Jacobo Antona-Makoshi, PhD.tripp.iitd.ernet.in/assets/newsimage/181103_28thTRIPP... · 2019. 2. 19. · Antona-Makoshi et al. 2018 Accident Analysis and Prevention. Adopted occupant

Headeandespineeinjuries

Document developed in collaboration with Prof. Karin Brolin, Prof. Johan Davidsson and Prof. Mats Svensson from Chalmers University

28th International CourseTransport Research Injury Prevention Program Course

Indian Institute of Technology Delhi

December 2018

Jacobo Antona-Makoshi, PhD.

Whateiseessentialetoeprotect?

• Life supporting functions– Brain– Cervical spine (above C3)

• Quadriplegia above T1• Paraplegia below T1

Societalecosts

• Estimations of social costs per body region injured in vehicle crashes, including medical costs, emergency services, lost work wages and loss of quality of life, among others, show that Head and Spinal Injuries comprise the two most costly (Zaloshnja et al. 2004, Blincoe et al. 2015)

Principalepartseofetheenervousesystem

• Central nervous system (CNS):– brain– spinal cord

• Peripheral nervous system (PNS):– numerous, paired nerves joining CNS with

different parts of the body– ganglia - clusters of nerve cells

Fig.e45.03(TEeArt)Nervous system

Centralnervoussystem

BrainSpinalcord

Peripheralnervoussystem

Somatic(voluntary)

nervous system

Motorpathways

Sensorypathways

Autonomic(involuntary)

nervous system

Sympatheticdivision

Parasympatheticdivision

Sensory pathways

Motor pathways

AISeexamplesebyebodyeregion

AIS Head Thorax Abdomen and pelvic contents

Spine Extremities and bony pelvis

1 Headache or dizziness

Single rib fracture

Abdominal wall: superficial

Acute strain (no fracture or disl.)

Toe fracture

2 Unconscious < 1 hr.; linear fracture

2-3 rib fracture; sternum fracture

Spleen kidney or liver: laceration or contusion

Minor fracture without any cord involvement

Tibia, pelvis or patella: simple fracture

3 Unconscious 1-6 hrs.; depressed fracture

≥ 4 rib fracture; 2-3 rib fracture with hemoth. or pneumoth.

Spleen or kidney: major laceration

Ruptured disc with nerve root damage

Knee dislocation; femur fracture

AIS Head Thorax Abdomen and pelvic contents

Spine Extremities and bony pelvis

4 Unconscious 6-24 hrs.; open fracture

≥4 rib fracture with hemoth. Or pneumoth.; flail chest

Liver major laceration

Incomplete cord syndrome

Amputation or crush obove knee pelvis crush (closed)

5 Unconscious> 24 hrs.; large hematoma

Aorta laceration (partial transection)

Kidney, liver or colon rupture

quadriplegia Pelvis crush (open)

AISeexamplesebyebodyeregion

HeadeInjuries

Howedoeweeprotectetheehead?

HeadeInjuries

Do not teach things people already know (Dinesh Mohan, Dec 2017)

BraineInjuries

Herculano et al 2012www.brainmuseum.org

Mammalebraineevolution

Corpus callosum

Medulla oblongataBreathing, Heart Rate,Blood Pressure

PonsMotor control Sensory analysisSleep

HypothalamusTemperature, Emotions, Hunger, Thirst

ThalamusSensory processingMovementLateral ventricle

Optic recess

HippocampusMemory Learning

Brain Neuronal Tracts Brain Vasculature

Brainecomplexity

WhateisesoespecialeabouteTraumatice

BraineInjurye(TBI)?

• Extremely mild bump can damage the brain• Bones often recover but TBI frequently causes permanent harm• TBI cannot be understood with dead brains• The brain is incompressible

Incompressibleebrain?

Courtesy of Lee Gabler

AcuteeSymptomsefollowingeTBI

Mild Brain Injury• Brief period of

unconsciousness• Headache• Confusion• Dizziness• Sensory problems• Mood changes• Concentration problems

Moderate to Severe• Persistent headache• Nausea• Spasm• Dilation pupils• Slurred speech• Weakness or numbness• Loss of coordination• Increased confusion

LongetermesymptomsefromeTBI

• Trouble remembering, concentrating, making decisions, and controlling impulses

• Suffer from serious motor, sensory, and emotional impairments

• Not all TBI-related disabilities are readily apparent to others (“The silent epidemic“)

• … depression, drug abuse, suicide

Traumatic Brain Injury

Diffuse Brain Injury

Concussion

Hematoma

Focal Brain Injury

Contusion

Diffuse Axonal Injury



Concussion

Hematoma

Focal Brain Injury

Contusion


• Coup• Contre-coup• Gliding

Contusions

• Bruise of the brain common at inferior surfaces of frontal and temporal lobes

• Frequently accompany other TBI of higher severity• Mechanism: Brain contact with rigid intracranial structures.



Concussion

Hematoma

Focal Brain Injury

Contusion


• Epidural• Subdural• Subarachnoidal• Intracerebal

Epidural hematoma Acute Subdural hematoma

Subarachnoid hematoma Intracerebral hematoma

• Artery ruptures between dura and skull

• Substantial mortality risk• More common in children

and teenagers.• Mechanism: mostly temporal

bone fracture

• Veins rupture• Blood accumulates between dura and

arachnoid.• Mortality rate 30-60%• Mechanisms:

– Penetrating objects and bone fragments

– Large contusions– Tearing of bridging veins

• Artery ruptures. • Bleeding into the cerebrospinal fluid of the

sub-arachnoid space.• Permanent brain damage from ischemia or

from the presence of hematoma.• Mechanism: Rotational acceleration in

conjunction with aneurysm (?)

• Blood in central parts of the brain.

• Mortality rate 6-72%• Blood irritates the brain

tissues, causing swelling or hematoma

• Mechanism: Laceration, shear deformation (?)



Concussion

Hematoma

Focal Brain Injury

Contusion


Concussion

• Loss of consciousness or confusion for a short period• CT/MRI normal but patient may have headache,

cognitive problems, etc• Anterograde and retrograde amnesia • Duration of amnesia correlates with injury severity • Rarely fatal• Post concussion syndrome, memory problems,

dizziness, and depression• Mechanism: Head rotational and linear acceleration (?)

Davante Adams ‘Moderate’ Concussion https://www.youtube.com/watch?v=WOkI_Blee-s



Concussion

Hematoma

Focal Brain Injury

Contusion


DiffuseeAxonaleInjurye(DAI)

• Lesions in white matter (corpus callosum and brainstem)• Unconscious and vegetative state (21%)• Frequently fatal (30%) • Secondary biochemical cascades largely responsible for the damage

to axons.• Mechanism: shearing forces due to rotational acceleration stretching

axons

Brain tissue

NASS-CDS database publicly available

TBIeinereal-worldecarecrashes

Increasing TBI Severity

TB

I cat

egor

ies

top 3

FrequencyeofeoccupantsewitheTBICrash Year 2001-15, Model Year 2001-15, Light Vehicles, Occupant Age 15+

Antona-Makoshi et al. 2018 Accident Analysis and Prevention

Life-threateningeTBIeriskebyeyear

No clear decrease of life-threatening injuries is observed with time


TBIeriskeandeseatbelt

Beltuse reduces risk of all TBI categories


TBIeriskeandespeed

The risk of all TBI categories increases with crash severity

Cars with AEB Cars without AEB

Reduction in risk of striking another vehicle in a rear-end crash

vs.

Fildes et al. 2015

• AEB very effective in preventing crashes• A shift in crash severity is expected in the coming years

AutonomouseEmergencyeBraking

TBIeriskeandespeed

The risk of all TBI categories increases with crash severity

Belted elderly occupants in frontal crashes are (10 times) more likely to sustain an Acute Subdural Hematoma than non-elderly.

SubDuraleHematomaeinjuryeriskefactors


Belted female occupants in frontal crashes are (1.5 times) more likely to sustain a Moderate Concussion than belted males.

Concussioneinjuryeriskefactors


Adopted occupant protection strategies are insufficient to achieve significant decreases in risk of both life-threatening brain injuries and concussions. Further effort is needed to develop occupant and injury

specific strategies for the prevention of brain injuries. Future traffic injury prevention strategies need to prioritize life-threatening vasculature brain

injuries, particularly in elderly occupants, and concussion injuries, particularly in female occupants.

TBIeinereal-worldecarecrashes

InjuryeBiomechanics

• Analyze real-world data

Scientific discipline that applies the principles of mechanics to human (surrogate) subjects with the objective of clarifying injury mechanisms

and quantifying injury tolerances

Injury Reduction

• Clarify injury mechanisms• Develop tools, injury criteria & tolerances• Evaluate Safety

Injuryemechanismefromedynamiceloading

• Direct contact– Linear acceleration

• Deformation• Stress waves• Pressure gradients

–Negative pressure–Cavitations–Shear strains

– Rotational acceleration• Relative motion between

skull and brain• Shear in brain tissue

• Non-contact– Inertia properties

• Relative motion between skull and brain

Radial impact Oblique impact

Radial vs. oblique impact

Kleiven, ESV2007


BiomechanicalebraineinjuryecriteriaCriteria areeneededethat can be used with crash tests dummies (or human models) to predict mild, moderate and severe TBIs which mechanisms (including head rotation) are not necessarily associated with skull fractures.


Headekinematicsemetrics

Takhounts et al 2013 Gabler et al 2018

Gabler et al 2017 Yanaoka et al 2015

Takahashi & Yanaoka 2017

Miyazaki et al 2018

Antona-Makoshi et al 2016

Kikuchi et al 2016

Kimpara & Iwamoto 2012Kimpara & Iwamoto 2012

UVA MB

EBrIC

UVAeheadeimpactedatabasee(N=1,595)

Gabler, L. F., Crandall, J. R., & Panzer, M. B. (2018). Development of a Metric for Predicting Brain Strain Responses Using HeadKinematics.Annals of biomedical engineering, 1-14.

for the evaluation of head kinematics metrics

Courtesy of Matthew Panzer

TBIecriteriaeandeassociatederiskefunctions

Volunteer experiments

Animal experiments

Sports impacts reconstructions

Methodsetoeestablishebraineinjuryetolerances

Real-world TBI data

TBIecriteriaeandeassociatederiskefunctions

UVAeExperimentaleInjuryeDatabase

Military Volunteer Football Laboratory Reconstruction

Animal Tests

Increasing Injury SeverityNo InjuryLife-threatening

Injury

Ewing et al. 1972~1975Sanchez et al. 2017

Pellman et al. 2003Sanchez et al. 2018

Gennarelli et al. 1980Ono et al. 1980

for the development of TBI risk curves

Courtesy of Taotao Wu

Animal experiments

Injury Criteria and thresholds for humans

Injury thresholds crude scaling

(Holbourn 1943)

Numerical model of animal test

Brain tissue risk functions

Numerical model of human

Head kinematics scaling

(Takhounts et al. 2013)

Applicability of animal data to humans

TBI mechanisms in (past) head impact experiments with monkeys

Simulation of monkey frontal head impact test

•24 impacts•8 specimens

•10 concussions

•19 impacts•7 specimens

•9 concussions

TBI injury risk curves

A kinematics brain injury criterion & thresholds

Brain Injury Thresholds Surface (BITS)

Monkey and human brains are similar at thetissue biomechanical level

2 padding materials, 3 impactors, 3 Impact speeds (4, 6 and 8 m/s)

Simulation of human head impacts

Transfer to humans via brain FE simulations

< 10% probability of concussion ~ 60% probability of concussion

TBI thresholds considering translational acceleration, rotational acceleration and duration

Du

ratio

n (

ms)

1. Helmets, seatbelts and speed control!2. Crash mitigation technologies (AEB)3. Brain injury criteria and risk functions

Life-threatening bleeding injuries (elderly)Concussions (women)Combination of human and animal data (applicability)

4. Testing tools (e.g dummies, FE models) and methods for safety evaluation

Howedoeweepreventebraineinjuries?

SPINEeINJURY

Spinaleanatomy

• Cervical spine (neck)

• Thoracic spine– Ribs

• Lumbar spine

• Sacrum• Coccyx

Neckeanatomy

Peripheralnervoussystem

Directionaledependence

Strengtheofetrabecularebone

(b)(a)

Compressive Tensile

Theeintervertebraledisc• Purposes:

– Damping– Restrict relative translations between the vertebrae– Allow for some rotation

• Hydrofilic gel– 90% to 70% water

• Collagen fibers in ground substance– Fiber direction ± 60º

Theeintervertebraledisc

αο α1

F

FvertebraAF

NP

cartilage endplate

(a) (b)

(c) (d)

• 10 times stiffer in compression than torsion, shear or flexion.

• The almost incompressible properties of the NP result in tensile loading of the collagen fibers when the disc is compressed.

• Rate dependent properties

• Viscoelasticity (fluid flow)

0

0,1

0 50 100 150

Saline stored Boiled

Ten

sile

load

(kN

)

Time (s)

(1)

(2)

(3)

(4)

Collagen & Elastin fibers Elastin fibers

Tensileetestingeofeligament

Tens

ile lo

ad [k

N]

Kneeeligamenteundereloading

unloaded

loaded

Young’s modulus

(MPa)

Yield strain (%)

Strain at failure (%)

Stress at failure (MPa)

Collagen 500 10-20 45-125

Elastin 3 130

Ground substance

3

Ligaments 20 25 > 100 20

Tendons 50-100 4 10 60

Apatit crystals 165,000

Trabecular bone 50-500 1-10 2-100

Cortical bone 15,000-21,000

1-2 100-200

Rubber 1.4 0.499

Oak 10,000 0.2 5 100

Steel 200,000 0.3 1 500

EpidemiologySevereespinalecordeinjury,eAISe3+

• 10.000 cases/year in the US–Motor vehicle 54%–Fall 16%–Diving 12%

• 20.000 cases/year in India–Traffic 45%–Fall 35%

• male:female 3:1• 20-40 years of age

EpidemiologySevereespinalecordeinjury,eAISe3+

• In modern cars– Roll-over – Unbelted all directions – Forward facing children age <2 years

• Motorcyclist, mopeds and bikes– All accident types

Ineautomotiveecrashes…

• If unbelted head contact the windscreen in frontal crashes–Axial compression–Shear loading –Bending

• Minor soft tissue neck injuries due to inertia–Axial tension–Shear loading–Bending

Severeeneckeloade- examples

Bad design

Out of position airbag injuries

Pedestrian accident

Compressioneloading

BURST FRACTUREIncreasing load Dislocation of facet

Unstable neck

JEFFERSON’S FRACTUREUnstable

Flexion-compressione

loading

Dislocation most often OC-C1

Tensioneextensioneloads

Hangman

http://www.mvd.chalmers.se/~mys/

Whiplash Associated Disorders (WAD)AIS 1

Prevention

Diagnosis

Treatment

Tension-extension loading, caused by inertia loading of the head.

Injury mechanism ?

Injuryemechanismse

• Facet joints ?–Pain (>40%)

• Muscle ?–Good prognosis

• CNS ?–Dorsal nerve root ganglion injury due to pressure

wave• Ligament ?• Disc ?

Still not know – research ongoing

Pain sensitization.

Whiplashemotioneofetheecervicale

spine

77

During a rear impact

The S-Shape of the cervical spine is: � characterised as a nonphysiologic curvature� hyphothesised to cause WADs

Grauer et al., 1997, Whiplash produces and S-Shape curvature of the neck with hyperextension at lower levels.

Result from rear impact sled tests with head-neck PMHSsInitial Position


Experimental studies

• Human subjects• Animal models

Operating-table

Head-

BackrestPull-rod

Straps

Rod

Linear displacement transducer

Angular displacement transducers

z-acc.

x-acc.

Pull-force

X

Z

Coordinate-system


Crash Dummies

BioRID II

RID 3D

Carlson A., Addressing female whiplash injury protection, PhD thesis, 2012

MenNormalized to 1

Carlson A., Addressing female whiplash injury protection, PhD thesis, 2012

Women

81

Cervicalspine

Thoracicspine

Lumbarspine

Female Male

Sato F, Female and Male Whole Spinal Alignment and Cervical Kinematic Responses in Rear Impacts, Lic. thesis, 2017

Toolserepresentingefemales

https://www.chalmers.se/en/projects/Pages/OpenHBM.aspx

Neckeinjuryecriteria

• AIS3+– Nij =Fz/Fint+My/Mint

• AIS1– NIC =0.2 arel + vrel

2

– Nkm = Fx/Fint+My/Mint

NijedummyevaluesproposedebyeNHTSA

Kleinberger M et.al. Development of improved injury criteria for the assessment of advanced automotive restraint systems - II, NHTSA report, Nov. 1999.

Nij=Fz/Fint+My/Mint

NIC = 0.2 arel + vrel2

arel = aT1 - ahead

vrel = vT1 - vhead

NICe=eNeckeInjuryeCriterion

ahead, Vhead

aT1, VT1

50% risk: NIC=25 m2/s2

NIC=15 m2/s2

Hypothesis: Pressure aberrations inside the spinal canal.

Nkm Neckeprotectionecriterion

load case Intercept value

Extension moment 47.5 Nm

Flexion moment 88.1 Nm

Shear 845 N

Hypothesis: Linear combination of shear and y-moment is responsible for relevant neck loading

Neckeinjuryecriteria

• AIS3+– Nij =Fz/Fint+My/Mint

• AIS1– NIC =0.2 arel + vrel

2

– Nkm = Fx/Fint+My/Mint

Kleinberger M et.al. Development of improved injury criteria for the assessment of advanced automotive restraint systems , NHTSA report, Sept. 1998.

Boström O, Svensson M, Aldman B, Hansson H, Håland Y, Lövsund P, Seeman T, Suneson A, Säljö A, Örtengren T (1996): A new neck injury criterion candidate based on injury findings in the cervical spinal ganglia after experimental neck extension trauma, Proc. IRCOBI Conf., pp. 123-136

Schmitt K-U, Muser M, Niederer P (2001): A new neck injury criterion candidate for rear-end collisions taking into account shear forces and bending moments, Proc. ESV Conf.

Schmitt K-U, Muser M, Walz F, Niederer P (2002): Nkm — a proposal for a neck protection criterion for low speed rear-end impacts, Traffic Injury Prevention, Vol. 3 (2), pp. 117-126

Kullgren A, Eriksson L, Krafft M, Boström O (2003): Validation of neck injury criteria using reconstructed real-life rear-end crashes with recorded crash pulses, Proc. 18th ESV Conf

Reflection

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Whatedideyouefindeinteresting?

Jacobo Antona-Makoshi, PhD.tripp.iitd.ernet.in/assets/newsimage/181103_28thTRIPP... · 2019. 2. 19. · Antona-Makoshi et al. 2018 Accident Analysis and Prevention. Adopted occupant

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