolateral cage, PLIF with one long posterolateral cage and simultaneous facet joint fixation, and PLIF with two posterior cages. Methods : Eighteen bovine lumbar functional spinal units were divided into three groups. All specimens were tested intact and with cage insertion. Group 1(n=12) had a long threaded cage($15{\times}36mm$) inserted posterolaterally and oriented counter anterolaterally on the left side by posterior approach with left unilateral facetectomy. Group 2(n=6) had two regular length cages($15{\times}24mm$) inserted posteriorly with bilateral facetectomy. Six specimens from group 1 were then retested after unilateral facet joint screw fixation in neutral(group 3). Likewise, the other six specimens from group 1 were retested after fixation with a facet joint screw in an extended position(group 4). Nondestructive tests were performed in pure compression, flexion, extension, lateral bending, and torsion. Results : PLIF with a single cage, group 1, had a significantly higher stiffnesses than PLIF with two cages, group 2, in left and right torsion(p<0.05). Group 1 showed higher stiffness values than group 2 in pure compression, flexion, left and right bending but were not significantly different. Group 3 showed a significant increase in stiffness in comparison to group 1 for pure compression, extension, left bending and right torsion(p<0.05). For group 4, the stiffness significantly increased in comparison to group 1 for extension, flexion and right torsion(p<0.05). Although there was no significant difference between groups 3 and 4, group 4 had increased stiffness in extension, flexion, right bending and torsion. Conclusion : Posterior lumbar interbody fusion with a single long threaded cage inserted posterolaterally with unilateral facetectomy enables sufficient decompression while maintaining a majority of the posterior elements. In combination with a facet joint screw fixation, adequate postoperative stability can be achieved. We suggest that posterolateral insertion of a long threaded cage is biomechanically an ideal alternative to PLIF.