High Rotation Rate Behavior of Cervical Spine Segments in Flexion and Extension

Numerical finite element (FE) models of the neck have been developed to simulate occupant response and predict injury during motor vehicle collisions. However, there is a paucity of data on the response of young cervical spine segments under dynamic loading in flexion and extension, which is essential for the development or validation of tissue-level FE models. This limitation was identified during the development and validation of the FE model used in this study. The purpose of this study was to measure the high rotation rate loading response of human cervical spine segments in flexion and extension, and to investigate a new tissue-level FE model of the cervical spine with the experimental data to address a limitation in available data. Four test samples at each segment level from C2–C3 to C7–T1 were dissected from eight donors and were tested to 10 deg of rotation at 1 and 500 deg/s in flexion and extension using a custom built test apparatus. There was strong evidence (p < 0.05) of increased stiffness at the higher rotation rate above 4 deg of rotation in flexion and at 8 deg and 10 deg of rotation in extension. Cross-correlation software, Cora, was used to evaluate the fit between the experimental data and model predictions. The average rating was 0.771, which is considered to demonstrate a good correlation to the experimental data.

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Investigation of Upper Cervical Spine Injury due to Frontal and Rear Impact Loading Using Finite Element Analysis

Volume 3: Biomedical and Biotechnology Engineering ◽

10.1115/imece2014-40209 ◽

2014 ◽

Cited By ~ 1

Author(s):

Tanvir Mustafy ◽

Kodjo Moglo ◽

Samer Adeeb ◽

Marwan El-Rich

Keyword(s):

Finite Element ◽

Cervical Spine ◽

Motor Vehicle ◽

Spine Injury ◽

Upper Cervical Spine ◽

Fe Model ◽

Facet Joints ◽

Element Analysis ◽

Effective Prevention ◽

Upper Cervical

Predicting neck response and injury resulting from motor vehicle crashes is essential for improving occupant protection, effective prevention, and in the evaluation and treatment of spinal injuries. Injury mechanism of upper cervical spine due to frontal/rear-end impacts was studied using Finite Element (FE) analyses. A FE model of ligamentous (devoid of muscles) occipito-C3 cervical spine was developed. Time and rate-dependent material laws were used for assessing bone and ligament failure. Frontal and rear-end impact loads at two rates of 5G and 10G accelerations were applied to analyze the model response in terms of stress distribution, intradiscal pressure change, and contact pressure in facet joints. Failure occurrence and initiation instants were investigated. Frontal and rear-end impacts increased stresses significantly producing failure in most components for both rates. However, transverse ligament and C2-vertebral endplate only failed under rear-end impact. No failure occurred in cortical bone, dens, disc, anterior or posterior longitudinal ligaments. The spine is more prone to injury under rear-end impact as most of the spinal components failed and failure started earlier. Ligaments and facet joints are the most vulnerable components of the upper cervical spine when subjected to frontal/rear end impacts and injury may occur at small ranges of displacement/rotation.

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Posttraumatic Ligamentous Disruption of the Cervical Spine, an Easily Overlooked Diagnosis: Presentation of Three Cases

Neurosurgery ◽

10.1227/00006123-199004000-00019 ◽

1990 ◽

Vol 26 (4) ◽

pp. 674-678 ◽

Cited By ~ 21

Author(s):

M. Fazl ◽

J. LaFebvre ◽

R. A. Willinsky ◽

S. Gertzbein

Keyword(s):

Cervical Spine ◽

Motor Vehicle ◽

Plain Film ◽

Neurological Deficits ◽

Magnetic Resonance Imaging Scan ◽

Disc Space Narrowing ◽

Disc Disease ◽

Disc Space ◽

Plain Films ◽

Flexion And Extension

Abstract Three patients with hyperflexion sprain of the cervical spine secondary to motor vehicle accidents are discussed. One patient exhibited tetraplegia and the other two only had paresthesia of the upper and/or lower extremities at the scene of the accident. All patients were young with no evidence of degenerative disc disease or osteoarthritis. Diagnosis of hyperflexion sprain is suggested by transient or persistent neurological deficits, local tenderness, or plain film findings, which include interspinous fanning, localized kyphotic angulation, subluxation, or disc space narrowing. Review of our patients' records revealed that some of these findings were evident at their initial presentation. In patients who have no neurological deficits, controlled flexion and extension views after routine plain films may be diagnostic of an unstable cervical spine. If there is a persistent neurological deficit, a magnetic resonance imaging scan is the examination of choice. If there is no compression of the thecal sac or spinal cord, supervised flexion and extension views of cervical spine should be done. Definitive management of the unstable spine is operative fixation.

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Multilevel Validation of a Male Neck Finite Element Model With Active Musculature

Journal of Biomechanical Engineering ◽

10.1115/1.4047866 ◽

2020 ◽

Vol 143 (1) ◽

Author(s):

Jeffrey B. Barker ◽

Duane S. Cronin

Keyword(s):

Cervical Spine ◽

Injury Risk ◽

Muscle Activation ◽

Computational Models ◽

Soft Tissues ◽

Motor Vehicle ◽

Experimental Studies ◽

Tissue Level ◽

Open Loop ◽

Frontal Impact

Abstract Computational models of the human neck have been developed to assess human response in impact scenarios; however, the assessment and validation of such models is often limited to a small number of experimental data sets despite being used to evaluate the efficacy of safety systems and potential for injury risk in motor vehicle collisions. In this study, a full neck model (NM) with active musculature was developed from previously validated motion segment models of the cervical spine. Tissue mechanical properties were implemented from experimental studies, and were not calibrated. The neck model was assessed with experimental studies at three levels of increasing complexity: ligamentous cervical spine in axial rotation, axial tension, frontal impact, and rear impact; postmortem human subject (PMHS) rear sled impact; and human volunteer frontal and lateral sled tests using an open-loop muscle control strategy. The neck model demonstrated good correlation with the experiments ranging from quasi-static to dynamic, assessed using kinematics, kinetics, and tissue-level response. The contributions of soft tissues, neck curvature, and muscle activation were associated with higher stiffness neck response, particularly for low severity frontal impact. Experiments presenting single-value data limited assessment of the model, while complete load history data and cross-correlation enabled improved evaluation of the model over the full loading history. Tissue-level metrics demonstrated higher variability and therefore lower correlation relative to gross kinematics, and also demonstrated a dependence on the local tissue geometry. Thus, it is critical to assess models at the gross kinematic and the tissue levels.

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Motion Analysis of the Cervical Spine

Guides Newsletter ◽

10.1001/amaguidesnewsletters.2004.sepoct01 ◽

2004 ◽

Vol 9 (5) ◽

pp. 1-11

Author(s):

Patrick R. Luers

Keyword(s):

Cervical Spine ◽

Intervertebral Disk ◽

Radiographic Evaluation ◽

Ligamentous Injury ◽

Pattern Of Injury ◽

Motion Segment ◽

Single Pattern ◽

Compensatory Motion ◽

Loss Of Motion ◽

Flexion And Extension

Abstract The AMA Guides to the Evaluation of Permanent Impairment (AMA Guides), Fifth Edition, defines a motion segment as “two adjacent vertebrae, the intervertebral disk, the apophyseal or facet joints, and ligamentous structures between the vertebrae.” The range of motion from segment to segment varies, and loss of motion segment integrity is defined as “an anteroposterior motion of one vertebra over another that is greater than 3.5 mm in the cervical spine, greater than 2.5 mm in the thoracic spine, and greater than 4.5 mm in the lumbar spine.” Multiple etiologies are associated with increased motion in the cervical spine; some are physiologic or compensatory and others are pathologic. The standard radiographic evaluation of instability and ligamentous injury in the cervical spine consists of lateral flexion and extension x-ray views, but no single pattern of injury is identified in whiplash injuries. Fluoroscopy or cineradiographic techniques may be more sensitive than other methods for evaluating subtle abnormal motion in the cervical spine. The increased motion thus detected then must be evaluated to determine whether it represents normal physiologic motion, normal compensatory motion, motion related to underlying degenerative disk and/or facet disease, or increased motion related to ligamentous injury. Imaging studies should be performed and interpreted as instructed in the AMA Guides.

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Child neck FE model development and validation

International Journal of Human Factors Modelling and Simulation ◽

10.1504/ijhfms.2008.022479 ◽

2008 ◽

Vol 1 (2) ◽

pp. 244 ◽

Cited By ~ 5

Author(s):

F. Meyer ◽

S. Roth ◽

R. Willinger

Keyword(s):

Model Development ◽

Fe Model ◽

Development And Validation

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Flexion and Extension Views Are Not Cost-Effective in a Cervical Spine Clearance Protocol for Obtunded Trauma Patients

Journal of Trauma and Acute Care Surgery ◽

10.1097/00005373-200201000-00011 ◽

2002 ◽

Vol 52 (1) ◽

pp. 54-59 ◽

Cited By ~ 31

Author(s):

Jeff Anglen ◽

Michael Metzler ◽

Paul Bunn ◽

Harry Griffiths

Keyword(s):

Cervical Spine ◽

Cost Effective ◽

Trauma Patients ◽

Flexion And Extension

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Cervical Spine Fractures Sustained by Young Children in Forward-Facing Car Seats

PEDIATRICS ◽

10.1542/peds.84.2.348 ◽

1989 ◽

Vol 84 (2) ◽

pp. 348-354

Author(s):

Susan Fuchs ◽

Martha J. Barthel ◽

Ann Marie Flannery ◽

Katherine K. Christoffel

Keyword(s):

Cervical Spine ◽

Young Children ◽

Parent Education ◽

Health Care Professionals ◽

Motor Vehicle ◽

Cervical Spine Injuries ◽

Car Seats ◽

Number Of Children ◽

Car Safety ◽

Safety Seat

Child passenger safety restraint laws have reduced the number of children killed or injured in motor vehicle accidents in the past few years. However, the increased used of child safety seats has brought with it an increase in the misuse of these devices. High cervical spine injuries sustained by five children less than 2 years of age while in forward-facing car seats are described. In the cases of three children, the car safety seat use was correct. Misuse of car seats and anatomic and biomechanical factors in the cervical spines of infants and young children appear to have contributed to the occurrence of these previously rare injuries. Like seat belts, car safety seats are now a factor in child passenger injury characteristics, and therefore, car safety seat design merits reevaluation. In light of this development, public and parent education by health care professionals concerning the correct use of car safety seats is necessary.

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Paramedic Documentation of Indicators for Cervical Spine Injury

Prehospital and Disaster Medicine ◽

10.1017/s1049023x00040826 ◽

1994 ◽

Vol 9 (1) ◽

pp. 40-43 ◽

Cited By ~ 10

Author(s):

Andre M. Pennardt ◽

Wm. John Zehner

Keyword(s):

Emergency Department ◽

Cervical Spine ◽

Motor Vehicle ◽

Motor Vehicle Accident ◽

Spinal Injury ◽

Medical Center ◽

Prehospital Care ◽

Retrospective Chart Review ◽

Spine Injury ◽

Status Assessment

AbstractIntroduction:Current paramedic training mandates complete immobilization of all patients, symptomatic or not, whose mechanism of injury typically is viewed as conducive to spinal trauma. It is common to observe confrontations between paramedics and walking, asymptomatic accident victims who fail to understand why they should “wear that collar and be strapped to that board.” Immobilized, frustrated patients then may wait for hours in a busy emergency department until a physician declares them to be without spinal injury. Patients frequently refuse treatment and transport.Hypothesis:Algorithms exist for physicians to “clear” the cervical spine (C-spine) without radiography. It was hypothesized that paramedics routinely assess and document these indicators in their patient evaluations.Methods:A retrospective chart review was conducted on 161 patients (Group 1) admitted to a regional medical center with a diagnosis of C-spine injury over a 52-month period. The charts of 225 motor vehicle accident (MVA) victims (Group 2) transported by ambulance to the emergency department over a five-month period then were studied. Indicators for C-spine injury documented by emergency medical service (EMS) personnel were abstracted.Results:All patients underwent mental status assessment and full spinal immobilization (neck and back) by EMS crews prior to transport to the hospital. Two or more indicators of possible C-spine injury were documented on each prehospital care report (PCR).Conclusion:Paramedics already assess most, if not all, of the criteria standard to C-spine clearance algorithms, but are inconsistent in their documentation of the presence or absence of all of the relevant findings.

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