Medico-Legal Investigations

Bruising

Definition

 Bruising is caused when an impact damages blood vessels such that the blood leaks into the perivascular tissues, and is evident on the skin surface as discoloration.

– Could be in skin (external bruising), muscles, or internal organs (internal bruising)

  Initial color of the bruise is the product of natural skin pigment , the color of pigment in the extravasated blood and any color added by the inflammatory reaction.

Such discoloration changes in color, shape and location as the blood pigment is broken down and resorbed.

  In some cases although blood vessel may be damaged, there may be no visible evidence on the skin.

In certain cases, it may take hours or days for a bruise to become apparent (as the blood diffuses through damaged tissue)

 A study (Langlois & Gresham1991) concluded that it was only possible to state that a bruise with a yellow color was more than 18 hour old and that the colors red, blue and purple/black could occur anytime within 1 hour of bruising to resolution (up to 21 day in the study)  The color of a bruise is further confused by the fact that many bruises exhibit multiple colors at the same site despite being caused at the same time.

Bruise after I.V injection taken 24 hours after injection

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The site of bruising doesn’t necessarily reflect the site of trauma because blood tends to spread out in diffused manner from the site of injury, for example a deep bruise in the mid thigh may later appear at the knee and a black eye may be to high scalp ( intra dermal bruises provide an exception to this rule )

Color changes in bruising

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Dark red. less than 24 hours

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Dusky purple.

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Brown. From 1-3 days

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Green. 3 to 5 days

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Yellow.5 to 7 days

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Straw.

-These changes give only a rough estimation of the bruise.

Factors that affect the appearance of a bruise

 The severity of the force applied to the area.

Factors that affect the appearance of a bruise

 Site The connective tissue support at the site of injury • increased extravasation of blood occurs around lax, loose areas of skin such as the eye.

The soft parts vs. areas underlying bones • Soft parts of the body e.g. abdomen rarely have visible bruising. those areas with underlying bone are more likely to bruise easily (e.g. limbs,scalp)

Factors that affect the appearance of a bruise

 Conditions that affect the fragility of blood vessels.

 Conditions which slow or prevent blood clotting Including :  underlying disease (e.g.hemophilia)  drugs (anticoagulants, aspirin, steroids)  Age Advanced age may predispose to an increased tendecy to bruise, as will as relatively young age.

Factors that affect the appearance of a bruise

 Alcoholism  Hepatobiliary dysfunction If necessary, clotting studies or liver function test should be undertaken.

 Skin color Bruising is more visible in pale skin.

 Gender. (Females more)  Obesity. (more in obese)

Blunt Trauma Wound

 Fresh Bruises & Trauma: – Age and color a bruise presents depends on certain factors – Bruises can vary in color (depending on person)   Age (Children and elderly bruise easier) – A bruise can appear or disappear depending on: Oxygen levels          Blood pigment & breakdown of hemoglobin Physical Health Antemortem Localized area of injury Cancer leukemia Scurvy Aspirin Anticoagulants (cumadine, heparin, warfarin, etc.) Temperature Hemophilia

Blunt Trauma Wound

 Dating Contusions: – This is not an exact science  Hemosiderin in macrophage  Bruises usually follow a color pattern but not always – Reddish-purple or bluish-purple to violet, green, dark yellow to greenish-yellow and then disappears – The edges of the bruise have the oldest colors

Can you Differentiate Ante- and Postmortem Contusions?

  Yes, Ante mortem – Swelling present – Color change – Not washable – More tissue infiltration (diffuse)

Blunt Trauma Wound

 Bruising – May take minutes to days to present  Take photograph incrementally during this time – Bruises can mask natural color – Estimation of age of bruise can be difficult after death

BFT

BFT

Types and patterns

Hand marks  Finger bruises consisting of circular or oval bruises from squeezing, poking, gripping or grabbing injuries.

Upper arm of a male who was gripped hard.

Sometimes clean pattern of four-finger or Fingertip bruises and a thumb bruise on the Opposite side of the arm may be seen.

In this case, abrasions are also evident From fingernail scratches.

 Artist’s impression of grip marks such as may be present when a young child has been gripped and force fed.

Note the round thumb imprint on one cheek with 3 or 4 finger-tip bruises on the other.

You should also examine for intra-oral injuries.

Types and patterns

Hand marks   Linear petechial bruises in the shape of a hand caused by capillary rupturing at the edge of the injury from high velocity impact of the hand slap.

Note the parallel lines of petechial bruising at finger-width spacing, the marks appearing in the gaps between the fingers

Types and patterns

Hand marks  Pinch marks consisting of paired, crescent-shaped bruises separated by a white line .

Pinch mark on the leg of a 7-year-old boy at a site where accidental bruising is unlikely.

Note the two small bruises separated by a clear space

Types & patterns of bruises

Implement marks



High velocity impact

causing a rim of petechiae outlining the pattern of the inflicting instrument.  E.g. parallel sided marks for sticks >> “tramline bruising”

Mechanism:

it is caused by the impact of a cylindrical solid subject (e.g. baseball bat). The strike of the cylinder expels blood from the center into small vessels, either side of the point of impact, which rupture and extravasate blood.

Is a specific of bruising represented by 2 linear bruises with a line sparing between them centrally.



Higher velocity impact

causes bruising underlying the injury in the shape of the object used. E.g. wedge-shaped bruises from kicks with shoes.

Demonstrates a right flank bruise in a 60-year-old man who died of an acute MI 20 minutes after being hit with a baseball at a game.

Illustrates a densely hemorrhagic nature of the affected area and the distinct margins between the affected and normal areas.



Pressure necrosis of the skin

from ligatures, causing well-demarcated bands partially or fully encircling limbs or the neck.

Types and patterns

Implement marks 

Coarse speckled (intradermal) bruises

from impact injuries through clothing. They lie just beneath the epidermis in the corium and are well defined.

These bruises may give an indication of the pattern or shape of either the impacting object, or something lying between the impacting object and the skin.

The next figure shows an example of a bruise which is patterned of textile material.

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Petechial bruises Pinprick bruises from ruptured capillaries e.g. suction bruises, squeezing, slapping, strangulation, and suffocation

Some bruises caused by suction or biting, the classic “lovebite” tends to be uniform of color , (as the suction force applied is similar over the area of suction and ovoid in shape ).

Location is often on the neck but may be elsewhere in the body.

Typical features of accidental injuries

Sites more commonly associated with non-accidental injury



Facial

: soft tissues of cheek, eye, mouth, ear, mastoid, lower jaw, frenulum and the neck.



Chest wall



Abdomen



Inner thighs and genitalia

abuse.

strongly associated with sexual 

Buttocks and outer thighs

punishment injury.

commonly associated with 

Multiple sites

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Typical features of non-accidental injuries (injuries that should raise concerns)

Differential Diagnosis of Bruising

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Accidental injury : commonly on bony surfaces.

Artifact : dirt, paint, felt tip, dye from clothing or footwear.

Benign tumors : halo nevus, blue nevus, hemangiomas.

Vascular and bleeding disorders : thrombocytopenic purpora, HSP, hemophilia, purpora in association with infection, e.g. meningococcal septicemia.

Disturbances of pigmentation : café-au-lait patches, mangolian blue spots Erythamtous lesions: erythema nodosum Hereditary collagen disorders: osteogenesis imperfecta, Ehlers-Danlos syndrome.

Medico-legal importance

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Age of injury.

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Degree of violence.

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Different colours in the same victim are important especially in child abuse.

What are the Diagnostic Features of Lacerations?

     Bridging Abraded Edges Edges irregular Contusions at edges Hair crushed

Blunt Trauma Wound

 Lacerations (Tears): – Tears in the skin due to pressure (BFT) are called lacerations – Lacerations are distinguished from incisions by “bridging” – Lacerations may or may not imprint the object used to create BFT – There may be no external signs of injury but avulsions may occur

Blunt Trauma Wound

 Lacerations – The wound usually has ragged or abraded edges – Wound margins are irregularly shaped – BFT injuries often contain evidence (trace) embedded in wound  Paint, bark, fibers, grease, metals, rubber, etc.

– May be scrapes and bruising around the wound as well

Blunt Trauma Wound

BFT

BFT

BFT

Blunt Trauma Wound

 Defense Wounds due to BFT – Mainly abrasions and contusions  On back of hands, wrists, forearms

Blunt Trauma Wound

 Fractures of Bone – Can determine “directionality” of the impact – Can present as clear breaks – Can present as compound fracture – Can present as hair-line fracture

Blunt Trauma Wound

 Fractures of the Extremities – Direct Force  Blunt object impacts a long bone causing breaking of the bone on the opposite side of impact  May be crushing on side of impact if force is great enough

Blunt Trauma Wound

 Direct Force – Penetrating Fractures  Large force acting on a small area – Gun shot wounds – Focal Fractures  Small force on a small area – Bat or pipe

Blunt Trauma Wound

– Crush Fractures  Large force over a large area – Motor vehicle (bumper fractures)

Blunt Trauma Wound

 Indirect Force – Produced by a force acting at a distance from the fracture site

Blunt Trauma Wound

 Indirect Fractures – Traction Fractures – bone is broken by a violent contraction – Angulation Fractures – bone is twisted (spiral fracture) – Verticle compression Fractures – oblique fracture of long bones

BFT

Case Study

 An elderly woman was discovered lying on her back in her sewing room. Rigor mortis was in its early stages. A prominent amount of blood was covering her face. At autopsy there were red-blue contusions to her chest and right side with associated lacerations of the spleen and liver. After washing her face, a patterned contusion of the left cheek was noted resembling a heel mark from a shoe or boot. There was no significant head trauma.

Case Study

  Numerous photographs of the facial contusion was taken. Within hours of the autopsy, a suspect was apprehended. He was present in the neighborhood the last day the woman was seen alive. He was wearing tennis shoes which the authorities confiscated for testing. Fingerprint powder was dusted on the soles.

Case Study

 A transparency print was made, and the transparency was placed over the photograph of the facial wound. A criminalist determined the comparison was a positive match and the pathologist agreed. On the basis of these examinations the suspect was indicted. No other incriminating evidence was found against him. Should these interpretations have been made? Was there enough information to indict? If not what other evidence would you want them to collect?

Case Discussions

 The approach by both the pathologist and criminalist were sound. Both looked at the shoes, transparency and photograph of the wound to make comparisons. A mark on the face can be matched with an offending weapon if the pattern is distinct. In this case, both examiners thought the match was perfect because the marks on the face corresponded to the depressed areas of the heel of a shoe.

Case Discussions

 Matching patterns on a body with objects that may have inflicted them is an important part of examining injuries caused by blunt trauma. These patterns, however, cannot be used to determine whether a specific weapon inflicted injury.

Case Discussions

 At best one can determine that a weapon of similar dimension caused damage. Although patterned injuries on the body are not commonly matched to a particular weapon, there may be other material transferred from a victim to a weapon such as hair, fibers and blood. Thus, the examination suggested that the mark was made by a boot with a certain type of sole.