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Transcript of Wounds
Mechanism of wounding
If the energy transfer can be
spread over a wider area
, then the intensity of force applied to the tissues per unit of time is
Classification of wounds
Definition of wound
Mechanism of wounding
Classification of wounds ..
Blunt force wounds
( abrasion, Bruises, laceration)
Sharp force wounds
( Incised, stab, chops, therapeutic)
Determination of Whether a Wound is Ante- or Postmortem ..!?
Survival period after wounding
A wound can best be defined as
'damage to any part of the body due the application of mechanical force'.
Postmortem insect bites and diaper rash are occasionally misinterpreted as abrasions.
Another artifact that can be confused with an abrasion is drying of the skin of the scrotum and, less commonly, of the vulva , The skin in these areas seems to be very susceptible to drying, especially if exposed to the open air..
Anatomy of the Skin
The wound occur when the intensity of the applied force exceeds the capability of the tissues to adapt or resist.
The effect of excessive mechanical forces on the tissues of the body can cause compression, traction, torsion, and tangential stresses.
The intensity of the force obeys the usual laws of physics,
The well-known formula:
Force = ½ mass X velocity²
Pathologist should classify them by their
appearance and the method of causation
The most used classification is :
- 'grazes or scratches'.
- ‘ tears'.
- 'cuts', 'slashes' or 'stabs‘.
Scrape (brush) (tangential ) abrasion
the condition and health of the victim,
the site and type of tissues struck.
Dating of Bruises
The method most commonly employed in dating contusions is based on the changes in color a contusion undergoes as it heals.
As a bruise ages, it undergoes an evolution in its color due to the degradation of the
As the hemoglobin in the bruise is broken down, the color gradually changes to
These changes can occur over a matter of days to weeks.
Since different components of soft tissue have different strengths, there is usually incomplete separation of the stronger elements, such as blood vessels and nerves, so that when one looks into the depth of the laceration, one sees
of tissue running from side to side.
The presence of bridging proves decisively that one is not dealing with an incised wound.
Internal organs (heart- lung) may show laceration with evidence of bridging
The depths of the laceration should be explored for the presence of foreign material that could have been deposited there by the weapon or surface that caused the laceration.
Incised wounds or cuts or slashes are clean cut wounds produced by sharp-edged weapons or instruments.
A knife is the classical example of a weapon used to inflict an incised wound, though, in fact, any instrument with a sharp edge can do so e.g., a piece of glass, sword, razor, scalpel, etc.
The sharp edge of the instrument is pressed into and drawn along the surface of the skin, producing a wound
whose length is greater than its depth.
The edges of an incised wound tend to
separate or gap
The extent to which the wound gaps and the shape it subsequently assumes depend on whether it is parallel, transverse, or oblique to the direction of the elastic fibers in the skin
In rare instances, a fatal self-inflicted incised wound of the neck may be accompanied by
with the knife or razor found firmly clenched in the victim’s hand.
Stab wounds are produced from penetration with long narrow instruments having
A stab wound is an incised wound that is
deeper than its wide.
Extremely common in homicide.
Blunt force wounds :
Fractures of the skeletal sys.
Sharp force wounds :
Therapeutic / diagnostic wounds
Di Maio , dolinak , spitz
Is a variation of an impact abrasion, Where The
pattern of the object
, or intermediary material,such as
, is imprinted or stamped on the skin underlying the point of the impact
Ex: when a motor tyre passes over the skin leaving a pattern where the skin has been squeezed into the grooves of the rubber tread.
is an area of hemorrhage into soft tissue due to rupture of blood vessels caused by blunt trauma.
Contusions may be present not only in skin, but also in internal organs.
A large focal collection of blood in an area of contusion is referred to as a
A contusion can be differentiated from an area of livor mortis (hypostasis) in that,
Eye and Eyelids
Surgical removal of corneas
or the globes of the eyes shortly after death can result in hemorrhage into the eyes indistinguishable from antemortem traumas .
Removal of vitreous
shortly after death can result in scleral hemorrhage at the puncture site .
Confluent hemorrhage in eyelids can occur after death in cases of head trauma with fracture of the orbital plates.
Is a tear or split of the tissue caused by either a shearing or a crushing force.
They are caused by blows from
impact from vehicles
, most commonly over bony prominences, such as in the head, where the skin is fixed and can more easily be stretched and torn.
Lacerations of the skin tend to be
abraded contused margins
, they may extend deep and bleed profusely.
one can have lacerations of internal organs as well as the skin.
Definition & Terminology :
An injury produced by a blunt object
striking the body or impact of the body against blunt object or surface
The severity, extent, and appearance of blunt trauma injuries depend on:
The shape & nature of the weapon .. ( flat or narrow , easly broken or not ..)
The amount of force delivered to the body
The time over which the force is delivered
The region struck
The extent of body surface over which the force is delivered
Blunt trauma wounds
bruising and crushing of the margins
The persistence of tissue strands across the interior of
, including fascial bands, vessels and nerves, in a wound from a sharp weapon these are divided.
absence of a sharply linear injury in the underlying
, especially if it is the skull. A knife or axe is likely
to chip or score the base of the wound
If the area is covered with hair, as on the scalp,
hairs will survive to cross the wound
; an incised injury would divide them.
A laceration can be distinguished from an incised wound by:
Tires passing over an extremity may avulse soft tissue off the bone, Internally, organs can be avulsed or torn off in parts.
In most of the cases of blunt trauma , lacerations , abrasions and bruises will occur in combination with each other.
Incised wounds of the neck
The wound inflicted is
The wound generally
starts below the ear
downward and medially
at an angle, then
straight across the midline
of the neck, and then
, ending on the opposite side of the neck,
its point of initiation.
Wounds caused by
sharp-edged and pointed
can be divided into categories:
Incised wounds (cuts or slashes)
are the weapons most frequently involved and their physical characteristics are important in shaping the wound …
The length, width and thickness of the blade
Whether it is single or double-edged
The face of the hilt guard adjacent to the blade
Any grooving, serration or forking of the blade
Most importantly, the sharpness of the edge and especially of the
of the blade.
THE CHARACTERISTICS OF A STAB WOUND
Length and breadth
of the wound
of the thrust
Length and Breadth
An important factor must always be taken into account, when the knife is withdrawn
the elasticity of the skin causes it to retract
, and the
contraction of the underlying muscles.
So, the wound length appears
than when the blade was in situ.
the breadth is more the thickness of the blade due to
, so approximation of the edges is needed.
Movement of the knife in the wound
can result in loss of evidence as to the size of the blade.
If, however, the knife is
in the wound, the skin defect will be enlarged.
This rocking can occur either by the knife being actively moved in the wound by the assailant - or by the body moving relative to the knife -or by a combination of the two.
depth of a stab wound
is the greatest dimension, but
its not usually a guide to the lenght of the blade ..
there are pitfalls to be avoided..
the probe may easily pass between fascial planes or within the muscle producing a false track.
caving-in of the body surface
differences in the position
of internal organs as measured at autopsy in a supine body, compared with their position in the living body in the upright posture.
In the chest and abdomen, visceral relationships vary with the stage of respiration.
Apart from bone or calcified cartilage, the tissue most
resistant to knife penetration is the
followed by muscle where large muscle bundles underlay the fascia.
sharpness of the extreme tip of the knife
is the most important factor in skin penetration. The cutting edge of the knife, once the tip has penetrated, is of relatively minor importance.
is easier to penetrate than lax skin e.g: chest wall
Uncalcified cartilage, especially that in the costal cartilages of young and middle-aged persons, is easily penetrated by a sharp knife, Calcified rib and bone provide a much more resistant barrier, but a forceful stab from a strong, sharp knife can penetrate rib, sternum or skull.
INJURIES FROM SCISSORS
Stabbing by a pair of scissors is not uncommon (familiar, near to hand).
The appearances of the wound will differ according to whether the scissors were used open or closed.
If open and one blade is stabbed into the victim, then the appearances will be virtually indistinguishable from a knife wound.
The skin wound made by closed scissors is typically shaped like a flat ‘Z'.
Sometimes, there are small lateral splits in the wound centre from a projecting hinge screw.
Chop wounds are produced by
heavy instruments with a cutting edge
, e.g., axes, meat cleavers.
The presence of an incised wound of the skin, with an underlying comminuted fracture or deep groove in the bone, indicates that one is dealing with a chopping weapon .
Usually the lower end (heel) of the axe strikes the surface first, produces a deeper wound than the upper (toe) end.
so, deeper end indicates the position of the assailant.
These are wounds produced by medical personnel during the treatment of a patient.
Common examples are thoracotomy incisions, laparotomy incisions.
Some of these surgical wounds may be mistaken for primary traumatic injury.
Occasionally, a homicidal stab wound is converted to a therapeutic use, e.g., a surgical drain might be placed into the chest cavity through a stab wound of the chest.
To avoid misinterpretation of therapeutic wounds, the
chart should be reviewed
prior to autopsy and, if any questions arise, the treating physicians should be consulted.
In assaults of any kind, the natural reaction of the victims is to protect themselves.
The limbs used for protection can be injured and these defence wounds may be of considerable medico-legal significance,
as they indicate that the victim was conscious
, at least partly mobile and not taken completely by surprise.
The classic position for them is on the
Other defence injuries may be inflicted on the
, when attempts are made to shield the genitals.
with attacks from
instruments or fists,
are the hallmark of defence attempts.
The most obvious defence, injuries are seen in
, as the victim often attempts to ward off the thrusts
by seizing the weapon.
When the fingers are closed around the blade, its withdrawal cuts across the flexures of the phalanges, slicing through the skin and perhaps tendons, or sometimes all four fingers.
Other knife wounds can be on the backs of the hands or fingers or forearm from nongrasping movements trying to ward off the weapon.
SURVIVAL PERIOD AFTER WOUNDING
The victims can do far more than might be expected after injury Bcuz of the adrenaline response of
'fight or flight'.
A cut artery will lose blood faster than a vein of the same general size.
Wound in right ventricle more fatal than in left ventricle.
Other factors, such as the possibility of
occurring in a cut jugular vein, might alter the usual pattern of expected events.
Spitz and Fisher's Medicolegal Investigation of Death
Knight’s forensic pathology
DiMaio forensic pathology , text and handbook
Dolinak's Forensic Pathology: Principles and Practice
Simpson’s forensic medicine
Color Atlas of Autopsy
Color atlas of forensic pathology
It means any injury where there is breach of natural continuity of skin or mucous membrane.
In medico-legal practice, wound will include any lesion, external or internal, caused by violence , with or without breach of continuity.
The keratinized dead layer of cells, the stratum corneum, which varies in thickness, that has a forensic relevance in the amount of injury that is needed to penetrate the skin and allow bleeding from the underlying tissues.
The living layers of the skin combines of :
- The Epidermis, (corrugated, has papillae)
- The Dermis consists of c.t carrying the skin adnexae, rich network of blood vs, lymphatics and nerve endings.
The subcutaneous layer (hypodermis) composed of fat and connective tissue.
Other ways in which the transfer of kinetic energy may be modified is in
the body in the direction of the force, ex꞉: boxer 'rides the punch'.
With a high-speed impact, such as a – bullet , stab or violent blow - the
of the victim's body prevents any significant loss of energy transfer by movement.
Another general scheme of classification is ..
, is a term commonly used to describe a scraping injury over a large area of the body (back), such injury when dry it will be very firm .
(graze or sliding abrasions)
are seen in pedestrians who slide across the pavement after being hit by motor vehicle.
linear abrasion known as the scratch
The blunt object scrapes off the superficial layers of the skin, leaving a
these abrasions may be fairly deep, extending down to the dermis. there may be leakage of fluids with deposit of a serosanguineous fluid on the surface of the abrasion, This dries, forming the familiar
Impact ( crushing / pressure) abrasions
The blunt force is directed perpendicular (vertical) to the skin, crushing it.
Seen overlying bony prominences where a thin layer of skin covers bone.
Impact abrasions over the supraorbital ridge and zygomatic arch are commonly seen when the individuals collapse, and strike their heads on the ground.
A contusion at a site does
necessarily indicate the point of trauma, since soft tissue bleeding will follow the path of
In other instances, deep bruises may not become visible externally until hours after death.
" delayed Bruises"
of a bruise, does not indicate that there was
no blunt force
to that area, This is especially true of the anterior abdominal wall, where there may be massive internal injury in the absence of external evidence of trauma.
Bruises can also be difficult to detect in dark-skinned individuals.
Children and the elderly bruise more easily because of
loose delicate skin and loss of subcutaneous supportive tissue.
seem to bruise more
, While well-conditioned muscular individuals are more resistant to bruising.
Soft, lax, vascular tissue, such as in the eyelid, is more susceptible to bruising than areas such as the palm.
Diseases and Drugs :
Alcoholics with cirrhosis, individuals with bleeding diatheses, and individuals taking aspirin bleed more easily.
: aspirin ( 7-d )
Certain factors influence the size and the
prominence of a contusion:
Not uncommonly, the color change goes directly from violet to yellow with no green coloration.
Unfortunately, the rate of change is quite variable, not only between persons, but in the same person and from bruise to bruise.
Contusions can be produced postmortem if a severe blow is delivered to a body within a few hours of death.
The blow can rupture capillaries, forcing blood into the soft tissue and producing a postmortem contusion
identical in appearance to an antemortem contusion.
This is partially caused by continued bleeding from the ruptured vs.
Another factor may be
, when the free hemoglobin is able to stain the tissue in more diffuse way and become more noticeable than intact red blood cells.
This is the reason not only for the well known post-mortem phenomenon of bruises becoming more prominent after death , but of new bruises appearing later.
An avulsion or avulsive injury is a form of laceration.
The essential feature of all incised wounds is
the clean division of the skin and underlying tissues
so that the margins are almost free from any damage (Microscopically there is always a narrow zone of injury, but this is minimal compared with the tissue destruction caused by blunt injury).
in the depth of the wound will occur.
Suicidal incised wounds
are generally inflicted on those parts of the body most accessible to the victim.
The victim may
the portion of the body to be incised.
Fatal incised wounds of the arm (wrists, antecubital fossae ..)
unless the scene indicate an accidental manner.
Right handed individual tend to cut his left wrist or arm and vice versa, cuts can be on both sides.
In self-inflicted incised wounds, one will often find
, these are superficial incised wounds adjacent to, a continuation of, or overlying the fatal incised wound.
are extremely rare.
( in one case, a 13-year-old male was struck by flying glass when a bottle containing dry ice exploded, the fragment of glass severed his left jugular vein).
The nature of the stabbing weapons
Blunt end of the wound may have small
splits in the skin
, forming the so-called
Determination of Whether a Wound is Ante- or Postmortem ..!?
The presence of bleeding into the tissue !!
Microscopic examination of the injury in search of an inflammatory reaction. !!
Techniques to identify antemortem injuries involving use of histochemistry, enzymology and biochemistry have been developed.
In addition to enzymes, other markers such as vasoactive amines and catecholamines have also been used.
Thus, histamine and serotonin are both increased in antemortem.
Dating of Abrasion
Bright red , oozing of serum and some blood.
Exudation dries to form a reddish scab Composing of blood, lymph, and epithelial cells, polymorphonuclear cells
Scab is dark brown
Scab is brownish black and starts falling , epith. grows from the margins ( epith. regeneration)
Scab dries, fall off , the area under getting pigmented ( subepidermal granulation)
Epith. become thinner and atrophic, new collagen, less vascularity ( regression).
wrinkled wounds are
produced where the
more than one
incised wounds may seen.
The pattern of arrangement of the dense network of intimately intermingled
dermal collagen and elastic fibres
is called the
lines of cleavage
of the skin and their linear representation on the skin are called
Depth and Direction :
at the commencement,
this known as
head of the wound;
towards termenation, the cut become
, known as
tailing of the wound
so, depth of the incised wound with tailing will suggest the direction in which the force was applied.
Other knife-like weapons include scissors, dagger, piece of glass, screwdrivers, pens, icepicks and fork.
weapon enters into the body cavity produce only one wound (wound of entry).
weapon after entering into body will come out through the other side, producing two wounds (entry and exit).
edges of the wounds are
usually no abrasions or bruising of the margins but in full penetration of the blade, a
patterned abrasion or bruising produced by the hilt-guard striking the skin.
However, injuries caused by pointed instruments have lacerated edges.
Direction of a stab wound
Defense wounds are absent if the victim is :
- Taken by surprise
- Attacked from behind
- Under the influence of alcohol /Drugs.
Terminology dilemma !
is an injury to the skin in which there is removal of the superficial layer of the skin by friction or sliding motion against a rough surface, or by compression.
infrequently can involve subQ. tissue, ms', even bone.
Antemortem abrasions appear
Abrasions produced after death are
and translucent with a
"all wounds are injureis ;
but not all injuries are wounds."
So; why abrasion bleeds/scars
Heaped up tags and direction !?
"Blunt force is probably the single most common type of trauma"
"Blunt force injuries are possibly the most common
injuries documented and interpreted by forensicذpathologist"
The duration of the healing process depends on :
- extent of the injury
- presence of 2ry infection
- reeated trauma to the same area
Black eyes " Raccoon eyes"
CLASSICAL PATTERNS OF BRUISING
Tramline bruising "railway appearance"
occurred by a
rod shaped weapon or stick
Compression of vessels centrally, not usually damaged unless crushed onto bone. Traction causes rupture of vessels along edges of rod.
Finger pad bruises
are round or oval,
Due to gripping by fingertips in forceful restraint
Found on -
limbs and face
(throttling (manual strangulation)),
(forceful restraint or post mortem movement of the body).
Patterned Intradermal bruise
Due to impact with a hard, patterned object with ridges/grooves.
Skin over ridges is compressed and vessels remain intact; and skin forced into grooves and dermal vessels ruptured.
The resulting accumulation of a small amount of blood, near the epidermis may demonstrate
the obvious pattern of the causal surface
(tyre, shoe tread, car bumper, clothing, gun muzzle)
Kicking (or shod foot assault)
Stamping, jumping may reproduce the pattern of the sole
Glancing kick may cause a scuffed abrasion
Typical target sites:
face, neck, loin, groin, back, chest
. Associated internal injury and fractures is often severe.
Battle sign :
represents ecchymosis around the mastoid process from head trauma that has caused a temporal bone fracture.
Deep bruises may not be visible externally and may be discovered only on
the soft tissue.
fist blow to orbit
fractured skull (R.T.A., gunshot, fall)
tracking from forehead bruise.
or flying injury
or grinding compression
Teeth marks may be abrasions, bruises or lacerations, or a combination.
is deeply arched or 'U-shaped'.
is near circular or shallow oval
Size -indicates whether inflicted by an adult or child
Human bite may present as a series of separate bruises with central linear abrasions or a continuous, curved line of bruising. The mark may represent only part of the dental arcade
Allows comparison with suspect, Early expert dental opinion and photographs required;
When fresh, may provide useful evidence of asssailant's identity
Seen on breasts, neck, thighs, abdomen and vulva in
. Any site in child abuse.
Self-inflicted (fabricated assault, psychiatric). Accessible!
incise looking wounds !!
No pattern can be distinguish from lacerated wounds ..
hammer , pistol whipping ?!!
a flexible strap or flex will wrap around the convexity producing a longer and often curved tramline bruise.
or road rash
Other damage may caused following autopsy, even the normal procedure of post-autopsy reconstruction and handling in the mortuary may cause dermal damage.
till 3 days
brownish due to hemosidein
green due to
Patterned injuries (abrasions and intradermal bruising) following pedestrian impact by the radiator grill of a vehicle.
PATTERNED BRUISE – INTRADERMAL BRUISING CAUSED BY STAMPING ON BACK WITH TEXTURED CLOTHING INTERVENING.
can we see patterned in laceration ?!
A variation of an avulsive laceration is one produced by shearing forces,
where the skin shows no signs of injury but the underlying soft tissue has been avulsed from the underlying fascia or connective tissue, creating
a pocket that may be filled with a large quantity of blood
. This injury is occasionally encountered on the backs of the thighs of pedestrians struck by motor vehicles.
Self-inflicted/ self suffered wounds are those inflicted by a person on his own body or by another With his consent.
Fabricated wounds are mostly
, and sometimes contusions, stab wounds and burns.
Incised wounds are usually superficial, multiple and parallel.
Location is easily reachable, the clothes are not cut and if cuts are seen they are not compatible with the nature of the wounds. The history of the assault is incompatible with the injuries.
Fabricated wounds (fictitious, forged or invented wounds)
They may be produced for the following reasons :
1) To charge an enemy with assault or attempted murder.
2) To make a simple injury appears serious.
3) By the assailant to pretend self-defense.
4) In thefts by servants or messengers for the above reason.
6) By prisoners, to bring a charge of beating against officers.
7) By recruits to escape military service.
8) By women to bring a charge of rape against an enemy.
parallel wound !?
transverse or oblique wounds ?!
what will happen with ?
Points of deffreentiation between sucidal & homicidal
weapon at site
It is not safe to find out the depth of a stab wound by introducing a probe, because it may disturb a loose clot and may lead to fatal hemorrhage, or cause serious damage and may produce multiple false tracks.
its indicated by the track of the wound but evidence of undercutting - if present- will give an idea about the direction.
Therapeutic or Diagnostic Wounds
Incised wounds of the neck can be
Homicidal incised wounds of the neck present two different pictures, depending on whether they are
produced from the back or the front
which tend to be
short and angled.
Most commonly, a person’s throat is cut from