A Novel Magnetic Resonance Quality Assurance Phantom (KMRP-4):Multi-Site Comparison With the American College of Radiology Phantom

Purpose@#To propose a novel standard magnetic resonance imaging (MRI) phantom, hereafter called the Korea Magnetic Resonance Phantom-4th edition (KMRP-4). Its related quality control (QC) assessment protocols and its comparison with the American College of Radiology (ACR) phantom and its QC assessment protocols. @*Materials and Methods@#Internally, the KMRP-4 phantom is composed of cubic and triangular vessels, brain tissue structures, and a uniform region designed to facilitate a variety of QC protocols. Using magnetic resonance (MR) images of these structures, we quantitatively evaluated a total of 10 parameters, seven from those of existing ACR protocols (i.e., geometric accuracy, high-contrast spatial resolution, slice thickness accuracy, slice position accuracy, image intensity uniformity, percent signal ghosting, and low-contrast object detectability) and three additional parameters for evaluating vessel conspicuity, brain tissue contrast, and signal-to-noise ratio (SNR) introduced in the KMRP-4 protocols. Twentytwo MRI systems of 0.32–3.0 T static magnetic field strength were tested using both ACR and KMRP-4 phantoms. Mann–Whitney U-tests were performed on the seven evaluation items of the ACR method to compare KMRP-4 and ACR methods. @*Results@#The results of Mann–Whitney U-test demonstrated that p-values were more than 0.05 for all seven items that could be assessed with both ACR and KMRP-4, indicating similar results between the two methods. Additionally, assessments of vessel conspicuity, brain tissue contrast, and SNR using the KMRP-4 method demonstrated utility of the KMRP-4 phantom. @*Conclusion@#A novel standard phantom and related QC methods were developed to perform objective, observer-independent, and semi-automatic QC tests. Quantitative comparisons of MR images with KMPR-4 and ACR phantoms were performed. Results demonstrated the utility of the newly proposed KMRP-4 phantom and its related QC methods.

Clinical application of cryolipolysis in Asian patients for subcutaneous fat reduction and body contouring

Background@#Cryolipolysis, a preferred method for minimally invasive body contouring, involves the noninvasive cooling of adipocytes to induce lipolysis without damaging other tissues. This study aimed to evaluate the safety and efficacy of cryolipolysis for the treatment of excessive fat tissue. @*Methods@#Between May 2014 and December 2017, 231 patients with 448 areas of interest were enrolled and their records were retrospectively reviewed. We used five different vacuum applicators, and the best-fitting applicator was used for each area. One cycle of cryolipolysis was applied at a cooling intensity factor of 41.6. The efficacy was evaluated 12 weeks after treatment via review of clinical photographs, the pinch test, and ultrasonographic measurements of fat thickness. The occurrence of any complications was also assessed. @*Results@#The volume was reduced in all of the areas to which cryolipolysis was applied. The rate of reduction of the fat layer as measured via the pinch test was 19.2%, and the rate of the decrease in fat layer thickness as measured via ultrasonography was 22.8%. Fat reduction of the upper arm differed significantly from that of the abdomen and flank, but no significant difference was found between sexes. The side effects were limited to erythema, edema, bruising, and numbness at the treatment site and resolved without treatment. @*Conclusions@#Cryolipolysis, with new and better-fitting applicators, is safe, fast, and effective for the reduction of excessive fat tissue on the abdomen, back, flank, and extremities. It is a good option for treating excess adipose tissue in Asian patients.

Activin A/BMP2 Chimera (AB204) Exhibits Better Spinal Bone Fusion Properties than rhBMP2

OBJECTIVE: To compare the spinal bone fusion properties of activin A/BMP2 chimera (AB204) with recombinant human bone morphogenetic protein (rhBMP2) using a rat posterolateral spinal fusion model.METHODS: The study was designed to compare the effects and property at different dosages of AB204 and rhBMP2 on spinal bone fusion. Sixty-one male Sprague-Dawley rats underwent posterolateral lumbar spinal fusion using one of nine treatments during the study, that is, sham; osteon only; 3.0 μg, 6.0 μg, or 10.0 μg of rhBMP2 with osteon; and 1.0 μg, 3.0 μg, 6.0 μg, or 10.0 μg of AB204 with osteon. The effects and property on spinal bone fusion was calculated at 4 and 8 weeks after treatment using the scores of physical palpation, simple radiograph, micro-computed tomography, and immunohistochemistry.RESULTS: Bone fusion scores were significantly higher for 10.0 μg AB204 and 10.0 μg rhBMP2 than for osteon only or 1.0 μg AB204. AB204 exhibited more prolonged osteoblastic activity than rhBMP2. Bone fusion properties of AB204 were similar with the properties of rhBMP2 at doses of 6.0 and 10.0 μg, but, the properties of AB204 at doses of 3.0 μg exhibited better than the properties of rhBMP2 at doses of 3.0 μg.CONCLUSION: AB204 chimeras could to be more potent for treating spinal bone fusion than rhBMP2 substitutes with increased osteoblastic activity for over a longer period.

Activin A/BMP2 Chimera (AB204) Exhibits Better Spinal Bone Fusion Properties than rhBMP2

OBJECTIVE: To compare the spinal bone fusion properties of activin A/BMP2 chimera (AB204) with recombinant human bone morphogenetic protein (rhBMP2) using a rat posterolateral spinal fusion model. METHODS: The study was designed to compare the effects and property at different dosages of AB204 and rhBMP2 on spinal bone fusion. Sixty-one male Sprague-Dawley rats underwent posterolateral lumbar spinal fusion using one of nine treatments during the study, that is, sham; osteon only; 3.0 μg, 6.0 μg, or 10.0 μg of rhBMP2 with osteon; and 1.0 μg, 3.0 μg, 6.0 μg, or 10.0 μg of AB204 with osteon. The effects and property on spinal bone fusion was calculated at 4 and 8 weeks after treatment using the scores of physical palpation, simple radiograph, micro-computed tomography, and immunohistochemistry. RESULTS: Bone fusion scores were significantly higher for 10.0 μg AB204 and 10.0 μg rhBMP2 than for osteon only or 1.0 μg AB204. AB204 exhibited more prolonged osteoblastic activity than rhBMP2. Bone fusion properties of AB204 were similar with the properties of rhBMP2 at doses of 6.0 and 10.0 μg, but, the properties of AB204 at doses of 3.0 μg exhibited better than the properties of rhBMP2 at doses of 3.0 μg. CONCLUSION: AB204 chimeras could to be more potent for treating spinal bone fusion than rhBMP2 substitutes with increased osteoblastic activity for over a longer period.

T1-Based MR Temperature Monitoring with RF Field Change Correction at 7.0T

PURPOSE: The objective of this study is to determine the effect of physical changes on MR temperature imaging at 7.0T and to examine proton-resonance-frequency related changes of MR phase images and T1 related changes of MR magnitude images, which are obtained for MR thermometry at various magnetic field strengths. MATERIALS AND METHODS: An MR-compatible capacitive-coupled radio-frequency hyperthermia system was implemented for heating a phantom and swine muscle tissue, which can be used for both 7.0T and 3.0T MRI. To determine the effect of flip angle correction on T1-based MR thermometry, proton resonance frequency, apparent T1, actual flip angle, and T1 images were obtained. For this purpose, three types of imaging sequences are used, namely, T1-weighted fast field echo with variable flip angle method, dual repetition time method, and variable flip angle method with radio-frequency field nonuniformity correction. RESULTS: Signal-to-noise ratio of the proton resonance frequency shift-based temperature images obtained at 7.0T was five-fold higher than that at 3.0T. The T1 value increases with increasing temperature at both 3.0T and 7.0T. However, temperature measurement using apparent T1-based MR thermometry results in bias and error because B1 varies with temperature. After correcting for the effect of B1 changes, our experimental results confirmed that the calculated T1 increases with increasing temperature both at 3.0T and 7.0T. CONCLUSION: This study suggests that the temperature-induced flip angle variations need to be considered for accurate temperature measurements in T1-based MR thermometry.

Comparison of the Effects of Sufentanil and Fentanyl Intravenous Patient Controlled Analgesia after Lumbar Fusion

OBJECTIVE: Postoperative pain is one of the major complaints of patients after lumbar fusion surgery. The authors evaluated the effects of intravenous patient controlled analgesia (IV-PCA) using fentanyl or sufentanil on postoperative pain management and pain-related complications. METHODS: Forty-two patients that had undergone surgery with lumbar instrumentation and fusion at single or double levels constituted the study cohort. Patients were equally and randomly allocated to a sufentanil group (group S) or a fentanyl group (group F) for patient controlled analgesia (PCA). Group S received sufentanil at a dose of 4 μg/kg IV-PCA and group F received fentanyl 24 μg/kg IV-PCA. A numeric rating scale (NRS) of postoperative pain was applied before surgery, and immediately and at 1, 6, and 24 hours (hrs) after surgery. Oswestry disability index (ODI) scores were obtained before surgery and one month after surgery. Opioid-related side effects were also evaluated. RESULTS: No significant intergroup difference was observed in NRS or ODI scores at any of the above-mentioned time points. Side effects were more frequent in group F. More specifically, nausea, vomiting rates were significantly higher (p=0.04), but pruritus, hypotension, and headache rates were non-significantly different in the two groups. CONCLUSION: Sufentanil displayed no analgesic advantage over fentanyl postoperatively. However, sufentanil should be considerable for patients at high risk of GI issues, because it had lower postoperative nausea and vomiting rates than fentanyl.

A Prospective Study with Cage-Only or Cage-with-Plate Fixation in Anterior Cervical Discectomy and Interbody Fusion of One and Two Levels

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.

Inter- and Intra-Observer Variability of the Volume of Cervical Ossification of the Posterior Longitudinal Ligament Using Medical Image Processing Software

OBJECTIVE: Computed tomography (CT)-based method of three dimensional (3D) analysis (MIMICS®, Materialise, Leuven, Belgium) is reported as very useful software for evaluation of OPLL, but its reliability and reproducibility are obscure. This study was conducted to evaluate the accuracy of MIMICS® system, and inter- and intra-observer reliability in the measurement of OPLL. METHODS: Three neurosurgeons independently analyzed the randomly selected 10 OPLL cases with medical image processing software (MIMICS®) which create 3D model with Digital Imaging and Communication in Medicine (DICOM) data from CT images after brief explanation was given to examiners before the image construction steps. To assess the reliability of inter- and intra-examiner intraclass correlation coefficient (ICC), 3 examiners measured 4 parameters (volume, length, width, and length) in 10 cases 2 times with 1-week interval. RESULTS: The inter-examiner ICCs among 3 examiners were 0.996 (95% confidence interval [CI], 0.987–0.999) for volume measurement, 0.973 (95% CI, 0.907–0.978) for thickness, 0.969 (95% CI, 0.895–0.993) for width, and 0.995 (95% CI, 0.983–0.999) for length. The intra-examiner ICCs were 0.994 (range, 0.991–0.996) for volume, 0.996 (range, 0.944–0.998) for length, 0.930 (range, 0.873–0.947) for width, and 0.987 (range, 0.985–0.995) for length. CONCLUSION: The medical image processing software (MIMICS®) provided detailed quantification OPLL volume with minimal error of inter- and intra-observer reliability in the measurement of OPLL.

Whole Spine Disc Degeneration Survey according to the Ages and Sex Using Pfirrmann Disc Degeneration Grades

OBJECTIVE: Pfirrmann disc grade is a useful scoring tool for evaluating disc degeneration, but normal values according to aging process has not been elucidated. This study was conducted to identify the prevalence and pattern of whole spine disc degeneration according to ages and gender differences. METHODS: Total 653 patients (336 male and 317 female patients, 48.1±58.7 years old) who took whole spine magnetic resonance images were enrolled in this study. There were 19 cases in their 2nd decades and 74 cases in 3rd decades, 141 cases in 4th decades, 129 cases in 5th decades, 139 cases in 6th decades, and 93 cases in 7th decades, 58 cases in over 8th decades. Pfirrmann disc grades were measured according to sex and ages by 2 neurosurgeons that were blind to this study. RESULTS: All spinal disc degeneration grades were correlated with ageing. The Pfirrmann disc grades of degeneration in all spine levels showed the statistically significant difference according to the ages (p < 0.001). The common Pfirrmann disc grades according to the ages were grade 3 among 2nd to 5th decades, and grade 4 was more common than 6th decades. The lower cervical level (C2–3 to C4–5) and lumbar level (L1–2 to L5–S1) were happened relatively early severe disc degeneration compared to other levels. The intersexual differences were increased after 6th decades. CONCLUSION: Disc degeneration is natural course after one’s 2nd decades. And its incidence and grade were increased with age, and more affected by sexual difference after 6th decades.

Early Decompression of Acute Subdural Hematoma for Postoperative Neurological Improvement: A Single Center Retrospective Review of 10 Years / 대한신경손상학회지

OBJECTIVE: This study was conducted to investigate survival related factors, as well as to evaluate the effects of early decompression on acute subdural hematoma (ASDH). METHODS: We retrospectively reviewed cases of decompressive craniectomy (DC) for decade. In total, 198 cases of DC involved ASDH were available for review, and 65 cases were excluded due to missing data on onset time and a delayed operation after closed observation with medical care. Finally, 133 cases of DC with ASDH were included in this study, and various factors including the time interval between trauma onset and operation were evaluated. RESULTS: In the present study, survival rate after DC in patients with ASDH was shown to be related to patient age (50 years old, p=0.012), brain compression ratio (p=0.042) and brain stem compression (p=0.020). Sex, preoperative mental status, and time interval between trauma onset and operation were not related with survival rate. Among those that survived (n=78), improvements in Glasgow Coma Scale (GCS) score of more than three points, compared to preoperative measurement, were more frequently observed among the early (less than 3 hours between trauma onset and operation) decompressed cases (p=0.013). However, improvements of more than 4 or 5 points on the GCS were not affected by early decompression. CONCLUSION: Early decompression of ASDH was not correlated with survival rate, but was related with neurological improvement (more than three points on the GCS). Accordingly, early decompression in ASDH, if indicated, may be of particular benefit.

A Faster and Wider Skin Incision Technique for Decompressive Craniectomy: n-Shaped Incision for Decompressive Craniectomy / 대한신경손상학회지

OBJECTIVE: Decompressive craniectomy (DC) is a useful surgical method to achieve adequate decompression in hypertensive intracranial patients. This study suggested a new skin incision for DC, and analyzed its efficacy and safety. METHODS: In the retrograde reviews, 15 patients underwent a newly suggested surgical approach using n-shape skin incision technique (Group A) and 23 patients were treated with conventional question mark skin incision technique (Group B). Two groups were compared in the terms of the decompressed area of the craniectomy, protruded brain volume out of the skull layer, the operation time from skin incision to bone flap removal, and modified Rankin Scale (mRS) which was evaluated for 3 months after surgery. RESULTS: The decompressed area of craniectomy (389.1 cm² vs. 318.7 cm², p=0.041) and the protruded brain volume (151.8 cm³ vs. 116.2 cm³, p=0.045) were significantly larger in Group A compared to the area and the volume in Group B. The time interval between skin incision and bone flap removal was much shorter in Group A (23.3 minutes vs. 29.5 minutes, p=0.013). But, the clinical results were similar between 2 groups. Group A showed more favorable outcome proportion (mRS 0-3, 6/15 patients vs. 5/23 patients, p=0.225) and lesser mortality cases proportion 1/15 patients vs. 4/23 patients, but these differences were not significantly observed (p=0.225 and 0.339). CONCLUSION: DC using n-shaped skin incision was a feasible and safe surgical technique. It may be an easier and faster method for the purpose of training neurosurgeons.

Clinical and Radiological Comparison of Semirigid (WavefleX) and Rigid System for the Lumbar Spine

OBJECTIVE: Spinal fusion operation is an effective treatment in the spinal pathology, but it could change the physiological distribution of load at the instrumented and adjacent segments. This retrospective study compared the radiological and clinical outcomes of patients undergoing lumbar fusion with semirigid rods versus rigid rods system. METHODS: Using transpedicular fixation and posterior lumbar interbody fusion at the level of L4/L5, 20 patients were treated with semirigid rods (WavefleX, SR group), and 20 patients with rigid rods (titanium, RR group). Clinical and radiological outcomes were evaluated, including visual analog score for lower back pain and leg pain, Prolo functional and economic scores, statues of implanted instruments, fusion rate, and complications during 24-month follow-up. RESULTS: Clinical scores were significantly improved until postoperative 24-month follow-up as compared with preoperative scores in both groups (p<0.05), with similar levels of improvement observed at the same time points postoperatively between the 2 groups. Prolo economic scores were significantly improved in SR group compared to RR until 12 months, but this improvement became similar after 18 months. The overall fusion rate was 94.1% until the 24-month follow-up for both groups. No significant complication was observed in both groups. CONCLUSION: The results of the present study indicate that semirigid rods system with posterior lumbar interbody fusion showed similar clinical and radiological result with rigid rods system until 2 years after instrumentation. The WavefleX rods system, as a semirigid rods with unique characteristics, may be an effective alternative treatment for patients in lumbar fusion.

Brain Activation Evoked by Sensory Stimulation in Patients with Spinal Cord Injury : Functional Magnetic Resonance Imaging Correlations with Clinical Features

OBJECTIVE: The purpose of this study is to determine whether the changes of contralateral sensorimotor cortical activation on functional magnetic resonance imaging (fMRI) can predict the neurological outcome among spinal cord injury (SCI) patients when the great toes are stimulated without notice. METHODS: This study enrolled a total of 49 patients with SCI and investigated each patient's preoperative fMRI, postoperative fMRI, American Spinal Injury Association (ASIA) score, and neuropathic pain occurrence. Patients were classified into 3 groups according to the change of blood oxygenation level dependent (BOLD) response on perioperative fMRI during proprioceptive stimulation with repetitive passive toe movements : 1) patients with a response of contralateral sensorimotor cortical activation in fMRI were categorized; 2) patients with a response in other regions; and 3) patients with no response. Correlation between the result of fMRI and each parameter was analyzed. RESULTS: In fMRI data, ASIA score was likely to show greater improvement in patients in group A compared to those belonging to group B or C (p<0.001). No statistical significance was observed between the result of fMRI and neuropathic pain (p=0.709). However, increase in neuropathic pain in response to the signal change of the ipsilateral frontal lobe on fMRI was statistically significant (p=0.030). CONCLUSION: When there was change of BOLD response at the contralateral sensorimotor cortex on perioperative fMRI after surgery, relief of neurological symptoms was highly likely for traumatic SCI patients. In addition, development of neuropathic pain was likely to occur when there was change of BOLD response at ipsilateral frontal lobe.

Efficacy of Percutaneous Epidural Neuroplasty Does Not Correlate with Dural Sac Cross-Sectional Area in Single Level Disc Disease

PURPOSE: Percutaneous epidural neuroplasty (PEN) is a minimally invasive treatment. The efficacy of PEN has been relatively well investigated; however, the relationship between the clinical effectiveness of PEN and the severity of spinal canal stenosis by disc material has not yet been established. The purpose of this study was to compare clinical outcomes of PEN according to the dural sac cross-sectional area in single level disc disease. MATERIALS AND METHODS: This study included 363 patients with back pain from single level disc disease with and without radiculopathy. Patients were categorized into groups according to spinal canal compromise by disc material: Category 1, less or more than 50%; and Category 2, three subgroups with lesser than a third, between a third and two thirds, and more than two thirds. Clinical outcomes were assessed according to the Visual Analog Scale (VAS) score for back pain and leg pain and Odom's criteria at 1, 3, 6, 12, and 24 months after treatment. RESULTS: The demographic data showed no difference between groups according to spinal canal compromise by disc material except age (older age correlated with more spinal canal compromise). The dural sac cross-sectional area did not correlate with the VAS scores for back and leg pain after PEN in single level disc disease in Groups 1 and 2. Odom's criteria after PEN were also not different according to dural sac cross-sectional area by disc material. CONCLUSION: PEN is an effective procedure in treating single level lumbar disc herniation without affecting dural sac cross-sectional area.

The Clinical and Radiological Effect of Abnormal Axis after Cervical Arthroplasty

OBJECTIVE: The clinical outcomes according to the radiological results after cervical total disc replacement (TDR) are not well established. Here, the authors reviewed the clinical results according to the asymmetry in radiographs. METHODS: This retrospective analysis included patients after TDR (Mobi-C(R) disc) with at least 12 months follow up, and the clinical and radiological data were obtained preoperatively and postoperatively for 12 months. Clinical outcome measures numerical rating scale (NRS) score for neck pain, visual analog scale (VAS) for arm pain, and the Oswestry disability index (ODI) value. The asymmetries of TDRs were evaluated on the anterior-posterior (AP) and the lateral radiographs, and the radiographic adjacent segment degenerations were evaluated for 12 months. RESULTS: A total of 24 patients (one level cervical TDR; 10 male and 14 female; aged 41.50+/-8.35 years) were included in this study. The clinical results including NRS for neck pain, VAS for arm pain, and ODIs were similar between the normal and asymmetrized TDRs in AP and lateral radiographs. The radiographic adjacent segment degenerations were significantly increased in deviated TDRs (AP>10 mm asymmetry and lateral>10 mm asymmetry). CONCLUSION: Asymmetrical location of TDR is not related to the clinical outcomes, but related to the risk of radiographic adjacent disc segment degeneration.

A Case of Hemifacial Spasm Caused by an Artery Passing Through the Facial Nerve

Hemifacial spasm (HFS) is a clinical syndrome characterized by unilateral facial nerve dysfunction. The usual cause involves vascular compression of the seventh cranial nerve, but compression by an artery passing through the facial nerve is very unusual. A 20-year-old man presented with left facial spasm that had persisted for 4 years. Compression of the left facial nerve root exit zone by the anterior inferior cerebellar artery (AICA) was revealed on magnetic resonance angiography. During microvascular decompression surgery, penetration of the distal portion of the facial nerve root exit zone by the AICA was observed. At the penetrating site, the artery was found to have compressed the facial nerve and to be immobilized. The penetrated seventh cranial nerve was longitudinally split about 2 mm. The compressing artery was moved away from the penetrating site and the decompression was secured by inserting Teflon at the operative site. Although the facial spasm disappeared in the immediate postoperative period, the patient continued to show moderate facial weakness. At postoperative 12 months, the facial weakness had improved to a mild degree. Prior to performing microvascular decompression of HFS, surgeons should be aware of a possibility for rare complex anatomy, such as compression by an artery passing through the facial nerve, which cannot be observed by modern imaging techniques.

Paralytic Ileus and Prophylactic Gastrointestinal Motility Medication after Spinal Operation

PURPOSE: To investigate the prevalence of paralytic ileus after spinal operation in the supine or prone operative position and to determine the efficacy of prophylactic gastrointestinal motility medications in preventing symptomatic paralytic ileus after a spinal operation. MATERIALS AND METHODS: All patients received spinal surgery in the supine or prone operative position. The study period was divided into two phases: first, to analyze the prevalence of radiographic and symptomatic paralytic ileus after a spinal operation, and second, to determine the therapeutic effects of prophylactic gastrointestinal motility medications (postoperative intravenous injection of scopolamine butylbromide and metoclopramide hydrochloride) on symptomatic paralytic ileus after a spinal operation. RESULTS: Basic demographic data were not different. In the first phase of this study, 27 patients (32.9%) with radiographic paralytic ileus and 11 patients (13.4%) with symptomatic paralytic ileus were observed. Radiographic paralytic ileus was more often noted in patients who underwent an operation in the prone position (p=0.044); whereas the occurrence of symptomatic paralytic ileus was not different between the supine and prone positioned patients (p=0.385). In the second phase, prophylactic medications were shown to be ineffective in preventing symptomatic paralytic ileus after spinal surgery [symptomatic paralytic ileus was observed in 11.1% (4/36) with prophylactic medication and 16.7% (5/30) with a placebo, p=0.513]. CONCLUSION: Spinal surgery in the prone position was shown to increase the likelihood of radiographic paralytic ileus occurrence, but not symptomatic paralytic ileus. Unfortunately, the prophylactic medications to prevent symptomatic paralytic ileus after spine surgery were shown to be ineffective.

Feasibility of Translaminar Screw Placement in Korean Population: Morphometric Analysis of Cervical Spine

PURPOSE: To analyze the feasibility of unilateral and bilateral translaminar screw placement in Koran population, and compare the acceptance rate using previously reported data in American population. MATERIALS AND METHODS: The translaminar lengths, thickness, heights, and sagittal-diagonal measurements were performed. The feasibility analysis was performed using unilateral and bilateral 3.5 mm cervical screw placement on the CT scans within 0.5 mm of safety margin. We also performed radiographic analysis of the morphometric dimensions and the feasibility of unilateral and bilateral translaminar screw placement at C3-C7. RESULTS: Korean population had similar or significantly shorter translaminar lengths and thickness (lengths and thickness in C7 among males; lengths in C6-C7 and thickness in C4 among females) than American population, but had similar or significantly longer translaminar heights and sagittal-diagonal measurements (heights in C3-C7 and sagittal-diagonal measurements in C3-C6 among males; heights in C7 and sagittal-diagonal measurements in C3-C7 among females). Unilaterally, translaminar screw acceptance rates in C3-C7 were similar between Korean and American male population, but the rates in C4-C6 were significantly smaller between Korean and American female population. Bilaterally, translaminar screw acceptance rates in C3 and C5-C6 were significantly larger between Korean and American male population, but the rates in C3-C7 were similar between Korean and American female population. CONCLUSION: The feasibility of unilateral and bilateral translaminar screw placement is different depending on different ethnics. Subaxial cervical unilateral translaminar screw placement among Korean male population and bilateral placement at C4-C7 among Korean female population are more acceptable than American population.

Delayed Vertebral Artery Dissection after Posterior Cervical Fusion with Traumatic Cervical Instability: A Case Report

Vascular injury presented immediately after the penetration, but delayed onset of vascular symptom caused by an embolism or vessel dissection after cervical fusion or traumatic event is extremely rare. We present a case of a 56-year-old woman who underwent an operation for cervical fusion for type II Odontoid process fracture. She presented symptoms of seizure with hemiparesis in 6 days after the operation. Multifocal acute infarction due to an embolism from the left VA (V3 segment) dissection was observed without a definite screw breach the transverse foramen. We hereby reported the instructive case report of delayed onset of vertebral artery dissection after posterior cervical fusion with type II odontoid process fracture patient. When a cervical operation performed in the cervical trauma patient, even if no apparent VA injury occurs before and during the operation, the surgeon must take caution not to risk cerebral infarction because of the delayed VA dissection.

Grisel's Syndrome Induced by Mycobacterium tuberculosis

Grisel's syndrome is a non-traumatic subluxation of the atlantoaxial joints, which is caused by an inflammatory process in the upper neck. It is rare to find literary reports of Grisel's syndrome with an evident pathogen in a lesion. For the first time in Korea, we report a 36-year-old female with Grisel's syndrome having an atlantoaxial subluxation, which was caused by a retropharyngeal abscess secondary to pulmonary Mycobacterium tuberculosis. The patient was treated with an anti-tuberculosis regimen and was prescribed a Philadelphia collar for the control of torticollis. The result of magnetic resonance imaging (MRI) showed an improved atlantoaxial alignment, after drug treatment and immobilization. This patient was neurologically intact and free from symptomatic complaints at follow-up visit. Dynamic cervical radiograph confirmed that the atlantoaxial joints had been stable. The pathophysiology of Grisel's syndrome, along with anatomical attributes, was explained on the basis of the patient's clinical course.