Download or read book Experimental and Analytical Modeling of the in Vivo and in Vitro Biomechanical Behavior of the Human Lumbar Spine written by Tov I. Vestgaarden and published by . This book was released on 2007 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: ABSTRACT: This dissertation has two major parts; Analytical and Experimental. The analytical section contains a study using Finite Element Analysis of dynamic instrumentation to demonstrate stress reduction in adjacent level discs. The experimental section contains biomechanical testing of facet fusion allograft technique and finally a comparison between In Vivo and In Vitro intradiscal pressures to determine forces acting on Lumbar spine segment L4-L5. A comprehensive study of available data, technology and literature was done. Conventional fusion instrumentation is believed to accelerate the degeneration of adjacent discs due to the increased stresses caused by motion discontinuity. A three dimensional finite element model of the lumbar spine was obtained which simulated flexion and extension. Reduced stiffness and increased axial motion of dynamic posterior lumbar fusion instrumentation designs results in a ~10% cumulative stress reduction for each flexion cycle. The cumulative effect of this reduced amplitude and distribution of peak stresses in the adjacent disc may partially alleviate the problem of adjacent level disc degeneration. Traditionally a pedicle screw system has been used for fixation of the lumbar spine and this involves major surgery and recovery time. Facet fixation is a technique that has been used for stabilization of the lumbar spine. The cadaver segments were tested in axial rotation, combined flexion/extension and lateral bending. Implantation of the allograft dowel resulted in a significant increase in stiffness compared to control. Facet fusion allograft provides an effective minimally invasive method of treating debilitating pain caused by deteriorated facet joints by permanently fusing them. An In Vitro biomechanical study was conducted to determine the intradiscal pressure during spinal loading. The intradiscal pressures in flexion/extension, lateral bending and axial rotation was compared to In Vivo published data. There is no data that explains the actual forces acting on the spine during flexion, extension, lateral bending or axial rotation. The functional spinal units were tested in combined axial compression and flexion/extension, combined axial compression and lateral bending and combined axial compression and axial rotation using a nondestructive testing method. Overall, this study found a good correlation between In Vivo and In Vitro data. This can essentially be used to make physiological relation from experimental and analytical evaluations of the lumbar spine. It is important to know how much load needs to be controlled by an implant.
Download or read book Characterization and Biomechanical Analysis of the Human Lumbar Spine with In Vitro Testing Conditions written by Dean Keith Stolworthy and published by . This book was released on 2011 with total page 328 pages. Available in PDF, EPUB and Kindle. Book excerpt: In conclusion, the biomechanical response was significantly altered due to testing temperature, loading-rate, and application of a compressive follower-load. The author emphasizes the necessity to simulate the physiological environment during ex vivo biomechanical analysis of the lumbar spine in order to obtain a physiological response. Simplified testing procedures may be implemented only after the particular effect is known.
Download or read book A Three Dimensional Finite Element Model to Study the Biomechanical and Kinematic Characteristics of the Human Lumbar Spine in Flexion written by Dhruv Jitesh Mehta and published by . This book was released on 2007 with total page 71 pages. Available in PDF, EPUB and Kindle. Book excerpt: The aim of the research was to develop a three-dimensional finite element model to study the biomechanical and kinematic characteristics of the human lumbar spine in flexion. An analytical model of the lumbar spine capable of taking into consideration the actual geometry, non-linear material properties and realistic loading would be of benefit in studying normal biomechanics, as well as in-vivo behavior in injured and surgically altered spines. Fundamental to this approach is an accurate model of the spine. This was achieved by modeling the lumbar segments L2-L4 from Computed Tomography (CT) data and analyzing them under loading conditions that best approximated the human lumbar segments in flexion. An in-vitro study was performed for validation of the finite element model. Human lumbar cadaveric spinal segments (L2-L4) were loaded based on test conditions similar to those defined in the finite element analysis. The results of the cadaver biomechanical study and finite element analysis were compared. The results suggest that the model is a valid approach to assessing the range of motion of the L3 segment under flexion. Rotation under lateral bending moments was additionally investigated to provide a thorough validation of the model.
Download or read book Experimental Measurements of Lumbar Spine Biomechanics to Validate a Finite Element Model of the Lumbar Spine written by Michael James Schendel and published by . This book was released on 1990 with total page 362 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Journal of Rehabilitation Research Development written by and published by . This book was released on 1988 with total page 752 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Human Orthopaedic Biomechanics written by Bernardo Innocenti and published by Academic Press. This book was released on 2022-02-24 with total page 759 pages. Available in PDF, EPUB and Kindle. Book excerpt: Human Orthopaedic Biomechanics: Fundamentals, Devices and Applications covers a wide range of biomechanical topics and fields, ranging from theoretical issues, mechanobiology, design of implants, joint biomechanics, regulatory issues and practical applications. The book teaches the fundamentals of physiological loading and constraint conditions at various parts of the musculoskeletal system. It is an ideal resource for teaching and education in courses on orthopedic biomechanics, and for engineering students engaged in these courses. In addition, all bioengineers who have an interest in orthopedic biomechanics will find this title useful as a reference, particularly early career researchers and industry professionals. Finally, any orthopedic surgeons looking to deepen their knowledge of biomechanical aspects will benefit from the accessible writing style in this title. - Covers theoretical aspects (mechanics, stress analysis, constitutive laws for the various musculoskeletal tissues and mechanobiology) - Presents components of different regulatory aspects, failure analysis, post-marketing and clinical trials - Includes state-of-the-art methods used in orthopedic biomechanics and in designing orthopedic implants (experimental methods, finite element and rigid-body models, gait and fluoroscopic analysis, radiological measurements)
Download or read book On the Experimental and Mathematical Modeling of the Viscoelastic Behavior of the Human Spine written by Heiko Visarius and published by . This book was released on 1994 with total page 392 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Determination of Biomechanical Properties and Mechanobiological Behavior of a Spinal Motion Segment with Scoliosis Treatment Using Finite Element Analysis written by Bharathwaj Kumar and published by . This book was released on 2011 with total page 76 pages. Available in PDF, EPUB and Kindle. Book excerpt: Scoliosis is a musculoskeletal abnormality causing complex three dimensional curvatures in the spine. Current surgical treatments for this adolescent spinal deformity are successful but invasive. Potential new treatments that are less invasive are being developed based on altering growth by mechanically redistributing stresses across the vertebral growth plates. In the literature, in vivo and in vitro tests have shown biomechanical changes in the disc and growth plates due to insertion of staple like implants used in these new methods. In order to understand the biomechanics behind these potential new methods, a nonlinear finite element analysis (FEA) is performed and various biomechanical properties of the spinal segment with and without the implant are determinedA three-dimensional FE model of T7-T8 motion segment was developed from a CT scan of a porcine spine and imported to ABAQUS (an FEA software). Various material properties and contact interactions were used from the literature in determining the model that best predicted the available experimental load-displacement curve and the compressive properties of the disc. Bending loads were applied to this FE model to determine the reduction in the motion of the spinal segment. Sensitivity of the implant features were examined against the compressive properties of the disc. Mechanobiological growth models have been partially developed to study various biomechanical factors causing deformities in spine. This available model was utilized in understanding how growth in a normal spine could be influenced due to the presence of these implants.
Download or read book Biomechanical Models of the Human Thoracic and Lumbar Spine written by Maria Elizete Kunkel and published by Sudwestdeutscher Verlag Fur Hochschulschriften AG. This book was released on 2012-04 with total page 80 pages. Available in PDF, EPUB and Kindle. Book excerpt: Severe cases of scoliosis are treated using implants. The effects of different types of implants have been investigated with mathematical models with modifiable geometry. Our aim was perform a nonlinear regression analyses with anatomical data to generate prediction equations for vertebral and intervertebral disc dimensions as a function of only one given dimension measurable by X-ray, the vertebral body height. Third-order polyno-mial regressions provided moderate to high correlation between the vertebral body heights and the endplates and spinal canal; pedicle heights and the spinous process, in addition to a reasonable correlation of the posterior vertebral structures (pedicle and facet). A set of 50 equations was generated for the prediction of the spine dimensions based on the radiographic measurement of the vertebral body height. It was possible to establish useful predictions for all investigated dimensions. This is an efficient approach for obtaining anatomical data for modeling of the human thoracic and lumbar from measurement of only one parameter per vertebra without the need for direct measurement or 3D reconstructions from medical images.
Download or read book Biomechanics of the Spine written by Fabio Galbusera and published by Academic Press. This book was released on 2018-04-23 with total page 458 pages. Available in PDF, EPUB and Kindle. Book excerpt: Biomechanics of the Spine encompasses the basics of spine biomechanics, spinal tissues, spinal disorders and treatment methods. Organized into four parts, the first chapters explore the functional anatomy of the spine, with special emphasis on aspects which are biomechanically relevant and quite often neglected in clinical literature. The second part describes the mechanics of the individual spinal tissues, along with commonly used testing set-ups and the constitutive models used to represent them in mathematical studies. The third part covers in detail the current methods which are used in spine research: experimental testing, numerical simulation and in vivo studies (imaging and motion analysis). The last part covers the biomechanical aspects of spinal pathologies and their surgical treatment. This valuable reference is ideal for bioengineers who are involved in spine biomechanics, and spinal surgeons who are looking to broaden their biomechanical knowledge base. The contributors to this book are from the leading institutions in the world that are researching spine biomechanics. - Includes broad coverage of spine disorders and surgery with a biomechanical focus - Summarizes state-of-the-art and cutting-edge research in the field of spine biomechanics - Discusses a variety of methods, including In vivo and In vitro testing, and finite element and musculoskeletal modeling
Download or read book Experimental Analysis and Modeling of the Effects of Facet Joints on Human Lumbar Biomechanics written by Jesse Shay Little and published by . This book was released on 2005 with total page 522 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Biomechanical Stability of the Human Lumbar Spine written by Joseph John Crisco and published by . This book was released on 1989 with total page 570 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book In Vitro Biomechanical Testing and Computational written by Mageswaran Prasath and published by . This book was released on 2012 with total page 127 pages. Available in PDF, EPUB and Kindle. Book excerpt: Abstract: Two separate in vitro biomechanical studies were conducted on human cadaveric spines (Lumbar) to evaluate the stability following the implantation of two different spinal fixation devices; interspinous fixation device (ISD) and Hybrid dynamic stabilizers. ISD was evaluated as a stand-alone and in combination with unilateral pedicle rod system. The results were compared against the gold standard, spinal fusion (bilateral pedicle rod system). The second study involving the hybrid dynamic system, evaluated the effect on adjacent levels using a hybrid testing protocol. A robotic spine testing system was used to conduct the biomechanical tests. This system has the ability to apply continuous unconstrained pure moments while dynamically optimizing the motion path to minimize off-axis loads during testing. Thus enabling precise control over the loading and boundary conditions of the test. This ensures test reliability and reproducibility. We found that in flexion-extension, the ISD can provide lumbar stability comparable to spinal fusion. However, it provides minimal rigidity in lateral bending and axial rotation when used as a stand-alone. The ISD with a unilateral pedicle rod system when compared to the spinal fusion construct were shown to provide similar levels of stability in all directions, though the spinal fusion construct showed a trend toward improved stiffness overall. The results for the dynamic stabilization system showed stability characteristics similar to a solid all metal construct. Its addition to the supra adjacent level (L3- L4) to the fusion (L4- L5) indeed protected the adjacent level from excessive motion. However, it essentially transformed a 1 level into a 2 level lumbar fusion with exponential transfer of motion to the fewer remaining discs (excessive adjacent level motion). The computational aspect of the study involved the development of a spine model (single segment). The kinematic data from these biomechanical studies (ISD study) was then used to validate a finite element model of the spine.
Download or read book In Vivo Lumbar Spine Biomechanics written by Shaobai Wang and published by . This book was released on 2012 with total page 271 pages. Available in PDF, EPUB and Kindle. Book excerpt: Knowledge of lumbar spine biomechanics in living human subjects is fundamental for understanding mechanisms of spinal injury and pathology, for improvement of corresponding clinical treatments, and for design of spinal prosthesis. However, due to the complicated spine anatomy and loading conditions as well as high risks in these direct measurements, it has been a challenge to determine the in vivo biomechanics of the lumbar spine. To address this problem, the overall objective of this thesis was to develop and implement a dual fluoroscopic imaging system to non-invasively study human lumbar spine biomechanics. In line with this objective, the first goal was to quantify the ability of the dual fluoroscopic imaging system to determine vertebral kinematics. The second goal was to implement this technique to investigate spinal motion in both healthy subjects and patients with pathology. The third goal was to explore the feasibility of using kinematic data obtained from this system as boundary conditions in finite element analysis to calculate the physiological loads on the intervertebral disc. The system was shown to be accurate and repeatable in determining the vertebral kinematics in all degrees of freedom. For the first time, six degree-of-freedom motion of different structures of the spine, such as the vertebral body, intervertebral disc, facet joint and spinous process were measured in vivo in both healthy subjects and subjects with pathology during functional activities. In general, the group of subjects with pathology showed a significantly abnormal kinematic response during various physiological functional activities. Preliminary studies have shown the applicability and high accuracy of finite element modeling to calculate disc loads using in vivo vertebral kinematics as displacement boundary conditions.
Download or read book Computational Modeling for the Assessment of the Biomechanical Properties of the Healthy Diseased and Treated Spine written by Enrico Dall’Ara and published by Frontiers Media SA. This book was released on 2022-09-22 with total page 271 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Computational Analysis of the Time dependent Biomechanical Behavior of the Lumbar Spine written by Naira Helen Campbell-Kyureghyan and published by . This book was released on 2004 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Abstract: Significant effort has been invested in developing finite element models in the field of spinal biomechanics. However, nearly all previous studies have applied artificially set static or short duration dynamic loads (
Download or read book The Lumbar Spine written by Harry N. Herkowitz and published by Lippincott Williams & Wilkins. This book was released on 2004 with total page 1018 pages. Available in PDF, EPUB and Kindle. Book excerpt: The official publication of the International Society for the Study of the Lumbar Spine, this volume is the most authoritative and up-to-date reference on the lumbar spine. This edition provides more balance between basic science and clinical material and has been completely reorganized for easy reference. New chapters cover gene therapy, outcomes assessment, and alternatives to traditional nonoperative treatment. The editors have also added chapters on preparation for surgery, surgical approaches, spinal instrumentation, and bone grafts. Chapters on specific disorders have a consistent structure—definition, natural history, physical examination, imaging, nonoperative treatment, operative treatment, postoperative management, results of surgery, and complications.
