• Journal of Trauma and Injury
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• v.35 no.1
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• pp.12-18
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• 2022

Purpose: Pedicle screw fixation provides 3-column stabilization, multidimensional control, and a higher rate of interbody fusion. Although computed tomography (CT) is recommended for the postoperative assessment of pedicle screw fixation, its use is limited due to the radiation exposure dose. The purpose of this preliminary retrospective study was to assess the clinical usefulness of low-dose mobile cone-beam CT (CBCT) for the postoperative evaluation of pedicle screw fixation. Methods: The author retrospectively reviewed postoperative mobile CBCT images of 15 patients who underwent posterior pedicle screw fixation for spinal disease from November 2019 to April 2020. Pedicle screw placement was assessed for breaches of the bony structures. The breaches were graded based on the Heary classification. Results: The patients included 11 men and four women, and their mean age was 66±12 years. Of the 122 pedicle screws, 34 (27.9%) were inserted in the thoracic segment (from T7 to T12), 82 (67.2%) in the lumbar segment (from L1 to L5), and six (4.9%) in the first sacral segment. Although there were metal-related artifacts, the image of the screw position (according to Heary classification) after surgery could be assessed using mobile CBCT at all levels (T7-S1). Conclusions: Mobile CBCT was accurate in determining the location and integrity of the pedicle screw and identifying the surrounding bony structures. In the postoperative setting, mobile CBCT can be used as a primary modality for assessing the accuracy of pedicle screw fixation and detecting postoperative complications.

• Journal of Korean Neurosurgical Society
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• v.40 no.6
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• pp.471-475
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• 2006

Complete vertebral tumor resection is important in order to prevent local recurrence. Among the available techniques for total spondylectomy, the total en bloc spondylectomy has been accepted as the most sophisticated one. After a total en bloc spondylectomy, anterior and posterior column reconstruction is mandatory in order to achieve stability. We experienced the usefulness of an expandable cage for anterior column reconstruction especially in this surgery. The chance of cutting the nerve root and damaging the spinal cord is minimized because the size of the expandable cage is initially small enough to be inserted into the anterior column. The technical details of total vertebral body replacement with an expandable cage after an en bloc lumbar spondylectomy are described herein.

• Journal of Korean Neurosurgical Society
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• v.49 no.1
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• pp.58-60
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• 2011

Ligamentum flavum hematoma (LFH) is a very rare condition of dural compression; most are observed in the mobile cervical and lumbar spine regions. A 67-year-old man who had a long level interbody fusion at L3-S1 four years ago presented with symptoms suggestive of dural compression. Magnetic resonance imaging showed a posterior semicircular mass located at the adjacent L2-L3 level. After decompression of the spinal canal and removal of the mass lesion, pathological examination of the surgical specimen revealed a hematoma within the ligamentum. The patient fully recovered to normal status after surgery. Here, we report our experience with a LFH in the adjacent segment after a long level fusion procedure and discuss the possible associated mechanisms.

• Journal of Korean Neurosurgical Society
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• v.67 no.1
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• pp.6-13
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• 2024

The integrity of the high cervical spine, the transition zone from the brainstem to the spinal cord, is crucial for survival and daily life. The region protects the enclosed neurovascular structure and allows a substantial portion of the head motion. Injuries of the high cervical spine are frequent, and the fractures of the C2 vertebra account for approximately 17-25% of acute cervical fractures. We review the two major types of C2 vertebral fractures, odontoid fracture and Hangman's fracture. For both types of fractures, favorable outcomes could be obtained if the delicately selected conservative treatment is performed. In odontoid fractures, as the most common fracture on the C2 vertebrae, anterior screw fixation is considered first for type II fractures, and C1-2 fusion is suggested when nonunion is a concern or occurs. Hangman's fractures are the second most common fracture. Many stable extension type I and II fractures can be treated with external immobilization, whereas the predominant flexion type IIA and III fractures require surgical stabilization. No result proves that either anterior or posterior surgery is superior, and the surgeon should decide on the surgical method after careful consideration according to each clinical situation. This review will briefly describe the basic principles and current treatment concepts of C2 fractures.

• Journal of Korean Neurosurgical Society
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• v.48 no.1
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• pp.37-45
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• 2010

Objective : Craniovertebral junction (CVJ) consists of the occipital bone that surrounds the foramen magnum, the atlas and the axis vertebrae. The mortality and morbidity is high for irreducible CVJ lesion with cervico-medullary compression. In a clinical retrospective study, the authors reviewed clinical and radiographic results of occipitocervical fusion using a various methods in 32 patients with CVJ instability. Methods : Thirty-two CVJ lesions (18 male and 14 female) were treated in our department for 12 years. Instability resulted from trauma (14 cases), rheumatoid arthritis (8 cases), assimilation of atlas (4 cases), tumor (2 cases), basilar invagination (2 cases) and miscellaneous (2 cases). Thirty-two patients were internally fixed with 7 anterior and posterior decompression with occipitocervical fusion, 15 posterior decompression and occipitocervical fusion with wire-rod, 5 C1-2 transarticular screw fixation, and 5 C1 lateral mass-C2 transpedicular screw. Outcome (mean follow-up period, 38 months) was based on clinical and radiographic review. The clinical outcome was assessed by Japanese Orthopedic Association (JOA) score. Results : Nine neurologically intact patients remained same after surgery. Among 23 patients with cervical myelopathy, clinical improvement was noted in 18 cases (78.3%). One patient died 2 months after the surgery because of pneumonia and sepsis. Fusion was achieved in 27 patients (93%) at last follow-up. No patient developed evidence of new, recurrent, or progressive instability. Conclusion : The authors conclude that early occipitocervical fusion to be recommended in case of reducible CVJ lesion and the appropriate decompression and occipitocervical fusion are recommended in case of irreducible craniovertebral junction lesion.

• Journal of Korean Neurosurgical Society
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• v.60 no.2
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• pp.225-231
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• 2017

Objective : Solid bone fusion is an essential process in spinal stabilization surgery. Recently, as several minimally invasive spinal surgeries have developed, a need of artificial bone substitutes such as demineralized bone matrix (DBM), has arisen. We investigated the in vivo bone growth rate of DBM as a bone void filler compared to a local autologous bone grafts. Methods : From April 2014 to August 2015, 20 patients with a one or two-level spinal stenosis were included. A posterior lumbar interbody fusion using two cages and pedicle screw fixation was performed for every patient, and each cage was packed with autologous local bone and DBM. Clinical outcomes were assessed using the Numeric Rating Scale (NRS) of leg pain and back pain and the Korean Oswestry Disability Index (K-ODI). Clinical outcome parameters and range of motion (ROM) of the operated level were collected preoperatively and at 3 months, 6 months, and 1 year postoperatively. Computed tomography was performed 1 year after fusion surgery and bone growth of the autologous bone grafts and DBM were analyzed by ImageJ software. Results : Eighteen patients completed 1 year of follow-up, including 10 men and 8 women, and the mean age was 56.4 (32-71). The operated level ranged from L3/4 to L5/S1. Eleven patients had single level and 7 patients had two-level repairs. The mean back pain NRS improved from 4.61 to 2.78 (p=0.003) and the leg pain NRS improved from 6.89 to 2.39 (p<0.001). The mean K-ODI score also improved from 27.33 to 13.83 (p<0.001). The ROM decreased below 2.0 degrees at the 3-month assessment, and remained less than 2 degrees through the 1 year postoperative assessment. Every local autologous bone graft and DBM packed cage showed bone bridge formation. On the quantitative analysis of bone growth, the autologous bone grafts showed significantly higher bone growth compared to DBM on both coronal and sagittal images (p<0.001 and p=0.028, respectively). Osteoporotic patients showed less bone growth on sagittal images. Conclusion : Though DBM alone can induce favorable bone bridging in lumbar interbody fusion, it is still inferior to autologous bone grafts. Therefore, DBM is recommended as a bone graft extender rather than bone void filler, particularly in patients with osteoporosis.

• Journal of Chest Surgery
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• v.32 no.5
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• pp.489-493
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• 1999

The pectus carinatum or anterior protrusion of the sternum is a less common than pectus excavatum. It occurs more frequently in boys than girls and associated musculoskeletal abnormalities, spinal scoliosis is most common. Ravitch first reported correction of chondromanubrial prominence in 1952, resecting the multiple deformed costal cartilages and performing a double osteotomy on sternum. We have experienced one case of pectus carinatum and obtained satisfactory postoperative results. The deformity was corrected by the subchondral resection of multiple deformed costal cartilage, bilaterally, with single osteotomy on sternum and fracture of the posterior cortex to correct anterior angulation. Postoperative course was uneventful. We report this case with brief review of the literature.

• Journal of Korean Neurosurgical Society
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• v.54 no.2
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• pp.128-131
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• 2013

Transforaminal lumbar interbody fusion (TLIF) is commonly used procedure for spinal fusion. However, there are no reports describing anterior cage dislodgement after surgery. This report is a rare case of anterior dislodgement of fusion cage after TLIF for the treatment of isthmic spondylolisthesis with lumbosacral transitional vertebra (LSTV). A 51-year-old man underwent TLIF at L4-5 with posterior instrumentation for the treatment of grade 1 isthmic spondylolisthesis with LSTV. At 7 weeks postoperatively, imaging studies demonstrated that banana-shaped cage migrated anteriorly and anterolisthesis recurred at the index level with pseudoarthrosis. The cage was removed and exchanged by new cage through anterior approach, and screws were replaced with larger size ones and cement augmentation was added. At postoperative 2 days of revision surgery, computed tomography (CT) showed fracture on lateral pedicle and body wall of L5 vertebra. He underwent surgery again for paraspinal decompression at L4-5 and extension of instrumentation to S1 vertebra. His back and leg pains improved significantly after final revision surgery and symptom relief was maintained during follow-up period. At 6 months follow-up, CT images showed solid fusion at L4-5 level. Careful cage selection for TLIF must be done for treatment of spondylolisthesis accompanied with deformed LSTV, especially when reduction will be attempted. Banana-shaped cage should be positioned anteriorly, but anterior dislodgement of cage and reduction failure may occur in case of a highly unstable spine. Revision surgery for the treatment of an anteriorly dislodged cage may be effectively performed using an anterior approach.

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

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

• Journal of Korean Neurosurgical Society
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• v.64 no.6
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• pp.944-949
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• 2021

Objective : The stability is an important factor to decide the treatment plan in thoracolumbar burst fracture patients. Patients with an unstable burst fracture generally need operative management. Decrease in vertebral body height, local kyphosis, involvement of posterior column, and/or canal compromise are considered important factors to determine the treatment plan. On the other hand, in thoracolumbar injury classification system (TLICS), surgery is recommended in patients with TLICS of more than 5 points. The purpose of this study was to apply the TLICS score in patients with thoracolumbar burst fractures and to distinguish the differences of treatment plan on burst fracture. Methods : All patients, diagnosed as a thoracolumbar burst fracture between January 2006 and February 2019 were included in this study. Unstable thoracolumbar burst fracture was defined as burst fracture with neurologic deficit, three-column injury, kyphosis over 30 degrees, decrease of anterior body height over 40 percent and canal comprise more than 50%. TLICS score was measured with morphology, neurological involvement and posterior ligamentous complex integrity. The existence of instability was compared with TLICS score. Results : Total 233 patients (131 men, 102 women) were included in this study. In Denis classification, 51 patients (21.9%) diagnosed as stable burst fracture while 182 patients (78.1%) had unstable burst fracture. According to TLICS, 72 patients (30.9%) scored less than 4, while 161 patients (69.1%) scored 4 or more. All the patients with stable burst fracture scored 2 in TLICS. Twenty-one patients (9.0) scored 2 in TLICS but diagnosed as unstable burst fracture. Thirteen patients had over 40% of vertebra body compression, four patients had more than 50% of canal compromise, three patients had both body compression over 40% and kyphosis over 30 degrees, one patients had both body compression and canal compromise. Fifteen patients presented kyphosis over 30 degrees, and three (20%) of them scored 2 in TLICS. Seventy-three patients presented vertebral body compression over 40% and 17 (23.3%) of them scored 2 in TLICS. Fifty-three patients presented spinal canal compromise more than 50%, and five (9.4%) of them scored 2 in TLICS. Conclusion : Although the instability of thoracolumbar burst fracture was regarded as a critical factor for operability, therapeutic strategies by TLICS do not exactly match with the concept of instability. According to the concept of TLICS, it should be reconsidered whether the unstable burst fracture truly unstable to do operation.