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000079311 005__ 20210520140804.0
000079311 037__ $$aTESIS-2019-097
000079311 041__ $$aspa
000079311 1001_ $$aCalvo Echenique, Andrea
000079311 24500 $$aHuman lumbar spine biomechanics: study of pathologies and new surgical procedures
000079311 260__ $$aZaragoza$$bUniversidad de Zaragoza, Prensas de la Universidad$$c2018
000079311 300__ $$amult. p
000079311 4900_ $$aTesis de la Universidad de Zaragoza$$v216$$x2254-7606
000079311 500__ $$aPresentado: 11 04 2018
000079311 502__ $$aTesis-Univ. Zaragoza, Instituto de Investigación en Ingeniería de Aragón (I3A), 2018$$bZaragoza, Universidad de Zaragoza$$c2018
000079311 506__ $$aby-nc-nd$$bCreative Commons$$c3.0$$uhttp://creativecommons.org/licenses/by-nc-nd/3.0/es
000079311 520__ $$aThis thesis aims to shed light on the process that undergoes the lumbar spine as a result of intervertebral disc degeneration and different lumbar surgeries, paying special attention on the main risk factors and how to overcome them. <br />Low back pain is the leading musculoskeletal disorder in all developed countries generating high medical related costs. Intervertebral disc degeneration is one of the most common causes of low back pain. When conservative treatments fail to relieve this pain, lumbar surgery is needed and, in this regard, lumbar fusion is the \textquotedblleft gold standard\textquotedblright technique to provide stability and neural decompression.<br />Degenerative disc disease has been studied through two different approaches. An in-vivo animal model was reproduced and followed-up with MRI and mechanical testing to see how the water content decreased while the stiffness of the tissue increased. Then, degeneration was induced in a single disc of the human lumbar spine and the effects on the adjacent disc were investigated by the use of the finite element models. <br />Further on, different procedures for segmental fusion were computationally simulated. A comparison among different intersomatic cage designs, supplemented with posterior screw fixation or placed in a stand-alone fashion, showed how the supplementary fixation drastically decreased the motion in the affected segment increasing the risk of adjacent segment disease more than a single placed cage. However, one of the main concerns regarding the use of cages without additional fixation is the subsidence of the device into the vertebral bone. A parametric study of the cage features and placement pointed to the width, curvature, and position as the most influential parameters for stability and subsidence.<br />Finally, two different algorithms for tissue healing were implemented and applied for the first time to predict lumbar fusion in 3D models. The self-repairing ability of the bone was tested after simple nucleotomy and after instrumentation with internal fixation, anterior plate or stand-alone intersomatic cage predicting, in agreement with previous animal and clinical studies, that instrumentation may be not necessary to promote segmental fusion. In particular, the intervertebral disc height was seen to play an important role in the bone bridge or osteophyte formation.<br />To summarize, this thesis has focused in the main controversial issues of intervertebral disc degeneration and lumbar fusion, such as degenerative process, adjacent segment disease, segment stability, cage subsidence or bone bridging. All the models described in this thesis could serve as a powerful tool for the pre-clinical evaluation of patient-specific surgical outcomes supporting clinician decisions. <br />
000079311 520__ $$aThis thesis aims to shed light on the process that undergoes the lumbar spine as a result of intervertebral disc degeneration and different lumbar surgeries, paying special attention on the main risk factors and how to overcome them. Low back pain is the leading musculoskeletal disorder in all developed countries generating high medical related costs. Intervertebral disc degeneration is one of the most common causes of low back pain. When conservative treatments fail to relieve this pain, lumbar surgery is needed and, in this regard, lumbar fusion is the \textquotedblleft gold standard\textquotedblright technique to provide stability and neural decompression. Degenerative disc disease has been studied through two different approaches. An in-vivo animal model was reproduced and followed-up with MRI and mechanical testing to see how the water content decreased while the stiffness of the tissue increased. Then, degeneration was induced in a single disc of the human lumbar spine and the effects on the adjacent disc were investigated by the use of the finite element models. Further on, different procedures for segmental fusion were computationally simulated. A comparison among different intersomatic cage designs, supplemented with posterior screw fixation or placed in a stand-alone fashion, showed how the supplementary fixation drastically decreased the motion in the affected segment increasing the risk of adjacent segment disease more than a single placed cage. However, one of the main concerns regarding the use of cages without additional fixation is the subsidence of the device into the vertebral bone. A parametric study of the cage features and placement pointed to the width, curvature, and position as the most influential parameters for stability and subsidence. Finally, two different algorithms for tissue healing were implemented and applied for the first time to predict lumbar fusion in 3D models. The self-repairing ability of the bone was tested after simple nucleotomy and after instrumentation with internal fixation, anterior plate or stand-alone intersomatic cage predicting, in agreement with previous animal and clinical studies, that instrumentation may be not necessary to promote segmental fusion. In particular, the intervertebral disc height was seen to play an important role in the bone bridge or osteophyte formation. To summarize, this thesis has focused in the main controversial issues of intervertebral disc degeneration and lumbar fusion, such as degenerative process, adjacent segment disease, segment stability, cage subsidence or bone bridging. All the models described in this thesis could serve as a powerful tool for the pre-clinical evaluation of patient-specific surgical outcomes supporting clinician decisions. <br />
000079311 521__ $$97098$$aPrograma de Doctorado en Ingeniería Biomédica
000079311 6531_ $$abiomecanica
000079311 6531_ $$asimulacion
000079311 700__ $$aPÉREZ DEL PALOMAR ALDEA, AMAYA$$edir.
000079311 7102_ $$aUniversidad de Zaragoza$$bInstituto de Investigación en Ingeniería de Aragón (I3A)
000079311 830__ $$9510
000079311 8560_ $$ftdr@unizar.es
000079311 8564_ $$s22725348$$uhttps://zaguan.unizar.es/record/79311/files/TESIS-2019-097.pdf$$zTexto completo (spa)
000079311 909CO $$ooai:zaguan.unizar.es:79311$$pdriver
000079311 909co $$ptesis
000079311 9102_ $$a$$bInstituto de Investigación en Ingeniería de Aragón (I3A)
000079311 980__ $$aTESIS