3,623 research outputs found
Impact of Supine Radiographs to Assess Curve Flexibility in the Treatment of Adolescent Idiopathic Scoliosis
Study Design: Retrospective cohort study. Objectives: The purpose of the study is to evaluate the role of supine radiographs in determining flexibility of thoracic and thoracolumbar curves. Methods: Ninety operative AIS patients with 2-year follow-up from a single institution were queried and classified into MT structural and TL structural groups. Equations were derived using linear regression to compute cut-off values for MT and TL curves. Thresholds were externally validated in a separate database of 60 AIS patients, and positive and negative predictive values were determined for each curve. Results: MT supine values were highly predictive of MT side-bending values (TL group: 0.63, P \u3c 0.001; MT group: 0.66, P = 0.006). Similarly, TL supine values were highly predictive of TL side-bending values (TL group: 0.56, P = 0.001 MT group: 0.68, P = 0.001). From our derived equations, MT and TL curves were considered structural on supine films if they were ≥ 30° and 35°, respectively. Contingency table analysis of external validity sample showed that supine films were highly predictive of structurality of MT curve (Sensitivity = 0.91, PPV = 0.95, NPV = 0.81) and TL curve (Sensitivity = 0.77, PPV = 0.81, NPV = 0.94). ROC analysis revealed that the area under curve for MT structurality from supine films was 0.931 (SEM: 0.03, CI: 0.86-0.99, P \u3c 0.001) and TL structurality from supine films was 0.922 (SEM: 0.03, CI- 0.84-0.98, P \u3c 0.001). Conclusions: A single preoperative supine radiograph is highly predictive of side-bending radiographs to assess curve flexibility in AIS. A cut-off of ≥ 30° for MT and ≥ 35° for TL curves in supine radiographs can determine curve structurality
An update on the occurrence of nematodes belonging to the genus Bursaphelenchus in the Mediterranean area
The genus Bursaphelenchus containsmore than100species ofnematodes. Knowledge of the occurrence ofnematodes
belonging to this genus is a prerequisite for monitoring issues and control measures to prevent the introduction
and establishment of pathogenic species such as Bursaphelenchus xylophilus into forest ecosystems.
According to data collected from the published literature and databases such as Web of Science, FSTA, CAB
Abstracts, Biological Abstracts and the EPPO Reporting Service, 22 Bursaphelenchus species have been recorded
to be present in the Mediterranean region. These species are classified into nine morphological groups sensu
Braasch, H., Burgermeister, W. and Gu, J. 2009 Revised intra-generic grouping of Bursaphelenchus Fuchs, 1937
(Nematoda: Aphelenchoididae). J.Nematode Morphol. Syst. 12, 65–88): abietinus, eggersi, eremus, fungivorus, hofmanni,
kevini, leoni, sexdentati and xylophilus, although two species are currently not assigned to a specific group.
Movement of insect vectors in international trade of wood and host plants into and within Mediterranean areas is
consideredthemainpathwayfor Bursaphelenchus species dispersal.Manyof the species representasignificant risk
for pine and possibly other forest types, an annotated check-list of Bursaphelenchus species in the Mediterranean
area, their main features, pathogenicity, host plants and insect vectors is presented
Interpars: An Anatomical Examination of the Lumbar Pars Interarticulares with Significance for Spinal Decompression
Background. Spine procedures continue to increase significantly. As such, a more precise understanding of the anatomy, especially the pars interarticularis (PI) is critical. Current data characterizing the PI level-by-level is lacking. This study analyzed the average PI width at each level of the lumbar spine in order to elucidate statistically significant PI variations between lumbar levels. Methods. The interpars distance, the narrowest distance between the lateral edges of the left and right PI, was mea- sured directly with calipers on 53 complete lumbar speci- mens and digitally via Fastrack measurements of 30 sets of lumbar vertebrae. For both methods, the mean interpars distances were compared moving down the lumbar spine. Results. For direct measurements, the average interpars distances increased from L2 to L5. Analysis revealed sig- nificant differences across all levels. A significant difference was noted between male and female vertebrae only at L1. For Fastrack measurements, the average interpars distances also increased from L2 to L5. An increase in spinal canal width was observed across all but L1-L2, and an increase in the interpars-to-spinal-canal-width ratio was noted at all levels except L1-L2 and L4-L5. Conclusions. The amount of bone in the PI available for surgical removal becomes smaller moving from L5 to L1. There is a larger “margin-for-error” at L4 and L5 when decompressing the spinal canal from one side to the other than there is in the upper lumbar spine. At L1 and L2, de- compressing the entire width of the spinal canal leaves only a millimeter of remaining pars on either side. Care should be taken to use “undercutting techniques” in upper lumbar decompressions to preserve the PI
Spino-femoral muscles affect sagittal alignment and compensatory recruitment: a new look into soft tissues in adult spinal deformity
Objective To quantify muscle characteristics (volumes and fat infiltration) and identify their relationship to sagittal malalignment and compensatory mechanism recruitment. Methods Female adult spinal deformity patients underwent T1-weighted MRI with a 2-point Dixon protocol from the proximal tibia up to the T12 vertebra. 3D reconstructions of 17 muscles, including extensors and flexors of spine, hip and knee, were obtained. Muscle volume standardized by bone volume and percentage of fat infiltration (Pfat) were calculated. Correlations and regressions were performed. Results A total of 22 patients were included. Significant correlations were observed between sagittal alignment and muscle parameters. Fat infiltration of the hip and knee flexors and extensors correlated with larger C7-S1 SVA. Smaller spinal flexor/extensor volumes correlated with greater PI-LL mismatch (r = − 0.45 and − 0.51). Linear regression identified volume of biceps femoris as only predictor for PT (R2 = 0.34, p = 0.005) and Pfat of gluteus minimus as only predictor for SVA (R2 = 0.45, p = 0.001). Sagittally malaligned patients with larger PT (26.8° vs. 17.2°) had significantly smaller volume and larger Pfat of gluteus medius, gluteus minimus and biceps femoris, but similar values for gluteus maximus, the hip extensor. Conclusion This study is the first to quantify the relationship between degeneration of spino-femoral muscles and sagittal malalignment. This pathoanatomical study identifies the close relationship between gluteal, hamstring muscles and PT, SVA, which deepens our understanding of the underlying etiology that contributes to adult spinal deformity.The manuscript submitted does not contain information about medical device(s)/drug(s). This work received funding from Youth Fund of Natural Science Foundation of Jiangsu Province (BK20180122). This work received funding from Key Project supported by Medical Science and Technology Development Foundation, Nanjing Department of Health (YKK18092)
Surgical versus nonsurgical treatment for lumbar degenerative spondylolisthesis.
BACKGROUND: Management of degenerative spondylolisthesis with spinal stenosis is controversial. Surgery is widely used, but its effectiveness in comparison with that of nonsurgical treatment has not been demonstrated in controlled trials.
METHODS: Surgical candidates from 13 centers in 11 U.S. states who had at least 12 weeks of symptoms and image-confirmed degenerative spondylolisthesis were offered enrollment in a randomized cohort or an observational cohort. Treatment was standard decompressive laminectomy (with or without fusion) or usual nonsurgical care. The primary outcome measures were the Medical Outcomes Study 36-Item Short-Form General Health Survey (SF-36) bodily pain and physical function scores (100-point scales, with higher scores indicating less severe symptoms) and the modified Oswestry Disability Index (100-point scale, with lower scores indicating less severe symptoms) at 6 weeks, 3 months, 6 months, 1 year, and 2 years.
RESULTS: We enrolled 304 patients in the randomized cohort and 303 in the observational cohort. The baseline characteristics of the two cohorts were similar. The one-year crossover rates were high in the randomized cohort (approximately 40% in each direction) but moderate in the observational cohort (17% crossover to surgery and 3% crossover to nonsurgical care). The intention-to-treat analysis for the randomized cohort showed no statistically significant effects for the primary outcomes. The as-treated analysis for both cohorts combined showed a significant advantage for surgery at 3 months that increased at 1 year and diminished only slightly at 2 years. The treatment effects at 2 years were 18.1 for bodily pain (95% confidence interval [CI], 14.5 to 21.7), 18.3 for physical function (95% CI, 14.6 to 21.9), and -16.7 for the Oswestry Disability Index (95% CI, -19.5 to -13.9). There was little evidence of harm from either treatment.
CONCLUSIONS: In nonrandomized as-treated comparisons with careful control for potentially confounding baseline factors, patients with degenerative spondylolisthesis and spinal stenosis treated surgically showed substantially greater improvement in pain and function during a period of 2 years than patients treated nonsurgically. (ClinicalTrials.gov number, NCT00000409 [ClinicalTrials.gov].)
A prospective, randomized, double-blinded single-site control study comparing blood loss prevention of tranexamic acid (TXA) to epsilon aminocaproic acid (EACA) for corrective spinal surgery
<p>Abstract</p> <p>Background</p> <p>Multilevel spinal fusion surgery has typically been associated with significant blood loss. To limit both the need for transfusions and co-morbidities associated with blood loss, the use of anti-fibrinolytic agents has been proposed. While there is some literature comparing the effectiveness of tranexamic acid (TXA) to epsilon aminocaproic acid (EACA) in cardiac procedures, there is currently no literature directly comparing TXA to EACA in orthopedic surgery.</p> <p>Methods/Design</p> <p>Here we propose a prospective, randomized, double-blinded control study evaluating the effects of TXA, EACA, and placebo for treatment of adolescent idiopathic scoliosis (AIS), neuromuscular scoliosis (NMS), and adult deformity (AD) via corrective spinal surgery. Efficacy will be determined by intraoperative and postoperative blood loss. Other clinical outcomes that will be compared include transfusion rates, preoperative and postoperative hemodynamic values, and length of hospital stay after the procedure.</p> <p>Discussion</p> <p>The primary goal of the study is to determine perioperative blood loss as a measure of the efficacy of TXA, EACA, and placebo. Based on current literature and the mechanism by which the medications act, we hypothesize that TXA will be more effective at reducing blood loss than EACA or placebo and result in improved patient outcomes.</p> <p>Trial Registration</p> <p>ClinicalTrials.gov ID: NCT00958581</p
Psoas Morphology Differs between Supine and Sitting Magnetic Resonance Imaging Lumbar Spine: Implications for Lateral Lumbar Interbody Fusion
Study DesignRetrospective radiological review.PurposeTo quantify the effect of sitting vs supine lumbar spine magnetic resonance imaging (MRI) and change in anterior displacement of the psoas muscle from L1–L2 to L4–L5 discs.Overview of LiteratureControversy exists in determining patient suitability for lateral lumbar interbody fusion (LLIF) based on psoas morphology. The effect of posture on psoas morphology has not previously been studied; however, lumbar MRI may be performed in sitting or supine positions.MethodsA retrospective review of a single-spine practice over 6 months was performed, identifying patients aged between 18–90 years with degenerative spinal pathologies and lumbar MRIs were evaluated. Previous lumbar fusion, scoliosis, neuromuscular disease, skeletal immaturity, or intrinsic abnormalities of the psoas muscle were excluded. The anteroposterior (AP) dimension of the psoas muscle and intervertebral disc were measured at each intervertebral disc from L1–L2 to L4–L5, and the AP psoas:disc ratio calculated. The morphology was compared between patients undergoing sitting and/or supine MRI.ResultsTwo hundred and nine patients were identified with supine-, and 60 patients with sitting-MRIs, of which 13 patients had undergone both sitting and supine MRIs (BOTH group). A propensity score match (PSM) was performed for patients undergoing either supine or sitting MRI to match for age, BMI, and gender to produce two groups of 43 patients. In the BOTH and PSM group, sitting MRI displayed significantly higher AP psoas:disc ratio compared with supine MRI at all intervertebral levels except L1–L2. The largest difference observed was a mean 32%–37% increase in sitting AP psoas:disc ratio at the L4–L5 disc in sitting compared to supine in the BOTH group (range, 0%–137%).ConclusionsThe psoas muscle and the lumbar plexus become anteriorly displaced in sitting MRIs, with a greater effect noted at caudal intervertebral discs. This may have implications in selecting suitability for LLIF, and intra-operative patient positioning
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