Blunt Force Trauma-final

7/27/2019 Blunt Force Trauma-final

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BLUNT FORCE TRAUMABerti Nelwan

[email protected]


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Guidelines for Reports by Autopsy Pathologists;

Vernard Irvine Adams, MD; Department of

Pathology and Cell Biology, University of South

Florida, Tampa, Florida, USA. 2008

Textbook of Traumatic Brain Injury; ThomasGenrelli MD. American Psychiatic. 2005

Clinical ForensicMedicine3rd editionEdited by

W.D.S. McLay. 2009 Blunt Force Trauma; Pathology Forensic Journal.

2010


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Forensic Pathology

Forensic Pathology is the branch of medicine

which analysesvictims of crime scenes

medically.

They are the last physicianfor the deceased

and their role is to discover and interpret the

evidence left during the autopsy.


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Analysis of Wounds

Not every crime victim is murdered.

Physicianscan contribute to proof of the

severity of a crime or that a crimeactually occurred in some cases for a

living victim.

Wounds provide evidence of the crime.


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Wound Categories

Bruises (or contusions)

Abrasions (or grazes or scratches)

Lacerations Incised wounds

Puncture (or stab) wounds

Gunshot wounds


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Definition

Injuries resulting from an

impact with a dull, firm surface

or object.


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The deaths resulting from blunt force trauma

occur in a variety of scenarios:

almost all transportation fatalities

jumping or falling from heights,

blast injuries,

Be struck by a firm object, such as a fist, crowbar,

bat, or ball.

Bite wounds and chop injuries may be considered

variants of blunt force trauma, sharp forcetrauma, or a class of injuries unto themselves.


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Blunt force trauma is routinely involved

in cases classified as accidents, as well asin cases of suicideand homicide.

it is importantto document evidence ofblunt force trauma in all autopsies

one should not immediately assume that

blunt force trauma is the cause of death


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For example,

Individuals may die of infections, thromboemboli, ororgan failure that occurs as a delayed result of previousblunt force trauma.

For purposes of death certification:

Proximate Cause of Death

the cause of death of an individual who dies ofpneumonia after being hospitalized for several days fortreatment of blunt force injuries following a motor

vehicle collision should be certified as "acutebronchopneumonia complicating blunt force injuriesdue to a motor vehicle accident."

the manner of death should then be certified as"accident."


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The severity of injuries inflicted as a result of

blunt force trauma is dependent on theamount of kinetic energy transferred and the

tissue to which the energy is transferred.

The kinetic energy associated with a moving

object is equal to one half the mass of that

object multiplied by the velocity of the object

squared (Ek= 1/2 mv2).


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Important: the characteristics of the

blunt objectand the surface that is

impacted.

Impacts involving a large surface will result in a

greater dispersion of energy over a larger area and

less injury to the impacted tissues.

an impact on a small area of a curved surface, such as

the head, will cause greater damage than would becaused were that same impact to occur on a flat

surface, such as the back, since there will be a more

concentrated point of impact on the head.


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The composition, or plasticity, of the

tissues impacted also affects theresultant injuries.

For example, a person who is kicked in the

chest may have only minimal injuries to the

elastic skin surface, whereas deeper, more

solid tissues such as ribs and internal organs

may experience fractures and lacerations.


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The another factor affecting the severity

of blunt force injuries is the amount oftime the bodyand the impacting object

are in contact.

A longer period of contact allows kinetic

energy to be dissipated over a prolonged

period, resulting in less damage to thetissues than an equally forceful impact with

dispersion of energy over a brief period.


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This lecture focuses on thecutaneous manifestations of blunt

force injury

Note:

The blunt force trauma may cause contusions and lacerations of the internal

organs and soft tissues, as well as fractures and dislocations of bonystructures.


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The major types of cutaneous

blunt force injuries are as follows: Contusion (bruise)

Abrasion Laceration

Avulsion

Fracture


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Bruises

A bruise is "a hemorrhage into tissues

produced by the escape of blood from blood

vessels".

Bruises may be found in the skin, muscles, and

internal organs.


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Bruises

Bruises are typically produced by a blunt force

impact, such as a blow or a fall.

They may also be produced by squeezing or

pinching, where the force is applied gradually

and then maintained.


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Contusions are

discolorations of the skin caused by bleedinginto the tissues from ruptured blood vessels.

Contusions (Bruises)


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Important: Natural Bruises

Bruises may occur in a variety of natural diseases inwhich there is an abnormality of the clottingmechanism of the blood, e.g. scurvy (vitamin Cdeficiency), leukemia, alcoholic liver disease.

This bruising is "spontaneous" because the injurywhich produces it is so insignificant as to typicallypass unnoticed.

The presence of such natural disease will exaggeratethe bruising effects of any trauma.


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Problems with Skin Bruises

Delayed appearance

Ageing (relative)

Site of Trauma Shape of object

Degree of force

Post-mortem bruises Post-mortem lividity


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Classic Causes of Bruises

Finger pad bruises: battered babies, manual

strangulation

Different ages: repeated assaults

Shoulders and arms: forceful restraint

Wrists and ankles: dragging

Inner thighs: forceful intercourse Chest: resuscitation

Bruising is uncommon in Suicides


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Bruises

The extent of bruising is inversely proportional to the

sharpness of the impacting object.

Bruises may be associated with other blunt force

injuries such as abrasions and lacerations. As a general rule bruising is not associated with

incised wounds or stab wounds where there is a free

flow of blood from the cut blood vessels rather than

leaking into the tissues.


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Site of Trauma

In contrast with abrasions, the location of a

bruise does not necessarily reflect the precise

point of injury.

Leaking blood will follow the path of least

resistance and gravity.


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Delayed Appearance

Deep bruises may have delayed appearance at theskin surface. Deep bruises may require as long as 12or 24 hours to become apparent, and some maynever do so

The more superficial the source of bleeding, thesooner the discoloration will be seen on the skinsurface.

In a living victim, a second examination in one or two

days may show bruising. In the dead, a further examination one or two days

after the original autopsy may show bruises whichwere not previously seen and reveal previously faintbruises.


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Autopsy and Bruising

Bruising in Deep Tissue

1. Possibly life-threatening

2. Sometimes no external injury

3. Revealed in autopsy

Documenting Bruising

1.Photography

2. Notes


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Degree of Force

The size of a bruise is an unreliable indicator

of the degree of force causing it.

However, a heavy impact is likely to produce a

large bruise and a light impact to produce a

small bruise.

If bruising is slight, it is reasonable to assume

that the degree of violence was slight.


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Determining Degree of Force in Bruise

Patterns

Location:

Some areas of the body bruise more easily than

others. The face bruises more readily than the

hands.

Bruising occurs more readily in loose tissues and

where there is a large amount of subcutaneous fat

Bruising is less apparent where the skin is stronglysupported by fibrous tissue or if the muscle tone is

good.


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Determining Degree of Force in Bruise

Patterns

Age Infants and the elderly tend to bruise more easily than

young and middle aged adults.

Infants have loose and delicate skin, and the abundant

subcutaneous fat. Elderly have degenerative changes in the tissues which

support the small blood vessels of the skin andsubcutaneous tissues.

Gender:

Women bruise more easily than men because they havemore subcutaneous fat and this is particularly true ofobese women.

Natural Disease

Skin color


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Causitive Object

The shape of the bruise is most likely to reflect

the shape of the causative object when the

object is small and hard and death occurs

soon after injury


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Causitive Object

A doughnut bruise is produced by an object

with a rounded contour (e.g. baseball).

Two parallel linear bruises result from a blow

with a rod or stick

Bruises can follow rounded contours if they

are caused by a flexible object like a lash


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Causitive Object

Bruises produced by fingerpads as a result of

gripping are usually larger than the fingerpads

themselves.

The pattern and location suggests the

mechanism of causation:

On the neck in throttling

On the upper arms in restraint.

Such bruises are referred to as patterned.


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Aging of Bruises

Color changes a bruise goes

through can give a rough estimate

of time of injury

Colors result from breakdown of

hemoglobin from tissuesDark blue/purple (1-18 hours)

Blue/brown (~1 to 2days)

Green (~ 2 to 3 days)Yellow (~3 to 7 days)

This rate assumes person is

healthy, however.


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red immediate

dusky purple / black soon after

green days 4 -5

Yellow days 7 - 10

resolution days 14 - 15

Camps:

violet immediate

blue day 3

green days 5 - 7

yellow days 8 - 10


Glaister:


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red dark / red black < 24 h

greenish tinge around day 7

yellow around day 14

resolution up to 30 days

red immediate

purple black soon after

green days 4 -5

yellow days 7 - 10


Polson and Gee:

Smith and Fiddes:


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Aging Bruises

While accurate estimation of the age of a singlebruise is not possible, a fresh bruise can bedistinguished easily from one which is several daysold.

Establishing that bruises are of different ages may beof medical importance where there is an allegationof repeated assaults: Child abuse

Wife beating

Where pre-existing injuries need to be distinguished fromthose produced by a recent assault like a chronic alcoholicwho was assaulted.


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Post MortemBruises

It requires considerable violence to produce a bruise

post mortemor after death.

These bruises are smaller relative to the degree of

force used. Post mortembruises are most readily produced in

areas of hypostasis (post mortem lividity, livor

mortis) or where tissues can be forcibly compressed

against bone.

A bruise can develop on the head after the body is

left lying on the back.


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Post Mortem Lividity

(hypostasis, livor mortis)

The settling, after death, of blood within the blood

vessels under the influence of gravity.

This results in a purplish discoloration of parts of the

body that are lower while sparing areas of pressurecontact - contact pallor.

The pattern and distribution of lividity distinguishes

it from bruising.

A body found on its back has livor mortison the

dorsal (back) side with pale areas where the bone

contacted the floor.


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Postmortem changes on the chest caused by insect activity.


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Patterns of Injury

Bruises to the knuckles of the hands, togetherwith bruises of the eyelids, bridge of the nose,cheeks and lips, suggest a fist fight.

Bruising around the eyes (spectacle bruises)may be produced by direct blows, but alsocommonly result from a fracture of the baseof the skull, e.g. in vehicle collisions orgunshot wounds to the head

They may also follow blunt impact to theforehead producing jolting of the eyeballs intheir sockets with tearing of small orbital

blood vessels.


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Patterns of Injury

Injuries in motor vehicle collisions almost

invariably include abrasions and lacerations as

well as bruises.

Patterns of injury may allow reconstruction of

incidents involving pedestrians or allow

distinction between driver and front seat

passenger.


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Patterned abrasion on the head due to impact by a motor vehicle.


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Two contusions on the skin of the chest


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A contusion

on the arm.


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BLUNT HEAD TRAUMA Blunt trauma to the scalp and face can produce contusions,

lacerations, and abrasions. Battles sign a bluish discoloration of the skin behind the

ear that occurs from blood leaking under the scalp after askull fracture.

Spectacle hemorrhage (raccoons eyes) a discoloration of

the tissues around the eyes usually due to a fracture of theskull.


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There are three major types of hemorrhages whichoccur in the skull.

The type of hemorrhage helps the examinerunderstand what may have caused death.

1) Epidural hemorrhage bleeding directly under

the skull on top of the dura mater. It is associated

with a skull fracture and a torn artery. This type

of hemorrhage accumulates rapidly and death

may occur quickly.


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2) Subdural hemorrhage bleeding under

duramater on top of the brain. It may or may

not be associated with trauma and is caused

by torn veins which forces the blood toaccumulate more slowly than the epidural

bleed.


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3) Subarachnoid hemorrhage caused by blunt

trauma or ruptured blood vessels. It is located

directly on the surface of the brain.


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Pathologists also look for the presence of coup andcontrecoup injuries to the brain to help differentiate

between a fall and a blow to the head by a second party.

Coup injury caused when a moving object (such as ahammer) strikes a stationary head. The injuries to thebrain will be directly beneath the point where the weaponstrikes the head.

Contrecoup injury caused when a moving head (as in afall) strikes a stationary object like the floor. The injuries to

the brain will be opposite the point ofimpact.


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Abrasions

A scraping injury to the superficial

layers of the skin (epidermis and

dermis) that results from frictionagainst a rough surface


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An abrasion is denuded skin caused byfriction. A wound may be either deep orsuperficial depending on the force and thecoarseness of the surface which caused theabrasion.

Abrasions (Scrapes)


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Abrasions

Side impact produces a moving abrasion:

Indicates direction.

Trace material (e.g. grit).

Direct impact produces an imprint abrasion: Pattern of causative object.

All abrasions reflect site of impact (in contrast with

bruises).

Assessment of age of abrasions is difficult.

Post-mortem abrasions - Brown, leathery


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Abrasion on the elbow. Abrasion on the knee.


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BRUSH-BURN ABRASION

One common type of blunt force injury is the so-

called brush-burn abrasion. Brush-burn abrasions

are broad, dried abrasions that often have a

yellow-orange or orange-red coloration. These abrasions are caused by dragging or

scraping the surface of the skin against a rugged

surface; they are most often encountered when a

body slides on pavement. These abrasions are

sometimes called "road rash."


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Brush-burn type abrasion on the left flank.


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Laceration:

A bursting of the skin or other tissues

resulting from compression or stretching

associated with impact by a blunt object

or surface


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Lacerations (Tears, Splits)

Splitting of the skin by the direct crushing

of blunt trauma.

Typically over bone, e.g. scalp, eyebrow,cheekbone.


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Lacerations

Distinguished from incised wounds by:

Adjacent abrasion/bruise

Ragged edge

Tissue bridges in depth

Forensic Importance

Not related to object shape

Trace evidence

Relatively little blood loss (except scalp)

Rarely suicidal


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Two abraded lacerations on the forehead. A laceration near the vertex of the scalp.


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Several chop injuries inflicted by a boat propeller.


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Avulsion:

A more severe form of laceration in

which the soft tissues, musculature,

and/or bone are torn away from thenormal points of attachment


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Avulsion of the right leg.


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Fracture:

A break, rupture,or separation of

tissue (most

often bone)resulting from an

impact


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Thank You

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Blunt Force Trauma-final