Forensic medicine INJURIES for mbbs.pptx

Seminar

1. INJURIES DEFINITIONS: INJURY: Any harm whatever illegally caused to any person , in body , mind , reputation or property. (S-44 IPC) WOUND: A break in the natural continuity of any of the tissues of living body.

2. TRAUMA: Trauma is an injury inflicted by force on a living tissue. MECHANICAL INJURIES: These are injuries produced by physical violence. HURT: Hurt means bodily pain, disease or infirmity caused to any person. (S-319)

3. CRIMINAL FORCE / BATTERY: Use of force on another person to cause injury , fear or annoyance. (S-350 IPC) ASSAULT: Making a gesture so that other person believes he is going to use criminal force on him. (S-351 IPC)

4. CLASSIFICATION OF INJURIES MEDICAL CLASSIFICATION: D octors when communicating among them selves would refer to this classification. (1)-Mechanical injuries. (a)-Due to blunt force. ( i )- Abrasions. (ii)-Contusion. (iii)-Laceration. (iv)-Fracture and dislocation.

5. (b)- Due to sharp force: ( i )- Incised wounds. (ii)-Chop wounds. (iii)-Stab wounds. (c)- Due to firearm. ( i )- Fire arm wound.

6. (2)-THERMAL INJURIES: (a)- Due to cold ( i )-With tissue freezing. -Frost bite. -Frost nip. (ii)-Without tissue freezing. -Trench foot. -Chilblains.

7. (b)- due to heat. ( i )-Burn. (ii)-Scald. (3)-CHEMICAL INJURIES: (a)-Due to corrosive acids. (b)-Due to corrosive alkalis. (c)-Due to corrosive salts.

8. (4)-PHYSICAL AGENTS: (a)-Electricity ( i )-High tension. (ii)-Low tension. (b)-Lightning. (c)-X-rays. (d)-Radioactive substances. (5)-EXPLOSIVE INJURIES.

9. LEGAL CLASSIFICATION: Court would generally follow this classification. (1)-Hurt (u/s 319 IPC) (2)-Grievous hurt (u/s 320 IPC) MEDICO-LEGAL CLASSIFICATION: D octors when advising in court would follow this classification.

10. (a)-Suicidal injuries. (b)-Homicidal injuries. (c)-Accidental injuries. (d)-Self inflicted injuries. (e)-Defense wounds. (f)-Iatrogenic injuries.

11. ABRASIONS DEFINITION: An abrasion is a destruction of the skin , which usually involves the superficial layers of the epidermis only. OR Removal of the superficial epithelial layer of the skin, usually epidermis, by fraction against rough surface.

12. OR An abrasion is an injury involving destruction of epidermal layers of the skin and dermal papillae. SALIENT FEATURES: -Force (Tangential / Perpendicular). -Healing (With out scaring./superficial scar). -Weapon (Rough surface). -Wet skin (Difficult to see).

13. TYPES OF ABRASIONS: 1-Scratch abrasions. 2-Graze abrasions. 3-Pressure abrasions. 4-Impact abrasions. SCRATCH ABRASIONS: Scratch abrasions (linear abrasions/scrapes) are abrasions with appreciable length but no significant width.

14. Salient features: -Produced by -sharp, pointed objects such as finger nails/pins and thorns. -Tip of knife/razor - point scratches. -Nails - semilunar abrasions. -Direction - heaped up in the direction of movement.(epithelial tag).

15. GRAZE ABRASIONS. (Grinding/scraping /glancing/sliding abrasion) They occur when there is movement between the skin and rough surface in contact with it. I t comprises of innumerable scratch A. Salient features. - Most common A. -Longitudinal ,parallel lines with heaped up epithelium at one end. EXAMPLES: Brush burn,friction burn,gravel burn,roadrash .

16. PRESSURE ABRASIONS. (Crushing / friction abrasions). Produced by crushing of epithelium,when a relatively small force is applied perpendicularly to the skin for a long period of time. EXAMPLES : Corneal abrasion by contact lens. Nappy A, Ligature mark in hanging,Shoe bite, Teeth bite mark.

17. IMPACT ABRASIONS. (Contact A / Imprint A) These are abrasions produced by crushing of epithelium , when a relatively large force is applied perpendicularly to the skin for a short time period. SALIENT FEATURES : S lightly depressed. There is underlying bruise.solid object produce abrasion at periphery. EXAMPLES: Radiator grill mark, Muzzle impression. Sole impression and Tire marks.

18. PATTERNED ABRASION: Patterned abrasions are special type of pressure and impact abrasions, where by the pattern of the object causing them is faithfully reproduced on the skin, helping in identification. EXAMPLES: Bicycle chain mark,cat -o-nine tail serrated knife, shoe sole, electric wire/rope pattern.

19. AGE OF ABRASIONS: Abrasions heal from periphery to centre. Age of abrasion can be determined by: -Gross examination. -Microscopic examination. GROSS EXAM: Fresh - Bright red. 1 day - Blood and lymph dries up. Bright red scab.

20. 2 - 3 days - Reddish brown scab. 4 - 5 days - Scab becomes dark brown. Epithelium grows below scab. >7 days Scab dries, shrinks and falls off. Leaves de-pigmented area Which gets pigmented.

21. MICROSCOPIC (HISTOLOGICAL) EXAM: - 4 to 6 hr Cellular infiltration. - 12 hr Three layers are seen: -Surface layer (fibrin +RBC). -Middle layer (polymorphs). -Deep layer (collagen). - 48 hrs -Scab well formed. -Epithelial regeneration.

22. 4 to 5 days Small - covered by epithelium Large - takes 5 to 7 days and heals by granulation tissue. 8 days Reticulum fibres appear. 9 to 12 days Collagen fibres appear. > 12 days Regression starts. Remodeling occurs. Becomes thin.

23. POST MORTEM ABRASIONS: Instances- -When dead body is dragged. -Dead body thrown in water. -Dead body is eaten/scratched by animal. Differentiation difficult because: -Superficial in nature. -In decomposed bodies. -In burn cases.

24. DIFFERENCE - AM AND PM ABRASIONS: Feature AM PM Site Any where Bony part. Colour Bright reddish Yellowish Brownish Parchment like Exudation More Less Raised Depressed Microscopic Vital reaction+ No vital reaction

25. DIFFERENTIAL DIAGNOSIS: -Burns -Erosions produced by ants. -Excoriation of skin by excreta. -Drying of skin. -Pressure sores

26. MLI OF ABRASIONS Direction of force. Force of impact. Foreign matter sticking to abrasion. Important and only sign. Manner of production. Nature of injury - simple. Time of assault. Type of offence and weapon of offence.

27. CONTUSIONS (BRUISES) DEFINITION: A bruise is an effusion of blood into the tissues underneath the skin, due to rupture of blood vessels - arterioles, venules and veins. OR A bruise is an effusion of blood into the tissues, due to rupture of blood vessels - veins, venules and arterioles.

28. OR Bruise is the extravasation of blood in the subepithelial / subcutaneous tissues due to rupture of blood vessels usually capillaries as a result of blunt force injury or pressure.

29. When the effusion of blood is in other tissues and organs (muscles , lung, heart spleen) it is called a contusion. FEATURES: site - Situated in dermis, subcutaneous tissues and sometimes in fat layer. colour -lighter in the center than periphery. caused by - Hard and blunt force.

30. Associated findings - -Tenderness. -Crushing or tearing of s/c tissues. -No destruction of skin. -May be along with abrasion/laceration. -With abrasion - abraded contusion. -When contusion dominant-contused A.

31. Size - Petechial hemorrhages - 0.1 to 2 mm. - Ecchymosis - 2 to 5 mm. -Bruise - > 5 mm -Hematoma - > 5 mm with swelling. fluctuant. can be aspirated.

32. SHAPE -Does not correspond to weapon. -Usually larger than weapon(bleeding). -Dough nut like look. MARGINS - Blurred. EXTENT - Proportionate to force. DIFFERENCIAL DIAGNOSIS – mongolian spot

33. CLASSIFICATION OF BRUISE: 1- Intradermal bruise (located in dermis, bleeding less ,pattern distinct) 2- Subcutaneous bruise(located in s/c tissue most common bruise, appear immidiately ) 3- Deep bruise (located deep in s/c tissue, appears after some time)

34. FACTORS MODIFYING SIZE AND SHAPE -Age (children and old age bruise easily). -Sex (female bruise easily). - Obesity (fat people bruise easily). - Colour of skin (easily visible in fair skin). -Effect of embalming (become prominent). - Type of tissue (vascular/loose – more,firm and fibrous - less. Weapon used ( soft,yielding – less.cain /whip- rail – road bruise)

35. Associated diseases : Atheriosclerosis - Bruise easily. Blood dyscrasias - Major bleeding. Poisoning- Bruise easily. On anticoagulant - Bruise easily gravity shifting of blood - (Spectacle hematoma/panda eye/raccoon eye, battle sign / Grey Turner sign /Cullen sign).

36. PATTERN BRUISES: Gives pattern of striking surface -Rail tract bruise -Radiator bruise -Muzzle impression. -Love bites. -Cane bruise.

37. AGE / DATING OF BRUISE : -Bruise heals by destruction and removal of leaked blood (RBC). RBC liberate Hb which brakes down into Hemosiderin , Hemotoidin and finally into Bilirubin . - Colour changes start at periphery and extend to centre. -Rate of colour change is variable.

38. Methods to date the bruise are: 1-Colour changes. 2-Histology. 3-Calorimetery. 4-Spectrophotometry.

39. COLOUR CHANGES TIME COLOUR PIGMENT Initially Red Oxy- Hb Few hr to 3d Blue Hb 4 th d Bluish-brown Hemosiderin 5-6d Greenish Hemotoidin 7-12d Yellow Bilirubin 2 wks Normal Oxy- Hb

40. Histological changes. 2hr Polymorph infiltration. 1-2d Increase in polymorph. Monocyte infiltration. Start of fibroblastic activity. >2d Decrease in polymorph. Increase in monocytes .

41. > 3d Collagen formation. > 4d Granules of hemsiderin . >5 d Granules of hemotoidin . Special cases: 1-Sub conjunctival B- No colour changes. Red to yellow. 2- CO poisoning - Cherry red colour .

42. ANTEMORTEM AND POSTMORTEM BRUISES AM PM Time of formation - During life within 2-3hrs Swelling - Present Absent Damage to epithelium- Present Absent Size - As per force Small Blood - More Less Site - Any where On bony prominances .

43. Tissue washing Difficult Easy Vital reaction Present Absent Colour changes Regular Dull bluish Histo -chemical Present Absent enzymes

44. ARTIFICIAL BRUISE: Artificial bruise or false bruise are fake bruises produced by rubbing some irritant substance on the skin. Reasons: -To bring false charges of assault. -To bring false charge of torture. -By malingers to take excuse.

45. DIFFERENCE BETWEEN TRUE AND ARTIFICIAL BRUISE TRUE B ARTIFICIAL B Cause Blunt force Irritant Site Any where A ccessable part Colour Change present Dark brown Shape Round/oval Irregular Margins Diffuse Well defined Itching No Yes Vesicles Absent Present

46. Inflammation On bruise -Around bruise Content Blood - Serum Chemical test Nil - Positive SUBSTANCES USED: - C alatropis - P lumbigo -Marking nut - D ithranol

47. MLI OF BRUISE Can indicate time of crime. Alcoholics more prone to bruises. Decomposition alters bruises. Confused with PM staining. Site of bruise can show character/manner. Child abuse - bruise of different ages. Strangulation - bruise on neck. Restraint sign - bruise on arms.

48. Sexual assault - bruise on inner thigh. Manner of production: -Self inflicted - rare. -Accidental - common. -Homicidal - associated injuries. Less valuable than abrasions. Pattern bruises may indicate weapon. Six penny bruise -child abuse,rape,throattling .

49. LACERATIONS DEFINITION: Lacerations are tear or splits of skin, mucus membrane, muscle or internal organs, produced by application of blunt force to the body , which stretches tissue beyond their limit of elasticity. OR

50. Lacerations are tears or splits of skin,mucus membranes, muscle or internal organs produced by application of blunt force to the broad area of the body which crushed or stretched tissues beyond the limits of their elasticity. OR

51. Laceration is tearing or splitting of skin mucus membranes , muscle or internal organ caused by either a shearing or crushing force and produced by application of a blunt force to a broad area of the body.

52. Salient features: - Margin - irregular, ragged, uneven. - Edges (a)-Angular impact: ( i )-skin undermined opposite the direction of force. (ii)-skin bevelled and abraded on the direction of force.

53. (b)-Perpendicular impact.– Equal undermining - Depth - Depends on force and soft tissue. - Shape and Size – -May not correspond with weapon. -Linear by long thin weapon. -Irregular by objects with flat surface - S tellate by blunt and round object - C rescentric by blunt object with edge

54. - Gapping - present. - Bruising - in skin and s/c tissue around. - Tissue bridges- present on the base of The wound.(indicate blunt force). - Hair bulbs- crushed. - Hair and epidermal tags - driven in wound. -Hemorrhage - less.(except-scalp). - Foreign matter - present.

55. TYPES OF LACERATIONS 1-TEAR LACERATION 2-SPLIT LACERATION 3-STRETCH LACERATION 4-CUT LACERATION 5-AVULSION LACERATION

56. TEAR: Tear occurs when blunt force is applied to skin having sufficient amount of fat and muscle, caused by heavy blunt weapon having rugged margins. ( lathi , bat,hockey stick)

57. SPLIT Split laceration occurs when blunt force is applied to the skin directly overlying a bone, with minimal amount of under lying fat and muscle. (scalp, chin, tip of shoulder, back of elbow) -Skin is split between weapon and bone. -Mimics incised wound.

58. STRETCH Stretch laceration is produced if the force applied in such a manner that skin is over stretched, resulting in a large flap of tissue Example- Glancing kick by foot.

59. CUT Cut laceration is produced by heavy cutting weapons wielded with a tremendous amount of force. (axe, bush knife, chopper,lawn mower blade large heavy knife, meat cleaver. -it is a cross between true laceration and true incised wound.

60. -The edges of the weapon do cut the skin but since the edges are heavy they crush and bruise the margins of the wound too. -The wounds show an ugly, wide gape. -The underlying bones are frequently fractured or show deep grooves or cuts. -Also called chop wound.

61. AVULSION An avulsion is a laceration produced by sufficient shearing force delivered at an acute angle to detach a portion of a traumatised surface or viscus from its attachments.(Example-passing of wheel) I t is also called flaying.Underlaying muscles are crushed and bones fractured

62. AGE OF LACERATION: Age determination is difficult unless clear signs of healing are present. DIFFERENTIAL DIAGNOSIS: H eat rupture

63. MLI OF LACERATIONS Disputed pregnancy - age of prineal tear. Combination of laceration, contusion and abrasion. (by different blows/by same as bomb explosion). Extraneous material - generally present which can connect with the crime. Pistol whipping (buffaloing). Bag nakh .