Introduction: Because brain regions are responsible for specific functions, regional damage may cause specific, predictable symptoms. However, the existing brain injury criteria focus on whole brain response. This study developed and validated a detailed human brain computational model with sufficient fidelity to include regional components and demonstrate its feasibility to obtain region-specific brain strains under selected loading.
View Article and Find Full Text PDFIntroduction: Prevention and treatment of traumatic brain injuries is critical to preserving soldier brain health. Laboratory studies are commonly used to reproduce injuries, understand injury mechanisms, and develop tolerance limits; however, this approach has limitations for studying brain injury, which requires a physiological response. The nonhuman primate (NHP) has been used as an effective model for investigating brain injury for many years.
View Article and Find Full Text PDFBrain injuries in automated vehicles during crash events are likely to include mechanisms of head impact in non-standard positions and postures (i.e., occupants not facing forward in an upright position).
View Article and Find Full Text PDFBackground: Our elderly population is growing and the number of spine fractures in the elderly is also growing. The elderly population in general may be considered as poor surgical candidates experience a high rate of fractures at C1 and C2 compared with the general population. Nonoperative management of upper cervical fractures is not benign as there is a high nonunion rate for both C1 and C2 fractures in the elderly, and orthosis compliance is often suboptimal, or complicated by skin breakdown.
View Article and Find Full Text PDFJ Mech Behav Biomed Mater
January 2022
The anterior, posterior, transforaminal, and circumferential lumbar interbody fusions (ALIF, PLIF, TLIF, CLIF/360) are used to treat spondylolisthesis, trauma, and degenerative pathologies. This study aims to investigate the biomechanical effects of the lumbar interbody fusion techniques on the spine. A validated T12-sacrum lumbar spine finite-element model was used to simulate surgical fusion of L4-L5 segment using ALIF, PLIF with one and two cages, TLIF with unilateral and bilateral fixation, and CLIF/360.
View Article and Find Full Text PDFIntroduction: 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.
View Article and Find Full Text PDFIntroduction: Accelerative events commonly expose military pilots to potentially injurious + Gz (axial, caudal to cranial) accelerations. The Naval Biodynamics Laboratory exposed nonhuman primates (NHPs) to + Gz loading in two subject orientations (supine or upright) to assess the effect of orientation and accelerations associated with injury at accelerations unsafe for human participation.
Materials And Methods: Archived care records, run records, and necropsy and pathology reports were used to identify acceleration-related injuries.
Introduction: Size-matched volunteer studies report gender-dependent variations in spine morphology, and head mass and inertia properties. The objective of this study was to determine the influence of these properties on upper and lower cervical spine temporal kinematics during G+x loading.
Methods: Parametrized three-dimensional head-neck finite element models were used, and impacts were applied at 1.
Purpose: The objective of this study is to directly compare different types of cervical artificial disc implants using an in vivo model capable of simulating the axial load on a neck that is similar to the human neck.
Methods: Cervical arthroplasty was performed at C3-4 in 14 healthy female adult Alpine goats. The goats were divided into three groups.
Objective: To determine role of lordosis in cervical spine injuries using a novel competing risk analysis model.
Methods: The first subgroup of published experiments (n = 20) subjected upright human cadaver head-neck specimens to impact loading. The natural lordosis was removed.
J Mech Behav Biomed Mater
July 2018
The human cervical spine sustains compressive loading in automotive events and military operational activities, and the contact and noncontact loading are the two primary impact modes. Biomechanical and anatomical studies have shown differences between male and female cervical spines. Studies have been conducted to determine the human tolerance in terms of forces from postmortem human subject (PMHS) specimens from male and female spines; however, parametric risk curves specific to female spines are not available from contact loading to the head-neck complex under the axial mode.
View Article and Find Full Text PDFObjective: The research objective was to conduct an initial analysis of non-human primate (NHP) data from frontal and rear impact events archived in the Biodynamics Data Resource (BDR) records of the Naval Biodynamics Laboratory (NBDL). These rare data, collected between 1973 and 1989, will inform the safety community of upper-end tolerance limits of NHP and may be related to severe crash scenarios.
Methods: Data from frontal and rear acceleration tests to 93 macaque NHP were examined.
Quantification of biomechanical tolerance is necessary for injury prediction and protection of vehicular occupants. This study experimentally quantified lumbar spine axial tolerance during accelerative environments simulating a variety of military and civilian scenarios. Intact human lumbar spines (T12-L5) were dynamically loaded using a custom-built drop tower.
View Article and Find Full Text PDFWorld Neurosurg
December 2016
Background: The authors present a case of delayed acute subdural hematoma and review all reported cases in the literature. The focus of this paper is to identify the subset of the population who are at risk, and determine whether they should be admitted for observation in the setting of mild traumatic brain injury.
Case Description: A 75-year-old woman taking daily aspirin (81 mg) had a fall with loss of consciousness.
Lumbar endplate fractures were investigated in different experimental scenarios, however the biomechanical effect of segmental alignment was not outlined. The objectives of this study were to quantify effects of spinal orientation on lumbar spine injuries during single-cycle compressive loads and understand lumbar spine endplate injury tolerance. Twenty lumbar motion segments were compressed to failure.
View Article and Find Full Text PDFJ Mech Behav Biomed Mater
January 2015
Experimental testing incorporating lumbar columns and isolated components is essential to advance the understanding of injury tolerance and for the development of safety enhancements. This study incorporated a whole column axial acceleration model and an isolated vertebral body model to quantify compression rates during realistic loading and compressive tolerance of vertebrae. Eight lumbar columns and 53 vertebral bodies from 23 PMHS were used.
View Article and Find Full Text PDFObject: Segmental instability in the lumbar spine can result from a number of mechanisms including intervertebral disc degeneration and facet joint degradation. Under traumatic circumstances, elevated loading may lead to mechanical yield of the annular fibers, which can decrease load-carrying capacity and contribute to instability. The purpose of this study was to quantify the biomechanics of intervertebral annular yield during tensile loading with respect to spinal level and anatomical region within the intervertebral disc.
View Article and Find Full Text PDFBackground Context: Clinical studies have indicated that thoracolumbar trauma occurs in the civilian population at its junction. In contrast, injury patterns in military populations indicate a shift to the inferior vertebral levels of the lumbar spine. Controlled studies offering an explanation for such migrations and the associated clinical biomechanics are sparse in literature.
View Article and Find Full Text PDFBackground Context: The objective of the North American Spine Society's (NASS) Evidence-Based Clinical Guideline for the Diagnosis and Treatment of Lumbar Disc Herniation with Radiculopathy is to provide evidence-based recommendations to address key clinical questions surrounding the diagnosis and treatment of lumbar disc herniation with radiculopathy. The guideline is intended to reflect contemporary treatment concepts for symptomatic lumbar disc herniation with radiculopathy as reflected in the highest quality clinical literature available on this subject as of July 2011. The goals of the guideline recommendations are to assist in delivering optimum efficacious treatment and functional recovery from this spinal disorder.
View Article and Find Full Text PDFBackground Context: The North American Spine Society's (NASS) Evidence-Based Clinical Guideline on Antibiotic Prophylaxis in Spine Surgery provides evidence-based recommendations to address key clinical questions regarding the efficacy and the appropriate antibiotic prophylaxis protocol to prevent surgical site infections in patients undergoing spine surgery. The guideline is intended to address these questions based on the highest quality clinical literature available on this subject as of June 2011.
Purpose: Provide an evidence-based educational tool to assist spine surgeons in preventing surgical site infections.
Background Context: The evidence-based clinical guideline on the diagnosis and treatment of degenerative lumbar spinal stenosis by the North American Spine Society (NASS) provides evidence-based recommendations to address key clinical questions surrounding the diagnosis and treatment of degenerative lumbar spinal stenosis. The guideline is intended to reflect contemporary treatment concepts for symptomatic degenerative lumbar spinal stenosis as reflected in the highest quality clinical literature available on this subject as of July 2010. The goals of the guideline recommendations are to assist in delivering optimum efficacious treatment and functional recovery from this spinal disorder.
View Article and Find Full Text PDFEjection from military aircraft exerts substantial loads on the lumbar spine. Fractures remain common, although the overall survivability of the event has considerably increased over recent decades. The present study was performed to develop and validate a biomechanically accurate experimental model for the high vertical acceleration loading to the lumbar spine that occurs during the catapult phase of aircraft ejection.
View Article and Find Full Text PDFBackground Context: The North American Spine Society (NASS) Evidence-Based Clinical Guideline on the Diagnosis and Treatment of Cervical Radiculopathy from Degenerative Disorders provides evidence-based recommendations on key clinical questions concerning the diagnosis and treatment of cervical radiculopathy from degenerative disorders. The guideline addresses these questions based on the highest quality clinical literature available on this subject as of May 2009. The guideline's recommendations assist the practitioner in delivering optimum efficacious treatment of and functional recovery from this common disorder.
View Article and Find Full Text PDFBackground: Neck muscles are important in the static and dynamic stability of the head-neck complex. Deep neck muscles act to maintain upright posture and superficial muscles are responsible for gross movements. Previous studies have quantified neck muscle geometry using traditional supine magnetic resonance imaging (MRI).
View Article and Find Full Text PDFSevere-to-fatal head injuries in motor vehicle environments were analyzed using the United States Crash Injury Research and Engineering Network database for the years 1997-2006. Medical evaluations included details and photographs of injury, and on-scene, trauma bay, emergency room, intensive care unit, radiological, operating room, in-patient, and rehabilitation records. Data were synthesized on a case-by-case basis.
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