Inter- and Intra-observer Reliability of MRI for Lumbar Lateral Disc Herniation

Background: The authors analyzed inter- and intra-observer agreement with respect to interpretation of simple magnetic resonance T1- and T2-weighted axial and sagittal images for the diagnosis of lumbar lateral disc herniation, including foraminal and extraforaminal disc herniations.Methods: Forty-two patients in whom lumbar lateral disc herniation was suspected or confirmed by simple magnetic resonance imaging at one institute between May 2003 and December 2004 were included. The magnetic resonance images consisting of T1- and T2-weighted axial and sagittal images, and these were reviewed blindly and independently by three orthopaedic spine surgeons in a random manner. The images were interpreted as positive or negative for lateral disc herniation on 2 different occasions 3 months apart. Results were analyzed using Cohens kappa statistic, and strengths of agreements were determined using the Landis and Koch criteria.Results: The kappa values for inter-observer agreement averaged 0.234 (0.282, 0.111, and 0.308 respectively) on the first occasion, and 0.166 (0.249, 0.111, and 0.137 respectively) on the second occasion, with an overall mean value of 0.200. Thus, the strength of agreement was only slight-to-fair according to the Landis and Koch criteria. Kappa values for intra-observer agreement averaged 0.479 (0.488, 0.491, and 0.459 respectively), indicating moderate agreement.Conclusions: The present study indicates that simple magnetic resonance imaging is not a reliable imaging modality for diagnosing lumbar lateral disc herniation. Another imaging study with improved diagnostic values should be developed to diagnose this pathologic finding.Keywords: Lumbar lateral disc herniation, Inter-observer reliability, Intra-observer reliability, Magnetic resonance imagingOAIID:oai:osos.snu.ac.kr:snu2009-01/102/0000004226/1SEQ:1PERF_CD:SNU2009-01EVAL_ITEM_CD:102USER_ID:0000004226EMP_ID:A076317DEPT_CD:801FILENAME:E019T_CiOS-2009_Kim_Inter-and Intra-observer Reliability of MRI for Lumbar.pdfDEPT_NM:의학과EMAIL:[email protected]_YN:NCONFIRM:YCONFIRM:

Factors influencing the surgical decision for the treatment of degenerative lumbar stenosis in a preference-based shared decision-making process

Introduction In a preference-based shared decision-making system, several subjective and/or objective factors such as pain severity, degree of disability, and the radiological severity of canal stenosis may influence the final surgical decision for the treatment of lumbar spinal stenosis (LSS). However, our understanding of the shared decision-making process and the significance of each factor remain primitive. In the present study, we aimed to investigate which factors influence the surgical decision for the treatment of LSS when using a preference-based, shared decisionmaking process. Methods We included 555 patients, aged 45–80 years, who used a preference-based shared decision-making process and were treated conservatively or surgically for chronic leg and/or back pain caused by LSS from April 2012 to December 2012. Univariate and multivariableadjusted logistic regression analyses were used to assess the association of surgical decision making with age, sex, body mass index, symptom duration, radiologic stenotic grade, Oswestry Disability Index (ODI), visual analog scale (VAS) scores for back and leg pain, Short Form-36 (SF-36) subscales, and motor weakness. Results In univariate analysis, the following variables were associated with a higher odds of a surgical decision for LSS: male sex; the VAS score for leg pain; ODI; morphological stenotic grades B, C, and D; motor weakness; and the physical function, physical role, bodily pain, social function, and emotional role of the SF-36 subscales. Multivariate analysis revealed that male sex, ODI, morphological stenotic grades C and D, and motor weakness were significantly associated with a higher possibility of a surgical decision. Conclusion Motor weakness, male sex, morphological stenotic grade, and the amount of disability are critical factors leading to a surgical decision for LSS when using a preference-based shared decision-making process.OAIID:oai:osos.snu.ac.kr:snu2015-01/102/0000004226/8ADJUST_YN:YEMP_ID:A079510DEPT_CD:801CITE_RATE:2.066FILENAME:2015_factors influencing the surgical decision for the treatment of degenerative lumbar stenosis.pdfDEPT_NM:의학과CONFIRM:

Risk of vertebral artery injury: comparison between C1-C2 transarticular and C2 pedicle screws.

BACKGROUND CONTEXT: To our knowledge, no large series comparing the risk of vertebral artery injury by C1-C2 transarticular screw versus C2 pedicle screw have been published. In addition, no comparative studies have been performed on those with a high-riding vertebral artery and/or a narrow pedicle who are thought to be at higher risk than those with normal anatomy.PURPOSE: To compare the risk of vertebral artery injury by C1-C2 transarticular screw versus C2 pedicle screw in an overall patient population and subsets of patients with a high-riding vertebral artery and a narrow pedicle using computed tomography (CT) scan images and three-dimensional (3D) screw trajectory software.STUDY DESIGN: Radiographic analysis using CT scans.PATIENT SAMPLE: Computed tomography scans of 269 consecutive patients, for a total of 538 potential screw insertion sites for each type of screw.OUTCOME MEASURES: Cortical perforation into the vertebral artery groove of C2 by a screw.METHODS: We simulated the placement of 4.0 mm transarticular and pedicle screws using 1-mm-sliced CT scans and 3D screw trajectory software. We then compared the frequency of C2 vertebral artery groove violation by the two different fixation methods. This was done in the overall patient population, in the subset of those with a high-riding vertebral artery (defined as an isthmus height ≤5 mm or internal height ≤2 mm on sagittal images) and with a narrow pedicle (defined as a pedicle width ≤4 mm on axial images).RESULTS: There were 78 high-riding vertebral arteries (14.5%) and 51 narrow pedicles (9.5%). Most (82%) of the narrow pedicles had a concurrent high-riding vertebral artery, whereas only 54% of the high-riding vertebral arteries had a concurrent narrow pedicle. Overall, 9.5% of transarticular and 8.0% of pedicle screws violated the C2 vertebral artery groove without a significant difference between the two types of screws (p=.17). Among those with a high-riding vertebral artery, vertebral artery groove violation was significantly lower (p=.02) with pedicle (49%) than with transarticular (63%) screws. Among those with a narrow pedicle, vertebral artery groove violation was high in both groups (71% with transarticular and 76% with pedicle screws) but without a significant difference between the two groups (p=.55).CONCLUSIONS: Overall, neither technique has more inherent anatomic risk of vertebral artery injury. However, in the presence of a high-riding vertebral artery, placement of a pedicle screw is significantly safer than the placement of a transarticular screw. Narrow pedicles, which might be anticipated to lead to higher risk for a pedicle screw than a transarticular screw, did not result in a significant difference because most patients (82%) with narrow pedicles had a concurrent high-riding vertebral artery that also increased the risk with a transarticular screw. Except in case of a high-riding vertebral artery, our results suggest that the surgeon can opt for either technique and expect similar anatomic risks of vertebral artery injury.This study was supported by a Research Grant (04-2008-006) of Seoul National University Bundang Hospital of JSY (04-2008-006) with US $9,000.OAIID:oai:osos.snu.ac.kr:snu2013-01/102/0000004226/9SEQ:9PERF_CD:SNU2013-01EVAL_ITEM_CD:102USER_ID:0000004226ADJUST_YN:NEMP_ID:A076317DEPT_CD:801CITE_RATE:3.29FILENAME:e051t_tsj-2013_yeom_risk of vertebral artery injury_comparison between c1-c2 transarticular.pdfDEPT_NM:의학과EMAIL:[email protected]_YN:YCONFIRM:

Biomechanical analysis of fusion segment rigidity upon stress at both the fusion and adjacent segments : A comparison between unilateral and bilateral pedicle screw fixation

PURPOSE:The purpose of this study was to investigate the effects of unilateral pedicle screw fixation on the fusion segment and the superior adjacent segment after one segment lumbar fusion using validated finite element models.MATERIALS AND METHODS:Four L3-4 fusion models were simulated according to the extent of decompression and the method of pedicle screws fixation in L3-4 lumbar fusion. These models included hemi-laminectomy with bilateral pedicle screw fixation in the L3-4 segment (BF-HL model), total laminectomy with bilateral pedicle screw fixation (BF-TL model), hemi-laminectomy with unilateral pedicle screw fixation (UF-HL model), and total laminectomy with unilateral pedicle screw fixation (UF-TL model). In each scenario, intradiscal pressures, annulus stress, and range of motion at the L2-3 and L3-4 segments were analyzed under flexion, extension, lateral bending, and torsional moments.RESULTS:Under four pure moments, the unilateral fixation leads to a reduction in increment of range of motion at the adjacent segment, but larger motions were noted at the fusion segment (L3-4) in the unilateral fixation (UF-HL and UF-TL) models when compared to bilateral fixation. The maximal von Mises stress showed similar patterns to range of motion at both superior adjacent L2-3 segments and fusion segment.CONCLUSION:The current study suggests that unilateral pedicle screw fixation seems to be unable to afford sufficient biomechanical stability in case of bilateral total laminectomy. Conversely, in the case of hemi-laminectomy, unilateral fixation could be an alternative option, which also has potential benefit to reduce the stress of the adjacent segment.OAIID:oai:osos.snu.ac.kr:snu2014-01/102/0000004226/8SEQ:8PERF_CD:SNU2014-01EVAL_ITEM_CD:102USER_ID:0000004226ADJUST_YN:NEMP_ID:A079510DEPT_CD:801CITE_RATE:1.306DEPT_NM:의학과SCOPUS_YN:YCONFIRM:

Postoperative occipital neuralgia with and without C2 nerve root transection during atlantoaxial screw fixation: a post-hoc comparative outcome study of prospectively collected data

BACKGROUND CONTEXT:Although routine transection of the C2 nerve root during atlantoaxial segmental screw fixation has been recommended by some surgeons, it remains controversial and to our knowledge no comparative studies have been performed to determine whether transection or preservation of the C2 nerve root affects patient-derived sensory outcomes.PURPOSE:The purpose of this study is to specifically analyze patient-derived sensory outcomes over time in patients with intentional C2 nerve root transection during atlantoaxial segmental screw fixation compared with those without transection.STUDY DESIGN:This is a post-hoc comparative analysis of prospectively collected patient-derived outcome data.PATIENT SAMPLE:The sample consists of 24 consecutive patients who underwent intentional bilateral transection of the C2 nerve root during posterior atlantoaxial segmental screw fixation (transection group) and subsequent 41 consecutive patients without transection (preservation group).OUTCOME MEASURES:A visual analog scale (VAS) score was used for occipital neuralgia as the primary outcome measure and VAS score for neck pain, neck disability index score and Japanese Orthopedic Association score for cervical myelopathy and recovery rate, with bone union rate as the secondary outcome measure.METHODS:Patient-derived outcomes including change in VAS score for occipital neuralgia over time were statistically compared between the two groups. This study was not supported by any financial sources and there is no topic-specific conflict of interest related to the authors of this study.RESULTS:Seven (29%) of the 24 patients in the transection group experienced increased neuralgic pain at 1 month after surgery either because of newly developed occipital neuralgia or aggravation of preexisting occipital neuralgia. Four of the seven patients required almost daily medication even at the final follow-up (44 and 80 months). On the other hand, only four (10%) of 41 patients in the preservation group had increased neuralgic pain at 1 month after surgery, and at ≥1 year, no patients had increased neuralgic pain. The difference in the prevalence of increased neuralgic pain between the two groups was statistically significant at all time points (3, 6, 12, and 24 months postoperatively) except at 1 month postoperatively. The intensity of neuralgic pain, which preoperatively had not been significantly different between the two groups, was significantly higher in the transection group at the final follow-up.CONCLUSIONS:C2 nerve root transection is not a benign procedure and, in our experience, more than a quarter of the patients experience increased neuralgic pain following C2 nerve root transection. Because the prevalence and intensity of postoperative neuralgia was significantly higher with C2 nerve root transection than with its preservation, we recommend against routine C2 nerve root transection when performing atlantoaxial segmental screw fixation.OAIID:oai:osos.snu.ac.kr:snu2013-01/102/0000004226/8SEQ:8PERF_CD:SNU2013-01EVAL_ITEM_CD:102USER_ID:0000004226ADJUST_YN:NEMP_ID:A076317DEPT_CD:801CITE_RATE:3.29FILENAME:postoperative occipital neuralgia.pdfDEPT_NM:의학과EMAIL:[email protected]_YN:YCONFIRM:

Risk of fracture according to temporal changes of low body weight changes in adults over 40years: a nationwide population-based cohort study

Background Low body weight is associated with an increased risk of fractures. However, the effect of temporal changes in the low body weight status on the risk of fracture remains unknown. This study aimed to evaluate the relationships between temporal changes in low body weight status and the risk of fractures in adults over the age of 40 years. Methods This study included data on adults over 40 years old who underwent two biannual consecutive general health examinations between January 1, 2007 and December 31, 2009 extracted from the National Health Insurance Database, a large nationwide population database. Fracture cases in this cohort were monitored from the time of the last health examination to the end of the designated follow-up period (from January 1, 2010 to December 31, 2018) or the participant's death. Fractures were defined as any fracture resulting in hospitalization or outpatient treatment claim after the date of general health screening. The study population was then separated into four groups based on the temporal changes in low body weight status as follows: low body weight to low body weight (L-to-L), low body weight to non-low body weight (L-to-N), non-low body weight to low body weight (N-to-L), and non-low body weight to non-low body weight (N-to-N). The hazard ratios (HRs) for new fractures, depending on weight changes over time, were calculated using Cox proportional hazard analysis. Results Adults in the L-to-L, N-to-L, and L-to-N groups had a substantially increased risk of fractures after multivariate adjustment (HR, 1.165; 95% confidence interval [CI], 1.113–1.218; HR, 1.193; 95% CI, 1.131–1.259; and HR, 1.114; 95% CI, 1.050–1.183, respectively). Although the adjusted HR was greater in participants who changed into having a low body weight, followed by those with consistently low body weight, those with low body weight remained to have an elevated risk of fracture independent of weight fluctuation. Elderly men (aged over 65 years), high blood pressure, and chronic kidney disease were significantly associated with an increase in fractures (p < 0.05). Conclusion Individuals aged over 40 years with low body weight, even after regaining normal weight, had an increased risk of fracture. Moreover, having a low body weight after having a normal body weight increased the risk of fractures the most, followed by those with consistently low body weight

Application of a Cumulative Summation test (CUSUM)in the Lumbar Spine

Study design: Retrospective analysisObjectives: The aim of this study was to monitor the quality control of pedicle screw fixation using a cumulativesummation test (CUSUM).Overview of Literature: CUSUM test has already been used in several different surgical settings including theassessment of outcomes in transplant, laparoscopic, and total hip replacement surgeries. However, there has been nodata regarding CUSUM analysis for spine surgery.Methods: Patients with lumbar spinal stenosis who underwent lumbar fusion surgery were included in this study.The primary outcome was the CUSUM analysis for monitoring the quality control of the accuracy of pedicle screwinsertion.Results: Seven screws of the 100 pedicle screw insertions were considered to have failed in the lumbar fusion surgery,respectively. Throughout the monitoring period, there was no indication by the CUSUM test that the quality ofperformance of the pedicle screw fixation procedure was inadequate.Conclusions: Thisstudy demonstrates the CUSUM test can be a useful tool for monitoring of the quality of proceduresrelated with spine surgery.OAIID:oai:osos.snu.ac.kr:snu2014-01/102/0000004226/7SEQ:7PERF_CD:SNU2014-01EVAL_ITEM_CD:102USER_ID:0000004226ADJUST_YN:NEMP_ID:A079510DEPT_CD:801CITE_RATE:0DEPT_NM:의학과SCOPUS_YN:NCONFIRM:

Ceramic fracture following cervical disc arthroplasty

Although ceramic fractures have been reported following total hip arthroplasty1-6, with an incidence ranging from 0.004% to 1.4%1-3, no cases of ceramic fracture following cervical disc arthroplasty have been reported, to our knowledge. We present the case of a patient with cervical radiculopathy who underwent total disc replacement at C5-C6 and C6-C7, which was complicated by the development of recurrent symptoms approximately one month after the index procedure. At the time of the revision surgery, the ceramic insert at the C6-C7 level was found to be fractured on its convex cranial side. The implant used was a semiconstrained ceramicon- ceramic prosthesis (Discocerv Cervidisc Evolution; Scientx, Guyancourt, France). Since the introduction of this prosthesis in April 20067, more than 2000 prostheses have been implanted. The patient was informed that data concerning the case would be submitted for publication, and he gave his consent.Copyright(2011) THE JOURNAL OF BONE AND JOINT SURGERY, INCORPORATED. This article may be downloaded for personal use only. Any other use requires prior permission of the author and the THE JOURNAL OF BONE AND JOINT SURGERY, INCORPORATED. The following article appeared in (citation of published article) and may be found at related URL.OAIID:oai:osos.snu.ac.kr:snu2011-01/102/0000004226/8SEQ:8PERF_CD:SNU2011-01EVAL_ITEM_CD:102USER_ID:0000004226ADJUST_YN:NEMP_ID:A076317DEPT_CD:801CITE_RATE:3.272FILENAME:E036T_JBJS-A-2011_Nguyen_Ceramic fracture following cervical disc arthroplasty.pdfDEPT_NM:의학과EMAIL:[email protected]_YN:NCONFIRM:

Finite Element Analysis for Comparison of Spinous Process Osteotomies Technique with Conventional Laminectomy as Lumbar Decompression Procedure

Purpose: The purpose of this study was to evaluate and compare the biomechanical behavior of the lumbar spine after posterior decompression with the spinous process osteotomy (SPiO) technique or the conventional laminectomy (CL) technique using a finite element (FE) model. Materials and Methods: Three validated lumbar FE models (L2-5) which represented intact spine and two decompression models using SPiO and CL techniques at the L3-4 segment were developed. In each model, the ranges of motion, the maximal von Mises stress of the annulus fibrosus, and the intradiscal pressures at the index segment (L3-4) and adjacent segments (L2-3 and L4-5) under 7.5 Nm moments were analyzed. Facet contact forces were also compared among three models under the extension and torsion moments. Results: Compared to the intact model, the CL and SPiO models had increased range of motion and annulus stress at both the index segment (L3-4) and the adjacent segments under flexion and torsion. However, the SPiO model demonstrated a reduced range of motion and annulus stress than the CL model. Both CL and SPiO models had an increase of facet contact force at the L3-4 segment under the torsion moment compared to that of the intact model. Under the extension moment, however, three models demonstrated a similar facet contact force even at the L3-4 model. Conclusion: Both decompression methods lead to postoperative segmental instability compared to the intact model. However, SPiO technique leads to better segmental stability compared to the CL technique.OAIID:oai:osos.snu.ac.kr:snu2015-01/102/0000004226/1SEQ:1PERF_CD:SNU2015-01EVAL_ITEM_CD:102USER_ID:0000004226ADJUST_YN:YEMP_ID:A079510DEPT_CD:801CITE_RATE:1.263FILENAME:ymj-2014_kim_finite element analysis for comparison of spinous process with conventional laminectomy.pdfDEPT_NM:의학과SCOPUS_YN:YCONFIRM: