• Journal of Korean Neurosurgical Society
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• v.29 no.11
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• pp.1456-1460
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• 2000

Objectives : Transpedicular screw fixation has become an important method for internal fixation in variety of disorders. However, acceleration of degeneration at the adjacent segment in any follow. The goal of this study is to review the change of motion ranges of vertebral joints adjacent to fused level in lumbar spine. Methods : This study consists of 22 patients with degenerative spinal instability. Treatment of spinal instability includes posterior fusion with transpedicular screw fixation or transpedicular screw fixation with posterior lumbar interbody fusion. The flexion-extension angle(FEA) was measured from dynamic views of lumbar spine taken both at preoperative and post operative period. Results : The FEA of upper vertebral joint adjacent(FEA-u) to a fused L4-5 level was increased(p＝0.010). The FEA-u was increased in case of L5-S1 fusion(p＝0.025). The change of FEA-u in case of L5-S1 fusion was greater than that in L4-5 fusion(p＝0.013). Conclusion : After L4-5 fusion, there seems to be more meaningful increase in FEA of L3-4 than that of L5-S1. The reason may be due to the damage of L3-4 facet joints during the operation, the other possible explanation may be the anatomical stability of L5-S1 vertebral joint. The change of FEA-u of L5-S1 fusion is increased more than that of L4-5 fusion. Because there are compensations in the adjacent vertebrae both above and below the fused L4-5, the compensatory motion in FEA-u of L5-S1 fusion was greater than that of the L4-5 fusion.

• Journal of Korean Neurosurgical Society
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• v.52 no.4
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• pp.281-287
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• 2012

Objective : To evaluate the effect of calcium supplementation on spinal bone fusion in ovariectomized (OVX) rats. Methods : Sixteen female Sprague Dawley rats underwent bilateral ovariectomy at 12 weeks of age to induce osteoporosis and were randomly assigned to two groups : control group (n=8) and calcium-supplemented group (OVX-Ca, n=8). Autologous spinal bone fusion surgery was performed on both groups 8 weeks later. After fusion surgery, the OVX-Ca group was supplemented with calcium in drinking water for 8 weeks. Blood was obtained 4 and 8 weeks after fusion surgery. Eight weeks after fusion surgery, the rats were euthanized and the L4-5 spine removed. Bone fusion status and fusion volume were evaluated by manual palpation and three-dimensional computed tomography. Results : The mean fusion volume in the L4-5 spine was significantly greater in the OVX-Ca group ($71.80{\pm}8.06mm^3$) than in controls ($35.34{\pm}8.24mm^3$) (p<0.01). The level of osteocalcin, a bone formation marker, was higher in OVX-Ca rats than in controls 4 weeks ($610.08{\pm}10.41$ vs. $551.61{\pm}12.34$ ng/mL) and 8 weeks ($552.05{\pm}19.67$ vs. $502.98{\pm}22.76$ ng/mL) after fusion surgery (p<0.05). The level of C-terminal telopeptide fragment of type I collagen, a bone resorption marker, was significantly lower in OVX-Ca rats than in controls 4 weeks ($77.07{\pm}12.57$ vs. $101.75{\pm}7.20$ ng/mL) and 8 weeks ($69.58{\pm}2.45$ vs. $77.15{\pm}4.10$ ng/mL) after fusion surgery (p<0.05). A mechanical strength test showed that the L4-5 vertebrae in the OVX-Ca group withstood a 50% higher maximal load compared with the controls (p<0.01). Conclusion : Dietary calcium given to OVX rats after lumbar fusion surgery improved fusion volume and mechanical strength in an ovariectomized rat model.

• Journal of Korean Neurosurgical Society
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• v.45 no.4
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• pp.213-218
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• 2009

Objective : This study is a retrospective clinical study over more than 4 years of follow up to understand the mechanism of load sharing across the graft-bone interface in the static locking plate (SLP) fixation compared with non-locking plate (NLP). Methods : Orion locking plates and Top non-locking plates were used for SLP fixation in 29 patients and NLP fixation in 24 patients, respectively. Successful interbody fusion was estimated by dynamic X-ray films. The checking parameters were as follows : screw angle (SA) between upper and lower screw, anterior and posterior height of fusion segment between upper and lower endplate (AH & PH), and upper and lower distance from vertebral endplate to the end of plate (UD & LD). Each follow-up value of AH and PH were compared to initial values. Contributions of upper and lower collapse to whole segment collapse were estimated. Results : Successful intervertebral bone fusion rate was 100% in the SLP group and 92% in the NLP group. The follow-up mean value of SA in SLP group was not significantly changed compared with initial value, but follow-up mean value of SA in NLP group decreased more than those in SLP group (p=0.0067). Statistical analysis did not show a significant difference in the change in AH and PH between SLP and NLP groups (p>0.05). Follow-up AH of NLP group showed more collapse than PH of same group (p=0.04). The upper portion of the vertebral body collapsed more than the lower portion in the SLP fixation (p=0.00058). Conclusion : The fused segments with SLP had successful bone fusion without change in initial screw angle, which was not observed in NLP fixation. It suggests that there was enough load sharing across bone-graft interface in SLP fixation.

• Journal of Korean Neurosurgical Society
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• v.63 no.3
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• pp.386-396
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• 2020

Objective : To generate synthetic spine magnetic resonance (MR) images from spine computed tomography (CT) using generative adversarial networks (GANs), as well as to determine the similarities between synthesized and real MR images. Methods : GANs were trained to transform spine CT image slices into spine magnetic resonance T2 weighted (MRT2) axial image slices by combining adversarial loss and voxel-wise loss. Experiments were performed using 280 pairs of lumbar spine CT scans and MRT2 images. The MRT2 images were then synthesized from 15 other spine CT scans. To evaluate whether the synthetic MR images were realistic, two radiologists, two spine surgeons, and two residents blindly classified the real and synthetic MRT2 images. Two experienced radiologists then evaluated the similarities between subdivisions of the real and synthetic MRT2 images. Quantitative analysis of the synthetic MRT2 images was performed using the mean absolute error (MAE) and peak signal-to-noise ratio (PSNR). Results : The mean overall similarity of the synthetic MRT2 images evaluated by radiologists was 80.2%. In the blind classification of the real MRT2 images, the failure rate ranged from 0% to 40%. The MAE value of each image ranged from 13.75 to 34.24 pixels (mean, 21.19 pixels), and the PSNR of each image ranged from 61.96 to 68.16 dB (mean, 64.92 dB). Conclusion : This was the first study to apply GANs to synthesize spine MR images from CT images. Despite the small dataset of 280 pairs, the synthetic MR images were relatively well implemented. Synthesis of medical images using GANs is a new paradigm of artificial intelligence application in medical imaging. We expect that synthesis of MR images from spine CT images using GANs will improve the diagnostic usefulness of CT. To better inform the clinical applications of this technique, further studies are needed involving a large dataset, a variety of pathologies, and other MR sequence of the lumbar spine.

• Current Research on Agriculture and Life Sciences
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• v.3
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• pp.197-202
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• 1985

A number of the remains of animals were unearthed from Anup pond in Kyungzu during the repair work in March, 1975. To determine the species of animal origin and the ages and sexes of them, some judgement and morphological examination of the animal remains were conducted and the results obtained with the bone remains believed to be of horses are summarized as follow. 1. The total of the remains of horses excavated were 28 teeth and 9 pieces of bones. The bones were classified into on each of skull, humerus, radius, the first phalanx, femur and tibia, the remaining 3 pieces being cervical vertebrae. 2. The cranial bone was relatively in fair preservation and, on the whole, the gross appearance was quite similar to that of current Korean native horses. With the defacement of the teeth, the horse remains could be of a mare with the age less than 10 years. 3. The size of the appendicular skeletons were a bit smaller than that of Korean native horse at present. 4. The results obtained in the present study strongly indicated that the horse remains excavated from the An up pond could be of at least 2 or more horses.

• Clinical and Experimental Pediatrics
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• v.49 no.10
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• pp.1067-1072
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• 2006

Purpose : The purpose of this study was to examine the clinical courses and long-term outcomes of children with Allagille syndrome in Korea, and to evaluate the prognostic potentials of identified variables. Methods : We reviewed the clinical manifestations and outcomes of 30 children with Alagille syndrome, investigated from 1984 to 2006 until the end of this study (defined as death or last visit; mean follow-up : 5 years). Results : Cholestasis occurred in 100 percent, cardiovascular abnormalities in 83.3 percent, butterfly vertebrae in 30.0 percent, posterior embryotoxon in 43.3 percent, and a characteristic facial appearance in 100 percent. At study conclusion, of these 30 patients, eight had died (26.7 percent); six related to Alagille syndrome. Five patients died of a liver disease complication. Liver transplantation was carried out in five of the 30 patients (16.7 percent) and one of these died due to hyperacute rejection. At age two, cholestasis improved in 17 of the 30 patients. Those who had severe cholestasis at 2 years of age tended to have a complication, such as liver cirrhosis or liver transplantation, or to have died. Conclusion : Hepatic complications account for the most mortalities in patients with Alagille syndrome. Careful and complete assessments should be made in children who have cholestasis at 2 years of age. Further investigations of more cases are required.

• Journal of Korean Neurosurgical Society
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• v.63 no.2
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• pp.237-247
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• 2020

Objective : Fixation of the C1-2 segment is challenging because of the complex anatomy in the region and the need for a high degree of accuracy to avoid complications. Preoperative 3D-computed tomography (CT) scans can help reduce the risk of complications in the vertebral artery, spinal cord, and nerve roots. However, the patient may be susceptible to injury if the patient's anatomy does not match the preoperative CT scans. The intraoperative 3D image-based navigation systems have reduced complications in instrument-assisted techniques due to greater accuracy. This study aimed to compare the radiologic outcomes of C1-2 fusion surgery between intraoperative CT image-guided operation and fluoroscopy-guided operation. Methods : We retrospectively reviewed the radiologic images of 34 patients who underwent C1-2 fusion spine surgery from January 2009 to November 2018 at our hospital. We assessed 17 cases each of degenerative cervical disease and trauma in a study population of 18 males and 16 females. The mean age was 54.8 years. A total of 139 screws were used and the surgical procedures included 68 screws in the C1 lateral mass, 58 screws in C2 pedicle, nine screws in C2 lamina and C2 pars screws, four lateral mass screws in sub-axial level. Of the 34 patients, 19 patients underwent screw insertion using intraoperative mobile CT. Other patients underwent atlantoaxial fusion with a standard fluoroscopy-guided device. Results : A total of 139 screws were correctly positioned. We analyzed the positions of 135 screws except for the four screws that performed the lateral mass screws in C3 vertebra. Minor screw penetration was observed in seven cases (5.2%), and major pedicle screw penetration was observed in three cases (2.2%). In one case, the malposition of a C2 pedicle screw was confirmed, which was subsequently corrected. There were no complications regarding vertebral artery injury or onset of new neurologic deficits. The screw malposition rate was lower (5.3%) in patients who underwent intraoperative CT-based navigation than that for fluoroscopy-guided cases (10.2%). And we confirmed that the operation time can be significantly reduced by surgery using intraoperative O-arm device. Conclusion : Spinal navigation using intraoperative cone-beam CT scans is reliable for posterior fixation in unstable C1-2 pathologies and can be reduced the operative time.

• Journal of Korean Neurosurgical Society
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• v.29 no.1
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• pp.78-86
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• 2000

Objective : Lumbar spinal instability occurs when normal biomechanics support in lumbar vertebrae interrupted. Despite the recent enthusiastic studies, the precise radiological assessment has not been fully established, yet. Therefore, we carefully studied our cases to analyze the radiologic findings in lumbar spinal instability. Patients and Methods : We have put together radiological analysis and assessment based on 38 patients who have been diagnosed and treated for lumbar spinal instabilities from June 1994 to December 1998, Patients who have been diagnosed and treated for trauma were excluded from study. Results : The outcomes are as follows : 1) Lumbar lordotic curve was statistically significant in unstable group by 23.7, compared to the control group ($17.0^{\circ}$). 2) According to the resting x-ray, sagittal plane angulation measured on unstable group was $21.1^{\circ}$, control group $18.0^{\circ}$. Therefore unstable group was noticeably higher(p<0.01). 3) According to the resting x-ray sagittal plane displacement, unstable group had 4.3mm, the comparison had 1.2mm. Therefore measurement from the unstable group were significantly higher(p<0.01). 4) According to stress view, sagittal plane translation was 4.1mm for the unstables and 2.7mm for the comparisons. Therefore unstables were noticeably higher(p<0.01). 5) According to stress view, sagittal plane rotation was $15.1^{\circ}$ at L3-4, $22.0^{\circ}$ at L4-5, $27.9^{\circ}$ at L5S1 for the unstable group and $11.3^{\circ}$, $18.1^{\circ}$, $21.0^{\circ}$ each for the comparison. 6) Facet angle for unstable group, left $29.3^{\circ}-61.5^{\circ}$, right $24.4^{\circ}-63.2^{\circ}$ and the mean for each are $43.1^{\circ}$, $47.2^{\circ}$. The difference between left and right facet angle was $3.5^{\circ}-20.7^{\circ}$ and the mean value $15.3^{\circ}$. Facet angle for the comparisons for the left was $29.3^{\circ}-59.5^{\circ}$, right was in between $25.7^{\circ}-64.5^{\circ}$ range and the each mean are $44.9^{\circ}$ and $47.6^{\circ}$. Also, the difference between left and right facet angle was $4.1^{\circ}-9.3^{\circ}$ and the average was $17.1^{\circ}$. The average and the difference between the left and right angle are found not to have statistic necessity for both unstable and stable measurements(p>0.01). 7) 19 patients were found to have vacuum facet phenomenon among unstable group etc. results were collected. Conclusion : According to above results, we attempted to prepare the application to the patient of radiological analysis and assessment for lumbar spinal instability early checkup.

• Journal of Korean Neurosurgical Society
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• v.29 no.1
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• pp.58-65
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• 2000

Objective : Thoracolumbar junction is second most common level of injury next to cervical spine. The object of this study is to study the usefulness of surgical titanium mesh instead of bone graft, as well as to evaluate the correction of spinal deformity and safety of early ambulation in patients with injury at thoracolumbar junction. Patients and Methods : This review included 51 patients who were operated from July 1994 to December 1997. The injured spine is considered to be unstable, if it shows involvement of two or more columns, translatory displacement more than 3.5mm, decrease more than 35% in height of vertebral body and progression of malalignment in serial X-ray. The decision to operate was determined by (1) compression of spinal cord or cauda eguina, (2) unstable fracture, (3) malalignment and (4) fracture dislocation. The procedure consisted of anterior decompression through corpectomy and internal fixation with anterior instrument and surgical titanium mesh which was impacted with gathered bone chip from corpectomy. Results : Fifty-one patients were followed up for at least 12 months. The main causes of injury were fall and vehicle accident. The twelfth thoracic and the first and the second lumbar vertebrae were frequently involved. Complete neural decompression was possible under direct vision in all cases. Kyphotic angulation occurred in a patient. Radiologic evaluation showed correction of deformity and no distortion or loosening of surgical titanium mesh with satisfactory fixation postoperatively. Conclusions : We could obtain neurological improvement, relief of pain, immediate stabilization and early return to normal activities postoperatively. Based on these results, authors recommend anterior decompression and internal fixation with surgical titanium mesh in thoracolumbar unstable spine injuries.

• Journal of Korean Neurosurgical Society
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• v.60 no.6
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• pp.691-700
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• 2017

Objective : The authors prospectively analyzed the effect of one-level or two-level anterior cervical discectomy and fusion (ACDF), comparing stand-alone cages and cage-with-plate fixation constructs with respect to clinical outcomes and radiologic changes. Methods : A total of 84 patients who underwent one-level (n=52) or two-level ACDF (n=32) for cervical disc disease and who completed 2 years of follow-up were included in this study. The patients were divided by cervical level and grouped into ACDF-Cage-only and ACDF-Cage-with-plate groups. The following parameters were assessed using radiographs : subsidence, C2-C7 lordosis angle, fusion segment angle, adjacent disc space narrowing, and fusion status. Clinical outcomes were assessed using the neck disability index (NDI) and visual analog scale scores for arm pain. Results : In the comparison of one-level ACDF-cage-only and ACDF-cage-with-plate groups, the NDI score was better in the cage-only group at the 3-, 12-, and 24-month follow-ups : however, no significant difference in clinical outcomes was observed. In the comparison of two-level ACDF-cage-only and ACDF-cage-with-plate groups, no difference in any clinical outcome was observed between the two groups. At the 24-month follow-up, subsidence was observed in 45.8% of patients in the one-level cage-only group and 32.1% of patients in the one-level cage-with-plate fixation group. There was no statistically significant difference in the incidence rate between the two groups (p=0.312). Subsidence in the two-level cage-only group (66.6%) was significantly more frequent than in the two-level cage-with-plate fixation group (30%; p=0.049). The fusion rate for patients in the one-level cage-only group was not significantly different from that in the one-level cage-with-plate fixation group (cage-only, 87.5%; cage-with-plate fixation, 92.9%; p=0.425) ; fusion rate in the two-level patients were also similar between groups (cage-only, 83.3%; cage-with-plate fixation, 95%; p=0.31). Conclusion : Our clinical results showed that for single-level cases, plate fixation had no additional benefit versus cage-only; for two-level ACDF cases, the fusion rate and clinical outcomes were similar, although the cage-with-plate fixation group had a lower incidence of cage subsidence than did the cage-only group. We conclude that physicians should be aware of this possible disadvantage associated with using cervical plates in one-level ACDF. However, in two-level ACDF, subsidence is more likely to occur without plate fixation, and thus the addition of plate fixation should be considered.