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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
241

Retrospektive Aufarbeitung der Revisionseingriffe aufgrund „Osteosyntheseversagen“ nach Wirbelsäulenoperationen der Jahre 2003 bis 2009

Böhme, Tina 24 June 2014 (has links)
Die demographische Entwicklung mit Zunahme des Anteils der älteren Bevölkerung hat in den vergangenen 20 Jahren zu einem Anstieg operationspflichtiger Wirbelsäulenverletzungen geführt. Neue Operationstechniken wurden entwickelt, um den Herausforderungen, die sich durch den größeren Anteil älterer Patienten ergeben, entgegen zu treten. Neben offen-chirurgischen Verfahren kommen mehr und mehr minimal-invasive Techniken zur Anwendung (Lendemans et al. 2011a). Doch unabhängig von der gewählten Methode birgt jeder operative Eingriff Risiken und die Gefahr intra- und postoperativer Komplikationen. Dazu gehören neben allgemeinen Komplikationen wie Blutungen, Verletzung umliegender Strukturen oder postoperativen neurologischen Ausfällen auch implantatbedingte Komplikationen wie z.B. Lockerung, Dislokation oder Bruch des eingebrachten Materials. Letzt genannte Komplikationsart ist ein gemeinsames Charakteristikum der in dieser Arbeit untersuchten Patienten. Ziel dieser Arbeit war es, die im Zeitraum vom 01.01.2003 bis 31.12.2009 an der Klinik für Unfall-, Wiederherstellungs- und Plastische Chirurgie der Universität Leipzig operierten Patienten, bei denen aufgrund von Hardwarekomplikationen Revisionseingriffe durchgeführt werden mussten, zu analysieren. Von insgesamt 57 Patienten (♂/♀=35/22) wurden u.a. Daten zu Unfallart, Lokalisation und Klassifikation der Verletzung, operative Details (Operationsdatum, Operationsdauer, Art der durchgeführten Operation einschließlich Einzelheiten zu den verwendeten Implantaten, Navigationsverfahren), postoperative Komplikationen, Nebendiagnosen (kardiale Nebenerkrankungen, Diabetes mellitus Typ II, Morbus Bechterew, Osteoporose, Nikotinabusus) und BMI ermittelt. Die statistische Auswertung wurde teilweise getrennt für die von uns festgelegten Gruppen (FRAKTUR – CARCINOM – SPONDYLODISZITIS – SPONDYLOLISTHESIS) vorgenommen. Das von uns untersuchte Patientengut kann als inhomogen beschrieben werden. Das Durchschnittsalter betrug 59 Jahre, die Altersspanne reichte von 21 bis 92 Jahre. Die Mehrheit der Patienten konnte der Frakturgruppe zugeordnet werden. Am häufigsten war der Abschnitt der LWS von Verletzungen bzw. den weiteren Krankheitsbildern betroffen. Die operative Stabilisierung erfolgte überwiegend von dorsal. Alle Eingriffe wurden Bildwandler-kontrolliert durchgeführt. In 4 Fällen kam zusätzlich eine CT-Navigation zum Einsatz. Als instrumentierungsbedingte Komplikationen wurden postoperativ am häufigsten Materialdislokation/-lockerung und Pedikelschraubenfehllage beobachtet. Bei 78,9% der Patienten (n=45) war ein einziger Revisionseingriff ausreichend. 12 Patienten (21,1%) mussten mindestens einer weiteren Revisionsoperation unterzogen werden. Als Nebendiagnosen wurden 28-mal (49,1%) kardiale Erkrankungen, 13-mal Osteoporose (22,8%), 11-mal (19,3%) Diabetes mellitus Typ II, und 3-mal (5,3%) Morbus Bechterew gezählt. Fast die Hälfte der Patienten (45,6%) hatte 2 oder mehr Begleiterkrankungen. Als weiterer Risikofaktor wurde bei 26,3% ein Nikotinabusus angegeben. Mit einem Anteil von 57,8% (n=33) waren mehr als die Hälfte der Patienten übergewichtig (BMI ≥ 25). In Zusammenschau mit den Angaben der Literatur können die von uns untersuchten Nebendiagnosen als Risikofaktoren für implantatbedingte Komplikationen angesehen werden. Der Einsatz computerassistierter Navigation, insbesondere bei der Implantation der Pedikelschrauben, kann dazu beitragen, die Komplikationsrate zu minimieren. Das Auftreten von Hardwarekomplikationen scheint multifaktoriell bedingt zu sein. Diverse Nebenerkrankungen, der Habitus des Patienten, das gewählte Operationsverfahren und nicht zuletzt die Erfahrung des Operateurs beeinflussen das postoperative Ergebnis.
242

The acquisition and extinction of morphine conditioned place preference have opposite effects on the morphology of neurons in the nucleus accumbens

Kobrin, Kendra 03 November 2015 (has links)
Drug-associated stimuli trigger craving and relapse in addiction. Murine morphine conditioned place preference (CPP) was used to model learning of opioid associations. We examined how morphine and learning interact to alter neuron morphology in the nucleus accumbens (NAc) core and shell after acquisition and extinction of CPP. Conditioning with morphine dose-dependently increased place preference compared to saline. In comparison to those from saline conditioned and morphine non-conditioned controls, neurons from the NAc core of morphine conditioned mice had increased dendritic complexity, as defined by increased dendritic length, number, and Sholl intersections. This effect is due to the combination of morphine and learning, which is different from effects of morphine or conditioning alone. Morphine administration without conditioning was associated with increased spine density in the core, which was reversed by CPP acquisition. Control conditioning with saline produced no morphology changes. Morphine CPP extinction was associated with decreased dendritic complexity, reversing the increased complexity seen after acquisition. Mice that extinguished CPP had similar dendritic complexity to saline conditioned mice, in terms of dendritic count and intersections, but less dendritic complexity than non-extinguished mice that retained CPP. Since dopamine release imbues salience to stimuli that coincide with drug use, and the dopamine D1 receptor mediates CPP acquisition, we tested the effect of SKF81297 D1 receptor agonist on CPP extinction and associated accumbal neuron morphology. SKF81297 (0.8 mg/kg) injected after each extinction training session impeded extinction, and produced increased dendritic complexity compared to controls. SKF81297 may have sustained conditioned associations, disrupted consolidation of extinction, and/or disrupted the decline in dopamine levels that may occur throughout extinction sessions. We hypothesize that changes occurred in the NAc core because this region mediates how stimuli and drug effects direct motor action. Since D1 receptors oppose extinction of drug-cue-induced behavior, they play a role in reinforcing opioid addiction. Acquisition and extinction may be opposite processes in the brain, as in behavior. Extinction may include some reversal of acquisition learning as well as being new learning with its own pathway. Interventions that target D1 receptors or that selectively reduce NAc core dendritic complexity may contribute to opioid addiction treatment.
243

Psychosomatika u vertebrogenních onemocnění / Psychosomatic in vertebrogenic disease

Bezděková, Anna January 2020 (has links)
Title: Psychosomatic in vertebrogenic disease Objectives: The aim of this master thesis is to determine common features of vertebrogenic disease in conection with psychosomatics using literary research, and to describe the treatement options for this disease used in literal sources. The first searched common feature is the most common localization of pain. Other searched common feature is the prevalence of gender and age. The last searched common feature is treatement option for psychosomatic vertebrogenic disease according to specialised literature. Methods: This master thesis is designed in a form of literary research. All studies and articles presented in this thesis were searched according to the following criteria: search in Czech or English language, search in electronic databases of Bibliographia Medica Čechoslovaca (BMČ), Medline (OIVID), PubMed and Google Scholar. The following keywords were used for the search: Psychosomatika, vertebrogenní onemocnění, bolest zad, deprese, úzkost, stres, bederní páteř, hrudní páteř, krční páteř, psychosomatická onemocnění a bolest zad, Psychosomatics, vertebrogenic diseases, back pain, depression, anxiety, stress, lumbar spine, thoracic spine, cervical spine, psychosomatic disorders and back pain. These sought sources are directly related to...
244

Effects of doc and water temperature on prey use and performance of nine-spine stickleback

Berg, Ivan January 2021 (has links)
Climate change is causing water temperature to rise, and many lakes in the boreal zone will experience browning of waters (brownification) due to increased input of dissolved organic carbon (DOC). In fish, warming may cause resource limitation and decrease both fish size and population abundance. Many fish species display ontogenetic niche shifts during their lifetime, shifting to larger prey as they grow. Brownification may change the timing for, the benefits from or prevent individuals from displaying ontogenetic niche shifts by decreasing large prey abundance in the benthic zone or making fast-moving prey harder to see. This can cause resource limitations, suppressing growth and population growth. This study investigated the effects of increasing DOC and water temperature on ontogenetic diet shifts, size structure, and population abundance in nine-spine stickleback (Pungitius pungitius) in an experimental pond system with a warming treatment and a gradient of DOC concentration. Warming had a negative effect on population number, biomass, maximum fish size, stomach fullness, and consumption of large prey. Contrary to expected outcomes, increasing DOC input resulted in higher population, biomass, and larger maximum sized fish as DOC increased. DOC did not negatively affect ontogenetic diet shifts. In the relatively shallow enclosures, the highest DOC concentration may not have reached the threshold where the shading effect of DOC overturns the benefits of extra nutrients associated with DOC. Hence, in shallow lake ecosystems, climate change induced DOC increase may support fish production, while warming may have strong negative effects on fish population abundance and size.
245

Time-dependent assessment of the human lumbar spine in response to flexion exposures: in vivo measurement and modeling

Toosizadeh, Nima 01 March 2013 (has links)
Among several work-related injuries, low back disorders (LBDs) are the leading cause of lost workdays, and with annual treatment costs in excess of $10 billion in the US. Epidemiological evidence has indicated that prolonged and/or repetitive non-neutral postures, such as trunk flexion, are commonly associated with an increased risk of LBDs. Trunk flexion can result in viscoelastic deformations of soft tissues and subsequent mechanical and neuromuscular alterations of the trunk, and may thereby increase LBD risk. While viscoelastic behaviors of isolated spinal motion segments and muscles have been extensively investigated, in vivo viscoelastic responses of the trunk have not, particularly in response to flexion exposures. Further, most biomechanical efforts at understanding occupational LBDS have not considered the influence of flexion exposures on spine loads. Four studies were completed to characterize viscoelastic deformation of the trunk in response several flexion exposures and to develop and evaluate a computational model of the human trunk that accounts for time-dependent characteristics of soft tissues. Participants were exposed to prolonged flexion at different trunk angles and external moments, and repetitive trunk flexion with different external moments and flexion rates. Viscoelastic properties were quantified using laboratory experiments and viscoelastic models. A multi-segment model of the upper body was developed and evaluated, and then used to estimate muscle forces and spine loads during simulated lifting tasks before and after prolonged trunk flexion at a constant angle and constant external moment. Material properties from the earlier experiments were used to evaluate/calibrate the model. Experimental results indicated important effects of flexion angle, external moment, and flexion rate on trunk viscoelastic behaviors. Material properties from fitted Kelvin-solid models differed with flexion angle and external moment. Nonlinear viscoelastic behavior of the trunk tissues was evident, and predictive performance was enhanced using Kelvin-solid models with ≥2 iii retardation/relaxation time constants. Predictions using the multi-segment model suggested increases in spine loads following prolonged flexion exposures, primarily as a consequence of additional muscle activity. As a whole, these results help to characterize the effects of trunk flexion exposures on trunk biomechanics, contribute to more effective estimates of load distribution among passive and active components, enhance our understanding of LBD etiology, and may facilitate future controls/interventions. / Ph. D.
246

Factors which affect the application and implementation of a spinal motion restriction protocol by prehospital providers in low resource settings: a scoping review

Geduld, Charlene 15 February 2022 (has links)
The South African Professional Board for Emergency Care prehospital Clinical Practice Guideline (CPG) recommends that emergency medical services (EMS) make use of the National Emergency X Radiography Utilization Study (NEXUS) rule and Canadian C-spine Rule (CCSR) when managing traumatic spinal injury. However, the safety and effectiveness of prehospital clinical spinal clearance or spinal motion restriction (SMR) decision support tools within poorly resourced settings are unclear. We conducted a scoping review on clinical spinal clearance and selective SMR decision support tools which aimed at identifying possible barriers to their implementation, safety, and effectiveness when used by EMS personnel. Studies were included if they described the use of clinical spinal clearance or SMR decision tools in first line management of blunt trauma patients by medical practitioners in the Emergency Department (ED) or by EMS personnel working in a prehospital setting. After screening, 42 documents fulfilled the inclusion criteria. Several selective SMR decision support tools have been implemented in the prehospital setting, the most common of which were those based on the NEXUS and the CCSR tools. Only one study evaluated the safety and efficacy of the NEXUS rule when used by EMS personnel. The limited prehospital literature available investigating either the NEXUS rule or CCSR therefore makes it difficult to determine its appropriateness for adoption and implementation by EMS personnel in other prehospital settings such as that of South Africa. Furthermore, commonly found prehospital NEXUS-based decision tools presented with unique challenges related to the subjective nature of some of the individual components of the decision tool. This leaves the decision tool open to interpretation by examiners and is especially relevant in settings, such as South Africa, where there are many different levels in scope of practices. This increases the risk of the patient being either under-triaged or over-triaged. More studies are therefore needed to definitively assess for the safety, efficacy and effectiveness of clinical spine clearance within the prehospital setting. It is believed that a selective SMR decision tool which has more specific instructions for the prehospital practitioner may be able to accommodate such challenges and is an area which needs further investigation.
247

Utilisation des bases de données médico-administratives pour la recherche clinique et épidémiologique en orthopédie / Utility of Administrative Databases in Orthopedic Surgery

Bouyer, Benjamin 18 December 2019 (has links)
Le Système National des Données de Santé comprend des données portant sur l’ensemble des activités de soins en France (soins de ville, séjour hospitalier, prestations sociales en lien avec la maladie), auxquelles doivent être notamment associées des données de mortalité (causes de décès, en cours) et sur le handicap (à terme). De multiples travaux ont déjà montré l’intérêt de l’analyse de ces données à des fins de recherche, dans des domaines variés (études épidémiologiques de pathologies ou de groupes de patients, évaluation de produits de santé ou études médico-économiques). L’application à des fins de recherche en orthopédie est assez récente. Cette discipline chirurgicale présente des spécificités en termes de données que nous avons développées dans la première partie de ce travail, en particulier concernant les dispositifs médicaux utilisés. La connaissance de ces données a permis de réaliser une évaluation du fardeau national engendré par les fractures en France. Plus de 562 000 évènements ont été identifiés en 2016 concernant 1 % de la population adulte et près de 12 000 (2%) étaient suivis de décès précoce. L’analyse détaillée a montré des spécificités par site fracturaire et par sexe avec pour tous les groupes une importante augmentation de l’incidence avec l’âge. La troisième partie de cette thèse est consacrée à l’analyse du risque thrombo-embolique après chirurgie rachidienne. L’analyse de données individuelles détaillées a permis de montrer que le risque (de près 1% en population générale) était largement modulé par des facteurs liés aux patients et aux actes réalisés.Le Système National des Données de Santé offre comme nous le montrons dans cette thèse de vastes opportunités pour la recherche en orthopédie. Des travaux préparatoires, notamment dans le domaine de la fiabilisation des mesures d’efficacité, sont encore nécessaires pour répondre à certaines questions. / The National Health Data System includes data on all health care activities in France (outpatient care, hospital stay and social benefits related to diseases), which should be associated with mortality (causes of deaths, ongoing) and disability data (in the middle term). Many studies have already shown the interest of the analysis of these data for research purposes, in various fields (epidemiological studies of pathologies or groups of patients, evaluation of health products or medico-economic studies). The application for orthopedic research purposes is fairly recent. This surgical discipline has specificities in terms of data that we have exposed in the first part of this work; especially with regard to medical devices. The knowledge of these data made it possible to carry out an assessment of the national burden caused by fractures in France. More than 562,000 events were identified in 2016 for 1% of the adult population and nearly 12,000 (2%) were followed by early deaths. The detailed analysis showed specificities by fracture site and by sex with a significant increase of incidence with age for all groups. The third part of this work is devoted to the analysis of thromboembolic risk after spinal surgery. Analysis of detailed individual data has shown an intermediate risk (close to 1% in the general population) largely modulated by factors related to patients and surgical procedures performed.The National System of Health Data offers as we show in this thesis vast opportunities for research in orthopedics. Preparatory works, particularly in the field of the reliability of measures of efficacity of treatments are still needed to answer certain questions.
248

Traditional Posterior Load Carriage: Ergonomic Assessment and Intervention Efficacy

Muslim, Khoirul 27 August 2013 (has links)
There is a high prevalence of musculoskeletal symptoms (MSS) among manual material handling (MMH) workers. However, limited investigations have been undertaken among one large group of workers using a particular MMH method called traditional posterior load carriage (PLC). Such load carriage is typically done without the use of an assistive device (e.g., backpack) in developing countries, and involves exposure to known risk factors for MSS such as heavy loads, non-neutral postures, and high levels of repetition. The current work was completed to investigate the characteristics of the PLC task and physical effects on workers, and to evaluate a practical intervention that may help improve the task. The first study investigated, through structured interviews with 108 workers, the types, prevalence, and impacts of MSS. PLC workers incur a relatively high MSS burden, primarily in the lower back, but also in the feet, knees, shoulders, and neck. These MSS were reported to interfere with daily activity, but only few workers sought medical treatment. Workers suggested several task improvements including the use of a belt, hook, or backpack/frame, and changes in the carriage method. The second and third study investigated, in a laboratory setting involving nine healthy males, the effects of load mass and size, and the use of a simple intervention, respectively, on factors related to low back pain risks during PLC. Increasing load mass caused increased torso flexion, lumbosacral flexion moment, abdominal muscle activity, and torso movement stability in the frontal plane. Increasing load size also caused higher torso flexion, peak torso angular velocity and acceleration, and abdominal muscle activity. Complex interactive effects of load mass and size were found on paraspinal muscle activity and slip risk. The intervention, involving a simple frame to support a load, and use with a higher load placement was found to be potentially beneficial as indicated by reduced lumbosacral moment and ratings of perceived discomfort in several anatomical regions compared to the traditional PLC. Outcomes of this research can facilitate future ergonomic guidelines and interventions to improve working conditions and occupational health and safety for PLC workers. / Ph. D.
249

Quantification of the Biomechanical Load When Handling Paint Buckets With and Without Assistive Devices.

Ross, Matthew 04 November 2019 (has links)
No description available.
250

Improvement of Ex Vivo Testing Methods for Spine Biomechanical Characterization

Taylor, Aubrie Lisa 03 June 2022 (has links) (PDF)
This dissertation contributed three main areas to flexibility testing and biomechanical characterization of human spinal segments. The first was a literature review of existing testing methodology, the second examined common spine fixation procedures, and the third developed an improved fixation method. Spine biomechanical characterization is the primary technique for assessing the healthy, diseased, and surgically treated response of spinal tissues. However, despite decades of use, no standard testing protocol or reporting methodology for flexibility testing conditions has been established. As part of the present work, a comprehensive, systematic literature review was performed, and the methods sections of 242 relevant journal articles provided key information regarding preparation processes, fixation methods, testing temperatures, loading rates, loading magnitudes, and pre-conditioning procedures. The collated information was utilized to recommend best practices for testing and reporting flexibility testing methodology. Exothermic cementing processes were the dominant spinal fixation method from the reviewed articles. In these cases, fixation occurred when the most superior and inferior vertebrae of a functional spinal unit (FSU) were embedded into a cementing material that bound tightly to the cortical surface of the vertebrae, yielding a strong and geometrically favorable attachment point. The four most common fixation materials are highly exothermic and were tested to quantify the temperature rise in the adjacent intervertebral disc (IVD), as well as any associated thermal iatrogenic damage. Three thermocouples, inserted into three distinct locations of the IVD, measured temperatures throughout the cementing process. Polymethyl methacrylate (PMMA), the most frequently used cementing material, resulted in the greatest temperature increases, with a mean temperature rise up to 57°C above room temperature. Visible macro- and microscopic changes occurred in each of the cemented FSU IVDs. Changes included morphological changes, tissue desiccation, cracks, a breakdown in striations in the annulus fibrosus (AF), and denaturation and cell migration in the nucleus pulposus (NP). Based on these results, alternative vertebral attachment methods were considered and investigated. A structured design process was followed, and a mechanical ex vivo spinal fixation device which comprised a compliant vertebral clamp was designed. The geometry of the vertebral clamp was optimized based on pseudo-rigid body and finite element analyses. The final design was fabricated in titanium alloy (Ti6Al4V) using a 3D laser sintering process. Three clamps were manufactured and functionally validated. The opening/deployment and physiological loads of ± 7.5 N•m were cyclically tested on each clamp. The clamps showed no signs of failure and remained securely attached to the vertebrae. The resultant device/vertebrae interface stiffnesses were 4 to 10x greater than their corresponding FSU stiffnesses. The clamp design eliminated thermal iatrogenic damage, had minimal structural iatrogenic damage, was reusable, adjustable, and resulted in less than 10% of the previous preparation time.

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