Ji Yong Kim

Comparison of Outcomes after Atlantoaxial Fusion with Transarticular Screws and Screw-Rod Constructs

Objective The purpose of this study was to compare the radiological and neurological outcomes between two atlantoaxial fusion method for atlantoaxial stabilization; C1 lateral mass-C2 pedicle screws (screw-rod constructs, SRC) versus C1-2 transarticular screws (TAS). Methods Forty-one patients in whom atlantoaxial instability was treated with atlantoaxial fixation by SRC group (27 patients, from March 2005 to May 2011) or TAS group (14 patients, from May 2000 to December 2005) were retrospectively reviewed. Numeric rating scale (NRS) for pain assessment, Oswestry disability index (ODI), and Frankel grade were also checked for neurological outcome. In radiologic outcome assessment, proper screw position and fusion rate were checked. Perioperative parameters such as blood loss during operation, operation time, and radiation exposure time were also reviewed. Results The improvement of NRS and ODI were not different between both groups significantly. Good to excellent response in Frankel grade is shown similarly in both groups. Proper screw position and fusion rate were also observed similarly between two groups. Total bleeding amount during operation is lesser in SRC group than TAS group, but not significantly (p=0.06). Operation time and X-ray exposure time were shorter in SRC group than in TAS group (all p<0.001). Conclusion Both TAS and SRC could be selected as safe and effective treatment options for C1-2 instability. But the perioperative result, which is technical demanding and X-ray exposure might be expected better in SRC group compared to TAS group.

Interobserver and Intraobserver Reliability of Sub-Axial Injury Classification and Severity Scale between Radiologist, Resident and Spine Surgeon.

Objective The sub-axial injury classification (SLIC) and severity scale was developed to decide whether to operate the cervical injured patient or not, but the reliability of SLIC and severity scale among the different physicians was not well known. Therefore, we evaluated the reliability of SLIC among a spine surgeon, a resident of neurosurgery and a neuro-radiologist. Methods In retrograde review in single hospital from 2002 to 2009 years, 75 cases of sub-axial spine injured patients underwent operation. Each case was blindly reviewed for the SLIC and severity scale by 3 different observers by two times with 4 weeks interval with randomly allocated. The compared axis was the injury morphology score, the disco-ligamentous complex score, the neurological status score and total SLIC score; the neurological status score was derived from the review of medical record. The kappa value was used for the statistical analysis. Results Interobserver agreement of SLIC and severity scale was substantial agreement in the score of injury morphology [intraclass correlation (ICC)=0.603] and total SLIC and severity sacle (ICC value=0.775), but was fair agreement in the disco-ligamentous complex score (ICC value=0.304). Intraobserver agreements were almost perfect agreement in whole scales with ICC of 0.974 in a spine surgeon, 0.948 in a resident of neurosurgery, and 0.963 in a neuro-radiologist. Conclusion The SLIC and severity scale is comprehensive and easily applicable tool in spine injured patient. Moreover, it is very useful tool to communicate among spine surgeons, residents of neurosurgery and neuro-radiologists with sufficient reproducibility.

Improvement in sensory function via granulocyte-macrophage colony-stimulating factor in rat spinal cord injury models

OBJECT The aim in this study was to determine whether granulocyte-macrophage colony-stimulating factor (GM-CSF) leads to sensory improvement in rat spinal cord injury (SCI) models. METHODS Thirty male Sprague-Dawley rats were included in this study: 10 in the sham group (laminectomy alone without SCI), 10 in the SCI group (SCI treated with phosphate-buffered saline), and 10 in the GM-CSF treatment group (SCI treated with GM-CSF). A locomotor function test and pain sensitivity test were conducted weekly for 9 weeks after SCI or sham injury. Spinal tissue samples from all rats were immunohistochemically examined for the expression of calcitonin gene-related peptide (CGRP) and abnormal sprouting at Week 9 post-SCI. RESULTS Granulocyte-macrophage colony-stimulating factor treatment improves functional recovery after SCI. In the tactile withdrawal threshold and frequency of the hindlimb paw, the GM-CSF group always responded with a statistically significant lower threshold than the SCI group 9 weeks after SCI (p < 0.05). The response of the forelimb and hindlimb paws to cold in the GM-CSF group always reflected a statistically significant lower threshold than in the SCI group 9 weeks after injury (p < 0.05). Decreased CGRP expression, observed by density and distribution area, was noted in the GM-CSF group (optical density 113.5 ± 20.4) compared with the SCI group (optical density 143.1 ± 18.7; p < 0.05). CONCLUSIONS Treatment with GM-CSF results in functional recovery, improving tactile and cold sense recovery in a rat SCI model. Granulocyte-macrophage colony-stimulating factor also minimizes abnormal sprouting of sensory nerves after SCI.

Risk Factors of Proximal Junctional Kyphosis after Multilevel Fusion Surgery : More Than 2 Years Follow-Up Data

Objective Proximal junctional kyphosis (PJK) is radiologic finding, and is defined as kyphosis of >10° at the proximal end of a construct. The aim of this study is to identify factors associated with PJK after segmental spinal instrumented fusion in adults with spinal deformity with a minimum follow-up of 2 years. Methods A total of 49 cases of adult spinal deformity treated by segmental spinal instrumented fusion at two university hospitals from 2004 to 2011 were enrolled in this study. All enrolled cases included at least 4 or more levels from L5 or the sacral level. The patients were divided into two groups based on the presence of PJK during follow-up, and these two groups were compared to identify factors related to PJK. Results PJK was observed in 16 of the 49 cases. Age, sex and mean follow-up duration were not statistically different between two groups. However, mean bone marrow density (BMD) and mean back muscle volume at the T10 to L2 level was significantly lower in the PJK group. Preoperatively, the distance between the C7 plumb line and uppermost instrumented vertebra (UIV) were no different in the two groups, but at final follow-up a significant intergroup difference was observed. Interestingly, spinal instrumentation factors, such as, receipt of a revision operation, the use of a cross-link, and screw fracture were no different in the two groups at final follow-up. Conclusion Preoperative BMD, sagittal imbalance at UIV, and thoracolumbar muscle volume were found to be strongly associated with the presence of PJK.

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.

Remote Cerebellar Hemorrhage after Surgery for Degenerative Lumbar Spine Disease: A Case Report

Spine surgery has been increased as the population ages, but the occurrence of unusual complication such as remote cerebellar hemorrhage (RCH) is not well understood. We recently experienced a case of RCH in a 60-year-old woman showed neurologic dysfunction after degenerative lumbar spine surgery. There was no definite dural tearing and cerebrospinal fluid (CSF) loss during operation. Brain magnetic resonance imaging showed cerebellar hemorrhage. The patient received conservative management and rehabilitation program. Most other reports have been suggested that RCH after spinal surgery might be related with excessive CSF drainage perioperatively. Minimizing of CSF loss during operation would be helpful to reduce the risk of RCH. If large volume of CSF has been lost accompanied by neurologic deterioration, brain imaging is necessary simultaneously.

Usefulness of Simple Rod Rotation to Correct Curve of Adolescent Idiopathic Scoliosis.

Objective To correct apical vertebral rotation for adolescent idiopathic scoliosis (AIS), direct vertebral derotation (DVD) or simple rod rotation (SRR) might be considered. The aim of the present study is to introduce the surgical experiences of AIS by a Korean neurosurgeon and to evaluate the effectiveness of SRR for apical vertebral rotation. Methods A total of 9 patients (1 male and 8 females) underwent scoliosis surgery by a neurosurgeon of our hospital. The Lenke classifications of the patients were 1 of 1B, 2 of 1C, 1 of 2A, 1 of 2C, 3 of 5C and 1 of 6C. Surgery was done by manner of simple rod rotation on the concave side and in situ coronal bending. Coronal Cobbs angles, vertebral rotation angles and SRS-22 were measured on a plain standing X-ray and CT before and after surgery. Results The mean follow up period was 25.7 months (range : 5–52). The mean number of screw positioning level was nine (6–12). The mean age was 16.4 years (range : 13–25) at surgery. The mean Risser grade was 3.7±0.9. The apical vertebral rotation measured from the CT scans was 25.8±8.5° vs. 9.3±6.7° (p<0.001) and the Coronal Cobbs angle was 53.7±10.4° vs. 15.4±6.5° (p<0.001) preoperatively and postoperative, respectively. The SRS-22 improved from 71.9 preoperatively to 90.3 postoperatively. There were no complications related with the operations. Conclusion SRR with pedicle screw instrumentation could be corrected successfully by axial rotation without complications. SRR might serve as a good option to correct AIS deformed curves of AIS.

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® 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.

Radiological Efficacy of Cervical Lateral Mass Screw Insertion and Rod Fixation by Modified Magerl's Method (Yoon's Method) with Minimum 2 Years of Follow-up.

Objective Cervical lateral mass screw insertion and rod fixation is a useful method for stabilizing the cervical disease, so various modified techniques were present. Many surgeons had reported the biomechanical safety according to the screw positioning method in the cervical spine, but the modified Magerls method (Yoons method) was not well studied. So, this study assessed the radiological efficacy of the modified Magerls method with long-term follow-up. Methods This study retrospectively reviewed 323 lateral mass screws of 50 patients who had followed-up at least 2 years. Radiologic data were analyzed as parameters of complications after operation, including kyphotic or lordotic change, bone fusion, pull-out or malposition of screw, foraminal stenosis, adjacent disc degeneration or aggravation, pseudoarthrosis, and vertebral artery injury. Results The mean follow-up period was 32 (24 to 52) months. There were kyphotic changes in 4.0%(2 of 50 cases). Unsuccessful bone fusion occurred in 4.0%(2 of 50 cases). Among the 323 screws, screw pull-out (4.0%. 2 of 50cases, 3 of 323 screws), foraminal invasion (1.2% of total screws), and facet injury (0.6% of total screws) occurred. Conclusion The lateral mass screw insertion and rod fixation by the modified Magerls method (Yoons method) is a safe and reliable technique with low rate of complication related to instruments in minimum 2 years follow-up.

Isolated Painless Foot Drop due to Cerebral Infarction Mimicking Lumbar Radiculopathy: A Case Report

Although they usually originate from peripheral problems, foot drop is caused by lesions affecting the neural pathway related to dorsiflexor muscles, whether of central or peripheral origin. We present a patient with sudden isolated foot drop caused by a small infarct in the primary motor cortex mimicking a peripheral origin. This report indicates that patients presenting isolated foot drop should be managed carefully and the possibility of both central and peripheral causes should be considered. To our knowledge, this is the first report of sudden isolated foot drop caused by a cortical infarction mimicking lumbar radiculopathy.