Mechanical Injuries Flashcards
Define injury
Discontinuation in the anatomical continuation of any living tissue
Define Hurt (319 IPC)
Bodily pain, disease or infirmity caused to any person
Classify mechanical injuries
- Blunt forces - abrasion, contusion, laceration, fracture
- Sharp forces - incision, stab, chop wound
- Firearm - smooth bored, rifled
What is abrasion?
- superficial injury involving superficial layer of skin due to impact against rough surface
- bleeds a little, heals rapidly
- leave no scar
Types of abrasion
Scratch
Graze
Patterned/imprint/impact
What is scratch abrasion?
- linear injury produced by sharp object drawn across skin
- objects: fingernail, pin, thorn
- deepest at the beginning and tails off
- concluding end epithelium gets heaped up
What is graze abrasion?
Produced by friction between broad surface of skin & rough surface
- longitudinal, parallel groove with epithelium which is heaped up at the end
- seen in RTAs
What is brush burns?
Graze abrasion formed when person is knocked down and dragged for some distance (dirt/grit present)
What is patterned/imprint/impact abrasion?
Impact with rough/hard surface, patterns gets imprinted
Crushing of superficial layers
Age of abrasion
Fresh = red
12-24 hrs = scab
2-3 days = reddish brown scab
3-7 days = fresh growth of epithelium
7-10 days = scab falling out; depigmented skin
Difference between AM and PM abrasions
AM - reddish brown with blurred margins due to vital reaction
PM - dark brown/black with sharply defined margins due to absence of vital reaction
MLI of abrasion
- Indicates nature of force
- scratch = sharp object, graze = rough surface, pressure = crushing force - Nature of weapon (patterned)
- Direction of force (scratch, graze)
- Age of injury estimated
- Manner of injury
- neck = throttling, face = smothering, breast, thigh, genitalia = rape
What is Contusion?
Infiltration of blood into tissue leading to rupture of vessels (capillaries) as a result of application of blunt force
(e.g stone, cane, iron rod)
Types of contusion
Superficial
Deep
Patterned
What are the characteristics of contusion?
- caused by blunt force
- skin is intact
- usually round (shape of causative agent)
- usually subcutaneous
- maybe superficial/deep
- presence of ectopic bruise
Factors affecting appearance of contusion
Age
Sex
Completion
Site
Vascularity
Disease
Gravity (ectopic)
Age of bruise
Immediate = red (oxyHb)
12-24 hrs = blue (deoxyHb)
2-4 days = brown (hemosiderine)
5-7 days = green (hemotoidin)
7-10 days = yellow (bilirubin)
14-15 days = healed
What is patterned bruise?
Usually doesn’t clearly indicate nature of weapon
Sometimes,
Fist blow = rounded
Stick = linear
Whip = elongated
What is the difference between AM and PM bruise?
AM - swelling, discoloration of skin, blurred margin, extravasation, infiltration of blood
PM - smaller in relation to degree of force, sharp well defined margin
MLI of bruise
- Indicates blunt force
- Patterned = nature of weapon
- Age of injury
- Manner
- neck = throttling, arm = sign of restraint, thigh & genitalia = sexual assault
What is the motive of fabricated wounds?
- Aggravation of simple to grevious injury
- False charge of assault/rape
- Escape from military services
- Pretended defense
Nature of fabricated wounds
- Contusion = irritant plant juice (semecarpus, calotropis, plumbago)
- Incised = superficial
- Stab = shallow on non-vital parts
- Burn = limbs, superficial
What are the difference between true & superficial bruises?
- true bruise = caused by trauma, which can be found anywhere in the body, blisters absent, color change present, extravasated blood, and itching is absent
- artificial bruise = caused by application of irritant juice, found in accessible parts of the body, blisters are present, color change absent, acrid serum (content) and itching is present
What is laceration?
Wound in which the skin, mucosa or underlying tissue are torn as result of application of blunt force
Types of lacerations
Split
Stretch
Avulsion
Tear
What is split laceration?
Compression of soft tissue between hard object & underlying bone
- edges appear clean cut like an incised wound
- described as “lacerated wound measuring 4cm x 1cm x bone deep”
What is stretch laceration?
Tangential impact causing overstretching of the skin which splits and produces a flap
E.g run over injury, kicking with shoe
What is avulsion?
Shearing stain by grinding force (grinding compression) causing separation of skin from underlying tissue over large area (degloving)
E.g run over injury
What is tear?
Irregular tearing of skin from impact against irregular object with trace evidence in depth of tear
What are the characteristics of lacerations?
- Irregular & ragged margins
- Bruising around edges
- Margins abraded
- Crushing of hair follicles
- Foreign particles in wound
- Less bleeding bcas of crushing of blood vessels
- Shape & size doesn’t correspond with weapon
- Healing followed by scar
MLI of laceration
- Indicates blunt force
- Estimation of age
- Permanent scarring
- Shape of object causing laceration can be deduced
- Usually accidental/homicidal
Causes of incised wound
Sharp, cutting weapon drawn across the skin (knife, razor, scalpel, sword)
What is the shape of an incised wound?
Usually elliptical
What are the characteristics of incised wound?
- Margins are clean cut, non abraded
- Usually spindle-shaped (due to gaping)
- Length is greatest dimension
- Profused hemorrhage as vessels are cleanly cut
- Depth is more at beginning, becomes increasingly shallow, tailing of wound
- Length and width have no relation to be dimensions of the weapon
- Healing is usually complete in 1-2 weeks
- There is permanent scarring
What is the cleavage line of langer?
Lines of tension determined by direction of collagenous & elastic fibers in the skin
- if incised wound parallel to cleavage line of langer = wound is slit shaped
- if incised wound are perpendicular to the cleavage line of langer = wound is gaping
Describe hesitation marks
- multiple, parallel, superficial cuts
- usually seen on neck in suicidal cut throat
- usually on the left side
- also seen on wrist, chest, etc
- never seen in homicide
Describe defense wounds
- seen in homicidal assaults
- victim raises his/her arm or grasps the weapon to ward off the attack
- nature of injury will depend on the weapon
- not seen if victim was unconscious or sleeping or taken by surprise
What are the common sites of defense wounds?
Outer aspects of hand, forearm, arm or palms
What is the difference between suicidal and homicidal cut throat?
Suicidal = usually situated on left side above the thyroid cartilage (above downwards), hesitation cuts are usually present, tailing present, single wound, defense wound absent, cadaveric spasm usually present, weapon present, clothes not damaged, scene isolated and in disturbed
Homicidal = situated either side on/below thyroid cartilage (below upwards), hesitation cuts and tailing absent, multiple wounds, defense wounds present, cadaveric spasm absent, weapon absent, clothes are usually cut/damaged, scene is disturbed
MLI of incised wound
- Indicate sharp force
- Direction of force can be ascertained by tailing
- Age can be estimated
- Manner of death can be ascertained
- Maybe suicidal, accidental, or homicidal
What is a chop wound?
Wounds caused by heavy weapon with a sharp splitting edge like axe, heavy sickle, butcher’s knife
Nature of chop wound
- combination of incised and lacerated injury
- margins shows abrasion and contusion
- weight of weapon contribute to its ability to penetrate the bone
- (may) result in splintering of bone
- wound deeper at heel than toe end
- severe damage - amputation, decapitation, dislocation
- beveling (undermined edges) seen
MLI of chop wound
- Homicide
- Accidental
- Direction of force can be ascertained from beveling
What are stab wounds?
Wounds produced by more or less pointed weapons when its is driven in though the skin and the depth is greatest dimension
Objects causing stab wounds
Knife
Arrow
Needles
Screw driver
Pointed iron rod
Features of stab wound
- margins = clean cut, inverted edges, abraded, confused
- length = breadth of weapon
- breadth = thickness of weapon
- depth = length of blade & thrusting force
- direction = beveling of wound & trace the track
How is stab wound grouped depending on severity?
- Punctured = doesn’t enter cavity
- Penetrating = enters body cavity
- Perforating = pierces whole thickness of body and has 2 surface wounds (entry & exit)
How is stab wound grouped depending on weapon?
- incised puncture wound (e.g knife)
- lacerated puncture wound (e.g screw driver)
What are concealed stab wounds?
- stabbing through natural orifices, nape of neck, inner canthus of eye, armpits etc.
- usually seen in cases of infanticide
MLI of stab wounds
- Nature of injury (most commonly homicidal)
- Type of weapon used
- Direction of force
Duties of doctors in relation to injuries
- Proper documentation
- Photographs
- Medicolegal requirements
- Wound certificate
- Informed written consent
- Dying declaration
- Intimation to police
Sec 44 IPC
Any harm illegally caused by body, mind, reputation and property
Sec 319 IPC
Any bodily pain, disease or infirmity caused to a person
Sec 302 IPC
Grevious hurt
What are grevious hurt?
- emasculation
- permanent privation of sight of either eye
- permanent privation of hearing of either ear
- privation of any member/joint
- destruction/permanent impairment of the powers of any member/joint
- permanent disfiguration of head/face
- permanent disfiguration of bone/tooth
- any hurt which endangers life/causes sufferer to be in severe bodily pain/unable to follow ordinary pursuits during space of 20 days
Sec 321 IPC
Voluntarily causing hurt
Sec 322 IPC
Voluntarily causing grevious hurt
Sec 323 IPC
Punishment for voluntarily causing hurt
Sec 324 IPC
Voluntarily causing hurt by dangerous weapons or means
Sec 325 IPC
Punishment for voluntarily causing grevious hurt
Sec 326 IPC
Voluntarily causing grevious hurt by dangerous weapons or means
