Primary glioblastoma of the spinal cord is a rare and aggressive tumor, comprising less than 1.5% of spinal neoplasms. It typically affects young adult males and arises in the cervical or thoracic regions. We report an unusual case of intradural extramedullary spinal glioblastoma in a 62-year-old man with prior lymphoma in remission. The patient presented with a 7-month history of progressive lower limb weakness, numbness, and radiating pain. MRI revealed a contrast-enhancing mass at the T6–7 level, initially suspected as lymphoma. Surgical resection via total laminectomy was performed, and en-bloc tumor removal achieved. Histopathological analysis confirmed WHO grade IV glioblastoma, IDH-wildtype, without Histone H3 mutation. This case highlights an atypical radiologic and anatomical presentation, complicating preoperative diagnosis. Histopathologic and molecular studies were essential for confirmation. Postoperative treatment included adjuvant radiotherapy and temozolomide, though their efficacy remains uncertain in spinal glioblastoma due to limited evidence and spinal cord radiosensitivity. Early biopsy and a multimodal diagnostic approach are critical for managing rare spinal tumors presenting with nonspecific clinical and imaging features.

Spinal artery aneurysms are exceedingly rare, and their natural history remains poorly understood. Diagnosis can be challenging due to their small size and the difficulty in detection by MR angiography (MRA) or CT angiography (CTA); Digital Subtraction Angiography (DSA) is considered the gold standard diagnostic tool. This case report presents two cases of ruptured thoracic radicular artery aneurysms leading to subdural hematoma (SDH) and subarachnoid hemorrhage (SAH). The first patient, a 71-year-old female, presented with bilateral leg weakness, headache, and severe back pain, where multiple fusiform dilatations of the left T9 radiculopial artery were identified. She showed significant improvement after surgical intervention. The second patient, a 75-year-old female, presented with paraplegia and severe back pain, and a saccular dilatation in the right T10 radiculopial artery was found. She underwent endovascular embolization but showed no neurological improvement. These cases highlight the diverse clinical presentations, diagnostic challenges, and uncertainties in management strategies for ruptured spinal artery aneurysms, emphasizing the need for prompt intervention, especially in cases with significant or progressive neurological deficits.

Osteoid osteoma is a benign bone-forming tumor that commonly affects young adults and often presents with severe nocturnal pain responsive to NSAIDs. While surgical resection is curative, lesions located in the spine, particularly near critical structures such as the vertebral artery and spinal cord, pose substantial diagnostic and surgical challenges. We report a case of a 24-year-old male with intractable night pain caused by an osteoid osteoma located at the superior margin of the right T1 pedicle. Despite extended NSAID therapy, the patient’s symptoms persisted. Multimodal imaging including MRI, CT, and PET-CT confirmed the diagnosis and revealed the lesion’s proximity to vital neurovascular structures. To minimize morbidity, we employed intraoperative O-arm navigation integrated with preoperative imaging to achieve precise localization and targeted resection through a limited posterior approach. The nidus was successfully excised en bloc without complications. Postoperatively, the patient experienced immediate pain relief and returned to normal activities within days. This case highlights the utility of real-time 3D navigation in managing spinal osteoid osteomas and supports its use as a safe, effective alternative to traditional wide exposure techniques, particularly in anatomically constrained regions of the spine.

Vertebroplasty or kyphoplasty is a widely accepted minimally invasive procedure for treating painful vertebral compression fractures. Although considered safe, rare but serious complications such as spinal subdural hematoma (SDH) can occur, particularly in patients receiving long-term anticoagulation therapy. We present a rare case of spinal SDH following kyphoplasty in a 78-year-old woman with a mechanical aortic valve on chronic warfarin therapy. Anticoagulation was managed perioperatively with warfarin discontinuation and bridging enoxaparin. Postoperative X-ray showed subtle posterior cement leakage. MRI on postoperative day 1 revealed lumbar SDH, which progressed cranially by day 2. The patient remained neurologically intact and was treated conservatively with corticosteroids and temporary suspension of anticoagulation. Follow-up imaging showed gradual hematoma resolution, and she was discharged without deficits. This case suggests the importance of maintaining a high index of suspicion for spinal hematoma in anticoagulated patients, especially when new symptoms or even minor cement leakage are present. Careful perioperative planning, including early imaging and multidisciplinary management, is crucial in such high-risk patients.

Study Design
Retrospective comparative study.
Purpose
To evaluate and compare the clinical outcomes and complication profiles of decompression alone versus decompression with instrumented fusion in elderly patients aged 75 and older with lumbar spinal stenosis. Overview of Literature: Lumbar spinal stenosis is a common cause of disability in elderly patients. The decision between decompression alone and fusion surgery in the geriatric population remains controversial due to surgical risks and comorbidities.
Methods
A retrospective analysis of 121 patients aged ≥75 years treated either with laminectomy alone (n=60) or with posterior lumbar interbody fusion (PLIF, n=61) from April 2016 to December 2022. Baseline characteristics, perioperative parameters, and postoperative outcomes were compared.
Results
There were no significant differences in baseline characteristics. The PLIF group showed longer operative times, greater blood loss, and longer hospital stay, but similar complication rates. Both groups showed significant postoperative improvement in VAS, ODI, and EQ-5D scores.
Conclusions
Decompression alone and fusion surgery both provide substantial clinical benefit in elderly patients with spinal stenosis. With careful selection, fusion may be safely considered even in the elderly.

Purpose
Thoracolumbar vertebral compression fractures (VCFs) are a leading cause of kyphosis and related biomechanical complications, often resulting in chronic back pain and reduced function. Balloon kyphoplasty has been widely used as a minimally invasive intervention to provide pain relief and restore vertebral height. The SpineJack system is a relatively novel technique that introduces mechanical distraction, offering potentially enhanced vertebral restoration. This study aims to compare these two effective treatments for thoracolumbar fractures.
Materials and Methods
This study analyzed 30 patients with thoracolumbar VCFs surgically treated, using the Spine-Jack system (n=10) or balloon kyphoplasty (n=20). Back pain was evaluated as VAS pain score and functional disability was assessed with Oswestry Disability Index (ODI) preoperatively and immediately postoperatively. Radiological outcomes were measured on plain lateral X-rays, including vertebral height restoration, segmental kyphosis angle, and sagittal vertical axis (SVA). Complications, such as cement leakage and adjacent vertebrae fractures, were recorded. Continuous variables – with t-tests and categorical variables- with chi-square tests, were analyzed. P-value less than 0.05 was considered statistically significant.
Results
Both the Spine-Jack system and balloon kyphoplasty were effective in reducing back pain and improving patients’ function, with significant improvements in VAS and ODI scores. However, the Spine-Jack system demonstrated superior vertebral height restoration (85% vs. 72%, p=0.03) and segmental kyphosis angle correction (12° vs. 9°, p=0.032) when compared to balloon kyphoplasty. Complication rates were all low and comparable between the two groups.
Conclusions
Although the Spine-Jack system and balloon kyphoplasty are all effective for thoracolumbar VCFs, the Spine-Jack system offered superior radiological outcomes in selected cases. Further studies may explore their complementary roles in managing thoracolumbar VCFs.

Purpose
This study aimed to compare the clinical effectiveness and potential benefits of ultrasound (US)-guided versus fluoroscopy (FL)-guided cervical retrolaminar block (RLB) in patients with cervical facet joint pain.
Materials and Methods
A total of 27 patients aged 40 years or older who were diagnosed with cervical facet joint syndrome based on physical examination and imaging modalities were included. 12 patients of group I treated with US-guided RLB and 15 patients of group II treated with FL-guided RLB. The position of the needle and the distribution of contrast agent were confirmed using fluoroscopic images, and the changes in numeric rating scale (NRS) and neck disability index (NDI) before and 2 weeks after the procedure were compared in the two groups.
Results
Radiologically, the target agreement of needle placement in group I was 75%. There was no difference in contrast medium spread between the two groups. Clinically, the mean NRS improved from 7.08±0.52 to 3.08±0.90 in group I (p=0.01) and from 7.20±0.56 to 3.33±0.72 in group II (p=0.01). The mean NDI decreased from 41.67±2.27 before the procedure to 20.83±2.33 after the procedure in group I (p=0.01), and from 40.87±2.61 before the procedure to 21.67±2.02 after the procedure in group II (p=0.01), with no difference between the two groups.
Conclusions
US-guided cervical RLB is an effective, radiation-free alternative to FL-guided RLB for managing cervical facet joint pain, offering comparable pain relief and functional improvement.

Advanced imaging technologies have revolutionized the diagnosis and management of spinal pathologies by providing superior precision and efficiency. Modalities such as PET-CT, SPECT, diffusion tensor imaging (DTI), and magnetic resonance spectroscopy (MRS) offer unique insights into the metabolic, structural, and functional aspects of spinal diseases, enabling better differentiation of lesions, improved surgical planning, and early detection of pathological changes. Furthermore, the integration of artificial intelligence (AI) has enhanced imaging workflows by enabling automated analysis, prediction of clinical outcomes, and segmentation of spinal structures. Despite these advancements, challenges such as technical limitations, high costs, and ethical concerns, including issues of data privacy and AI-generated inaccuracies, hinder widespread adoption. This review explores the clinical applications, limitations, and future directions of these emerging technologies, highlighting the need for multidisciplinary collaboration and large-scale research to standardize protocols and optimize patient outcomes. The seamless integration of advanced imaging and AI represents a transformative potential for improving diagnostic accuracy and treatment efficacy in spinal care.

Purpose
This study was conducted to identify risk factors predicting the loss of cervical lordosis (LCL) in patients with multilevel ossification of the posterior longitudinal ligament (OPLL) following laminoplasty. Material and Methods: We conducted a retrospective analysis of data from patients who underwent laminoplasty at Chonnam National University Hospital between January 2013 and December 2022. Various radiological parameters and clinical outcome measures were collected perioperatively. Patients were divided into 2 groups according to the severity of LCL. We examined preoperative radiological parameters associated with LCL.
Results
We analyzed data from 109 patients (92 men and 17 women; mean age, 60.31±10.80 years). A higher T1 slope (odds ratio [OR], 1.420; p<0.001) and a lower extension ratio (OR, 0.883; p=0.019) were associated with a higher risk of LCL. T1 slope was shown to be an excellent predictor of LCL, with a cut-off value of 28° (p<0.001, area under the curve=0.918). Also, The T1 slope and extension ratio were statistically significant correlated with clinical outcomes.
Conclusions
T1 slope and extension ratio were significantly associated with LCL in patients with multilevel OPLL following laminoplasty. The cut-off value for the T1 slope was 28°, and the cut-off value for the extension ratio was 33. Therefore, in multilevel OPLL patients with a T1 slope exceeding 28° or an extension ratio below 33, a warning regarding the potential LCL should be given before performing cervical laminoplasty.

Objective
Postoperative urinary retention (POUR) is a common complication following lumbar spine surgery, significantly affecting functional recovery and Enhanced Recovery After Surgery (ERAS) protocols. POUR can lead to bladder overdistension, infections, prolonged hospital stays, and long-term detrusor dysfunction. Postoperative delirium (POD) can impair cognitive function and mobility, potentially triggering or exacerbating POUR. This study aims to investigate whether POD serves as an independent risk factor for POUR and to analyze other contributing factors to provide clinical management strategies.
Materials and Methods
A retrospective cohort study was conducted involving 420 patients who underwent lumbar spine surgery at a single tertiary medical institution between March 2021 and February 2024. POUR was defined as a post-void residual (PVR) bladder volume ≥300 mL measured via bladder ultrasound or requiring catheter reinsertion due to urinary retention. POD was diagnosed within 72 hours postoperatively using the Confusion Assessment Method (CAM) and was classified into three subtypes: hyperactive, hypoactive, and mixed. Multivariate logistic regression analysis was employed to identify the relationship between POD and POUR, with sensitivity and specificity assessed through Receiver Operating Characteristic (ROC) curve analysis.
Results
Among 420 lumbar spine surgery patients, 44 (10.5%) experienced POD. Of these, 16 (36.4%) were classified as hyperactive, 20 (45.5%) as hypoactive, and 8 (18.2%) as mixed type. POUR occurred in 28 of the POD patients (63.6%) compared to 71 of 376 patients without POD (18.9%), demonstrating a statistically significant difference (p<0.001). The analysis of POUR incidence by POD subtype revealed rates of 62.5% (10/16) for hyperactive POD, 60.0% (12/20) for hypoactive POD, and 75.0% (6/8) for mixed POD. Patients with mixed POD showed the highest POUR incidence, with a significant difference compared to hyperactive and hypoactive POD (p<0.05). Multivariate logistic regression analysis identified POD as an independent risk factor for POUR, increasing the likelihood by approximately 3.7 times (Odds Ratio, OR: 3.71; 95% Confidence Interval, CI: 1.95–7.06; p<0.001). Among POD subtypes, mixed POD presented the strongest association with POUR, increasing the risk by 4.8 times (OR: 4.84; 95% CI: 2.10–11.15; p<0.001). Hyperactive and hypoactive POD were also significant risk factors, increasing POUR risk by 3.0 times (OR: 3.04; 95% CI: 1.45–6.35; p=0.003) and 3.5 times (OR: 3.48; 95% CI: 1.69–7.19; p=0.001), respectively.
Conclusions
This study confirms that postoperative delirium (POD) is an independent risk factor for postoperative urinary retention (POUR) in lumbar spine surgery. The occurrence and subtype of POD significantly influence POUR incidence, with mixed POD presenting the highest risk. These findings highlight the importance of early diagnosis and prevention of POD as a strategy to effectively reduce POUR. A multidisciplinary approach integrating POD and POUR management could optimize postoperative outcomes and improve patient recovery.

Spinal cord injury (SCI) distinguishes itself from peripheral nerve injury by causing devastating and irreversible damage to the spine, resulting in profound motor, sensory, and autonomic dysfunction. The ensuing complex microenvironment of SCI, characterized by hemorrhage, inflammation, and scar formation, poses substantial challenges to regeneration and complicates numerous transplantation strategies. Recent research has shifted its focus towards manipulating the intricate SCI microenvironment to enhance regeneration, with some approaches demonstrating significant therapeutic efficacy. Consequently, the reconstruction of an appropriate microenvironment post-transplantation emerges as a potential therapeutic solution for SCI. This review aims to provide a comprehensive overview, firstly summarizing the influential compositions of the microenvironment and their diverse effects on regeneration. Secondly, we highlight recent research employing various transplantation strategies to modulate distinct microenvironments induced by SCI, aiming to facilitate regeneration. Lastly, we discuss prospective transplantation strategies for SCI, emphasizing the importance of addressing the complex microenvironment for successful therapeutic outcomes.

Objective
Proximal junctional fracture (PJFx) at the uppermost instrumented vertebra (UIV) or UIV+1 is the most common mechanism of PJF. There are few studies assessing the radiographic progression after PJFx development. Therefore, this study sought to identify the risk factors for radiographic progression of PJFx in surgical treatment for ASD.
Methods
In this retrospective study, among 317 patients aged > 60 years who underwent ≥5-level fusion from the sacrum, 76 with PJFx development were included. According to the change in proximal junctional angle (PJA), two groups were created: Group P (change ≥10°) and Group NP (change <10°). Patient, surgical, and radiographic variables were compared between the groups to demonstrate risk factors for PJFx progression using uni- and multivariate analysis. The receiver operating characteristic (ROC) curve was used to calculate cutoff values. Clinical outcomes, such as visual analog scale (VAS) scores for back and leg pain, the Oswestry Disability Index (ODI) score, and the Scoliosis Research Society (SRS)-22 score, and revision rate were compared between the two groups.
Results
The mean age at the index surgery was 71.1 years, and there were 67 women enrolled in the study (88.2%). There were 45 patients in Group P and 31 in Group NP. A mean increase of PJA was 15.6° (from 23.2° to 38.8°) in Group P and 3.7° (from 17.2° to 20.9°) in Group NP. The clinical outcomes were significantly better in Group NP than Group P, including back VAS score, ODI value, and the SRS-22 scores for all items. Revision rate was significantly greater in group P than in group NP (17.8% vs. 51.6%, p=0.001). Multivariate analysis revealed that overcorrection relative to the age-adjusted ideal pelvic incidence (PI)–lumbar lordosis (LL) target at the index surgery (odds ratio [OR]=4.484, p=0.030], PJA at the time of PJFx identification (OR=1.097, p=0.009), fracture at UIV versus UIV+1 (OR =3.410, p=0.027) were significant risk factors for PJFx progression. The cutoff value of PJA for PJFx progression was calculated as 21° using the ROC curve.
Conclusions
The risk factors for further progression of PJFx were overcorrection relative to age-adjusted PI–LL target at the index surgery, PJA > 21° at initial presentation, and fracture at the UIV level. Close monitoring is warranted for such patients not to miss the timely revision surgery.

Purpose
The biplanar whole body imaging system (EOS) is a new tool for measuring whole body sagittal alignment in a limited space. This tool may affect the sagittal balance of patients compared to conventional whole spine radiography (WSX). This study is to investigate the difference in sagittal alignment between WSX and EOS.
Materials and Methods
We compared spinal and pelvic sagittal parameters in 80 patients who underwent EOS and WSX within one month between July 2018 and September 2019.The patients were divided based on sagittally balanced and imbalanced groups according to pelvic tilt (PT) >20˚, pelvic incidence-lumbar lordosis >10°, C7-sagittal vertical axis (SVA) > 50 mm in WSX.
Results
In sagitally imbalanced group, for WSX versus EOS, the pelvic parameters demonstrated compensation in EOS with smaller PT (27.4±11.6° vs. 24.9±10.9°, p=0.003), greater sacral slope (SS), and patients tended to stand more upright with smaller C7-SVA (58.4±17 mm vs. 48.9±57.3 mm, p=0.003), T1-pelvic angle (TPA), T5-T12, and T2-T12. However, in sagitally balanced group, these differences were less pronounced only with smaller PT (10.8±6.9° vs. 9.4±4.7°, p=0.04), TPA and T2-T12 angle, but SS and C7-SVA were similar (p>0.05).
Conclusions
EOS shows a negative SVA shift and lesser pelvic tilt than WSX especially in patients with sagittal imbalance. When making a surgical plan, surgeon should consider these differences between EOS and WSX.

Background
It is well reported that the patient’s age plays an important role associated with proximal junctional failure (PJF) development. Various characteristics of adult spinal deformity (ASD) patients were different between younger and older age groups. We hypothesized that the radiographic risk factors for PJF would different according to younger and older age groups. This study aimed to evaluate different radiographic risk factor of PJF according to the two age groups undergoing thoracolumbar fusion for ASD.
Methods
ASD patients aged ≥ 60 years who underwent thoracolumbar fusion from low thoracic level (T9~T12) to sacrum were included. The minimum follow-up duration was two years. PJF was defined as proximal junctional angle (PJA) ≥ 20°, fixation failure, fracture, myelopathy, or necessity of revision surgery. Using various radiographic risk factors including age-adjusted ideal pelvic incidence (PI)-lumbar lordosis (LL), univariate and multivariate analyses were performed separately according to the two age groups : <70 years and ≥70 years.
Results
A total of 186 patients were enrolled (mean age=68.5 years old, 90.3% female). Mean follow-up duration was 67.4 months. PJF developed in 98 patients (32.0%). There were fracture in 53 patients, PJA ≥ 20° in 26, fixation failure in 12, and myelopathy in 6. PJF developed more frequently in patients older than 70 years than in younger than 70 years. In patients aged less than 70 years, preoperative LL, PI-LL and change in LL were significant risk factors in univariate analysis. Multivariate analysis showed only change in LL was significant for PJF development (Odds ratio [OR]=1.025, p=0.021). On the other hand, in patients older than 70 years, postoperative LL, postoperative PILL, overcorrection relative to conventional PI-LL target (within ±10°) as well as age-adjusted ideal PI-LL target were significant. On multivariate analysis, only overcorrection of PI-LL relative to age-adjusted ideal target was a single significant factor to cause PJF (OR=5.250, p=0.024).
Conclusions
In patients younger than 70 years, greater change in LL was associated with PJF development regardless of PI-related value. However, in older patients, overcorrection of PI-LL relative to the age-adjusted PI-LL target was important to cause PJF.

Background
Percutaneous-short segment screw fixation (SSSF) without bone fusion has proven to be a safe and effective modality for thoracolumbar spine fractures (TLSFs). When fracture consolidation is confirmed, pedicle screws are no longer essential, but clear indications for screw removal following fracture consolidation have not been established.
Methods
In total, we enrolled 31 patients with TLSFs who underwent screw removal following treatment using percutaneous-SSSF without fusion. Plain radiographs, taken at different intervals, measured local kyphosis using Cobb’ angle (CA), vertebra body height (VBH), and the segmental motion angle (SMA). A visual analogue scale (VAS) and the Oswestry disability index (ODI) were applied pre-screw removal and at the last follow-up.
Results
The overall mean CA deteriorated by 1.58º (p<0.05) and the overall mean VBH decreased by 0.52 mm (p=0.001). SMA preservation was achieved in 18 patients (58.1%) and kyphotic recurrence occurred in 4 patients (12.9%). SMA preservation was statistically significant in patients who underwent screw removal within 12 months following the primary operation (p=0.002). Kyphotic recurrence occurred in patients with a CA ≥20º at injury (p<0.001) with a median interval of 16.5 months after screw removal. No patients reported worsening pain or an increased ODI score after screw removal.
Conclusion
Screw removal within 12 months can be recommended for restoration of SMA with improvement in clinical outcomes. Although, TLSFs with CA ≥20º at the time of injury can help to predict kyphotic recurrence after screw removal, the clinical outcomes are less relevant.

Purpose
Minimally invasive technique in spinal surgery have evolved including cortical bone trajectory (CBT) screw technique which is s new lumbar pedicle screw path, as an alternative fixation technique for lumbar spine. Theoretical advantage is that it provides enhanced screw torque and has biomechanical characteristics, also it minimizes approach-related damages. Midline lumbar fusion (MIDLF) has appeared with CBT screw technique. Many studies of CBT screw reported the effectiveness of MIDLF. We adopted this technique for lumbar degenerative spondylolisthesis and evaluated early radiological outcomes.
Materials and Methods
From May 2014 to March 2015, 17 patients (mean age 65.6±7.5 years; 4 males, 13 females) underwent MIDLF procedures for the treatment of single level lumbar spondylolisthesis. Average follow-up period was 8.8±2.7 months. Initial and last follow-up X-ray and computed tomography (CT) were evaluated for screw malposition, detection of peri-screw halo, loosening of the construct, or signs of spinal instability.
Results
The average bone mineral density (BMD) was -1.9±0.8. Eleven patients were fused at L4-5, 5 were at L3-4, and 1 was at L2-3. Five CBT screws were converted into pedicle screws due to intraoperative misposition of screws, so total 63 CBT screws were evaluated for peri-screw halo and malposition. There were no findings of screw pull-out or breakage in all screws. Four out of 63 (6.3%) screws were judged as peri-screw halo, and 20 (41.2%) screws were judged as malposition (1 medial; 2 superior; 17 lateral pedicle violation). But, there were no screw related nerve root injury. In all cases, interbody bony mass were identified. Four out of 17 (23.6%) patients were detected more than 2 degrees motions on flexion-extension lateral X-rays at final follow-up, and 1 out of these 4 patients was identified loss of reduction. There was no operation related complication.
Conclusion
There is no doubt that MIDLF with CBT screw is the minimally invasive method. Many numbers of screw malposition identified in our series were thought to be due to our earlier experience of trying free hands technique. We recommend the use of intraoperative fluoroscopy, which achieve accuracy. Although MIDLF with CBT has theoretical strengths, we must evaluate further long-term clinical follow-up and measure outcome.

Objective
To evaluate the efficacy and safety of anorganic bone matrix (ABM)/P-15 compared with local autograft bone in posterior lumbar interbody fusion (PLIF) with pedicle screws for degenerative lumbar diseases.
Methods
This is a retrospective analysis of consecutive series of 138 patients undergoing 1 or 2 levels PLIF from 2015 to 2020 in our single institute. Local autograft bone or ABM/P-15 (i-factor, Cerapedics Inc., Westminster, Colorado USA) were used for interbody fusion. The successful fusion was defined as the segmental cobb angle of less than 5 degrees of in flexion/extension X-rays and continuity of the trabecular bony bridging in computed tomography (CT) images.
Results
Among a total of 138 patients, total levels of fusion were 202, of which 74 were in 1 level fusion and 128 were in 2 level fusion. And 93 used ABM/P-15 and 109 used local autograft bone. The evaluation time of fusion status was 1 year after surgery. Successful fusion based on X-ray images was achieved 84.1% (90/107) for local autograft bone and 91.3% (84/92) for ABM/P-15 (p=0.127). Based on CT images, 86.9% (93/107) of autograft group and 95.6%(87/91) of AMP/P-15 group showed successful fusion respectively (p=0.034). Occurrence rate of autolysis was 14% (15/107) for local autograft bone and 17.6% (16/91) for ABM/P-15. Subsidence rates were 11.2% (12/107) for local autograft bone and 9.99% (9/91) for ABM/P-15. Hollow formation around pedicle screw was noted in 9.3% (10/107) for local autograft bone and 2.2% (2/91) for ABM/P-15.
Conclusions
The use of AMP/P-15 for lumbar interbody fusion surgery can be a good substitute for local autograft bone in terms of better fusion rate and similar complication rate on radiologically.

Background
Oblique and anterior lumbar interbody fusion have been widely performed in the lumbar spinal disease but we cannot get a direct decompression effect with these procedure. Objective: The purpose of this study is to report clinical and imaging outcomes of microscope assisted direct decompression combined with oblique lumbar interbody fusion (OLIF) or anterior lumbar interbody fusion (ALIF).
Methods
Twelve patients who received microscope assisted direct decompression during OLIF or ALIF for lumbar spinal stenosis were enrolled. The OLIF was performed for the lesion upper than the L4-5 or in the case of multisegmental disease. The ALIF was performed for the lesion at the L5-S1. After anterior-approaching surgery, percutaneous fixation of pedicle screw was performed and we did not perform an additional decompression posteriorly in all cases. For the clinical outcomes, we evaluated short form 36 (SF-36), Oswestry disability index (ODI) score and visual analog scale (VAS) pain score. For the imaging outcomes, we obtained postoperative lumbar magnetic resonance imaging (MRI).
Results
The OLIF was performed for 9 patients and the ALIF was performed for 3 patients. In the clinical outcomes, SF-36 was improved from 25.40 to 69.83 and ODI score was also improved from 69.83 to 16.50. VAS pain score of back was improved from 4.3 to 1.6 and VAS pain score of leg was improved from 7.5 to 2.2. In the imaging outcomes, all patients had severe stenosis before surgery. After surgery the severity of the stenosis was reduced to mild state in 9 cases and moderate state in 3 cases postoperatively.
Conclusions
We could obtain the good clinical outcomes and effective decompression through microscope assisted direct decompression during OLIF or ALIF.

Oblique lumbar interbody fusion (OLIF) is one of surgical techniques for patients with spondylolisthesis, but an insertion of cage at an ideal location (anterior 1/3 of disc space) is challenging for patient with high grade spondylolisthesis, because vertebra are not aligned. Recently, a technique of simultaneous insertion of pedicle screw and rod system from the back of patient and insertion of cage via retroperitoneal route from the front of patient is possible by using spinal navigation system (OLIF-360). The author present a case and surgical technique of simultaneous re-alignment of high-grade spondylolisthesis at L4-5 and insertion of interbody cage by using OLIF-360. An intervertebral cage was inserted at the ideal location after re-alignment of spondylolisthesis with OLIF-360. Postoperative images showed re-aligned vertebra and successful decompression. The specific utilization of OLIF-360 has not been underscored yet.

Purpose
The current study aims to report the results of analyzed factors that ultimately undergo surgical treatment after selective nerve root block in patients with spinal structural pathology that cause lower back pain and radiating pain in the lower extremities. Material and methods: A retrospective study was performed on 537 patients diagnosed with spinal canal stenosis or disc herniation among patients who underwent selective nerve root block at our hospital for five years from May 2015 to December 2017. The patients were divided into Group A (patients with an only selective spinal nerve root, n=99) and Group B (patients with surgical treatment, n=20). We evaluated the primary demographic factors, including age, sex, onset, symptom duration, diabetes mellitus, hypertension, angina, osteoporosis. The clinical variables included in the analysis were the preoperative visual analog scale (VAS) pain score, the Korean version of the Oswestry Disability Index (K-ODI), and the Roland-Morris disability questionnaire (RMDQ).
Results
The average symptom duration was 22.6±1.2 weeks in group A, and 35.7±0.9 in group B. Of a total of 20 patients (16.8%), four males (20%) and 16 females (80%) were underwent surgical procedures because there was no improvement in symptoms. Group B had a significantly higher proportion of female patients and longer symptom duration than group A. And there were no statistically significant differences between groups in other variables.
Conclusions
Although the frequency of surgical treatment decreased after selective nerve root block, the longer symptom duration and the female gender might be related to the risk factors for surgical treatment.

Background
S2-alar-iliac (S2AI) screws are one of the options for spinopelvic fixation to improve stability across the lumbosacral junction. The S2AI screws cross the cortical surfaces of the sacroiliac joint, which can increase the biomechanical strength of the instrumentation. Objective: To investigate the durability and failure types of S2AI screw by finite element model (FEM) analysis.
Methods
Through the FEM, complex material and geometrical properties of the biological system can be evaluated, and various physical variables, such as stress, and fracture, can be analyzed. We examined the biomechanical stress distribution at the set screw and screw head by using a FEM. Von Mises (V.M.) stress (MPa) is derived from 3-dimensional status of stress. The finite element software Abaqus^® version 6.5 (ABAQUS Inc., Johnston, RI, USA) was used to create a FEM.
Results
We quantified the peak V.M. stress applied to the set screw and screw head when rod to S2AI screw trajectory angle was 30º angled and perpendicular. In FEM analysis, at an angle of 30 degrees rather than perpendicular, the stress increased further around the area where the screw head and rod contacted and the displacement distribution of set screw also increased.
Conclusion
S2AI screw fixation has several drawbacks such as screw fracture and dislodgement of the set screw. This FEM analysis can support the result.

Spinal subdural hematoma (SDH) is a rare complication after spinal surgery. Only a few cases are reported on spinal SDH following open lumbar spinal decompression or fusion surgery. Moreover, there has been no case report on spinal SDH following percutaneous transforaminal endoscopic lumbar discectomy. We report a case of spinal SDH following endoscopic discectomy, review the literature of this complication and discuss the etiology to it and methods to prevent it. A 63-year-old woman presented with severe radiating pain. Pain was not improved with conservative management. Lumbar magnetic resonance imaging (MRI) was checked and revealed right L3-4 ruptured disc with severe L4 root compression. Percutaneous transforaminal endoscopic decompression was performed and the pain subsided promptly after the endoscopic procedure. On 7th post-operative day, pain on Rt. buttock, anterior thigh was deteriorated severely, more than in pre-operatively. Deteriorated pain was not controlled by oral medications and epidural block. Repeat MRI showed no definite recurrence of disc herniation at decompressed level but spinal SDH, severely compressing cauda equina was seen on T12-sacral area. Spinal SDH is a rare complication following spine surgery, including percutaneous endoscopic surgery. A spine surgeon should be aware of the possibility of spinal subdural hematoma, having severe sequel.

Objective
To investigate the association of quantitative paraspinal muscle measurements to the Oswestry disability index (ODI) in patients with lumbar spondylolisthesis.
Materials and Methods
Ninety two patients (mean age, 61.6 years; male, mean age, 71.8 years ; female; mean body mass index [BMI], 24.9 kg/m² ) who had undergone lumbar fusion due to spondylolisthesis with available selfcompleted postoperative ODI were included. The total cross-sectional area (CSA) and functional CSA (FCSA; i.e., area containing only lean muscle tissue) of the paraspinal muscle group (multifidus and erector spinae muscles) and the psoas muscles were measured at L2–L3, L3–L4, and L4–L5 disc levels each on preoperative magnetic resonance imaging (MRI) and the sum of areas at each level served as representative values for each muscle. The FCSA/total CSA ratio and the skeletal muscle index (SMI=muscle area [cm² ]/patient height2 [m² ]) were calculated. Pearson’s correlation analyses were performed to evaluate the relationship between preoperative paraspinal muscle measurements and postoperative ODI.
Results
Quantitative values of low paraspinal muscle showed significant correlation with high ODI values. As a result of this study, the preoperative paraspinal muscle was quantified in the group of patients undergoing spinal fusion. Patients with low value in CSA and FCSA of paraspinal muscle could observe the tendency to transition to low clinical outcomes. Therefore, quantitative values of surrounding muscles are factors affecting clinical outcomes of patients undergoing spinal surgery Conclusion: Smaller muscle bulk (total CSA) of psoas muscles and lean muscle mass (FCSA) of paraspinal muscle group and psoas muscles combined on preoperative MRI were associated with significant postoperative disability based on ODI in patients with lumbar spondylolisthesis.

Lumbar fusion surgery for lumbar degenerative diseases has increased in the past several decades and many techniques for fusion surgery have been introduced. Recently lateral lumbar interbody fusion with minimally invasive technique was introduced and accepted as a useful method for various lumbar degenerative disease. It can produce good correction for sagittal and coronal imbalance with relatively decreased morbidity. The advantage of lateral lumbar interbody fusion is that it can avoid injury to the abdominal large vessels and neural structures which is more common during posterior approaches. However various complications had been reported. Complications related with lateral lumbar interbody fusion include neurologic complications including thigh pain and numbness, vascular complications including arterial injury, cage related complication such as cage subsidence and vertebral body fractures. Therefore special care should be taken to avoid possible complications in lateral lumbar interbody fusion surgery.

Objectives
The primary surgical goals when treating a spinal metastasis are usually pain relief and preservation of ambulatory function. Minimally invasive techniques have become popular, being associated with less morbidity and mortality than conventional open surgeries.
Materials and Methods
Between April 2012 and September 2016, 15 consecutive patients underwent percutaneous pedicle screw fixation (PPSF) to treat spinal metastases. We retrospectively analyzed prospectively collected data, including visual analog scale (VAS) pain scores, Frankel scale scores, and complications.
Results
Fifteen patients (8 males, 7 females; mean age 61 years) underwent surgery under general anesthesia. PPSF was performed on all patients, and two with poor bone quality underwent cement augmentation of the manipulated vertebra(e) just prior to pedicle screw insertion. Seven patients underwent fixation plus distraction (indirect decompression via ligamentotaxis) and two laminectomies (direct decompression) of the spinal cord. Two patients developed screw pullout requiring revision surgery. One patient died 7 days after surgery from liver cirrhosis and sepsis. All patients reported that pain was reduced after surgery. After surgery, 12 patients regained ambulatory capacity. Nine patients died during follow-up; the mean overall survival time was 14.1 months.
Conclusions
PPSF is a safe and minimally invasive palliative surgery option for patients with spinal metastases.

Recently, favorable results of minimally invasive spinal surgery have been reported in comparison to the open decompression or fusion surgery. Biportal endoscopic spine surgery (BESS) has several benefits and Indications for BESS are nearly identical to those for general open spinal surgery. However, it remains a challenging procedure even for an experienced endoscopic surgeon. because it takes a a long operation time while early learning period. If the operation time is prolonged, the advantages of endoscopic surgery are reduced and the incidence of complications can be increased. Therefore, we will investigate the factors affecting the operation time and how to minimize it before and during operation.

Among the complex causes of chronic low back pain, suboptimal injury of ligament in the lumbosacral spine is common. Injured ligaments can become a primary pain source and raise secondary pain with referred pain pattern. Due to the low blood supply to the ligaments, ligaments are notoriously poor healer. In order to compensate the poor healing of ligament, prolotherapy has been introduced and used for more 60 years. To date, no definite recommendations have not been made based on literature available. However, if conventional treatment modalities have failed in patient with chronic back pain in lumbosacral spine, prolotherapy targeted on ligaments around lumbosacral spine should be considered in appropriate patients.

Background
Context: There are few reports of changes in global sagittal alignment and corresponding factors like hand grip strength (HGS) and muscle performance tests to detect changes in global sagittal alignment after surgery for lumbar spinal stenosis (LSS).
Purpose
The purpose of the study was to determine whether HGS can be a useful predictive marker of global sagittal alignment changes after decompression with fusion surgery for LSS. Study Design: This is a retrospective observational study. Patient Sample: Patients who underwent spine surgery for LSS were included in the present study. Outcome Measures: Radiological spinopelvic parameters including sagittal vertical axis (SVA), lumbar lordosis (LL), pelvic tilt (PT), pelvic incidence (PI), global tilt (GT), and T1 pelvic angle (T1PA) were assessed. Clinical outcomes parameters like Oswestry Disability Index (ODI), Euro-QOL (EQ-5D), visual analog scale (VAS) scores for back or leg pain were assessed. To assess muscle performance, three functional mobility tests (6-meter walk test, timed up and go test, sit-to-stand test) and HGS were checked.
Materials and Methods
A total 91 consecutive patients who underwent spine fusion surgery for LSS were included. 1 year after posterior decompression and fusion surgery, the patients were further classified into four groups according to preoperative and postoperative SVA. We analyzed radiological parameters like SVA, LL, PT, PI, GT, and T1PA. The ODI, the EQ-5D and VAS scores for back or leg pain were recorded as clinical outcomes assessment. To assess muscle performance, SMT, TUGT, STS, and HGS were checked.
Results
HGS was significantly correlated with age, postoperative SVA, ODI, EQ-5D and muscle performance test. HGS was related with change of preoperative sagittal alignment 1yr after surgery. Using a receiver operating characteristic (ROC) curve to determine the cutoff values of HGS as predictors of postoperative balanced sagittal alignment according to SVA, cutoff value of HGS demonstrated 19.5 kg with a sensitivity of 82.1% and specificity of 66.7%.
Conclusion
Patients with non-balanced sagittal alignment in LSS demonstrated decreased muscle function and muscle strength. If the muscle strength was weak in the group in which the sagittal balance was maintained preoperatively, it could be converted to non-balanced sagittal alignment. Thus, preoperative HGS may be a good predictor of postoperative SVA change.

Purpose
of Study: Purpose of this study is to summarize the technique of UBE surgery in lumbar interbody fusion and review the clinical outcomes and complications of UBE surgery in lumbar interbody fusion.
Materials and Methods
Medical databases were searched for the key words of unilateral biportal endoscopic surgery and lumbar spinal stenosis using PubMed from 2005 to the present.
Conclusion
UBE spinal surgery is a new technique that can be a feasible alternative and an effective treatment modality for spinal degenerative diseases and can achieve the necessary surgical skills for experienced microscopic surgeons, which is still expanding the indications for lumbar spinal surgery.

Spinal cord injury is a devastating condition that leaves permeant disability. Surgical decompression and stabilization with various pharmacological treatments have been tried to prevent secondary injury, however, their results have been disappointing. Therefore, novel therapeutic options are required enthusiastically. Cell transplantation that has the potential of neuroregenerative and neuroprotective ability is regarded as a promising remedy. We would like to describe about the micro-anatomy and the mechanism of injury of spinal cord injury. We also delineate transplanted cells; embryonic stem cell, induced pluripotent stem cell, mesenchymal stem cell as stem cells and Schwan cell, olfactory ensheathing cell as supporting cells with brief reviews of their experimental results.

Interspinous process devices for spinal surgery are designed to keep the spine in a flexed position, to achieve indirect decompression of the mobile segment. Such devices have been fabricated using numerous materials and designs. In this study, the fundamental knowledge required for choosing an appropriate interspinous process device for spinal surgery was reviewed.

Objectives
To verify the hypothesis that nerve compression by postoperative spinal epidural hematoma (POSEH) can be reduced by instillation of heparin through suction drains.
Materials and Methods
The patients who underwent posterior decompression and instrumentation between Jan. 2016 and Jun 2016 were allocated to study (using heparin) group and control group according to the operation date alternately. There were 61 cases in study group and 60 cases in control group. Two lines of suction drain were used in all cases. Thousand unit of heparin and 5ml of normal saline were instilled through the drain lines into the epidural space just before the wound closure. To prove the homogeneity between the two groups, demographic, patient related, operation related and clotting related data were compared. At day 7 after the operation, their MRIs were examined. The area of thecal sac was measured at the T2 weighted axial image that showed the maximal compression of the thecal sac by epidural hematoma. Two orthopedic doctors who were blinded to this study measured independently and the average values of the two were counted as final measured values.
Results
The two groups were homogenous in age, sex, number of fusion segments, whether virgin or revision operation, total blood loss, operation time, blood loss/10 min, whether taking anti-platelet drugs or not, platelet count, PT, aPTT and platelet function analysis. The smallest area of thecal sac in axial MRI was 124.4±49.9 mm² in study group and 121.7±47.4 mm² in control group. There was no significant difference (p=0.761)
Conclusions
In a posterior spine surgery, thecal sac compression by POSEH was not reduced by instillation of heparin into the epidural space.

Purpose
There were few available data regarding the prognosis after the surgical treatment for spinal metastases from non-small cell lung cancer (NSCLC) despite its great frequency. The aim of this study was to investigate the prognostic factors for patients who underwent the surgical treatment for spinal metastases from NSCLC.
Materials and Methods
Eighty-seven patients who underwent surgical treatment for spinal metastases from NSCLC were followed up semi-prospectively. There were 43 patients with metastatic spinal cord compression (MSCC) and 44 patients without MSCC. The prognosis analysis was performed according to 3-categorical variables: patients’ , oncologic, and treatments’ factors. Major complications and mortality rate were recorded. The impact of postoperative chemotherapy was evaluated separately.
Results
The overall survival time was median 6.8 months. Postoperative ECOG-PS (0-2 vs. 3, 4) was shown as a significant prognostic factors in both MSCC and non-MSCC groups with HR (hazards ratio) of 2.46 and 2.54, respectively. Major complications developed in 26 patients and 30-day mortality rate was 8.0%. The presence of major complications was also prognostic factor in both groups with HR of 2.55 and 4.47. Earlier surgery within 72 hours showed better prognosis in MSCC group with HR of 2.46. Patients who underwent postoperative chemotherapy survived longer significantly than those who couldn’t with median survival time of 12.0 vs 2.8 months.
Conclusions
Postoperative ECOG-PS and complications were significant prognostic factors in both groups and earlier surgery in MSCC group. The postoperative chemotherapy was another independent prognostic factor affecting the survival time

The foramen of L5-S1 can develop several degenerative diseases such as extraforaminal lumbar disc herniation, foraminal stenosis with disc height collapse, degenerative or spondylolytic spondylolisthesis, and far-out syndrome. The floating technique in biportal endoscopic spine surgery (BESS) keeps a certain distance between instruments and spinal structures. 1) This key point makes the floating technique different from conventional endoscopic surgery, which uses the Kambin’s safe triangle as a work zone. The floating view can enable the surgeon to see the structures panoramically, under high magnification: consequently, fine discrimination of their margin and safe manipulation of neural structures can be guaranteed. A certain gap between the floating scope and lesion can permit various instruments, generally used in open spine surgery, to be inserted from the sides with fewer limitations. Extraforaminal or foraminal lesions under the lamina can be reached by avoiding the iliac crest, and total facetectomy, which has the potential of iatrogenic instability, is not required to explore the foraminal structures. However, the floating view can be obstructed by small bleeds from laminectomized bone and/or surrounding vessels. This present article describes the technique and provides tips on how to perform BESS with floating technique safely and successfully for various lesions at the L5-S1 foramen.

Purpose
To report a rare case of alveolar soft-part sarcoma in the spine. Alveolar soft-part sarcoma (ASPS) is a rare, distinctive sarcoma typically occurring in young adults. Although it shows a relatively indolent clinical course, the ultimate prognosis is poor and often characterized by late metastases. However, with radical resection, long-term survival is possible. ASPS usually arises in the skeletal muscle and occurs most frequently in the lower limbs.
Materials and Methods
A 17-year-old male patient presented with a palpable mass on the back that enlarged about 1 year before admission. The mass was approximately 4×3 cm, located on the right side of the thoracic midline, and was palpated to be relatively soft and fixed, with no pain. On preoperative magnetic resonance imaging (MRI), a 2.5 ×2.0×4.1-cm lobulating contoured intermuscular mass was located between the spinalis thoracis and logissimus thoracis muscles in the right lumbar area at the T5–6 level. In the T1- and T2-weighted images with enhanced view, the tumor was enhanced with homogeneous intensity.
Results
We considered the possibility of a benign tumor that is frequently found in back muscle, rather than the possibility of a malignant tumor. We performed mass excision and biopsy without prior fine-needle biopsy or incisional biopsy, with the patient under general anesthesia. The tumor was confirmed to be ASPS.
Conclusions
The possibility of malignancy should be considered in the treatment of all tumors, and accurate diagnosis is important before surgery.

A 77-year-old female suffering from severe degenerative scoliosis, spinal stenosis and lumbar disc herniation underwent Direct lateral lumbar interbody fusion (DLIF) at L2-4. On the 3rd postoperative day, she complained of severe back pain without any trauma history. Simple radiograph revealed L3 vertebral fracture and cage subsidence. Pain was subsided after conservative treatment including TLSO and medication. Radiographic union was achieved at fractured vertebra after 3 months. Solid fusion was observed at operated level after 6 months. Patient has visited our clinic without any pain. DLIF is one of novel minimally invasive spine procedures available today. It is designed to maximize benefits and minimize risks of other traditional techniques such as anterior approach and posterior approach. However, there can be some risk of cage subsidence and vertebral fracture after DLIF. Therefore, care should be taken to avoid cage subsidence during the operation.

Purpose
The purpose of this review is the current understanding of proximal junctional kyphosis (PJK) and proximal junctional failure (PJF) following adult spinal deformity (ASD) surgery.
Materials and Methods
We carried out a systematic search of PubMed for literatures published up to September 2016 with “proximal junctional kyphosis” and “proximal junctional failure” as search terms. A total of 57 literatures were searched. Finally, the 33 articles were included in this review.
Result
PJK and PJF are recognized complications after long instrumented posterior fusion in ASD surgery. PJK is multifactorial in origin and likely results from surgical, radiographic, and patient related risk factors. PJF is a progressive form of the PJK spectrum including bony fracture of uppermost instrumented vertebra (UIV) or UIV+1, subluxation between UIV and UIV+1, failure of fixation, neurological deficit, which may require revision surgery for proximal extension of fusion. Variable risk factors for PJK and PJF have been investigated, and they can be categorized into surgical, radiographic, and patient-related factors. There are several strategies to minimize PJK and PJF. Soft tissue protections, adequate selection of the UIV, prophylactic rib fixation, hybrid instrumentation such as hooks, vertebral cement augmentation at UIV and UIV+1, and age-appropriate spinopelvic alignment goals are worth consideration.
Conclusion
The ability to perform aggressive global realignment of spinal deformities has also led to the discovery of new complications such as PJK and PJF. Continuous research on PJK and PJF should be proceeded in order to comprehend the pathophysiology of these complications.

Background
Owing to its new introduction, there are few documents on pit-falls of biportal endoscopic spine surgery (BESS) clinically. The authors reported etiologies in need of early exploration after BESS for lumbar degenerative diseases and strategies to overcome them.
Methods
BESS were performed for lumbar spine diseases (LSDs) by two spine surgeons from December 2013 to March 2016. Postoperative MRI was checked for all cases and following-up MRIs in the case in need of revision surgery within six months after the first surgery due to pain intolerable, sustained or recurred. The complicated cases were reviewed and classified as radiographic and operative findings to reveal the main reasons for early explorations.
Results
The 562 cases (M:295, F:267, Age 58.5±14.1 yrs, 20~88 yrs) included lumbar disc herniation (LDH) (255 cases), extraforaminal disc herniation (22 cases), spinal stenosis (218 cases), degenerative spondylolisthesis (27 cases), revision surgery after recurred disc herniation or restenosis after open surgery (24 cases), juxtafacet cyst (11 cases), adjacent segment stenosis with fusion surgery (3 cases), and spondylolytic spondylolisthesis (2 cases). Early explorations were needed in 43 cases (7.7%) at 26.1±31.5 days after the initial operations. Causative etiologies were listed as recurred LDH (12 cases, 27.9%), remnant stenosis (7 cases, 16.3%), remained ruptured disc fragment (6 cases, 14.0%), root edema (5 cases, 11.6%), synovitis (4 cases, 9.3%), hematoma (3 cases, 7.0%), dura tear (2 cases, 4.7%), recurred stenosis (2 cases. 4.7%), wrong level (1 case, 2.3%) and postoperative fungal infection (1 case, 2.3%). Thirty-one cases (72.1%) were revised within 4 weeks and most conditions (40 cases, 93.0%) were improved after early exploration using BESS. Two cases of dura tear were conversed to open repair. One case of fungal infection was suspected to related with the patient’s medical illness including long-term steroid use for chronic lung disease with pulmonary fibrosis and Diabetes mellitus.
Conclusions
Preoperative planning should be prepared carefully to decrease early exploration. It was helpful to comparing MRIs immediately postoperative and early following-up to find the reasons. Don’t hesitate to explore the operated site again using BESS, because most etiologies are supposed to be controlled by early exploration without need of converting to open surgery except in the case of dura tear in need of dural repair.

Seventy-five-year female patient with diabetes, hypertension and hyperthyroidism visited our clinic for left shoulder radiating pain. In cervical radiologic study, multiple nodules were seen on both lung fields. In chest MDCT, active pulmonary tuberculosis and miliary tuberculosis were suspected and mass on 1st and 2nd thoracic vertebral body with destruction was seen. In cervico-thoracic MRI, 1st thoracic vertebral pathologic fracture was found. Miliary tuberculosis with spinal tuberculosis was diagnosed with right middle lobe biopsy. After 3 weeks with chemotherapy, lesion got advanced on MRI and radiating pain got worse. We performed 1st thoracic vertebral corpectomy with auto iliac bone graft, after 1 week posterior instrumentation was performed. After surgery, radiating pain and weakness got better, the patient is followed up at the outpatient. In general, spinal tuberculosis treats with antituberculous agent at first. But, if spinal deformity or neurologic symptom was accompanied, surgical correction will be necessary. In this case, advanced cervico-thoracic spinal tuberculosis with conservative therapy was treated 1st thoracic vertebral corpectomy with auto iliac bone graft and posterior instrumentation. The patient’s neurologic symptom was got better after surgery.

Objective
To compare the pull-out strength of polyaxial general screws and rescue screws when inserted into the lateral mass through cadaveric biomechanical experiment
Materials and Methods
Twenty three segments of the human cervical spine (from C3 to C7) were prepared. Two biomechanical studies were progressed. In the first experiment (13 segments), each segment was instrumented with 3.5×12 mm polyaxial screws on both sides. In one side, the inserted screw was removed and then the rescue screw was inserted to the same screw hole. In the second experiment (10 segments), all segments were instrumented with 3.5×12 mm polyaxial screws on both sides and all screws were removed. In one side, removed same screw was reinserted and in the other side, the rescue screw was inserted without change of the screw trajectory. All specimens were fixed to the specially designed frame with the cement. Universal Material Test Machine (Mini Bionix 858) was used to assess the pull-out strength of the screws. All data were compared with non-parametric paired test (Wilcoxon’s signed rank test).
Results
There was no crack or fracture around the screw hole. No significant difference was noted between the original screws (not reinserted) and the rescue screws in the first experiment (p=0.753). There is no significant difference between the same screw reinsertion and the conversion to the rescue screw (p=0.646).
Conclusions
The overall results of this study showed the conversion to the rescue screw with the same screw trajectory could offer no biomechanical advantage over reinsertion of the same screw. In case of secure screw hole after removal of the screw, the reinsertion of the same screw could be recommended.

Minimally invasive TLIF has been reported to be a useful treatment option for the patients with various degenerative lumbar diseases. Many studies have reported the favorable clinical results of MIS TLIF. However it remains technically demanding, leading to higher complication rates and longer operative times during the early period of the learning curve. It showed some potential complications due to small working space and visual field. In this study, authors tried to find out various possible complications and some tips avoiding these complications through the review of various articles and authors’ clinical experiences. In many studies, the general complication fusion rates of MIS TLIF have been reported to be similar to that of open fusion. The technical difficulty of the procedure, combined with inadequate training, is evident in initial studies of MIS TLIF. A difficult learning curve of MIS TLIF demands that surgeons have sufficient preclinical training, and education is obtained before the application of MIS TLIF in clinical practice.

Purpose
Despite the increasing prevalence of spinal deformity correction using lateral lumbar interbody fusion (LLIF) for degenerative adult spinal deformity, the amount of sagittal plane correction is reported to be suboptimal. Thus, authors have performed mini-open anterior lumbar interbody fusion (ALIF) at the most caudal segment in adjunct to LLIF to make sufficient lumbar lordosis (LL). This study is performed to demonstrate the feasibility of mini-open anterior lumbar interbody fusion (ALIF) combined with lateral lumbar interbody fusion (LLIF) followed by 2-stage posterior fixation in terms of the correction capacity and complications by comparing with a matched control group undergoing posterior-only surgery.
Materials and Methods
This study was case-control study. Thirty patients who underwent ALIF with LLIF followed by 2-stage posterior fixation (ALIF/LLIF group) for adult spinal deformity were compared to 60 patients who underwent posterior-only surgery (posterior group) and were matched according to age, sex, diagnosis, fusion length, pelvic incidence (PI), and follow-up duration. Spinopelvic parameters, hospitalization data, clinical outcomes, and complications were evaluated and compared between ALIF/LLIF and posterior groups.
Results
In the ALIF/LLIF group, interbody fusions were performed for a mean of 4.0 levels, comprising 1.6 and 2.4 levels for ALIF and LLIF, respectively. Interbody fusion in the posterior group was performed for a mean of 3.3 levels. The mean follow-up duration did not differ between two groups (16.7 mo vs. 19.2 mo, p=0.056). Postoperative LL was greater in the ALIF/LLIF than in the posterior group (52.0° vs. 40.9°, p<0.001). The reduction in the sagittal vertical axis was also greater for the ALIF/LLIF group than the posterior group (62.3 mm vs. 24.7 mm). The operation time of the ALIF/LLIF group was longer than the posterior group (11.2 hr vs. 8.6 hr, p<0.001), while estimated blood loss and red cell transfusion was less in the ALIF/LLIF group. Medical complications developed more frequently in the posterior group, while perioperative surgical complications were not different between groups. Delayed surgical complications were observed more in the posterior group. In the posterior group, there were 7 patients who experienced nonunion and rod breakage and 10 patients who experienced decompensation, while there were no such cases in the ALIF/LLIF group.
Conclusion
Mini-open ALIF combined with LLIF can restore sagittal balance more appropriately with a lower rate of complications compared with posterior-alone surgery for the correction of ASD.

The minimally invasive technique to correct deformity in scoliosis is not a familiar concept among spine surgeons but is interesting, as this innovative surgery, if it proves successful, will have the advantages of the minimally invasive technique in the final outcomes and will be the future of scoliosis surgery. We operated on 18 adolescent idiopathic scoliosis (AIS) patients using a newly designed technique which utilizes two or three 1-inch midline incisions to insert pedicle screws with a rod, facet fusion and de-rotation maneuver to correct the deformity. Post-operative complications were minimal and the results of the deformity corrections were comparable to the open scoliosis surgery in the follow up. The advantages of minimally invasive surgery observed in all cases include cosmetically fainter scars, reduced blood loss, shorter hospital stay, early mobilization and minimal need of analgesics for pain. Even though many challenges were faced in executing this procedure, the goal of inventing this novel approach was accomplished. We feel this technique is a good alternative to open surgery in certain curve types of AIS but large scale studies are needed in the future to recommend its routine use.

Purpose
Recently, there is concern for spinal sagittal alignment associated with back pain. Nowadays many women wear high heels or high-heeled shoes for their beauty. We study change of spinal sagittal alignment when women are wearing high heels.
Materials and Methods
We raised 15 female adult volunteers to accept our study. They do not have past history, operation history and especially back pain. We applied X-rays for anteroposterior and lateral whole spine radiography when women were bare foot (Group I). In addition, we applied each X-rays when women were wearing 5 cm high heels (Group II) and 12 cm high heels (Group III). We estimate the spinal sagittal alignment distinguishing pelvic index from spinal index. We use ANOVA test of SPSS v18.0 statistically.
Results
The average age of women was 29.3(23-41) years old, and mean BMI (Body Mass Index) was 18.7(16.2-24.5) kg/m 2 . When volunteers were bare foot, the average pelvic incidence (PI) was 49.3 degree, pelvic tilt (PT) was 10.8 degree, and sacral slope (SS) was 37.9 degree. The each average of lumbar lordosis (LL), thoracic kyphosis (TK), T12 slope, and sagittal vertical line on middle point of C7 (C7 SVA) and T12 (T12 SVA) was 55.5 degree, 28.5 degree, 19.3 degree, -1.2 cm, and -3.8 cm. When women were wearing 5 Cm high heels, the average was each 49.2 degree, 18.9 degree, 35.4 degree, 54.9 degree, 29.1 degree, 20.5 degree, -2.0 cm, -2.5 cm. When women were wearing 12 cm high heels, the average was each 49.9 degree, 18.2 degree, 31.2 degree, 52.6 degree, 30.8 degree, 22.8 degree, -4.1 Cm, -4.1 cm. Compared with each group, sacral slope (SS) and vertical line on middle point of C7 was statistically significant in group III (p<0.05). There was no statistically correlation between group I and group II.
Conclusion
Spinal sagittal alignment can be changed if adult women wear high heels excessively. For maintaining of normal spinal sagittal alignment, We conclude adult women wearing high heels for a long time pay attention to change of their spinal sagittal alignment.

Purpose
Pull-out of pedicle screw in posterior pedicle fixation for thoracic and lumbar burst fractures causes delayed rehabilitation, persistant pain, and imblance of sagittal plane. In this study we try to analyse the factors that cause the pull-out of pedicle screw.
Materials and Methods
From March 01, 2006 to December 31, 2009, we assorted into two group; Group I for pullout pedicle, Group II for control. Plane lateral x-ray view film of thoracolumbar spine was taken on preoperation, postoperation, the first time when screw was pulled out and last follow up. we measure inserted angle for the upper endplate of screw, convergency angle and change of body height loss and kyphotic angle. We analysed corelation between these measuring values and pedicle screw pull-out by Mann-Whitney test and T-test.
Results
Pull-out of pedicle screw was found at mean 5weeks among nine cases. For inserted pedicle screws, which place in upper and lower vertebral body of fractured one, Value of inserted angle for upper end plate and convergency angle was found non-significant(p>0.05, Mann-Whitney test). Restoration of height loss and kyphotic angle of fractured vertebral body was statically significant(p<0.05, T-test).
Conclusion
In posterior pedicle fixation for thoracic and lumbar burst fractures, sufficient restoration of height loss and kyphotic angle is important factor for prevention of screw pull-out than inserted angle for upper end plate and convergency angle at a short period of time. Therefore we think that sufficient anterior fixation of vertebral body and restoration of kyphotic angle have a decisive effect on prognosis of patients.

Purpose
To analyze the risk of a fall in patients with cervical spondylotic myelopathy (CSM) and its clinical significance.
Materials and methods
40 patients with CSM who visited to our hospital From May 2014 to April 2015 were enrolled in this study. After confirmation of CSM based on MRI and Physical examination, patients were divided into three groups according to m-JOA score (Group A; severe; score <8, Group B; moderate; score 8-12, Group C; mild score >13). All patients enrolled in this study performed 4 functional assessment test including Alternative-Step Test (AST), Six-MeterWalk Test (SMT), Sit-to-Stand test (STS), and Timed Up and Go test (TUGT) to assess the risk of a falls (ROF).
Results
There were statistical significance between m-JOA score and ROF except for SMT. Average time (seconds) for STST was 26.12±5.60, 20.99±5.92 and 15.37±3.41 in group A, B, C, respectively (p=0.001), Although average time(s) for AST was 16.81±3.83, 14.39±4.05 and 12.37±3.95 in group A, B, C with no statistical significance (p=0.106), there was a significance between the value of Group A and C (p=0.047). Average time(s) for TUGT was 31.86±17.05, 15.09±4.59,18.04±9.32 in group A, B, C, respectively, showed statistical significance (p=0.000).
Conclusion
According to its severity of myelopathy, it took more time to carry out each ROF assessment tests. Among 4 functional assessment tests of ROF, STST showed the most highest correlation with mJOA socre. Careful attention of ROF will be needed in patients with myelopathy.

Background
Cervical kyphosis is frequently observed in the patients without axial neck pain and sigmoid curvatures are parts of the variety of cervical kyphosis.
Purpose
This study was designed to investigate the characteristics of the static and dynamic alignment of the cervical spine with sigmoid configurations.
Methods
Figty patients without changes of the cervical curvatures after subsidence of axial neck pain were enrolled in this study. Based on the alignment of cervical spine on lateral radiographs, cervical alignments were classified: kyphotic (K), kypho-lordotic (KL), lordo-kyphotic (LK), and Lordotic (L) group. The sagittal alignment angles and each segmental angle were measured using the Harrison method on neutral, flexion, and extension-lateral radiographs.
Results
The mean ratio of segmental ROM to C2-7 ROM revealed a similar pattern across the cervical levels without statistical difference between the groups. In the KL and LK group, the linear graphs for the mean ratio of segmental angles to C2-7 angles in flexion and extension showed a mirror image with respect to the C4-5 level. The lordotic components of both curves demonstrated larger ratio of segmental angles in flexion than the kyphotic components. The kyphotic components of both curves demonstrated larger ratio of segmental angles in extension than the lordotic components.
Conclusions
The lordotic and kyphotic components regardless of the type of sigmoid curvatures seem to adhere to constant dynamic behavior during flexion and extension. Therefore, the KL and LK cervical alignments may have the opposite dynamic behaviors in the high and low cervical levels.

Purpose
To evaluate the method of inserting cortical bone trajectory pedicle screws (cortical screws) and potential complications when performing lumbar fusion.
Methods
Lumbar fusion with cortical screw fixation in the hard cortical bone of the pars interarticularis of vertebrae was introduced to replace conventional pedicle screws. We review the literature on the biomechanics of cortical screw insertion and on the clinical outcomes.
Results
In vitro biomechanical testing has shown that cortical screws have greater pullout strength than traditional pedicle screws due to the strong bone–screw interface in cortical bone. Cortical screws have the advantages of requiring minimal muscle dissection and shortening the surgery. However, early screw loosening and loss of reduction have been reported.
Conclusions
When inserting cortical screws, the entry point and trajectory of the screws are important and a meticulous surgical technique is needed to prevent potential screw-related complications.

Purpose
To analyze the serial changes of the lumbar sagittal alignment from preop. to final follow-up and to evaluate the role of the posterior spinal instrumentation, especially, short level fusion in correction and maintenance of the lumbar sagittal alignment in degenerative lumbar disease.
Materials and Methods
Various lumbar sagittal profiles such as lumbar lordosis(LL), lordosis above, within and below instrumentation(LAI, LWI, LBI), horizontal vertebra and sacral inclination were serially measured in 54 patients whose radiographs at preop., intraop., immed. postop. postop. 2wks and final follow up(>1 yr) were completely equipped.
Results
Intraop. posture, instrumentation itself and interbody fusion could not increase the LL and LWI sufficiently irrespective of the length of fixation. LWI was decreased compared with preop. values irrespective of length of fixation, while interbody fusion has a great role in maintaining the LWI. Loss of LWI was overcompensated at the segments above instrumentation in 1 or 2 levels fixation while compensation has not occurred in longer fixations.
Conclusions
The longer the fixation, the more correction could be obtained. However, maintenance of this correction is more difficult in longer fixations. Prudent consideration should be taken in restoring sufficient lumbar lordosis and maintenance for favorable long term results.

Spinal cord tumors are uncommon lesions and can lead to significant neurologic morbidity and mortality. The classification of spinal cord tumors is based on their location as intradural intramedullary, intradural extramedullary, and extradural. Ependymomas are more common among intradural intramedullary tumors, and can often be surgically resected, whereas, astrocytomas infiltrate the spinal cord and show unclear marginality between the tumor and spinal cord. Complete surgical resection is obtained rarely. Intradural extramedullary tumors include schwannomas, neurofibromas, and meningiomas. These types are relatively curable with surgical resection than intradural intramedullary tumors. Radiotherapy is applied for malignant variants and recurrent tumors, whereas chemotherapy is usually recommended for recurrent lesions which are not effective with surgery or radiotherapy. Preoperative neurological status, histologic grade of the tumor, and the extent of surgical resection result in different outcomes.