scholarly journals Cortical Bone Trajectory Screw Fixation of Lumbar Spine in Adult Patients with Degenerative and Traumatic Spine Disorders

QJM ◽  
2020 ◽  
Vol 113 (Supplement_1) ◽  
Author(s):  
A M Elbadrawy ◽  
T M S Elkhateeb ◽  
E M M A Hassan
Keyword(s):  
Lumbar Spine ◽  
Random Effects ◽  
Screw Fixation ◽  
Meta Analysis ◽  
Pedicle Screws ◽  
Fusion Rate ◽  
Random Effects Models ◽  
Fixed And Random Effects ◽  
Spine Disorders ◽  
Lumbar Pedicle

Abstract Background the CBT for placing lumbar pedicle screws is a technique used to improve fixation during instrumented fusion of the lumbar spine. In comparison with traditional trajectory (TT) for pedicle screws, CBT screws (otherwise known as pars screws or cortical screws) have a more medial starting point and are aimed in a medial to lateral, caudal to cranial direction. First reported in 2009 as a method to increase the purchase of lumbar pedicle screws within bone.(1) Aim of the Work to perform a systematic review and meta-analysis to determine whether traditional Pedicles Screw Fixation (PS Fx) or Cortical Bone Trajectory Screw Fixation (CBT Fx); has been successful for the treatment and fixation of lumbar spine in adult patients with degenerative and traumatic spine disorders; and to compare the 2 techniques to identify risk factor for unfavorable outcome through the recent researches about that issue. Methodology this review was done using standard methodology outlined in the Cochrane Handbook and reported the findings in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) statement guidelines. Results meta-analysis study showed that; Successful fusion rate in fixed and random-effects models were (92.24% respectively); in SP group.Successful fusion rate in fixed and random-effects models were (92.44% respectively); in CBT group.Fixed and random-effects models showed non-significant difference in successful fusion rate; between the 2 groups of studies (p > 0.05). We calculated safety for each technique through post-operative (failed fusion rate). Conclusion Although there were insignificant p-values in the most of the comparative items but the CBT showed lower average of intraoperative blood loss, operation time and higher average of decrease in VAS & increase in ODI, slightly higher fusion rate in comparison with PS. So we recommend, the use of CBT as an acceptable alternative of PS in lumbar spine fixation.

Meta-analysis in Sociological Research: Power and Heterogeneity

2019 ◽  
pp. 004912411988247 ◽  
Author(s):  
Guangyu Tong ◽  
Guang Guo
Keyword(s):  
Random Effects ◽  
Science Studies ◽  
Meta Analysis ◽  
Sociological Research ◽  
Random Effects Models ◽  
Sociological Inquiry ◽  
Wide Range ◽  
Fixed And Random Effects ◽  
Study Heterogeneity ◽  
Analysis Models

Meta-analysis is a statistical method that combines quantitative findings from previous studies. It has been increasingly used to obtain more credible results in a wide range of scientific fields. Combining the results of relevant studies allows researchers to leverage study similarities while modeling potential sources of between-study heterogeneity. This article provides a review of the core methodologies of meta-analysis that we consider most relevant to sociological research. After developing the foundation of the fixed- and random-effects models of meta-analysis models, this article illustrates the utility of the method with regression coefficients reported from two sets of social science studies. We explain the various steps of the process including constructing the meta-sample from primary studies, estimating the fixed- and random-effects models, analyzing the source of heterogeneity across studies, and assessing publication bias. We conclude with a discussion of steps that could be taken to strengthen the development of meta-analysis in sociological research, which will eventually increase the credibility of sociological inquiry via a knowledge-cumulative process.

Fixed- and random-effects models in meta-analysis.

1998 ◽  
Vol 3 (4) ◽  
pp. 486-504 ◽  
Author(s):  
Larry V. Hedges ◽  
Jack L. Vevea
Keyword(s):  
Random Effects ◽  
Meta Analysis ◽  
Random Effects Models ◽  
Fixed And Random Effects

Detecting and correcting for publication bias in meta-analysis – A truncated normal distribution approach

2016 ◽  
Vol 27 (9) ◽  
pp. 2722-2741 ◽  
Author(s):  
Qiaohao Zhu ◽  
KC Carriere
Keyword(s):  
Normal Distribution ◽  
Publication Bias ◽  
Random Effects ◽  
Effect Size ◽  
Meta Analysis ◽  
Truncated Normal Distribution ◽  
Random Effects Models ◽  
Funnel Plot ◽  
Fixed And Random Effects ◽  
Truncated Normal

Publication bias can significantly limit the validity of meta-analysis when trying to draw conclusion about a research question from independent studies. Most research on detection and correction for publication bias in meta-analysis focus mainly on funnel plot-based methodologies or selection models. In this paper, we formulate publication bias as a truncated distribution problem, and propose new parametric solutions. We develop methodologies of estimating the underlying overall effect size and the severity of publication bias. We distinguish the two major situations, in which publication bias may be induced by: (1) small effect size or (2) large p-value. We consider both fixed and random effects models, and derive estimators for the overall mean and the truncation proportion. These estimators will be obtained using maximum likelihood estimation and method of moments under fixed- and random-effects models, respectively. We carried out extensive simulation studies to evaluate the performance of our methodology, and to compare with the non-parametric Trim and Fill method based on funnel plot. We find that our methods based on truncated normal distribution perform consistently well, both in detecting and correcting publication bias under various situations.

Percutaneous pedicle screw fixation of the lumbar spine: preliminary clinical results

2002 ◽  
Vol 97 (1) ◽  
pp. 7-12 ◽  
Author(s):  
Kevin T. Foley ◽  
Sanjay K. Gupta
Keyword(s):  
Lumbar Spine ◽  
Pedicle Screw ◽  
Screw Fixation ◽  
Pedicle Screws ◽  
Pedicle Screw Fixation ◽  
Posterior Fixation ◽  
Content Type ◽  
Insertion Device ◽  
Lumbar Pedicle ◽  
Fine Print

Object. Standard techniques for pedicle screw fixation of the lumbar spine involve open exposures and extensive muscle dissection. The purpose of this study was to report the initial clinical experience with a novel device for percutaneous posterior fixation of the lumbar spine. Methods. An existing multiaxial lumbar pedicle screw system was modified to allow screws to be placed percutaneously by using an extension sleeve that permits remote manipulation of the polyaxial screw heads and remote engagement of the screw-locking mechanism. A unique rod-insertion device was developed that linked to the screw extension sleeves, allowing for a precut and -contoured rod to be placed through a small stab wound. Because the insertion device relies on the geometrical constraint of the rod pathway through the screw heads, minimal manipulation is required to place the rods in a standard submuscular position, there is essentially no muscle dissection, and the need for direct visual feedback is avoided. Twelve patients (six men and six women) who ranged in age from 23 to 68 years underwent pedicle screw fixation in which the rod-insertion device was used. Spondylolisthesis was present in 10 patients and osseous nonunion of a prior interbody fusion was present in two. All patients underwent successful percutaneous fixation. Ten patients underwent single-level fusions (six at L5—S1, three at L4–5, and one at L2–3), and two underwent two-level fusions (one from L3–5 and the other from L4—S1). The follow-up period ranged from 10 to 19 months (mean 13.8 months). Conclusions. Although percutaneous lumbar pedicle screw placement has been described previously, longitudinal connector (rod or plate) insertion has been more problematic. The device used in this study allows for straightforward placement of lumbar pedicle screws and rods through percutaneous stab wounds. Paraspinous tissue trauma is minimized without compromising the quality of spinal fixation. Preliminary experience involving the use of this device has been promising.

scholarly journals Percutaneous pedicle screw fixation of the lumbar spine

2001 ◽  
Vol 10 (4) ◽  
pp. 1-9 ◽  
Author(s):  
Kevin T. Foley ◽  
Sanjay K. Gupta ◽  
Jeff R. Justis ◽  
Michael C. Sherman
Keyword(s):  
Lumbar Spine ◽  
Pedicle Screw ◽  
Screw Fixation ◽  
Pedicle Screws ◽  
Pedicle Screw Fixation ◽  
Posterior Fixation ◽  
Insertion Device ◽  
Locking Mechanism ◽  
Percutaneous Pedicle Screw ◽  
Lumbar Pedicle

Object Standard techniques for lumbar pedicle screw fixation involve open exposures and extensive muscle dissection. The purpose of this study was to report the initial clinical experience with a novel device for percutaneous posterior fixation of the lumbar spine. Methods An existing multiaxial lumbar pedicle screw system was modified so that screws could be placed percutaneously by using an extension sleeve that would allow for remote manipulation of the polyaxial screw heads and remote engagement of the screw locking mechanism. A unique rod insertion device was developed that linked to the screw extension sleeves, allowing for a precut, precontoured rod to be placed through a small stab wound. Because the insertion device relies on geometrical constraint of the rod pathway through the screw heads, rods can be placed in a standard submuscular position with minimal manipulation, essentially no muscle dissection, and without the need for direct visual feedback. Twelve patients (six men and six women who ranged in age from 23–68 years) underwent pedicle screw fixation in which the rod insertion device was used. Spondylolisthesis was present in 10 patients and nonunion of a prior interbody fusion was present in two. All patients underwent successful percutaneous fixation. Ten patients underwent single-level fusions (six at L5–S1, three at L4–5, and one at L2–3), and two underwent two-level fusions (one from L–3 to L–5 and the other from L–4 to S–1). The follow-up period ranged from 3 to 12 months (mean 6.8 months). Conclusions Although percutaneous lumbar pedicle screw placement has been described previously, longitudinal connector (rod or plate) insertion has been more problematic. The device used in this study allows for straightforward placement of lumbar pedicle screws and rods through percutaneous stab wounds. Paraspinous tissue trauma is minimized without compromising the quality of spinal fixation. Preliminary experience with this device has been promising.

scholarly journals Triggered Electromyography is a Useful Intraoperative Adjunct to Predict Postoperative Neurological Deficit Following Lumbar Pedicle Screw Instrumentation

2021 ◽  
pp. 219256822110184
Author(s):  
Rajiv P. Reddy ◽  
Robert Chang ◽  
Dominic V. Coutinho ◽  
Justin W. Meinert ◽  
Katherine M. Anetakis ◽  
...  
Keyword(s):  
Lumbar Spine ◽  
Pedicle Screw ◽  
Neurological Deficit ◽  
Meta Analysis ◽  
Pedicle Screws ◽  
Neurological Deficits ◽  
Lumbar Spine Surgery ◽  
Postoperative Neurological Deficit ◽  
Alarm Threshold ◽  
Lumbar Pedicle

Study Design: Systematic review and meta-analysis. Objectives: Malposition of pedicle screws during instrumentation in the lumbar spine is associated with complications secondary to spinal cord or nerve root injury. Intraoperative triggered electromyographic monitoring (t-EMG) may be used during instrumentation for early detection of malposition. The association between lumbar pedicle screws stimulated at low EMG thresholds and postoperative neurological deficits, however, remains unknown. The purpose of this study is to assess whether a low threshold t-EMG response to lumbar pedicle screw stimulation can serve as a predictive tool for postoperative neurological deficit. Methods: The present study is a meta-analysis of the literature from PubMed, Web of Science, and Embase identifying prospective/retrospective studies with outcomes of patients who underwent lumbar spinal fusion with t-EMG testing. Results: The total study cohort consisted of 2,236 patients and the total postoperative neurological deficit rate was 3.04%. 10.78% of the patients incurred at least 1 pedicle screw that was stimulated below the respective EMG alarm threshold intraoperatively. The incidence of postoperative neurological deficits in patients with a lumbar pedicle screw stimulated below EMG alarm threshold during placement was 13.28%, while only 1.80% in the patients without. The pooled DOR was 10.14. Sensitivity was 49% while specificity was 88%. Conclusions: Electrically activated lumbar pedicle screws resulting in low t-EMG alarm thresholds are highly specific but weakly sensitive for new postoperative neurological deficits. Patients with new postoperative neurological deficits after lumbar spine surgery were 10 times more likely to have had a lumbar pedicle screw stimulated at a low EMG threshold.

scholarly journals Effects of dutasteride on prostate cancer incidence: A systematic review and meta-analysis

2020 ◽  
Vol 11 (4) ◽  
pp. 7266-7270
Author(s):  
Gyeong-Eun Min ◽  
Haesoo Kim ◽  
Da Eun Lee ◽  
Kisok Kim
Keyword(s):  
Prostate Cancer ◽  
Random Effects ◽  
Fixed Effects ◽  
Meta Analysis ◽  
Adult Males ◽  
Fixed Effects Model ◽  
Random Effects Models ◽  
Benign Prostate Hypertrophy ◽  
Fixed And Random Effects ◽  
Meta Analyses

5-Alpha-reductase inhibitors (5-ARIs) are used in the treatment of benign prostate hypertrophy (BPH). 5-ARIs, such as finasteride and dutasteride, suppress the biosynthesis of dihydrotestosterone (DHT), a precursor of androgen, which is closely related to the incidence of prostate cancer (PCa). A previous meta-analysis demonstrated a relationship between finasteride use and the incidence of PCA. However, there have been no meta-analyses on the relationship between PCa and dutasteride alone. This meta-analysis was performed to examine the prevalence of PCa in adult males taking dutasteride. We searched PubMed for reports regarding PCa risk and dutasteride use. The study was conducted according to the PRISMA guidelines for systematic reviews and meta-analyses. The analytic hierarchy process (AHP) method was used to weight the studies. Odds ratios (ORs), 95% confidence intervals (CIs), and P-values were calculated using fixed- and random-effects models. A total of eight articles were included in the meta-analysis. The overall OR for both the fixed- and random-effects models was 0.669 and the 95% CI for the random-effects model (0.526–0.851; P = 0.006) was wider than that for the fixed effects model (0.548–0.817; P < 0.001). This study confirmed that the incidence of PCa was significantly reduced by taking dutasteride.

scholarly journals Dyslipidaemia and mortality in COVID-19 patients - a meta-analysis

QJM ◽  
2021 ◽  
Author(s):  
Marco Zuin ◽  
Gianluca Rigatelli ◽  
Claudio Bilato ◽  
Carlo Cervellati ◽  
Giovanni Zuliani ◽  
...  
Keyword(s):  
Random Effects ◽  
Mortality Risk ◽  
Meta Analysis ◽  
Random Effect ◽  
Final Analysis ◽  
Short Term ◽  
Random Effects Models ◽  
Pooled Prevalence ◽  
Statistical Heterogeneity ◽  
Trim And Fill

Abstract Objective The prevalence and prognostic implications of pre-existing dyslipidaemia in patients infected by the SARS-CoV-2 remain unclear. To perform a systematic review and meta-analysis of prevalence and mortality risk in COVID-19 patients with pre-existing dyslipidaemia. Methods Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines were followed in abstracting data and assessing validity. We searched MEDLINE and Scopus to locate all the articles published up to January 31, 2021, reporting data on dyslipidaemia among COVID-19 survivors and non-survivors. The pooled prevalence of dyslipidaemia was calculated using a random effects model and presenting the related 95% confidence interval (CI), while the mortality risk was estimated using the Mantel-Haenszel random effects models with odds ratio (OR) and related 95% CI. Statistical heterogeneity was measured using the Higgins I2 statistic. Results Eighteen studies, enrolling 74.132 COVID-19 patients [mean age 70.6 years], met the inclusion criteria and were included in the final analysis. The pooled prevalence of dyslipidaemia was 17.5% of cases (95% CI: 12.3-24.3%, p &lt; 0.0001), with high heterogeneity (I2=98.7%). Pre-existing dyslipidaemia was significantly associated with higher risk of short-term death (OR: 1.69, 95% CI: 1.19-2.41, p = 0.003), with high heterogeneity (I2=88.7%). Due to publication bias, according to the Trim-and-Fill method, the corrected random-effect ORs resulted 1.61, 95% CI 1.13-2.28, p &lt; 0.0001 (one studies trimmed). Conclusions Dyslipidaemia represents a major comorbidity in about 18% of COVID-19 patients but it is associated with a 60% increase of short-term mortality risk.

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