• Journal of Korean Neurosurgical Society
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• v.42 no.1
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• pp.46-48
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• 2007

Distant metastasis of squamous cell carcinoma from the anal canal is an uncommon event. However, hematogenous spread to the vertebrae may occur in the course of this disease. The route of metastasis from the anal canal seems to be Batson's vertebral venous system. A 52-year-old female patient presented with lower back and right leg pain of one-week history. She has undergone radiotherapy and chemotherapy for squamous cell carcinoma of the anal canal and then was followed by surgical resection. Three months later, magnetic resonance images of the lumbar spine disclosed a well-enhanced mass of L5 vertebral body compressing the thecal sac. Surgical decompression and biopsy were performed. Histopathological study confirmed carcinoma of the squamous cell origin. We report a ra re case of vertebral metastasis from squamous cell carcinoma of the anal canal with a pertinent review of literature.

• Journal of Dental Anesthesia and Pain Medicine
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• v.18 no.3
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• pp.183-187
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• 2018

Complex cervical spine fractures are a serious complications of maxillofacial trauma and associated with high mortality and neurological morbidity. Strict vigilance in preventing further insult to the cervical spine is a crucial step in managing patients who are at risk for neurologic compromise. We report a rare case of a right transverse process of atlas fracture with right-sided vertebral artery injury that was associated with a comminuted fracture of the body and angle of the mandible, which restricted mouth opening. Airway management was performed by an awake fiber-optic nasotracheal intubation, where neck movement was avoided with a cervical collar. Vertebral artery injuries may have disastrous consequences, such as basilar territory infarction and death, and should be suspected in patients with head and neck trauma. After mandibular plating, the patient was on cervical collar immobilization for 12 weeks and anti-coagulant therapy.

• Journal of Korean Neurosurgical Society
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• v.39 no.2
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• pp.92-95
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• 2006

Objective : Severe vertebral body collapse [vertebra plana] is considered a contraindication to vertebroplasty by most authors. The purpose of this study is to determine the efficacy of vertebroplasty in treating severe compression fracture patients with osteoporosis. Methods : 16 patients underwent 18 vertebroplasties following postural reduction for vertebra plana. The fractures were defined vertebrae that have collapsed to more than 75% of their original height. Imaging and clinical features were analyzed, including involved vertebrae level, vertebral height after postural reduction for 2 days, injected cement volume, clinical outcome and complications. Results : Involved veretebra were located from level T7 to L4. Vertebral body collapse averaged 79% [range $12{\sim}25%$] of the original height. After pillow reduction for 2 days, vertebral body height increased 35% of the original height [range $15{\sim}45%$]. The kyphotic wedge was $12^{\circ}$ before procedure and was decreased $7.0^{\circ}$ after vertebroplasty. The mean injected cement volume was 3.8ml [range $2.0{\sim}4.9ml$]. After the procedure, surgical outcome was excellent in 8 [50%] of 16 patients, good in 7 [42%] and unchanged in one [8%]. The mean pain score [VAS score] prior to vertebroplasty was 8.3 and it changed 3.2 after the procure. Cement leakage to the adjacent disc [5 cases] and paravertebral soft tissues [4 cases] developed but there were no major complications. Conclusion : We propose that vertebra plana due to osteoporosis is not a contraindication to vertebroplasty. Vertebroplasty following postural reduction for severe compression fracture is safe and effective treatment.

• Korean Journal of Radiology
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• v.20 no.1
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• pp.126-133
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• 2019

Objective: To compare the lumbar vertebral bone marrow fat-signal fractions obtained from six-echo modified Dixon sequence (6-echo m-Dixon) with those from single-voxel magnetic resonance spectroscopy (MRS) in patients with low back pain. Materials and Methods: Vertebral bone marrow fat-signal fractions were quantified by 6-echo m-Dixon (repetition time [TR] = 7.2 ms, echo time (TE) = 1.21 ms, echo spacing = 1.1 ms, total imaging time = 50 seconds) and single-voxel MRS measurements in 25 targets (23 normal bone marrows, two focal lesions) from 24 patients. The point-resolved spectroscopy sequence was used for localized single-voxel MRS (TR = 3000 ms, TE = 35 ms, total scan time = 1 minute 42 seconds). A 2 × 2 × 1.5 cm³ voxel was placed within the normal L2 or L3 vertebral body, or other lesions including a compression fracture or metastasis. The bone marrow fat spectrum was characterized on the basis of the magnitude of measurable fat peaks and a priori knowledge of the chemical structure of triglycerides. The imaging-based fat-signal fraction results were then compared to the MRS-based results. Results: There was a strong correlation between m-Dixon and MRS-based fat-signal fractions (slope = 0.86, R² = 0.88, p < 0.001). In Bland-Altman analysis, 92.0% (23/25) of the data points were within the limits of agreement. Bland-Altman plots revealed a slight but systematic error in the m-Dixon based fat-signal fraction, which showed a prevailing overestimation of small fat-signal fractions (< 20%) and underestimation of high fat-signal fractions (> 20%). Conclusion: Given its excellent agreement with single-voxel-MRS, 6-echo m-Dixon can be used for visual and quantitative evaluation of vertebral bone marrow fat in daily practice.

• Journal of the Korean Society for Precision Engineering
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• v.33 no.11
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• pp.937-941
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• 2016

Stand-alone cervical cage consists of a PEEK body, Ti plate, and screw, which are configured as a single-piece. Through a single operation, this implantable medical device is capable of completely fixing the cervical vertebral body. For example, instead of a plate, which is normally used, the intervertebral disc is removed and replaced with a cervical cage. It should be noted that in Korea, KFDA guidelines for a stand-alone cervical cage have not yet been suggested. Therefore, the aim of this study is to present the systematic study of the static compression test, static torsion test, dynamic compression test, and expulsion test. Further, the test method is designed to refer to the ASTM standard and relative literature.

• Journal of the Korean Orthopaedic Association
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• v.54 no.1
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• pp.24-29
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• 2019

Purpose: To evaluate the characteristics and the risk factors of early onset subsequent vertebral compression fractures after percutaneous vertebroplasty. Materials and Methods: A total of 44 patients, who had a new subsequent vertebral fracture after percutaneous vertebroplasty for an osteoporotic vertebral compression fracture between January 2013 and December 2015, were recruited. The patients were divided into two groups according to the onset period of subsequent fracture. The number of patients who had a fracture within 3 months following vertebroplasty were 22 cases (Group A); after 3 months were 22 cases (Group B). Variables, including age, sex, bone mineral density (BMD), body mass index (BMI), preexisting vertebral compression fracture, location of the initial fracture, intradiscal cement leakage, injected cement volume, restoration of vertebral body height, and correction of kyphosis, in the two groups were analyzed and compared retrospectively. Results: The age, sex, BMD, BMI, preexisting vertebral compression fracture, location of the initial fracture, intradiscal cement leakage, and correction of kyphosis were similar in the two groups. Both a greater volume of bone cement injected and a greater degree of vertebral height restoration contributed significantly to the risk of fracture within 3 months. Conclusion: The cement volume and degree of height restoration are risk factors for early onset fracture at the adjacent vertebrae after percutaneous vertebroplasty and close attention is needed during the follow-up period.

• Proceedings of the KSMRM Conference
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• 1999.11a
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• pp.102-102
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• 1999

• Progress in Medical Physics
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• v.24 no.3
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• pp.145-153
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• 2013

Stereotactic body radiation therapy (SBRT) is increasingly used to treat spinal metastases. To achieve the highest steep dose gradients and conformal dose distributions of target tumors, intensity-modulated radiation therapy (IMRT) and volumetric-modulated arc therapy (VMAT) techniques are essential to spine radiosurgery. The purpose of the study was to qualitatively compare IMRT and VMAT techniques with International Spine Radiosurgery Consortium (ISRC) contoured consensus guidelines for target volume definition. Planning target volume (PTV) was categorized as TB, $T_{BPT}$ and $T_{ST}$ depending on sectors involved; $T_B$ (vertebral body only), $T_{BPT}$ (vertebral body+pedicle+transverse process), and $T_{ST}$ (spinous process+transverse process). Three patients treated for spinal tumor in the cervical, thoracic, and lumbar region were selected. Eacg tumor was contoured by the definition from the ISRC guideline. Maximum spinal cord dose were 12.46 Gy, 12.17 Gy and 11.36 Gy for $T_B$, $T_{BPT}$ and $T_{ST}$ sites, and 11.81 Gy, 12.19 Gy and 11.99 Gy for the IMRT, RA1 and RA2 techniques, respectively. Average fall-off dose distance from 90% to 50% isodose line for $T_B$, $T_{BPT}$, and $T_{ST}$ sites were 3.5 mm, 3.3 mm and 3.9 mm and 3.7 mm, 3.7 mm and 3.3 mm for the IMRT, RA1 and RA2 techniques, respectively. For the most complicated target $T_{BPT}$ sites in the cervical, thoracic and lumbar regions, the conformity index of the IMRT, RA1 and RA2 is 0.621, 0.761 and 0.817 and 0.755, 0.796 and 0.824 for rDHI. Both IMRT and VMAT techniques delivered high conformal dose distributions in spine stereotactic radiosurgery. However, if the target volume includes the vertebral body, pedicle, and transverse process, IMRT planning resulted in insufficient conformity index, compared to VMAT planning. Nevertheless, IMRT technique was more effective in reducing the maximum spinal cord dose compared to RA1 and RA2 techniques at most sites.

• Journal of Korean Neurosurgical Society
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• v.52 no.4
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• pp.300-305
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• 2012

Objective : The purpose of this study is to elucidate the anatomic relationships between the uncinate process and surrounding neurovascular structures to prevent possible complications in anterior cervical surgery. Methods : Twenty-eight formalin-fixed cervical spines were removed from adult cadavers and were studied. The authors investigated the morphometric relationships between the uncinate process, vertebral artery and adjacent nerve roots. Results : The height of the uncinate process was 5.6-7.5 mm and the width was 5.8-8.0 mm. The angle between the posterior tip of the uncinate process and vertebral artery was $32.2-42.4^{\circ}$. The distance from the upper tip of the uncinate process to the vertebral body immediately above was 2.1-3.3 mm, and this distance was narrowest at the fifth cervical vertebrae. The distance from the posterior tip of the uncinate process to the nerve root was 1.3-2.0 mm. The distance from the uncinate process to the vertebral artery was measured at three different points of the uncinate process : upper-posterior tip, lateral wall and the most antero-medial point of the uncinate process, and the distances were 3.6-6.1 mm, 1.7-2.8 mm, and 4.2-5.7 mm, respectively. The distance from the uncinate process tip to the vertebral artery and the angle between the uncinate process tip and vertebral artery were significantly different between the right and left side. Conclusion : These data provide guidelines for anterior cervical surgery, and will aid in reducing neurovascular injury during anterior cervical surgery, especially in anterior microforaminotomy.

• Journal of Korean Neurosurgical Society
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• v.37 no.2
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• pp.116-123
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• 2005

Objective: Percutaneous kyphoplasty using a balloon-catheter is an widely accepted method which achieves the restoration of vertebral height and the correction of kyphotic deformity with little complication in osteoporotic vertebral compression fractures. The authors assess the results of 59 patients who underwent kyphoplasty, and analyze the factors that could affect the prognosis. Methods: From December 2001 to May 2003, fifty-nine patients underwent kyphoplasty. The patients included 49 women and 10 men aged 52-85 years. Average t-score on bone marrow density was -3.58. About 7cc of polymethylmethacrylate(PMMA) was injected into the fractured vertebral body using $Kyphon^{(R)}$ under local anesthesia. The vertical height of all fractured vertebrae was measured both before and after surgery. Outcome data were obtained by comparing pre- and post-operative VAS score and by assessing postoperative satisfaction, drug dependency and activity. Various clinical factors were analyzed to assess the relationship with the outcome. Results: The VAS score improved significantly, and the mean percentage of restored vertebral height was 53%. The mean improvement in kyphosis was $3.6^{\circ}$. Eighty-nine percent of the patients gained excellent or good results. Any of the clinical factors including the interval between fracture and operation, the degree of height loss, the degree of the vertebral height restoration or the correction rate of kyphosis did not affect the clinical results. Conclusion: Kyphoplasty is associated with a statistically significant improvement in pain and function with little complication. The clinical results are not affected by any clinical parameters. Further follow-up study is needed to determine whether the restoration affects the long-term clinical results.