• Journal of Korean Neurosurgical Society
• /
• v.64 no.6
• /
• pp.901-912
• /
• 2021

Objective : In the cervical spine, many surgical procedures have been developed to achieve optimal results for various disorders, including degenerative diseases, traumatic injury, and tumor. In this study, we report our experience and follow-up results with a new surgical technique for cervical spine entitled posterior floating laminotomy (PFL) in comparison with conventional laminectomy and fusion (LF). Methods : Data for 85 patients who underwent conventional LF (n=66) or PFL (n=19) for cervical spine disorders between 2012 and 2019 were analyzed. Radiological parameters, including cervical lordosis (CL), T1 slope (T1S), segmental lordosis (SL), and C2-7 sagittal vertical axis (SVA), were measured with lateral spine X-rays. Functional outcomes, comprising the modified Japanese Orthopaedic Association (mJOA), neck disability index (NDI), and visual analog scale (VAS) scores, were also measured. For the patients who underwent PFL, postoperative magnetic resonance image (MRI) was performed in a month after the surgery, and the degree of decompression was evaluated at the T2-weighted axial image, and postoperative computed tomography (CT) was conducted immediately and 1 year after the operation to evaluate the gutter fusion. Results : There was no difference in CL, T1S, SL, and C2-7 SVA between the groups but there was a difference in the preoperative and postoperative SL angles. The mean difference in the preoperative SL angle compared with that at the last follow-up was -0.3° after conventional LF and 4.7° after PFL (p=0.04), respectively. mJOA, NDI, and VAS scores showed significant improvements (p<0.05) during follow-up in both groups. In the PFL group, postoperative MRI showed sufficient decompression and postoperative CT revealed gutter fusion at 1 year after the operation. Conclusion : PFL is a safe surgical method which can preserve postoperative CL and achieve good clinical outcomes.

• Asian Spine Journal
• /
• v.12 no.6
• /
• pp.1092-1099
• /
• 2018

Study Design: In-vitro biomechanical investigation. Purpose: To evaluate the biomechanical effects of the degeneration of the biodegradable cervical plates developed for anterior cervical discectomy and fusion (ACDF) on fusion and adjacent levels. Overview of Literature: Biodegradable implants have been recently introduced for cervical spine surgery. However, their effectiveness and safety remains unclear. Methods: A linear three-dimensional finite element (FE) model of the lower cervical spine, comprising the C4-C6 vertebrae was developed using computed tomography images of a 46-year-old woman. The model was validated by comparison with previous reports. Four models of ACDF were analyzed and compared: (1) a titanium plate and bone block (Tita), (2) strong biodegradable plate and bone block (PLA-4G) that represents the early state of the biodegradable plate with full strength, (3) weak biodegradable plate and bone block (PLA-1G) that represents the late state of the biodegradable plate with decreased strength, and (4) stand-alone bone block (Bloc). FE analysis was performed to investigate the relative motion and intervertebral disc stress at the surgical (C5-C6 segment) and adjacent (C4-C5 segment) levels. Results: The Tita and PLA-4G models were superior to the other models in terms of higher segment stiffness, smaller relative motion, and lower bone stress at the surgical level. However, the maximal von Mises stress at the intervertebral disc at the adjacent level was significantly higher in the Tita and PLA-4G models than in the other models. The relative motion at the adjacent level was significantly lower in the PLA-1G and Bloc models than in the other models. Conclusions: The use of biodegradable plates will enhance spinal fusion in the initial stronger period and prevent adjacent segment degeneration in the later, weaker period.

• Journal of Korean Neurosurgical Society
• /
• v.62 no.6
• /
• pp.700-711
• /
• 2019

Objective : The treatment of multiple thoracolumbar spine fractures according to fracture continuity has rarely been reported. Herein we evaluate the clinical features and outcomes of multiple thoracolumbar fractures depending on continuous or noncontinuous status. Methods : From January 2010 to January 2016, 48 patients with acute thoracic and lumbar multiple fractures who underwent posterior fusion surgery were evaluated. Patients were divided into two groups (group A : continuous; group B : noncontinuous). We investigated the causes of the injuries, the locations of the injuries, the range of fusion levels, and the functional outcomes based on the patients' general characteristics. Results : A total of 48 patients were enrolled (group A : 25 patients; group B : 23 patients). Both groups had similar pre-surgical clinical and radiologic features. The fusion level included three segments (group A : 4; group B : 5) or four segments (group A : 19; group B : 5). Group B required more instrumented segments than did group A. Group A scored 23.5 and group B scored 33.4 on the Korean Oswestry Disability Index (KODI) at the time of last follow-up. In both groups, longer fusion was associated with worse KODI score. Conclusion : In this study, due to the assumption of similar initial clinical and radiologic features in both group, the mechanism of multiple fractures is presumed to be the same between continuous and noncontinuous fractures. The noncontinuous fracture group had worse KODI scores in long-term follow-up, thought to be due to long fusion level. Therefore, we recommend minimizing the number of segments that are fused in multiple thoracolumbar and lumbar fractures when decompression is not necessary.

• Journal of Korean Neurosurgical Society
• /
• v.61 no.4
• /
• pp.494-502
• /
• 2018

Objective : The loosening of pedicle screws (PS) is one of the frequent problems of spinal surgery in the patients with osteoporosis. Previous studies had revealed that intermittent injection of teriparatide could reduce PS loosening by improving bone mass and quality when their patients took parathyroid hormone for a considerable duration before surgery. However, although the teriparatide is usually used after spine surgery in most clinical situations, there was no report on the efficacy of teriparatide treatment started after spine surgery. The purpose of this retrospective study was to examine the efficacy of teriparatide treatment started immediately after lumbar spinal surgery to prevent pedicle screw loosening in patients with osteoporosis. Methods : We included 84 patients with osteoporosis and degenerative lumbar disease who underwent transforaminal interbody fusion and PS fixation and received parathyroid hormone or bisphosphonate (BP) postoperatively. They were divided into teriparatide group (daily injection of $20{\mu}g$ of teriparatide for 6 months, 33 patients, 172 screws) and BP group (weekly oral administration of 35 mg of risedronate, 51 patients, 262 screws). Both groups received calcium (500 mg/day) and cholecalciferol (1000 IU/day) together. The screw loosening was evaluated with simple radiographic exams at 6 and 12 months after the surgery. We counted the number of patients with PS loosening and the number of loosened PS, and compared them between the two groups. Clinical outcomes were evaluated using visual analog scale (VAS) and Oswestry disability index (ODI) preoperatively, and at 12 months after surgery. Results : There was no significant difference in the age, sex, diabetes, smoking, bone mineral density, body mass index, and the number of fusion levels between the two groups. The number of PS loosening within 6 months after surgery did not show a significant difference between the teriparatide group (6.9%, 12/172) and the BP group (6.8%, 18/272). However, during 6-12 months after surgery, it was significantly lower in the teriparatide group (2.3%, 4/172) than the BP group (9.2%, 24/272) (p<0.05). There was no significant difference in the number of patients showing PS loosening between the teriparatide and BP groups. The teriparatide group showed a significantly higher degree of improvement of the bone mineral density (T-score) than that of BP group (p<0.05). There was no significant difference in the pre- and post-operative VAS and ODI between the groups. Conclusion : Our data suggest that the teriparatide treatment starting immediately after lumbar spinal fusion surgery could reduce PS loosening compared to BP.

• Journal of Korean Neurosurgical Society
• /
• v.51 no.3
• /
• pp.127-134
• /
• 2012

Objective: To analyze the prognostic factors thought to be related with survival time after a spinal metastasis operation. Methods: We retrospectively analyzed 217 patients who underwent spinal metastasis operations in our hospital from 2001 to 2009. Hematological malignancies, such as multiple myeloma and lymphoma, were excluded. The factors thought to be related with postoperative survival time were gender, age (below 55, above 56), primary tumor growth rate (slow, moderate, rapid group), spinal location (cervical, thoracic, and lumbo-sacral spine), the timing of radiation therapy (preoperative, postoperative, no radiation), operation type (decompressive laminectomy with or without posterior fixation, corpectomy with anterior fusion, corpectomy with posterior fixation), preoperative systemic condition (below 5 points, above 6 points classified by Tomita scoring), pre- and postoperative ambulatory function (ambulatory, non-ambulatory), number of spinal metastases (single, multiple), time to spinal metastasis from the primary cancer diagnosis (below 21 months, above 22 months), and postoperative complication. Results: The study cohort mean age at the time of surgery was 55.5 years. The median survival time after spinal operation and spinal metastasis diagnosis were 6.0 and 9.0 months. In univariate analysis, factors such as gender, primary tumor growth rate, preoperative systemic condition, and preoperative and postoperative ambulatory status were shown to be related to postoperative survival. In multivariate analysis, statistically significant factors were preoperative systemic condition (p=0.048) and postoperative ambulatory status (p<0.001). The other factors had no statistical significance. Conclusion: The factors predictive for postoperative survival time should be considered in the surgery of spinal metastasis patients.

• Journal of Korean Neurosurgical Society
• /
• v.29 no.2
• /
• pp.255-260
• /
• 2000

The authors report a posttraumatic syringomyelia in a 30-year-old man who has complained pain, weakness of upper arm and dissociation sensory loss since 2 months before. He was underwent by decompressive laminectomy from T12 to L1, reduction of encroached bony fragments, transpedicular screw fixation from T12 to L2 and posterolateral bony fusion due to burst fracture of L1 at other hospital 3 years ago. Preoperative spinal MRI was highly suggestive of wide-spread, multiseptated syringomyelia from C3 to thoracolumbar junction. We performed wide decompressive laminectomy from T10 to L2 and subarachnoid space reconstrucion composed of microdissection of meningeal fibrosis widely, iatrogenic meningocele formation with lefting the dura mater opened for treatment of spinal-spinal pressure dissociation. Clinical manifestations and radiological findings of the patient were improved after the operation. This technique was thought to be superior to shunting procedures in cases of wide-spread, multiseptated post-traumatic syringomyelia.

• Journal of Korean Neurosurgical Society
• /
• v.64 no.4
• /
• pp.495-504
• /
• 2021

Three-dimensional printing (3DP) applications possess substantial versatility within surgical applications, such as complex reconstructive surgeries and for the use of surgical resection guides. The capability of constructing an implant from a series of radiographic images to provide personalized anatomical fit is what makes 3D printed implants most appealing to surgeons. Our objective is to describe the process of integration of 3DP implants into the operating room for spinal surgery, summarize the outcomes of using 3DP implants in spinal surgery, and discuss the limitations and safety concerns during pre-operative consideration. 3DP allows for customized, light weight, and geometrically complex functional implants in spinal surgery in cases of decompression, tumor, and fusion. However, there are limitations such as the cost of the technology which is prohibitive to many hospitals. The novelty of this approach implies that the quantity of longitudinal studies is limited and our understanding of how the human body responds long term to these implants is still unclear. Although it has given surgeons the ability to improve outcomes, surgical strategies, and patient recovery, there is a need for prospective studies to follow the safety and efficacy of the usage of 3D printed implants in spine surgery.

• Journal of Korean Neurosurgical Society
• /
• v.60 no.5
• /
• pp.597-603
• /
• 2017

Objective : Several surgical methods have been reported for treatment of ossification of the posterior longitudinal ligament (OPLL) in the thoracic spine. Despite rapid innovation of instruments and techniques for spinal surgery, the postoperative outcomes are not always favorable. This article reports a minimally invasive anterior decompression technique without instrumented fusion, which was modified from the conventional procedure. The authors present 2 cases of huge beak-type OPLL. Patients underwent minimally invasive anterior decompression without fusion. This method created a space on the ventral side of the OPLL without violating global thoracic spinal stability. Via this space, the OPLL and anterior lateral side of the dural sac can be seen and manipulated directly. Then, total removal of the OPLL was accomplished. No orthosis was needed. In this article, we share our key technique and concepts for treatment of huge thoracic OPLL. Methods : Case 1. 51-year-old female was referred to our hospital with right lower limb radiating pain and paresis. Thoracic OPLL at T6-7 had been identified at our hospital, and conservative treatment had been tried without success. Case 2. This 54-year-old female with a 6-month history of progressive gait disturbance and bilateral lower extremity radiating pain (right>left) was admitted to our institute. She also had hypoesthesia in both lower legs. Her symptoms had been gradually progressing. Computed tomography scans showed massive OPLL at the T9-10 level. Magnetic resonance imaging of the thoracolumbar spine demonstrated ventral bony masses with severe anterior compression of the spinal cord at the same level. Results : We used this surgical method in 2 patients with a huge beaked-type OPLL in the thoracic level. Complete removal of the OPLL via anterior decompression without instrumented fusion was accomplished. The 1st case had no intraoperative or postoperative complications, and the 2nd case had 1 intraoperative complication (dural tear) and no postoperative complications. There were no residual symptoms of the lower extremities. Conclusion : This surgical technique allows the surgeon to safely and effectively perform minimally invasive anterior decompression without instrumented fusion via a transthoracic approach for thoracic OPLL. It can be applied at the mid and lower level of the thoracic spine and could become a standard procedure for treatment of huge beak-type thoracic OPLL.

• Journal of Korean Neurosurgical Society
• /
• v.64 no.5
• /
• pp.776-783
• /
• 2021

Objective : The purpose of this study was to identify risk factors for distal adding on (AO) or distal junctional kyphosis (DJK) in adolescent idiopathic scoliosis (AIS) treated by posterior spinal fusion (PSF) to L3 with a minimum 2-year follow-up. Methods : AIS patients undergoing PSF to L3 by two senior surgeons from 2000-2010 were analyzed. Distal AO and DJK were deemed poor radiographic results and defined as >3 cm of deviation from L3 to the center sacral vertical line (CSVL), or >10° angle at L3-4 on the posterior anterior- or lateral X-ray at ultimate follow-up. New stable vertebra (SV) and neutral vertebra (NV) scores were defined for this study. The total stability (TS) score was the sum of the SV and NV scores. Results : Ten of 76 patients (13.1%) were included in the poor radiographic outcome group. The other 66 patients were included in the good radiographic outcome group. Lower Risser grade, more SV-3 (CSVL doesn't touch the lowest instrumented vertebra [LIV]) on standing and side bending films, lesser NV and TS score, rigid L3-4 disc, more rotation and deviation of L3 were identified risk factors for AO or DJK. Age, number of fused vertebrae, curve correction, preoperative coronal/sagittal L3-4 disc angle did not differ significantly between the two groups. Multiple logistic regression results indicated that preoperative Risser grade 0, 1 (odds ratio [OR], 1.8), SV-3 at L3 in standing and side benders (OR, 2.1 and 2.8, respectively), TS score -5, -6 at L3 (OR, 4.4), rigid disc at L3-4 (OR, 3.1), LIV rotation >15° (OR, 2.9), and LIV deviation >2 cm from CSVL (OR, 2.2) were independent predictive factors. Although there was significant improvement of the of Scoliosis Research Society-22 average scores only in the good radiographic outcome group, there was no significant difference in the scores between the groups. Conclusion : The prevalence of AO or DJK at ultimate follow-up for AIS with LIV at L3 was 13.1%. To prevent AO or DJK following fusion to L3, we recommend that the CSVL touch L3 in both standing and side bending, TS score is -4 or less, the L3/4 disc is flexible, L3 is neutral (<15°) and ≤2 cm from the midline and the patient is ≥ Risser 2.

• Journal of radiological science and technology
• /
• v.29 no.3
• /
• pp.157-165
• /
• 2006

In order to analyze clinical characteristics like sex- and age-based onset frequency and onset region from vertebral disease cases, this study investigated total 1,291 cases of vertebral disease that were diagnosed via magnetic resonance imaging(MRI) from January to December 2004 at B University Hospital in metropolitan area. For higher diagnostic accuracy in cases of spinal disorder diagnosed, this study analyzed findings from data reading conducted by veteran specialists in diagnostic radiology. But this study excluded uncertain lesion cases, the cases requiring differential diagnosis from other disorders and so on from subjects under analysis. This study employed superconductive 1.5 Tesla SIGNA MR/i for MRI test and basically received resulting images via FSE(fast spin echo). In particular, this study obtained T1 and T2 myelogram with regard to regional characteristics(such as cervical vertebrae, thoracic vertebrae and lumbar vertebra) and imaging characteristics for sagittal and transverse section. As a result, this study came to the following conclusions : 1. In terms of general characteristics of subjects under analysis, male group comprised 53.5% and female 46.5% out of total 1,291 subjects. 2. The regional onset frequency of spinal disorders was converged primarily on lumbar vertebra(65.5%), which was followed by cervical vertebrae(27.3%) and thoracic vertebrae(7.0%) respectively. 3. Top 10 cases with high onset frequency of spinal disorders can be listed as follows : 1) posterior bulging disc 65.8% 2) narrowing of neural foramen 23.8% 3) herniated intervertebral disc (HIVD) 22.4% 4) spinal stenosis 16.7% 5) osteochondrosis 6.4% 6) compression fracture 6.4% 7) facet joint arthropathy 6.2% 8) spondylolisthesis 6.0% 9) spinal cord tumor 3.5% 10) inter body fusion 2.6%