1. Medico-Legal Investigations
Bruising

2. What is a Contusion?
Bleeding under intact skin due to heavy blunt instrument
Hemorrhage into the skin, the tissues under the skin or both
Caused by crushing or squeezing of tissue

3. 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)

5. 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.
Changes in color, shape and location of the blood as the pigment is broken down and resorbed.
In some cases although blood vessels 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)

6. Extravasated blood will follow the path of least resistance and seep along natural or traumatic planes of cleavage of the tissues under the influence of gravity and body movements.

8. One 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.

11. Bruise after I.V injection taken 24 hours after injection

12. 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 high on the scalp (intra-dermal bruises provide an exception to this rule)

13. Color changes in a bruise:
1st day- red
2nd day- 3rd day -bluish
4th day- brown day(hemosiderin)
5th-6th day- green(hematoidin = bilirubin)
7th-12th day- yellow(biliverdin)
13th-15th day– normal
These changes give only a rough estimation of the bruise.
Biliverdin is a green tetrapyrrolic bile pigment, and is a product of heme catabolism
Hematoidin or bilirubin yellow breakdown product of normal heme catabolism.

14. Factors that affect the appearance of a bruise
 The severity of the force applied to the area.

15. 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)

16. 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.

17. Factors that affect the appearance of a bruise
 Alcoholism
 Hepatobiliary dysfunction
 Skin color
Bruising is more visible in pale skin.
 Gender. (Females more)
 Obesity. (more in obese)

18. 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

19. 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
Hemosiderin often forms after bleeding (hemorrhage).[1] When blood leaves a ruptured blood vessel, the red blood cells dies, and the hemoglobin of the cell is released into the extracellular space. White blood cells called macrophages engulf (phagocytose) the hemoglobin to degrade it, producing hemosiderin and biliverdin.

20. Can you Differentiate Ante- and Postmortem Contusions?
Yes,
Ante mortem
Swelling present
Color change
Not washable
More tissue infiltration (diffuse)

21. Can you Differentiate Ante- and Postmortem Contusions?
Antemortem
Swelling present
Color change
Not washable
More tissue infiltration (diffuse)
Postmortem
Not present

22. 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

23. Deep bruises may require as long as 12 or 24 hours to become apparent
some may never do so.
In a living victim, a second examination after an interval of one or two days may disclose bruising where previously there had been only swelling or tenderness on pressure.
In the dead, a further examination one or two days after the original autopsy may disclose bruises which were not previously evident
Revealing more distinctly bruises which previously appeared faint.

26. Blunt Trauma Wound Bruising Bruises can formulate easier in:
Loose tissue
Fat
Older adults and/or children
Women (less muscle mass)
Disease of the vascular system

27. Types & patterns of bruises
Hand marks
Finger
Linear petecheal
Pinch marks
Implement marks
High velocity
Higher velocity
Pressure necrosis
Coarse speckled bruise

28. 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 a clean pattern of four-fingers 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.

29. Grip marks Note the round thumb imprint on one cheek
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.

30. 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

31. 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

32. High Velocity Impact Implement marks
Causing a rim of petechiae outlining the pattern of the inflicting instrument.
E.g. parallel sided marks by a stick
“tramline bruising”
Mechanism: it is caused by the impact of a cylindrical solid object (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 represented by 2 linear bruises with a line spacing between them centrally.

33. Higher velocity impact
Implement marks
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.

34.  Pressure necrosis of the skin Implement marks
From ligatures, causing well-demarcated bands partially or fully encircling limbs or the neck.

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

36. 5 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.

37. Typical features of accidental injuries

38. 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 strongly associated with sexual abuse.  Buttocks and outer thighs commonly associated with punishment injury.  Multiple sites.

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

40. Differential Diagnosis of Bruising
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.
Halo nevi are common benign skin lesions that represent melanocytic nevi in which an inflammatory infiltrate develops, resulting in a zone of depigmentation surrounding the nevus.
Blue nevus (also known as "Blue neuronevus," "Dermal melanocytoma," and "Nevus bleu"[1]) is a type of melanocytic nevus. The blue color is caused by the pigment being deeper in the skin than in ordinary nevi.
A hemangioma is a benign and usually self-involuting tumor (swelling or growth) of the endothelial cells that line blood vessels
Erythema nodosum (EN) is an inflammatory condition characterised by inflammation of the fat cells under the skin
Ehlers-Danlos syndrome – a connective tissue disorder

41. Medico-legal importance
Age of injury.
Degree of violence.
Different colors in the same victim are important especially in child abuse.

42. 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

43. What are the Diagnostic Features of Lacerations?
Bridging
Abraded Edges
Edges irregular
Contusions at edges
Hair crushed

45. Blunt Trauma Wound Lacerations
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

46. Laceration of the liver

47. Is This a Blunt Trauma Wound?

48. Is This Wound Due To BFT?

49. BFT

50. BFT

51. Blunt Trauma Wound Defense Wounds Due to BFT
Mainly abrasions and contusions
On back of hands, wrists, forearms

53. Blunt Trauma Wound Fractures of Bone
Can determine “directionality” of the impact
Can present as clean breaks
Can present as compound fracture
Can present as hair-line or stress fracture
Compound - a broken bone in which a part of the bone sticks out through the skin.
Stress Fractures - Caused by application of repetitive strain and excessive training, hairline fractures are minute cracks on the bones,
a hair line fracture is where the bone is broke but not separated
Clean Break - A non-displaced fracture
A non-displaced fracture is one where the bone breaks but keeps alignment.

55. Hairline Fracture

56. Compound Fracture

57. Blunt Trauma Wound Fractures of the Extremities Direct Force
Bone is broken at the area of impact
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

58. Penetrating Fractures
Large force acting on a small area
Gun shot or blast wound

59. Penetrating Fracture

60. Focal Fractures
Small force on a small area - Bat or pipe

61. BFT

62. Crush Fractures
Crush fractures in long bones result from a compression force that is applied transversely with respect to the long axis of a bone.
For non-long bones, the axis of compression could be from any direction.
The spine is a special case.

63. Blunt Trauma Wound Indirect Force
Bone is broken in an area away from the point of impact.
The force is transferred from the point of impact then along the limb until the force comes across a weak bone or a weak spot in a bone.
Produced by a force acting at a distance from the fracture site

64. Blunt Trauma Wound Indirect Fractures
Traction Fractures – Bone is broken by a violent contraction

65. Angulation Fractures
Bone is twisted (spiral fracture)

66. Vertical Compression Fractures
Oblique fracture of long bones