KJC Korea
Journal Central

Study Design: An experimental study. Objectives: To define the phases of chronic spinal cord injury by researching the changes in gene expression. Summary of the Literature Review: The exact time of conversion from acute stage to chronic stage in spinal cord injury is unknown. Materials and Methods: We used 18 month-old Beagle dogs as study subjects. Under spinal cord monitoring, we underwent laminectomy on thoracic vertebra 10 and 11, and induced cord injury by a weight-drop injury method. Dogs in each group with spinal cord injury and group without spinal cord injury on POD 1, 7, 30, and 90. The motor functions were evaluated using the Tarlov scale. Tissues were prepared from 0.5cm up and down from the 10th thoracic level. Additional cephalic and caudal lesions from the injured site were prepared. We have checked the differentially expressed gene(DEG). Results: The mean Tarlov value was 0.67 which indicated a significant cord injury. 4 DEG (GP3, 9, 25, 34) were detected among 40primers after screening, the detection percentage of which was 10. In the tissues of study subjects with spinal injury, DEG was found at the injury site and cephalic lesion. DEG expressed GP3, GP9 and GP34 started expression on day 30, and GP25 was expressed on day 90. Conclusions: According to the changes in gene expression, the day 30 would be considered as the date of conversion from acute to chronic phase of cord injury. Inhibiting secondary inflammatory change and apoptosis following spinal cord injury until this period would maximize the effect of chronic phase therapy such as cell-transplantation. Key Words: Spinal cord injury, Differentially expressed gene

Study Design: Multi-center study, questionnaire survey. Objectives: To offer a database of spinal cord injury (SCI) by reviewing statistics and literatures of other countries, investigating the overall mechanism, injury patterns and treatment of SCI. Summary of Literature Review: There are no preexisting domestic studies (collectively conducted by multi-centers) of the prevalence and treatment of SCI. Materials and Methods: From September 2006 to August 2009, 47 cases of SCI in 6 universities were investigated retrospectively. 17questionnaire contents including the courses of injury-to-treatment were studied with data gathered from surveys. Results: The average age of patients was 48.4-years-old, male to female ratio was 33 to 14. The cases of falling from a height were 22cases (47%), lumbar area 19 cases (40%), and unstable bursting fracture 24 cases (51%) the most. Complete and incomplete paralyses were 19 cases (40%) and 28 cases (60%), respectively. High dose steroids were injected in 16 cases (NASCIS II) and 9 cases (NASCIS III). 14 cases presented complications and operations were performed 46 cases (98%). 12 cases (26%) arrived at the hospital within 4 hours of injury, 11 cases (23%) in 8 hours. On the way to the hospital, proper emergency treatment was performed in 25 cases (53%), and 30cases (64%) had a clear understanding of SCI after the final diagnosis. Conclusions: This is the first study that offers a comprehensive database of spinal cord injury (SCI), by investigating the overall mechanism, injury patterns, and treatment of SCI; this study is expected to be used in the future as an important reference material for spinal cord injury statistics and a standard for care. Key Words: Spinal cord injury, Multi-center study, Prevalence

Study Design: A retrospective study. Objectives: This study was performed by probing vertebral artery injuries and their radiologic characteristics in cervical spine fractures,and analyzing MRI findings of vascular injuries. Summary of Literature Review: Vertebral artery injuries are found relatively often in cervical spine fractures. Materials and Methods: We evaluated 57 cases of cervical spine fractures that occurred beginning in June 2011 and ending in February 2003. The characteristics of each fracture were evaluated using conventional radiographs, CT, and MRI. The presence of a vertebral artery injury was based on the absence of signal void in multilevel transverse foramens. Results: Twelve out of the 57 cases (21.1%) were found to have unilateral vertebral artery injuries. Clinically, impairment in cerebral circulation was not found. We found no statistical correlation between the signal change in the spinal cord and in the vertebral artery injury (P=0.424). We noted fractures of transverse processes in 7 cases, 6 of which showed vertebral artery injuries. Thus, the transverse process facture was associated with t vertebral artery injury (P=0.000). There seemed to be no relationship between the vertebral artery injury and each of following: fracture level (P=0.416), fracture type (P=0.723) and severity of soft tissue injury (P=0.195). Conclusions: Unilateral vertebral artery injuries were frequently found in the cervical spine fractures. And of all radiographic factors associated with vertebral artery injury, only the presence of transverse process fracture was statistically significant. Absence of signal void at multi-section MR images is considered to be a useful guide to commence additional vascular evaluation. Key Words: Vertebral artery injury, Cervical spine fracture, MRI

Study Design: A prospective radiological assessment. Objectives: Changes in the height, area, and width--captured using computed tomography (CT)--of the neural foramen with respect to changes in the intervertebral disc height, after undergoing an anterior cervical disc removal and fusion procedure. Summary of Literature Review: The multiple authors of this study, by obtaining central canal and area of neural foramen by increasing the disc spacing height and area of the neural foramen, attempted to assess the height increase of disc spacing. It is necessary to consider the synergistic effects of decompression through dissection of the posterior longitudinal ligament (PLL). Materials and Methods: The authors studied 17 patient cases that underwent one segment anterior cervical discectomy and fusion (ACDF) for degenerative cervical disease from June 2006 to March 2007. All patient cases underwent autogenous iliac bone graft or cage insertion with plate fixation procedure. We measured the areas of the neural foramen, heights of the vertebra body above and below the removed intervertebral disc with CT before and after ACDF. Radiographic measurements were averaged. Results: Among the 17 cases, the height of the cervical disc increased in 15 cases and decreased in 2 cases. The heights of the neural foramen increased in 19 cases and showed no changes in 13 cases. The areas of the neural foramen increased in 23 cases and decreased in 6 cases. The heights of vertebral body above and below the removed disc increased by 5.4% (p=0.734), and the heights of the neural foramen increased by 13.3% (p=0.002). The area of the neural foramen increased by 13.6% (p=0.192). The widths of the neural foramen increased by 2.3% (p=0.586). The intervertebral disc height, neural foramen height, and neural foramen area increased by 39.6%, 8.4%,and 17.9%, respectively, after a 2mm lengthening of bone transplant. The intervertebral disc height, neural foramen height, and neural foramen area increased by 59.8%, 22.9%, and 10.3%, respectively, after a 3mm lengthening of bone transplant. The height and area of neural foramen increased by 18.3% and 18.2%, respectively, after the PLL removal and dissection. Conclusions: The follow-up observations of the intervertebral disc height, neural foramen height, and neural foramen area showed increases after one segment ACDF in cervical disease cases, when compared to the preoperative radiographic findings. As the height of bone transplant increased, the intervertebral disc height, neural foramen height, and neural foramen area increased. The neural foramen height and neural foramen area significantly increased, when PLL was dissected. Key Words: Intervertebral disc, Neural foramen, Anterior interbody fusion, Cage

Study Design: A retrospective study. Objectives: To evaluate the safety and usefulness of implant removal based on fusion by radiological change analyses and non-fused segment motion angle after open reduction, multi-segment fixation, and single segment fusion. Summary of Literature Review: There have been reports that discuss possible fracture of fixator, loss of reduction, or failure of fixation in certain cases of single segment fixation consistent with thoracolumbar fracture. Materials and Methods: We analyzed 83 patients who had undergone treatment by fixation of the top 2 segments and the bottom segment. The posterolateral fusions were performed for the top segment for thoracolumbar fractures. The mean follow-up was 21.3months. Wedge and local kyphotic angles, anterior, and posterior heights of the vertebral body were measured on plain radiograph. The range of motion of each segment was recorded by flexion-extension lateral radiographs at 6 month after the removal of implants. Results: Radiologic assessments performed on 83 patients demonstrated preoperative mean wedge angle, kyphotic angle, mean anterior body height of 20.1°, 18.5° and 62.0%, respectively, and, postoperatively, these were corrected by 9.0°, 9.3° and 24.6%, respectively. In the 44 cases that had the implants removed, the correction losses were 0.4°(P=0.258) and 3.7°(P=0.000), 0.5 %( P=0.756), and at the last follow-up, compared to measurements prior to the removal. There was no statistical significance in wedge angle or anterior body height. The range of motion measured on the non-fused segment was 3.9°on average at 6-months after the hardware removal. Conclusions: The multi-segments fixation and single-segment fusion for the thoracolumbar fracture can preserve correction and the motion of non-fusion segment. Although the implant removal after union can sustain motion, further studies regarding degenerative change of the non-fused segment are necessary. Key Words: Thoracolumbar spine, Fracture, Pedicular screw, Implant Removal

Study Design: A retrospective study. Objectives: The aim of this study was to examine the usefulness of axial and sagittal-reconstructed CT images in the evaluation of spinal canal encroachment by thoracolumbar burst fractures. Summary of Literature Review: The dimensions of spinal canal encroachment by burst fractures have been described using axial CT images in the thoracolumbar region and sagittal-reconstructed images in the lower cervical region. However, the validity and reliability,depending on the measuring method, have not been fully evaluated. Materials and Methods: A hundred and ninety-nine patients, who had diagnosed as a thoracolumbar burst fracture, were included in this study. Three orthopedic surgeons independently measured the canal encroachment of the burst fragment in the axial CT images and the sagittal-reconstructed images using the ratio of spinal length (method 1) and the ratio of area (method 2). The validity for the evaluation of the deformity and fracture stability was evaluated. In addition, the reliability of each method was assessed. Results: Sixty-seven stable burst fractures and 132 unstable burst fractures were assessed. The mean kyphotic angle of stable and unstable burst fracture were 11.89 ± 8.49°and 15.90 ± 9.63°(P=0.005). The mean canal encroachment ratios of stable fracture were 17.21 ± 15.82 % (axial-method 1), 16.71 ±16.49 % (axial-method 2), 19.54 ± 17.03 % (sagittal reconstructed-method 1), and 11.75 ± 12.33% (sagittal reconstructed-method 2). The mean canal encroachment ratios of unstable fracture were 31.54 ± 17.10 % (axial-method 1), 29.67 ± 18.47 % (axial-method 2), 28.53 ± 18.60 % (sagittal reconstructed-method 1), and 21.20 ± 15.11 % (sagittal reconstructedmethod 2). There was no relationship between the fracture deformity and the canal encroachment ratio in all 4 methods. All ratios in the 4 method showed significant differences in the evaluation of fracture stability. All methods except method 1 in the sagittal-reconstructed images showed significant differences in the assessment of neurologic compromise. Conclusions: The measurement of a canal encroachment area using axial and sagittal-reconstructed images was valid in the description of fracture stability. Key Words: Thoracolumbar, Burst fracture, Canal encroachment, Computed tomography

Study Design: A retrospective study. Objectives: To assess the diagnostic value of the sedimentation sign seen on MRI with lumbar spinal stenosis and to compare postoperative clinical results. Summary of Literature Review: Nerve root sedimentation sign is an additional tool to diagnose lumbar spinal stenosis. Materials and Methods: There were 302 patients enrolled that had been diagnosed with lumbar spinal stenosis by MRI, which were reviewed to identify a sedimentation sign and all underwent the operative treatment. There were 142 patients who could not have their spinal stenosis diagnosis confirmed by MRI, and thus were selected as the control group to estimate the diagnostic value of nerve root sedimentation sign. Correlation with the duration of preoperative symptoms and the number of involved segments were compared and analyzed between sedimentation sign positive (Group I) and negative (Group II). We estimated Million Visual Analogue Score (MVAS) and Korean Oswestry Disability Index (KODI) for the assessment of the pain and the functional disability. Results: A positive sedimentation sign was found in 265 patients (87.7%) and diagnostic value was statistically significant (P<0.001). The involvement of 2 or more segments was significantly correlated with the sedimentation sign in the positive group (P<0.001). MVAS presented the improvement of 64.5±4.6%, KODI, 62.9±3.9% after surgical treatment in Group I. In Group II, each score showed improvement of 34.6±2.3% (MVAS), 37.1±1.8% (KODI). The improvement of these scores in Group I was better than in Group II. Conclusions: The nerve root sedimentation sign is an additional tool to diagnose lumbar spinal stenosis and the considerable factor to decide the operation. Key Words: Lumbar spine, Spinal stenosis, Sedimentation sign, Value of sedimentation sign

Study Design: Prospective study. Objectives: To investigate the clinical results of conservative treatment for mid-to-large lumbar disc herniation diagnosed via magnetic resonance imaging (MRI) and the factors influencing treatment. Summary of Literature Review: There is limited information regarding the clinical results of conservative treatment for lumbar disc herniation. The recent studies using MRI have suggested favorable treatment results. Materials and Methods: The study subjects were 39 cases of herniated disc patients with over a 1/3 spinal canal encroachment -- based on MRI -- that were followed up for at least 1 year. The average age was 42.6-years-old (range of 12-76 years-old), and the average follow-up period was 28 months. The neurological deficit and the visual analogue scale (VAS) of back pain and radiating pain at the time of initial diagnoses and final follow-ups were compared, and the clinical results were evaluated based Kim & Kim’s criteria. Results: Although 4 of the 39 patients needed to undergo surgery during the follow-up period, 33 of the remaining 35 patients showed satisfactory (excellent and good ratings) results: 27 excellent, 6 good, 2 fair, i.e., a 85% (33 out of 39) satisfactory results. Of the 14 cases that had neurological defect at the initial diagnosis, only 1 case needed surgery, thereby resulting in a 93% (13 out of 14) satisfactory result. There were no statistically significant correlations among the degree of spinal canal encroachment and other factors such as age, sex, herniation type, and neurological deficit at initial diagnosis, and the clinical results at the final follow-up, conversion to surgery during follow-up, and remaining pains. Conclusions: The clinical results of conservative treatment in lumbar disc herniation were satisfactory even in cases of high degree of spinal canal encroachment. Therefore, conservative treatment of lumbar disc herniation should be considered first before resorting to surgical treatment. Key Words: Lumbar Disc Herniation, Conservative Treatment, MRI, Spinal Canal Encroachment

Study Design: A retrospective study. Objectives: The authors found that problems such as axial pain, donor site pain, loss of reduction, loosening or failure of fixation materials occurred relatively frequently after posterolateral fusion. For this, we had views on the ideas that the problems could be improved by an operation that fused vertebral bodies. Furthermore, we performed posterior lumbar interbody fusion and wanted to know the results. Summary of Literature Review: We performed posterior lumbar inter-body fusion as an alternative, due to complications of autoiliac bone graft that has complications, such as donor site pain. Materials and Methods: Sixty patients with single segment degenerative lumbar disease were treated with decompression,pedicle screws fixation, and spinal fusion. The patients were followed-up for more than 2 years. Thirty patients, who had undergone posterolateral fusion with autologous iliac bone graft, were classified as the “group 1”. The second 30 patients, who underwent posterior lumbar interbody fusion with cage and local bone graft, were classified as the “group 2”. The operation time, blood loss, fusion rate,lumbar lordotic angle, segmental angle were compared between the 2 groups. The clinical outcomes were evaluated by Kim’s functional evaluation scale. Results: The operation time was shorter in group 2 (142.74 minutes vs 171.64 minutes), there was a statistical difference between the 2groups. Intraoperative blood loss was more in group 2 (563.40 vs 551.78 mL), but total blood loss, including postoperative drained blood was less in group 2. The bony fusion rate was 90% in group 1, 97% in group 2. For the lumbar lordotic angle, the last outcome was less than the preoperative value. There was no statistical difference between the 2 groups. The segmental angle in group 1, the last outcome was less than the preoperative value. The segmental angle in group 2 was maintained the value through pre-operation to post-operation. Clinical outcomes were satisfactory in group 1 (96.67%) & in group 2 (100%). In group 1, 7 patients experienced pain at the iliac graft donor site. In group 2, there were 2 cases of retroposition of the cage. Conclusions: In the posterior lumbar interbody fusion group, operation time was shorter, total blood loss was less than in the posterolateral fusion group. Restoration and maintenance of the segmental angle in sagittal and coronal radiographs showed better outcomes, axial pain and iliac donor site pain were less. It is the authors’ position that posterior lumbar interbody fusion is an alternative operation to supplement the faults of posterolateral fusion. Key Words: Degenerative lumbar spinal disorders, Posterior lumbar interbody fusion, Posterolateral fusion

Study Design: Retrospective study. Objectives: We analyzed to verify clinical result and recurrence of long term follow-up after open lumbar discectomy. Summary of Literature Review: There are many reports concerning the clinical result of open discectomy. However, long-term result is not frequently reported. Materials and Methods: From 1989 to 2000, 289 patients underwent open discectomies. 142 patients who was followed more than 5years were enrolled in this study. Follow-up rate, clinical outcome were analyzed as gender, age at the operation and operated level. Reoperation rate was analyzed as gender, age at the operation, operated level divided into same level-same side, same level-contralateral side and other level and the time at reoperation. Clinical outcomes were evaluated by Kim and Kim criteria. Results: More than 5 years follow-up rate was 49.1%. Average follow-up period were 99.2 months. Clinically successful result was obtained in 75.4%, and it was not related with gender, age at the operation and operated level. Reoperations were needed in 21patients(14.8%). Reoperation rate was not related with gender, age at the operation. Same level-same side reherniation were frequent before 6 months after first surgery, but other side and different level were similar more than 2 years after first surgery. Conclusions: Our clinical result was acceptable(75.4%). Main cause of reoperations before 6 months after first surgery was recurrence at the same level and same side, but cause of reoperation more than 2 years after first surgery were herniation at the other side and different level increased with time. Key Words: Lumbar spine, Herniated intervertebral disc, Open discectomy, Reoperation

Study Design: This is a retrospective study. Objectives: To evaluated the clinical and radiological effectiveness of sacral alar screws for augmentation of S1 pedicle screws in longlevel fusion including L5-S1 segment. Summary of Literature Review: The fusion rates of lumbosacral junction in long-level fusion are various when S1 pedicle screws are used without augmentation. But, reports of sacral alar screw augmentation are rare. Material and Methods: From 1996 to 2005, 63 patients performed more than two-level fusion including lumbosacral junction were reviewed. 47 patients underwent lumbosacral fusion with S1 pedicle screws only (S1 group), and 16 patients with sacral alar screws augmentation in addition to S1 pedicle screws (S1-2 group). Radiologically, bony union, halo sign, and breakage of implants were evaluated. Clinically, complications associated with screw placement and general complications were evaluated. Results: Bony union was obtained in 56 cases(89%) at postoperative 4.3 months. Nonunion was observed in 7 cases(11%, S1 group:5,S1-2 group:2). Loosening of S1 pedicle screw was observed in 32 cases(89%) of S1 group and in 4 cases(25%) of S1-2 group. It showed statistical significance between two groups. Sacral alar screw loosening occurred in 8 cases(50%) of S1-2 group. Metal breakage was developed in 2 cases of S1 group without nonunion or loosening. Postoperative infection occurred in 7 cases(11%, S1 group:5, S1-2group:2). Conclusions: Sacral alar screw augmentation was effective on protecting the loosening of S1 pedicle screw. Additional sacral alar screw can improve the rate of fusion for lumbosacral junction despite no statistical significance. Key Words: Lumbosacral fusion, Long level fusion, Sacral alar screw augmentation

Study Design: This is retrospective study. Objectives: To evaluate the risk of operative techniques using Motor Evoked Potential (MEP) in high-risk spinal surgery. Summary of Literature Review: There are few studies regarding the evaluation of operative techniques by MEP. Materials and Methods: We studied 33 cases that had MEP during surgery from July 2007 to March 2009. Diagnoses included posttraumatic kyphosis (PTK) in eight cases, congenital deformity in eight cases, degenerative lumbar deformity in eight cases, ankylosing spondylitis (AS) in three cases, spinal tumor in three cases, adjacent segmental disease in two cases, and post-surgical kyphosis in one case. Posterior vertebral column resection (PVCR) and pedicle subtraction osteotomy (PSO) were performed in 27 cases (81.8%) and, in the others, posterior decompression with discectomy was performed. We analyzed the risk of operative techniques and evaluated the MEP. Results: MEP showed abnormal signal change in five cases (PVCR: one case, compression and distraction: four cases). The AS case did not demonstrate neurological change after surgery. Though the PTK on T12 operated by PVCR case did not show an abnormal MEP result,neurological change was observed postoperatively. The sensitivity, specificity, percent of false negatives, and percent of false positives of MEP were 80.0%, 96.4%, 20.0%, and 3.6%, respectively. Conclusions: MEP monitoring is a useful method to detect neurological injury during high-risk spinal surgery with satisfactory specificity. For low sensitivity and a high false negative rate, increased monitoring of cases and continuous follow-up is needed. In conclusion, compression and distraction and PVCR are high-risk techniques in kyphotic deformity correction. Key Words: High-risk Spinal surgery, Motor Evoked Potential (MEP), Operative technique, Neurological complication

Study Design: This is a case report. Objectives: We wanted to report on the spontaneous dissolution of acute spontaneous epidural hematoma of the cervical spine and the effectiveness of conservative treatments, in the cases where the symptoms related to spontaneous epidural hematoma improve by themselves in a short period. Summary of Literature Review: Cases of acute spontaneous epidural hematoma of the cervical spine are rarely reported; surgical decompression procedures have been performed in most of the cases as treatment. However, there are some reported cases of hematoma dissolving spontaneously after a certain period of conservative treatment. Material and Methods: A 29 year-old female, who had no history of recent trauma, appealed neck pain with radiating pain in her upper right extremity due to acute epidural hematoma of the cervical spine which was diagnosed with MRI. The neck pain and radiating pain showed early recovery and gradual improvement during a period of the following 7 days after occurrence. MRI studies were done after 3days, 7days, and 1 month from the day of occurrence of the symptoms. Results: In comparing MRI studies there were significant decreases in the sizes of hematoma, which implied spontaneous dissolution. Almost all the symptoms related to acute spontaneous epidural hematoma vanished after a 1-month period of conservative treatment. Conclusions: Decompressive surgical procedure may not be necessary, if the symptoms related to spontaneous epidural hematoma improve by themselves in short period of conservative treatment. Key Words: Cervical, Epidural hematoma, Spontaneous, Resolution

Study Design: A case report. Objectives: We report a case of a female patient initially diagnosed as osteoporotic vertebral fracture without any noticeable injuries to posterior ligament complex, who later developed with incomplete paraplegia resulting from an unrecognized trauma after vertebroplasty. Summary of Literature Review: Vertebroplasty remains a safe and effective procedure for osteoporotic vertebral fracture. However,there have been many reports regarding neural injury associated with cement leakage. Materials and Methods: An 81-year old woman with a sudden motor weakness and a sensory loss on her lower extremities after an unrecognized trauma was admitted to our clinic. She had undergone a vertebroplasty twelve days before the admission. At the time of vertebroplasty, Magnetic resonance (MR) imaging showed a compression fracture at T10 vertebra without any posterior ligament complex (PLC) injury. Follow up MR imaging was taken 12 days after vertebroplasty, and it revealed posterior shift of T10 body with a fracture of spinous process, tear of left facet joint capsule, partial tear of interspinous ligament of T10-11 with retrolisthesis, and narrowing of spinal canal at T10-11 by T11 lamina. Results: Immediate surgical treatment was performed to decompress the neural structures, and to stabilize the spinal column. However,neurological recovery was unsatisfactory. Conclusions: Spinal surgeons should be aware of the possibility of the development of any neurologic deterioration, even if successful vertebroplasty is performed. Key Words: Paraplegia, Vertebroplasty, Osteoporosis, Compression fracture

Study Design: A review of literature regarding evidence-based medicine in spinal surgery. Objectives: To understand the philosophy of evidence-based medicine (EBM) in order to support clinical decision making. Summary of Literature Review: Evidence-based medicine is a commonplace phrase representing the hallmark of excellence in clinical practice. However, there has been misunderstanding and indiscriminate use of the concept of EBM in clinical practice. It is necessary to understand true philosophy of EBM. Materials and Methods: Narrative and review of the literature. Results: EBM is not for research to supplant individual clinical experience and the patients’ informed preference but to integrate these factors with the best available research. Conclusions: Treatment recommendations are no longer based on level of evidence, but also the risk benefit ratio and cost effectiveness. Key Words: Evidence-based medicine, Spine surgery