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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.
231

Aplicabilidade de analise corporal e de rocabado na avaliação postural de individuos com e sem disfunção temporomandibular

Araujo, Luciane Farias de 03 January 2005 (has links)
Orientador: Francisco Haiter Neto / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Odontologia de Piracicaba / Made available in DSpace on 2018-08-04T03:59:30Z (GMT). No. of bitstreams: 1 Araujo_LucianeFariasde_D.pdf: 1820402 bytes, checksum: 03ccca96db91bba812e586ce3a350bc6 (MD5) Previous issue date: 2005 / Resumo: No presente trabalho propõe-se avaliar a existência de evidências clínicas e/ou radiográficas que identifiquem indivíduos com disfunção temporomandibular e da região cervical, bem como avaliar a eficácia da análise corporal computadorizada e da análise cefalométrica de Rocabado no diagnóstico destes pacientes. Para isso, foram avaliadas radiografias cefalométricas de perfil e fotografias de corpo inteiro de 100 pacientes, sendo 50 destes com sinais e sintomas de disfunção temporomandibular e 50 indivíduos assintomáticos, constituindo o grupo controle. A amostra foi selecionada a partir de ficha clínica de documentações ortodônticas em arquivo de uma clínica odontológica da cidade de Recife ¿ PE. Foi realizada avaliação fisioterapêutica das radiografias e fotografias, para fins de diagnóstico. Análise corporal e de Rocabado foram executadas para averiguação de sua aplicabilidade na detecção de desarmonias posturais da cabeça e dos segmentos corporais. As avaliações fisioterapêuticas diagnosticaram alterações posturais em ambos os grupos, sugerindo não existir associação entre elas e as disfunções temporomandibulares (p>0,05). Valores de Kappa indicaram que, na análise de Rocabado, o índice de curvatura da coluna cervical e o ângulo crânio-cervical apresentaram diagnósticos significantemente equivocados, o mesmo acontecendo com a predição da curva da coluna cervical pela análise fotográfica, não devendo, portanto, ser aplicados como instrumentos de diagnóstico. As análises corporais frontal, de perfil e de costas mostraram-se confiáveis quanto aos seus resultados, podendo ser utilizada como forma de avaliação de alterações posturais / Abstract: The aim of this paper was to evaluate the existence of clinical and/or radiographic evidences that identify patients with temporomandibular dysfunction and cervical region, as well as evaluating the effectiveness of the computerized corporal analysis and the cephalometric analysis of Rocabado in the diagnosis of these patients. In order to this, lateral cephalometric radiography and photographs of the entire body of 100 patients, being 50 of these with signals and symptoms of temporomandibular dysfunction and 50 asymptomatic individuals, constituting the control group. The sample was selected from the clinical information of orthodontic documentations in a file of a Dental clinic of the city of Recife - PE. It was carried through physiotherapeutic analysis of the x-rays and photographs for diagnosis ends. Corporal analysis and of Rocabado were executed for scertainment of its applicability in the detention of postural disharmony of the head and the corporal segments. The physiotherapeutics evaluations diagnosed postural alterations in both groups, suggesting not to exist association between them and the temporomandibular dysfunction (p>0,05). Values of Kappa indicated the same that, in the analysis of Rocabado, bending of the skull-cervical angle and the index column cervical were ignificantly presented making a diagnostic mistake, happening with the prediction of the curve of the cervical column for the photographic analysis, not having, therefore, to be applied as diagnosis instruments. The frontal corporal analyses of the profile and coasts revealed trustworthy how much to its results, being able to be used as form of evaluation the postural alterations / Doutorado / Radiologia Odontologica / Doutor em Radiologia Odontológica
232

The effects of L4/5 fusion on the adjacent segments in the lumbar spine

Martinez Lozada, Francisco Mauricio January 2016 (has links)
Lumbar intervertebral disc disorder is a spinal condition that affects the normal function of the intervertebral discs mainly due to the natural aging process. This condition can manifest itself in pain and limited motion in the legs, amongst others. Posterolateral Fusion (PLF) and Posterior Lumbar Interbody Fusion (PLIF) are two of the most used surgical procedures for treating lumbar intervertebral disc disease. Although these procedures are commonly used and performed successfully the impact in terms of the stresses developed in the posterior implants employed and in the spinal components adjacent to the surgical site has not been exhaustively investigated. In addition, the consequences of the procedure on the reduction of the Range of Motion of the lumbar spine is not clearly understood. The objective of this research is to investigate the effect of one-level spinal fusion of lumbar segment L4-L5 on the stresses and the range of motion at the remaining, adjacent lumbar levels. Four 3 dimensional finite element models of a lumbosacral spine were created from Computer Tomography data (CT scan). The models were used to investigate four surgical scenarios, including the use of 0o and 4o interbody cages, in addition to the un-instrumented spine for flexion, extension, torsion and lateral bending motions. The predictions obtained from the models enabled the mechanical behaviour of the lumbar spine following fusion surgery using 0 o and 4o cages to be investigated and compared. In addition, a clinical study was performed to quantify the reduction in the range of motion for subjects who had undergone L4/5 posterior lumbar interbody fusion surgery. The clinical results were compared to those of subjects who had not undergone surgery and to the range of motion predictions from the computational model. The results from this research demonstrate that the insertion of posterior instrumentation does not have an impact on the spinal structures above the L3/4 intervertebral disc. However, the pedicle screws and the insertion of the interbody cages causes stress levels in the area adjacent to the surgical site to rise which could promote accelerated degeneration of the discs. Additionally, this study demonstrates how the pedicle screws are affected by the surgical spinal fusion techniques. Furthermore, the investigation demonstrates how posterior lumbar interbody fusion causes the range of motion of patients that had undergone this surgery to decrease. The results from the comparison of the behaviour of the use of 0º and 4º interbody cages in L4-5 posterolateral fusion demonstrates that the stress levels in the adjacent vertebrae, intervertebral discs and pedicle screw fixation system increase when 4º are used cages than when 0º cages were employed. The results from the in-vitro study show a decrease in the range of motion of the subjects who had undergone L4/5 posterior lumbar interbody fusion surgery when compared with the subjects with no low back pain history. This indicates that the PLIF surgery combined with the normal disc degeneration is subjected to higher stresses than the healthy spine.
233

A comparison of action potential simulation therapy verses placebo effect for the treatment of chronic lumbar pain

Baker, Jaqueline Ann 14 May 2014 (has links)
M.Tech. (Chiropractic) / The purpose of this study is to evaluate whether action potential simulation (APS) therapy is more effective than placebo therapy in terms of pain relief and improvement in lumbar spine range of motion when treating chronic lumbar spine pain. The comparison of the two therapies was accomplished by objective and subjective assessments. The study was conducted by means of a double blind clinical trial with two experimental groups. Thirty subjects eighteen years of age and older who suffered from chronic lumbar spine pain were chosen from the general population who responded to the advertisements and from Tarentaal Home for the Aged. The researcher examined each of these subjects in order to be accepted into the study. Each subject was treated ten times over a two-week period and underwent a one-month follow-up consultation to be re-examined. Subjects in both groups received therapy for eight minutes at an amplitude of 1-2mA. Only the APS group received the electric current and the placebo group did not receive the electric current. The objective assessment was by means of measurement of the lumbar spine ranges of motion using an inclinometer. The subjective assessment was measured by means of two questionnaires, which are widely accepted in the research community namely: a) Oswestry Low Back Pain and Disability Questionnaire b) McGill Pain Questionnaire. The results, which were obtained, were statistically analyzed using the Mann-Whitney Rank Sum test (inter-group comparison) and the Wilcoxon Signed Rank test (intra-group comparison). Graphs were created using the actual values of each patient in each group and using the medians obtained. The study concluded that both the APS and the placebo group improved in terms of lumbar spine range of motion and pain relief even though not all the results were statistically significant. The graphs representing the mean values at the first, final and one-month follow-up consultations of each group showed the apparent improvement in terms of range of motion in the lumbar spine and pain relief. The APS group's mean values, at the above mentioned consultations, showed a greater improvement in range of motion and pain relief when being compared to the placebo group's mean values that are represented on the respective graphs.
234

The correlation of the self-reported Leeds assessment of neuropathic symptoms and signs score, clinical neurological examination findings and magnetic resonance imaging findings in patients with Lumbo-sacral radiculopathy

Tawa, Nassib January 2014 (has links)
Philosophiae Doctor - PhD / Lumbo-sacral radiculopathy (LSR) is clinically defined as low back and referred leg symptoms accompanied by an objective sensory and/or motor deficit due to nerve root compromise. LSR is a common condition encountered by physiotherapists in clinical practice and the assessment and diagnosis remains a challenge owing to the complex anatomy of the lumbo-sacral spine segment and the various differentials. Moreover, LSR imposes a significant impact on patients’ health, functional ability, socio-economic status and quality of life. There are several diagnostic tools and procedures which are commonly utilised in practice, including diagnostic neuropathic pain screening questionnaires, clinical neurological tests, electro-diagnostics and imaging. However, the diagnostic utility and correlation of these tests have not been fully explored and remains debatable among clinicians and researchers in the fields of musculo-skeletal health and neurology. The aim of this study was to determine a correlation of the S-LANSS score, clinical neurological examination (CNE) findings and magnetic resonance imaging (MRI) reports in the diagnosis of LSR among patients who presented with low back and referred leg symptoms. The study was conducted in three phases. In phase one, two systematic literature reviews were conducted; firstly, to establish the evidence-based accuracy of CNE in diagnosing LSR, and secondly, to establish the evidence-based accuracy of MRI in diagnosing LSR. In both systematic literature reviews, the diagnostic tests accuracy (DTA) protocol was used in planning, design and execution of literature search, selection of relevant studies, quality assessment, data analysis and presentation of the results. In phase two, clinical validation of an adopted S-LANSS scale and lumbar MRI reporting protocol were established, and a standardised evidence based lumbar CNE protocol developed.The face and content validity of the original S-LANSS score was established among a sample of Kenyan physiotherapists and patients who presented with low back and referred leg symptoms, using both quantitative and qualitative research designs. This was followed by a test-re-test reliability study on the adapted version of the S- LNASS score. The face and content validity of the adopted lumbar MRI reporting protocol was established among a sample of Kenyan radiologists followed by an inter-rater reliability. An evidence-based lumbar CNE protocol was developed; standardised and inter-examiner reliability was also examined among a sample of Kenyan physiotherapists. Finally, in phase three, a cross-sectional blinded validity study was conducted in six different physiotherapy departments. Participants (patients, physiotherapists and radiologists) were recruited using strict in- and exclusion criteria and data was collected using a pain and demographic questionnaire, the S-LANSS scale, the CNE protocol, the Oswestry Disability Index (ODI) and the MRI lumbar spine reporting protocol. Data was captured, cleaned and analysed using SPSS version 21. Descriptive analysis was done using frequencies, means and percentages, while inferential analysis was conducted using Spearman’s rank correlation coefficient test r to establish the correlation between the diagnostic tests. Cross tabulations, receiver operating curves (ROC) and scatter plots were used to establish the sensitivity and/or specificity of S-LANSS scale and individual CNE tests as defined by MRI. In phase three, which formed the main study of the research project, a total of 102 participants were recruited in this study with a gender distribution of 57% females and 43% males. The majority (67%) had neuropathic pain according to the S-LANSS scale and their pain intensity ranged from moderate (4-6) to severe (7-9) as recorded on a Numeric Pain rating Scale (NPRS), and was more common among manual workers. Similarly, patients whose pain had a neuropathic component had moderate to severe disability. The S-LANSS scale and lower limb neuro-dynamic tests were the most sensitive tests 0.79 and 0.75 respectively, while deep tendon reflexes were the most specific tests (0.87). The S-LANSS and CNE correlated fairly but significantly with MRI (r=0.36, P=0.01).LSR is a common condition and its assessment and diagnosis remains a clinical challenge among physiotherapists. MRI is a high-cost diagnostic tool but is being used by many clinicians in making decisions regarding the management of patients. Rapid and low-cost neuropathic pain screening by the use of the S-LANSS scale, together with use of evidence-based CNE of neuro-conduction and neuro-dynamic tests may be used in confirming nerve-root related MRI findings. These may be used in making a decision on whether to manage a patient conservatively using pharmacological agents and manual physiotherapy and therapeutic exercise, or consider surgery in the initial management of patients with clinical suspicion of LSR. This is especially valuable in the resource-poor settings like Kenya and other sub-Saharan African countries where MRI is costly or unavailable.
235

Axis Fractures in Elderly : Epidemiology and Treatment related outcome

Robinson, Anna-Lena January 2018 (has links)
Background: Axis fractures are a common injury in the elderly population. Treatment is often complicated due to osteoporosis and patient comorbidity. Knowledge of the incidence of these fractures, as well as their treatment, outcome and mortality rate, will improve knowledge and decision-making processes for this fragile group of patients. Objectives: This thesis aims (1) to review the literature on the non-surgical and surgical treatment of odontoid fractures type 2 in the elderly population, (2) to provide an updated overview of axis fracture subtypes, their incidence and their treatment in a cohort in two university cities, (3) to map the incidence of fractures and the treatment of these patients in Sweden, (4) to investigate the effect on mortality of both the surgical and non-surgical treatment of axis fractures and (5) to present the protocol for a randomized controlled trial (RCT) on the treatment of odontoid fractures type 2 in the elderly population. Methods: A systematic review was performed using the MeSH keywords “odontoid AND fracture AND elderly”. The data for the cohort study were extracted from the regional hospital information system. The radiographs were reviewed retrospectively. Data were extracted from the Swedish National Patient Registry (NPR) and the mortality registry for the national registry studies. Finally, the RCT protocol was carried out according to the SPIRIT and CONSORT statements for clinical trial reporting. Results and conclusions: So far, there has been a scarcity of existing evidence on treatment of odontoid fractures type 2 in the elderly population. In this thesis, we found in two university cities an increased incidence, and a trend towards more surgical treatment of type 2 and 3 odontoid fractures 2002-2014. Between 1997 and 2014 in Sweden, there was an increasing incidence of C2 fractures, but the treatment trend went towards more non-surgical treatment. Surgically treated patients had a greater survival rate than non-surgically treated patients. Among those over 88 years of age, surgical treatment lost its effect on survival. In the RCT we will study the function of patients with odontoid fractures type 2 and by comparing non-surgical treatment with posterior C1-C2 fusion, the cost-effectiveness of the treatment options.
236

The inferior angle of the scapula as a landmark to locate the seventh thoracic spinous process

Else, Jeanette Mary 04 June 2012 (has links)
M. Tech. / Although Chiropractors rely on palpation as a clinical tool, its reliability still remains to be proven (O‟Haire and Gibbons, 2000). Motion palpation is based on the assumption that Chiropractors‟ and other manual medicine practitioners‟ static palpation is performed correctly to identify bony anatomical landmarks (O‟Haire and Gibbons, 2000). The most common method taught to chiropractic students on the location of the seventh thoracic spinous process, is to place the patient‟s hand in the small of their back, forcing the inferior angle of the scapula to become more prominent. The horizontal line from the inferior angle of the scapula to the vertebral column is said to be on the seventh thoracic spinous process (T7). Therefore the scapula is a widely used anatomical landmark. One would therefore expect the literature to all be in agreement to the position of this line, but according to the literature consulted, it seems to vary. This study aimed to determine whether palpation of the inferior angle of the scapula was a reliable, accurate and/or a valid method of determining the location of the seventh thoracic spinous process. Sixty participants were marked by three examiners in the seated position, using the inferior angle of the scapula to locate the seventh thoracic spinous process. After being marked by all three examiners, measurements were then made on CT scan films as well as visual assessments by examiners to assess the location of the markers on the thoracic anatomy. The results demonstrated substantial inter-examiner reliability, and poor accuracy in locating the seventh thoracic spinous process. This is disappointing as the ability to palpate spinal levels is a basic skill and the cornerstone of Chiropractic assessment.
237

Condições de trabalho e desordens musculoesqueléticas relacionadas à coluna vertebral em dentistas

Alexandre, Márcia Augusta Basso de January 2013 (has links)
O cirurgião dentista é constantemente exposto a um elevado número de doenças ocupacionais. Alterações no sistema musculoesquelético são freqüentes, principalmente nos membros superiores e coluna vertebral, que podem interferir negativamente, na capacidade funcional desses profissionais. O objetivo deste trabalho é contribuir para o entendimento das doenças ocupacionais associadas ao sistema musculoesquelético relacionado à coluna vertebral dos odontólogos, durante sua atividade laboral, bem como as questões psicossociais associadas. Este documento contempla uma sequência de dois artigos sobre as condições de trabalho e desordens musculoesqueléticas relacionadas à coluna vertebral em dentistas. O primeiro apresenta uma revisão teórica sobre a atividade laboral dos dentistas, evidenciando os problemas relacionados à coluna vertebral, à carga de trabalho, aos riscos biomecânicos, às principais patologias e fatores psicossociais associados. Desta maneira, se evidenciou que estes profissionais estão sujeitos a uma alta carga de trabalho e desenvolvendo posturas que comprometem a integridade da coluna vertebral gerando dor e incapacidade para o trabalho. O segundo apresenta um método de análise e um estudo aplicado para investigar as desordens musculoesqueléticas relacionadas à coluna vertebral e fatores associados às condições ocupacionais de dentistas. Este artigo explicita as regiões da coluna vertebral mais acometida por queixas musculoesqueléticas e fatores associados. O método investigativo proposto mostrou que os problemas concernentes ao trabalho dos dentistas estão provocando dores e alterações musculoesqueléticas na região da coluna vertebral e são devidos principalmente à postura de trabalho, o esforço físico, os movimentos repetitivos e carga horária de trabalho. / The dental surgeon is constantly exposed to a large number of occupational illnesses. Alterations in the musculoskeletal system are frequent, especially in the upper limbs and spine, which can interfere negatively in the functional capacity of these professionals. The aim of this study is to contribute to the understanding of occupational diseases associated to the musculoskeletal system. Mainly those related to the spine of dentists during their work activities as well as psychosocial issues. This document includes a sequence of two articles about the working conditions and musculoskeletal disorders related to the spine of dentists. The first one presents a theoretical review about labor activity of dentists, highlighting the problems related to the spine, the workload, the biomechanical risks, the major pathologies and psychosocial factors associated. In this way, it is evidenced that these professionals are subject to a high workload and developing postures that compromise the integrity of the spine causing pain and inability to work. The second presents a method of analysis and an applied study to investigate musculoskeletal disorders related to the spine and occupational factors associated with conditions of dentists. This article explains the spinal regions most affected by musculoskeletal complaints and associated factors. The investigative method proposed, showed that problems regarding to the work of dentists are causing pain and musculoskeletal alterations in the spinal region and are due mainly to the working posture, physical effort, repetitive movements and workload.
238

"Validação de testes de flexibilidade da coluna lombar" / VALIDATION OF LUMBAR SPINE FLEXIBILITY TESTS

Abdallah Achour Júnior 22 March 2006 (has links)
Esta pesquisa teve como principal objetivo, validar o teste de flexibilidade da coluna lombar (Testprop), utilizando-se da radiografia como teste critério e o teste flexibilidade da coluna lombar de ADRICHEM e KORST (1973) para o sexo feminino e masculino. Participaram 19 mulheres (média de idade= 23,2 anos e desvio padrão= 1,3) e 18 homens (média de idade= 22,3 anos e desvio padrão= 1,4), universitários, saudáveis e ativos do Curso de Educação Física e Ciências do Esporte da Universidade Estadual de Londrina - PR. Inicialmente, verificou-se a fidedignidade e objetividade dos testes de flexibilidade da coluna lombar (Testprop e Testeips). O coeficiente de correlação intraclasse mostrou que o teste de flexibilidade Testprop apresenta fidedignidade elevada para o sexo feminino (R= 0,86) e elevada para o sexo masculino (R=0,85), e demonstrou haver objetividade moderada (R= 0,73) para o sexo feminino e elevada (R= 0,96) para o sexo masculino. Quanto ao teste de flexibilidade Testeips, a fidedignidade foi elevada (R= 0,85) e (R= 0,86) para o sexo feminino e masculino, respectivamente. A objetividade do teste de flexibilidade Testeips foi moderada (R= 0,62) para o sexo feminino e elevada para o sexo masculino (R= 0,91). Em relação à validade, o coeficiente de correlação de Pearson mostrou correlação baixa para o teste de flexibilidade Testprop (r= 0,11) para o sexo feminino e correlação moderada (r= 0,52) para o sexo masculino. No que diz respeito ao teste de flexibilidade Testeips, o coeficiente de correlação de Pearson foi baixo para o sexo feminino (r= 0,24) e moderado para o sexo masculino (r= 0,50). Concluiu-se que os testes de flexibilidade da coluna lombar Testprop e Testeips foram fidedignos e objetivos, mas não foram considerados válidos. / The main goal was to validate the flexibility test for the lumbar spine (Testprop), using x-ray as a criteria and the flexibility test of the lumbar spine designed by ADRICHEM and KORST (1973) for females and males, 19 women participated (mean age= 23,2 years old; standard deviation= 1,3 year old) and 18 men (mean= 22,3 year old and standard deviation = 1,4) healthy and active students from the Physical Education and Sport Science Course at the Universidade Estadual de Londrina-PR. Initially, it was verified reliability and objectivity (Testprop and Testeips) the lumbar spine flexibility. The intraclass correlation coefficient showed that the reliability of test of flexibility Testprop was high for woman (R= 0.86) and high for men (R= 0.85), there was a moderate objectivity (R= 0.73) for women and high (R= 0.96) for men. Concerning the flexibility test Testeips, the reliability was high (R= 0.85) and (R= 0.86) for woman and men, respectively. The objectivity for the flexibility test Testeips was moderate (R= 0.62) for women and high for men (R= 0.91). Concerning the validity, Pearson correlation coeficient demonstrated a low correlation for the flexibility test Testprop (r= 0.11) for women and moderate for men (r= 0.52). About the flexibility test, Testeips, Pearson correlation coefficient was low for woman (r= 0.24) and moderate for men (r= 0.50). It was concluded that the flexibility tests of the lumbar spine Testprop and Testeips were reliable and objective, but they were not considered valid.
239

Avaliação do efeito do uso de sequências sensíveis a líquido na classificação das alterações do tipo Modic na coluna lombar / Evaluation of the effect of the use of fluid sensitive sequences on the classification of Modic type endplate changes in the lumbar spine

Nascimento, Eduardo Deroide do 23 May 2019 (has links)
As alterações de sinal no osso subcondral dos corpos vertebrais foram descritas primeiramente por Modic, correlacionando o espectro das alterações da medula óssea no corpo vertebral relacionadas a discopatias degenerativas. O Modic tipo I representa a alteração de sinal do tipo edema, já o Modic II representa a alteração de sinal com padrão de lipossubstituição e o Modic III representa alteração de sinal relacionada a esclerose óssea. O objetivo primário deste estudo foi avaliar se há alteração na detecção dos padrões da classificação Modic na coluna lombar comparando a técnica Dixon com o protocolo tradicional. Como objetivo secundário avaliamos a correlação intra-observador e interobservador. O estudo foi realizado de forma retrospectiva com a inclusão de pacientes cujas ressonâncias magnéticas (RM) foram realizadas na Central de Diagnóstico Ribeirão Preto (CEDIRP). Dois médicos radiologistas de forma independente classificaram as alterações do tipo Modic permitindo uma avaliação interobservador e um dos radiologistas realizou uma segunda análise dos exames possibilitando uma avaliação intra-observador. Os resultados evidenciaram que a técnica Dixon apresentou superioridade na detecção do Modic I em todas as análises e também apresentou médias mais altas da espessura das alterações no osso subcondral. Houve correlações intra-observador moderadas e substanciais no protocolo tradicional e substanciais a altas com a técnica Dixon. A correlação interobservador demonstrou uma correlação moderada na avaliação deste tipo de alteração nos platôs superior e inferior de L3 e correlação inversa e não significativa para a o platô superior de L5 utilizando o protocolo tradicional. Já a correlação interobservador com a técnica Dixon evidenciou concordância perfeita entre os observadores na avaliação de tipo de alteração de sinal no osso subcondral do platô inferior de L1, correlação inversa para o platô inferior de L3 e superior de L4, correlação substancial entre o platô inferior de L2, platô inferior de L5 e superior de L5. Concluímos que a técnica Dixon apresentou superioridade na detecção do Modic I em relação ao protocolo tradicional, assim como permitiu detectar médias mais altas da espessura das alterações no osso subcondral. Também conclui-se que houve boa reprodutibilidade intra-observador e correlação interobservador variável entre os platôs vertebrais analisados / Signal changes in the subchondral bone of the vertebral bodies were first described by Modic, correlating the spectrum of bone marrow changes in the vertebral body to degenerative disc diseases. Modic type I represents the change of edema type signal, while Modic II represents the change of signal with liposubstitution pattern and Modic III represents signal change related to bone sclerosis. The main objective of this study was to evaluate if there is difference in the detection of Modic classification in the lumbar spine comparing the Dixon technique with the traditional protocol. We evaluated the intraobserver and interobserver correlation as a secondary objective. The study was performed retrospectively, including patients whose magnetic resonance imaging (MRI) was performed at the Ribeirão Preto Diagnostic Center (CEDIRP). Two radiologist physicians independently classified the Modic type endplate changes allowing an interobserver evaluation and one of the radiologists performed a second analysis of the exams making possible an intraobserver evaluation. The results showed that the Dixon technique presented superiority in the detection of Modic I in all the analyzes and also presented higher averages of the thickness of the alterations in the subchondral bone. There were moderate and substantial intraobserver correlations in the traditional protocol and substantial to high Dixon technique. The interobserver correlation was moderate in the evaluation of this type of alteration for the upper and lower plateau of L3 and inverse and nonsignificant for the upper plateau of L5 using the traditional protocol. On the other hand, the interobserver correlation with the Dixon technique showed perfect agreement among the observers in the evaluation of type of signal change in the subchondral bone of the lower plateau of L1, an inverse correlation for the lower plateau of L3 and higher of L4, a substantial correlation between the lower plateau of L2, lower of L5 and higher of L5. We conclude that the Dixon technique presented superiority in the detection of Modic I compared with the traditional protocol, as well as allowed the detection higher averages of the thickness of alterations in the subchondral bone. It was also concluded that there was good intraobserver reproducibility and a variable interobserver correlation between the vertebral plateaus analyzed
240

The biomechanics of the sheep cervical spine: an experimental and finite element analysis

DeVries, Nicole Ann 01 July 2011 (has links)
Animal models are essential for making the transition from scientific concepts to clinical application. Such models have proven valuable for spinal research. The cervical spine of sheep is often used because there is similar geometry between sheep and human. Although anatomical similarities are important, biomechanical correspondence is imperative to understand the effects of disorders, surgical techniques, and implant designs. Therefore, the purpose of this study was to conduct a comprehensive study of the sheep cervical spine biomechanics, including experimental and finite element analysis. To determine the flexibility of the multilevel spine, ten adult Suffolk sheep C2-C7 spines were tested, undergoing flexion-extension, lateral bending, and axial rotation. In addition to intact multilevel testing, the roles of the stabilizing structures were studied by sequentially destabilizing function spinal units. The sheep spine is highly flexible, especially in lateral bending (±65˚); motion increases with caudal progression. The sheep spine also has a large neutral zone accounting for 50-75% of the total motion. The facets and capsular ligaments play a key role in stabilization, providing the most stability at the C2-C3 level. In addition to flexibility testing, the sheep spinal ligaments underwent tensile testing until failure to determine the material properties. The ligamentum flavum has the largest failure stress and the capsular ligaments have the largest mean failure force. The longitudinal ligaments have the largest failure strain and the lowest failure force. Overall, the C2-C3 ligaments had the highest failure forces as compared to the ligament type at different levels. This corresponds to the stability the ligaments have at the C2-C3 level during flexibility testing. Moreover, a finite element model of the C2-C7 sheep cervical spine was developed and validated to provide additional insight in the sheep biomechanics. The model compared favorably with experimental testing for all loading cases except extension. In general, the model matched the experimental results within one standard deviation for the multilevel motion as well as the motion at each level. Since the sheep is highly flexible and there is a large neutral zone it was difficult to capture the nonlinearity in all loading directions. The model was used to study the effects of fusion at the C3-C4 level. As expected the motion at the fusion was less than one degree, with the non-fused levels accommodating the loss in motion. The motion increased 15-27%, with the largest increase at C6-C7. To obtain the same rotation as the intact model (±2.5 Nm), larger moments were required, increasing to over 5 Nm for flexion and lateral bending and over 3 Nm for extension and axial rotation. The study provides insight into the sheep cervical spine biomechanics. Researchers and scientists should consider the high flexibility and large neutral zone when designing a study that is to correlate to human spines. The model provides additional details such as stresses in the bone and intervertebral disc that can help researchers determine the effects of different surgical techniques and implant designs. Overall, this study provides valuable biomechanical data that can aid designing preclinical animal studies of the sheep.

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