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 A Nonlinear Finite Element Study of a Lumbar Intervertebral Motion Segment microform written by Fan Chang and published by National Library of Canada. This book was released on 1987 with total page 184 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book A Biomechanical Study of Spinal Motion Segment Based on a Three Dimensional Nonlinear Poroelastic Finite Element Method written by and published by . This book was released on 2009 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Finite Element Method and Medical Imaging Techniques in Bone Biomechanics written by Rabeb Ben Kahla and published by John Wiley & Sons. This book was released on 2019-12-05 with total page 165 pages. Available in PDF, EPUB and Kindle. Book excerpt: Digital models based on data from medical images have recently become widespread in the field of biomechanics. This book summarizes medical imaging techniques and processing procedures, both of which are necessary for creating bone models with finite element methods. Chapter 1 introduces the main principles and the application of the most commonly used medical imaging techniques. Chapter 2 describes the major methods and steps of medical image analysis and processing. Chapter 3 presents a brief review of recent studies on reconstructed finite element bone models, based on medical images. Finally, Chapter 4 reveals the digital results obtained for the main bone sites that have been targeted by finite element modeling in recent years.

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 Finite Element Analysis of an Instrumented Lumbar Vertebra written by Ronald Mark McGregor and published by . This book was released on 1995 with total page 300 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Advanced pre clinical and pre surgical assessment of musculo skeletal medical devices written by Richard Mark Hall and published by Frontiers Media SA. This book was released on 2023-09-19 with total page 228 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Finite Elements in Biomechanics written by Richard H. Gallagher and published by John Wiley & Sons. This book was released on 1982 with total page 430 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Biomechanical Evaluation of a Lumbar Interspinous Spacer written by Avanthi Chikka and published by . This book was released on 2011 with total page 127 pages. Available in PDF, EPUB and Kindle. Book excerpt: Lumbar interspinous spacers have recently become popular as an alternative treatment for low back pain. These devices are primarily used to treat spinal stenosis and facet arthritis and are intended to unload the facet joints, restore foraminal height and provide stability mainly in extension while allowing normal range of motion in other loading modes at the index level and also at the adjacent segments. The goals of this study were three fold: (i) to evaluate the biomechanical stability provided by the Superion Interspinous Spacer (ISS) (Vertiflex®, San Clemente, CA) implanted in the lumbar spine; (ii) to study the effect of transection of supraspinous ligament (SSL) on the lumbar spine implanted with ISS; and (iii) to investigate the effect of graded facetectomies (50%, 75%, 100% facetectomies for both unilateral and bilateral cases) following the placement of ISS in the lumbar spine. This study is basically divided into two parts: an in vitro investigation and finite element analysis. The in vitro biomechanical study was conducted on six human lumbar motion segments (3 L2-L3 and 3 L4-L5) in the following test sequence: (i) intact, (ii) implanted (SSL intact), (iii) SSL dilated longitudinally at the center (with ISS), (iv) 50% resection of SSL (with ISS), (v) 100% resection of SSL (with ISS) (vi) injured (ISS removed). A finite element (FE) analysis was performed for the same test cases and also to investigate the effect of graded facetectomies using an experimentally validated 3D L3-S1 model. A bending moment of 10 Nm was applied in all loading modes (flexion-extension, right/left lateral bending, and right/left axial rotation) while a bending moment of 10 Nm with 400N compressive follower load was applied only in flexion-extension. Range of motion (ROM) was recorded for each of the test constructs. In addition to ROM, intradiscal pressure (IDP), facet loads and stress contour plots for these test constructs were obtained from the FE model. Repeated measures one way ANOVA was used to perform statistical analysis to determine the statistically significant differences between different test constructs for the in vitro data. The in vitro results showed that the mean ROM was significantly (p0.05) reduced in extension post-implantation. There was a minimal decrease in mean ROM in flexion as well, but it was not significant (p0.05). ROM in lateral bending and axial rotation were not affected. Also, there was no significant difference in ROM in any of the loading modes for the instrumented cases with and without SSL. The FE results were in agreement with the in vitro results except in flexion. Unlike the in vitro results, the flexion ROM increased slightly with progressive transection of SSL. From the FE data, it was observed that there was a significant reduction in IDP and facet loads in extension following the placement of ISS. However, there was no considerable difference in IDP and facet loads for the implanted cases with partial or complete transection of SSL. ROM, IDP and facet loads were not affected at the adjacent levels in any of the loading modes for any of the test constructs. It was also observed that there was an effect of graded facetectomies (50%, 75% and 100%) on the instrumented spine with a significant increase in ROM in flexion in case of both unilateral and bilateral facetectomies. The ISS provided an increased stability in extension while preserving motion comparable to intact in the other loading modes. Also, it can be inferred that SSL plays an insignificant role in segmental stability in extension, lateral bending and axial rotation and has nominal effect in flexion. In addition, the results suggest that ISS may not be used in combination with graded facetectomies for both unilateral and bilateral cases.

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 Biomechanical Implications of Lumbar Spinal Ligament Transection written by Gregory A. Von Forell and published by . This book was released on 2012 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The purpose of this work was to determine the possible effects of isolated spinal ligament transection on the biomechanics of the lumbar spine. A finite element model of a lumbar spine was developed and validated against experimental data. The model was tested in the primary modes of spinal motion in the intact condition, followed by comparative analysis of isolated removal of each spinal ligament. Results showed that stress increased in the remaining ligaments once a ligament was removed, potentially leading to ligament damage. Results also showed changes in bone remodeling "stimulus" which could lead to changes in bone density. Isolated ligament transection had little effect on intervertebral disc pressures. All major biomechanical changes occurred at the same spinal level as the transected ligament, with minor changes at adjacent levels. The results of this work demonstrate that iatrogenic damage of spinal ligaments disturbs the load sharing within spinal-ligament complex and may induce significant clinical changes in the spinal motion segment.

Download or read book Mechanical Properties of Lumbar Cancellous Bone and Finite Element Analysis of the L2 L3 Motion Segment written by Rajesh Anantharaman and published by . This book was released on 2004 with total page 176 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Clinical Implications of Normal Biomechanical Stresses on Spinal Function written by Herbert Junghanns and published by . This book was released on 1990 with total page 424 pages. Available in PDF, EPUB and Kindle. Book excerpt: Here is a how-to manual For The conservative treatment of everyday back problems. Clinical Implications combines theories of spinal biomechanics with thorough instructions for prevention, therapy, and follow-up care of spinal disorders. This manual is comprehensive in its coverage of spinal anatomy, physiology, function, biochemistry, and pathology; influences of daily activities; examination and treatment; effects of individual sports on spinal function; and much more. Extensively illustrated and referenced.

Download or read book Development of Deformity Specific Finite Element Models for Surgical Simulation of Anterior Vertebral Body Tether for Treating Scoliosis in Pediatric Subjects written by Girish Viraraghavan and published by . This book was released on 2019 with total page 288 pages. Available in PDF, EPUB and Kindle. Book excerpt: Adolescent Idiopathic Scoliosis (AIS) is a three - dimensional (3D) deformity which is characterized by lateral bending and axial rotation of the spine. Severe cases of AIS deformity (Cobb angle>45℗ʻ) undergo surgical intervention. Recently growth friendly interventions for skeletally immature AIS subjects have shown promising results. Anterior Vertebral Body Tethering (AVBT) is one such growth friendly intervention that provides 3D correction of the deformity along with restoration of range of motion (ROM) of the spine. However, various parameters affect the outcome of this surgery, such as curve location, number of screws and amount of tether tension. Therefore, the objective of this study was to develop and validate a 10-year-old normative pediatric thoracic and lumbar spine Finite Element (FE) model with pelvis that can be used to create deformity-specific AIS FE models to simulate and optimize surgical intervention using AVBT. Chest and abdominal Computed Tomography (CT) scans were used to create a normative 10-year-old thoracic and lumbar spine FE model with pelvis with age-, and level-appropriate material properties for vertebrae, intervertebral discs and spinal ligaments. This normative FE model was morphed to a 16-year-old Lenke 1AN deformity-specific AIS FE model using dual kriging and used to simulate AVBT surgeries. A total of 48 AVBT simulations were performed with various parametric combinations of number of instrumented levels (2: all and alternate), screw placement (2: lateral and anterior-lateral), applied force levels (3: all, ends only, and apex℗ł1) and tether force (4: 100, 200, 300 and 400 N). Clinical parameters of interest such as Cobb angle, thoracic kyphosis, lumbar lordosis and axial vertebral rotation were computed, and optimal parameter combinations for surgical planning were identified. Such FE models could serve as valuable preoperative clinical tools to aid in patient-specific surgical planning and interventional prognosis for AIS spine deformity treatment along with the potential to optimize surgical parameters and reduce surgery times, and thereby minimize the risk to pediatric patients.

Download or read book Biomechanical Evaluation of the Aspen Lumber Interspinous Fusion Device written by Manoj Kumar Kodigudla and published by . This book was released on 2011 with total page 142 pages. Available in PDF, EPUB and Kindle. Book excerpt: Degenerative disc disease (DDD) and spondylolisthesis are the most common spinal disorders that lead to low back pain in the lumbar region. The treatment options for low back pain may range from conservative treatment to fusing the vertebrae by surgical methods. Although there are many fusion devices available to treat low back pain, interspinous fusion device (Aspen) is an alternative to other fusion devices. The device consists of two plates (wide plate, lock plate) and a set screw, and can be implanted using minimally invasive surgical procedure. The purpose of the current study was to evaluate the stability and loosening of the Aspen device under complex cyclic loading with resection of interspinous and supraspinous ligaments. An in vitro study of motion analysis and cyclic loading on six lumbar motion segments was conducted. The range of motion of Aspen implanted segments was assessed before and after cyclic loading, to evaluate the stability provided and loosening of the implant. A three dimensional, non linear and validated finite element model of L3-S1 lumbar spine was also used for additional biomechanical analysis. The in vitro study suggested that Aspen interspinous device stabilized the segments after resecting the interspinous and supraspinous ligaments. Aspen reduced motion across the segment than intact but more significantly in flexion and extension (p

Download or read book Investigation of Stability of a Lumbar Motion Segment Using Finite Element Method written by Kim Kheng Lee and published by . This book was released on 2004 with total page 202 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book A Novel Testing Platform for Characterizing Cervical Spine Biomechanics written by Ira J. Hill and published by . This book was released on 2013 with total page 87 pages. Available in PDF, EPUB and Kindle. Book excerpt: The biomechanics and medical communities deserve a better understanding of cervical spine properties to allow improvement of current treatment methods for spinal trauma and disease. It is inherently difficult to make experimental in-vivo measurements of cervical spine kinematics and current in-vitro methods and results with cadaveric specimens can have significant variations. Previous methods have included custom cable-pulley systems, material tensile testers, parallel robots, and other platforms intended to apply pure moment loading to specimens. I propose a new spine testing paradigm using a six degrees of freedom serial manipulator for characterizing biomechanical properties, including range of motion (ROM), neutral zone (NZ), and other general spinal properties. This tool will be able to test individual functional spinal units (FSU) as well as multi-body segments in a modular framework. With this method, the various changes in kinematics can be characterized under a wide range of testing conditions, e.g., different implants, disk degeneration, ligament detachment, and other conditions. Another advantage of this test design is the ability to re-create complex physiological motion; which is clinically beneficial for studying specific motions. Previous studies were limited to analyzing flexion-extension, lateral bending, and axial rotation to their extreme values. This new system can perform motions such as flexion with axial rotation under a compressive load, representing common neck motion. With the ability to create richer data, the fundamental understanding of the cervical spine will be improved. Furthermore, these data can be used to calibrate and validate finite element (FE) and multi-body dynamic models.