Subaxial Cervical Spine Motion With Different Sizes of Head-supported Mass Under Accelerative Forces.

Introduction: The evolution of military helmet devices has increased the amount of head-supported mass (HSM) worn by warfighters. HSM has important implications for spine biomechanics, and yet, there is a paucity of studies that investigated the effects of differing HSM and accelerative profiles on spine biomechanics. The aim of this study is to investigate the segmental motions in the subaxial cervical spine with different sizes of HSM under Gx accelerative loading.

Comparison of Load-Sharing Responses Between Graded Posterior Cervical Foraminotomy and Conventional Fusion Using Finite Element Modeling.

Following the diagnosis of unilateral cervical radiculopathy and need for surgical intervention, anterior cervical diskectomy and fusion (conventional fusion) and posterior cervical foraminotomy are common options. Although patient outcomes may be similar between the two procedures, their biomechanical effects have not been fully compared using a head-to-head approach, particularly, in relation to the amount of facet resection and internal load-sharing between spinal segments and components. The objective of this investigation was to compare load-sharing between conventional fusion and graded foraminotomy facet resections under physiological loading.

Finite element modeling of the human cervical spinal cord and its applications: A systematic review.

Background Context: Finite element modeling (FEM) is an established tool to analyze the biomechanics of complex systems. Advances in computational techniques have led to the increasing use of spinal cord FEMs to study cervical spinal cord pathology. There is considerable variability in the creation of cervical spinal cord FEMs and to date there has been no systematic review of the technique.

Determinants of spinal cord stress and strain in degenerative cervical myelopathy: a patient-specific finite element study.

Degenerative cervical myelopathy (DCM) is the commonest cause of spinal cord dysfunction in older adults and is characterized by chronic cervical spinal cord compression. Spinal cord stress and strain during neck motion are also known contributors to the pathophysiology of DCM, yet these factors are not routinely assessed for surgical planning. The aim of this study was to measure spinal cord stress/strain in DCM using patient-specific 3D finite element models (FEMs) and determine whether spinal cord compression is the primary determinant of spinal cord stress/strain.

Spinal Cord Stress After Anterior Cervical Diskectomy and Fusion: Results from a Patient-Specific Finite Element Model.

Degenerative cervical myelopathy (DCM) is the commonest cause of cervical spinal cord dysfunction in older adults and is characterized by spinal cord compression and stress during neck motion. Although surgical decompression eliminates static spinal cord compression, cord stress resulting from flexion-extension motion of the spinal column has not been determined for single and multi-level surgical interventions. The effect of surgery on spinal cord stress is expected to change with the number of surgical levels as well as patient-specific anatomy.

Gender Differences in Cervical Spine Motions and Loads With Head Supported Mass Using Finite Element Models.

While many studies have been conducted to delineate the role of gender in rear impact via experiments, clinical investigations, modeling, and epidemiological research, the effect of the added head mass on segmental motions has received less attention. The objective of the study is to determine the role of the head supported mass on the segmental motions and loads on the cervical spinal column from rear impact loading. The study used finite element modeling.

Biomechanical Analysis of 3-Level Anterior Cervical Discectomy and Fusion Under Physiologic Loads Using a Finite Element Model.

Objective: Pseudarthrosis and adjacent segment degeneration (ASD) are 2 common complications after multilevel anterior cervical discectomy and fusion (ACDF). We aim to identify the potential biomechanical factors contributing to pseudarthrosis and ASD following 3-level ACDF using a cervical spine finite element model (FEM).

Methods: A validated cervical spine FEM from C2 to C7 was used to study the biomechanical factors in cervical spine intervention.

Normalized vertebral-level specific range of motion corridors for female spines in rear impact.

Objective: It is well known that the biomechanical responses of female and male spines are different in rear impacts. Female-specific finite element models are being developed as improvements over generic models. Such advancements need female-specific segmental responses for validation.

Biomechanical effects of uncinate process excision in cervical disc arthroplasty.

Background: Studies on the role of uncinate process have been limited to responses of the intact spine and patient's outcomes, and procedures to perform the excision. The aim of this study was to determine the role of uncinate process on the biomechanical response at the index and adjacent levels in three artificial discs used in cervical disc arthroplasty.

Methods: A validated finite element model of cervical spine was used.

Biomechanical Study of Cervical Disc Arthroplasty Devices Using Finite Element Modeling.

Many artificial discs for have been introduced to overcome the disadvantages of conventional anterior discectomy and fusion. The purpose of this study was to evaluate the performance of different U.S.

Effects of different severities of disc degeneration on the range of motion of cervical spine.

Aims And Objectives: The human spine degenerates with age. Intervertebral disc degeneration occurs in the cervical spine. The objective of this study is to determine the effects of degenerative disc diseases on the range of motion (ROM) of the human cervical spinal column using a validated finite-element model.

Comparative Finite Element Modeling Study of Anterior Cervical Arthrodesis Versus Cervical Arthroplasty With Bryan Disc or Prodisc C.

Introduction: Cervical disc arthroplasty (CDA), a motion-preserving alternative to anterior cervical discectomy and fusion (ACDF), is used in military patients for the treatment of disorders such as spondylosis. Since 2007, the FDA has approved eight artificial discs. The objective of this study is to compare the biomechanics after ACDF and CDA with two FDA-approved devices of differing designs under head and head supported mass loadings.

Neck Vertebral Level-specific Forces and Moments Under G-x Accelerative Loading.

Introduction: It is important to determine the local forces and moments across the entire cervical spine as dysfunctions such as spondylosis and acceleration-induced injuries are focused on specific levels/segments. The aims of the study were to determine the axial and shear forces and moments at each level under G-x accelerative loading for female and male spines.

Methods: A three-dimensional finite element model of the male head-cervical spinal column was developed.

A Comparison Study of Four Cervical Disk Arthroplasty Devices Using Finite Element Models.

Study Design: The study examined and compared four artificial cervical disks using validated finite element models.

Purpose: To compare and contrast the biomechanical behavior of four artificial cervical disks by determining the external (range of motion) and internal (facet force and intradiscal pressure) responses following cervical disc arthroplasty (CDA) and to elucidate any device design effects on cervical biomechanics.

Overview Of Literature: Despite CDA's increasing popularity most studies compare the CDA procedure with anterior cervical discectomy and fusion.

External and internal responses of cervical disc arthroplasty and anterior cervical discectomy and fusion: A finite element modeling study.

Surgical treatment for spinal disorders, such as cervical disc herniation and spondylosis, includes the removal of the intervertebral disc and replacement of biological or artificial materials. In the former case, bone graft is used to fill the space, and this conventional procedure is termed anterior cervical discectomy and fusion (ACDF). The latter surgery is termed as artificial disc replacement ADR) or cervical disc arthroplasty (CDA).

Compression-based injury variables from chestbands in far-side impact THOR sled tests.

This study seeks to determine compression () and compression-related injury variables (velocity and viscous injury criterion: and ) from chestband data in pure lateral and oblique far-side impact sled tests. The 3-point belt-restrained mid-sized male Test Device for Human Occupant Restraint (THOR) dummy was placed on a buck and subjected to side impacts with and without center-mounted airbags. The change in velocity was 8.

Unique biomechanical signatures of Bryan, Prodisc C, and Prestige LP cervical disc replacements: a finite element modelling study.

Purpose: The purpose of the study is to examine the biomechanical alterations in the index and adjacent levels of the human cervical spine after cervical arthroplasty with Bryan, Prodisc C, or Prestige LP.

Methods: A previously validated C2-T1 osteoligamentous finite element model was used to perform virtual C5-6 arthroplasty using three different FDA-approved artificial cervical discs. Motion-controlled moment loading protocol was used.

Assessment of trace metal contamination in the marine sediment, seawater, and bivalves of Parangipettai, southeast coast of India.

Industrial and domestic discharge into the coastal environment has driven us to propose an integrated approach to delineate stations contaminated with metals on the Parangipettai coast by collecting sediment and seawater samples monthly at 18 stations from 2015 to 2017. Descriptive statistics revealed that the concentrations of some metals in the sediment and seawater samples were beyond the permissible level. Further, factor analysis showed a sampling adequacy of 0.

THOR dummy chest deflection response in oblique and lateral far-side sled tests.

The focus of this study is side impact. Though occupant injury assessment and protection in nearside impacts has received considerable attention and safety standards have been promulgated, field studies show that a majority of far-side occupant injuries are focused on the head and thorax. The 50th percentile male Test Device for Human Occupant Restraint (THOR) has been used in oblique and lateral far-side impact sled tests, and regional body accelerations and forces and moments recorded by load cells have been previously reported.

Forces and moments in cervical spinal column segments in frontal impacts using finite element modeling and human cadaver tests.

Experiments have been conducted using isolated tissues of the spine such as ligaments, functional units, and subaxial cervical spine columns. Forces and or moments under external loading can be obtained at the ends of these isolated/segmented preparations; however, these models require fixations at the end(s). To understand the response of the entire cervical spine without the artificial boundary/end conditions, it is necessary to use the whole body human cadaver in the experimental model.

Evaluation of the environmental quality of Parangipettai, Southeast Coast of India, by using multivariate and geospatial tool.

The anthropogenic pressure in recent years has driven us to investigate the environmental quality at 22 stations in Parangipettai by collecting seawater samples monthly from 2014 to 2015. The sampling stations were grouped into three different environments, namely, Vellar Estuary (VE), Coleroon Estuary (CE), and Open Sea (OS). Factor analysis showed a total variance of 65.