Mechanical injury 3

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Transcript of Mechanical injury 3

INCISED WOUNDS:

LACERATED WOUNDS, INCISED WOUNDSSTAB WOUNDSFABRICATED WOUNDS

LACERATION:DEFINITION: A laceration is a rupture or tear or a split in the skin, mucous membrane, muscle, any internal organ or underlying tissues as a result of application of blunt force. CAUSATIVE WEAPON: Blows with club, stones, bricks, punch, kicks, iron bars.

DIAGNOSTIC FEATURES: -Margins frequently abraded.Edges irregular, ragged,inverted, swollen, bruised.Angels torn, irregular.Depth (base) uneven, non uniform depth, strand of tissue found, bridging/ crossing over at the varying depths. Hairs bulbs crushed. B. Vessels crushed.Skin flapping. Foreign material usually found

4Besides blows from blunt objectsLacerations are also caused by Fall on hard surfacesMachineryTraffic accidents

MECHANISM OF CAUSATION OR TYPES: On the basis of mechanism of causation laceration.1) Split / slit laceration. 2) Stretch laceration 3) Avulsion/grinding compression of skin 4) Tears 5) INTERNAL LACERATIONS

1) split / slit laceration.1) split / slit laceration. Splitting of skin and underlying tissues occur, when there is compression/ crushing of the affected tissue between two hard objects that is bone & blunt instrument or ground. Impact is perpendicular. Example: commonly seen over scalp, cheek (zygomatic arches) chin, eye brow etc.Resemblance: apparently or on cursory examination they are confused with incised wounds.

2) STRETCH LACERATION

2) STRETCH LACERATION:-It refers to laceration caused by overstretching of the skin to produce a flap by Blunt tangential impact. PRODUCED BY Blunt tangential impact Sudden deformity of bone occurring after fracture.Glancing kicks with a boot

9COMMONLY SEEN INAreas of body where skin is supported loosely like wrist, forearm, axilla, abdomenIndustry - when parts of body get trapped in running belts.Road traffic accidents

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3) AVULSION/GRINDING COMPRESSION OF SKINIt refers to the lacerations caused by grinding compression of tissues causing de-gloving of skin and crushing of the underlying muscles. These result from Horizontal impact.

Localized pressure due to heavy weight causes tearing of skin, crushing of muscles & separation of skin from the underlying tissues, forming a space.

There will be extravasation of blood, foreign bodies in the potential space. Impact is horizontal.

12The underlying muscles are crushed.The bones may be fractured.

4) TEARS: There is irregular tearing of skin & tissues.lacerations caused by impact against irregular or sharp projecting object. This is another form of over stretching. Example: broken bottles or motor car door handles.

145. INTERNAL LACERATIONSBlunt force exceeds the tensile strength and elasticity of an organ laceration may produced.May or may not be an abrasion at the site of impact.

15MEDICO-LEGAL IMPORTANCE OF LACERATIONMay Indicate:The cause of the injuryThe shape of the blunt weapon e.g Hammer-crescentic lacerationBlunt pointed rod stellate laceration

16ANTE-MORTEM / POST-MORTEMCan be easily ascertainedAccidental Laceration (most common)Exposed parts of the bodyHomicidal LacerationUsually seen on the headSuicidal Laceration (rare)Seen in mental patients

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INCISED WOUNDS:Synonyms: cut, slash, slice. (when it is longer than deep) Definition: It refers to an open wound resulting from a cut or an incision in the skin or underlying tissues. It is caused by a weapon with sharp cutting edge when it is drawn across the skin.3. Causative weapons: - Light cutting weapons knives, razor, blades, scissors.- Heavy cutting weapons daggers, swords, axe chopper. 4. Mechanism: pressure + movement of instrument+ sharpness.

Appearance & severity depends upon:-Shape of weapon. -Sharpness of edge. -Manner of infliction.-Tissue involved.

Diagnostic features: A) shape: usually spindle shaped & gaping.B) margins:clean & regularly cut

C) edges: sharp, evenly divided, everted, smooth,

D) angles: sharp , acute.

E) base: intervening deeper tissues are cleanly & evenly divided.

F) dimensions: length is greater than depth and Width of wound is.

G) bleeding: bleed freely & profusely (vessels are cut).

H) tailing: gradual decrease in depth of wound is seen towards terminal end. So a superficial wound involving only skin is seen. This is called tailing of the wound. Tailing indicates direction of force.

I) clothes: cuts on clothes may correspond with the wound but if the clothes are loose, folded or drawn up during struggle, cuts in clothes may not coincide with the wounds.

MEDICOLEGAL ASPECTSSURGICAL

ACCIDENTAL

HOMICIDAL

DISFIGURMENT

SUICIDAL: FOUND ON CERTAIN ELECTIVE SITES. =SIDES + FRONT OF NECK. =FRONT OF WRIST (RADIAL ARTERY).=FRONT OF THIGH (FEMORAL).=FRONT OF CHEST (HEART).

FEATURES: MULTIPLE, SUPER IMPOSED, PARALLEL OF VARYING DEPTHS FOUND ON OPPOSITE SIDE OF THE WORKING, HESITATION OR TENTATIVE CUTS.

Hesitation Cuts Or tentative cutsIt refers to the preliminary cuts made by a person intending to commit suicide by a cutting instrument before gathering a sufficient courage to make a final deep incision.

CHARACTERISTICS OF HESITATION OR TENTATIVE CUTS. These are generally small, multiple superficial cuts found at the commencement of incised wound & merging with the main incision.

DIFFERENTIATION B/W SUICIDAL & HOMICIDAL CUT THROAT. 1.CIRCUMSTANTIAL EVIDENCE (EXTRA CORPORAL EVIDENCE).

INDICATOR SUICIDAL CUT THROATHOMICIDAL CUT THROAT. Placesegregated lonely. Not necessary. Scene.Undisturbed. Disturbed.Selection of weaponLight, sharp edge.Heavy with sharp edge.Presence of weapon at the scene. Present.Usually absent. Clothes.Orderly. Blood stained on anterior portions of clothes. Deranges suggesting scuffle. Blood stained on back of neck. Farwell letters. Mostly present. Absent. If present, compare hand writing.Personality trait.Depressed. Normal.

Cadaveric spasm. HANDS CLENCHED holding INSTRUMENT.Hands may be clenched, contains belonging of the assailant. Defence wounds.Absent. Present. Distribution of injuries. Confined to certain elective site (neck).Additional injuries over the body. Wound complex. Site.Left side of neck in right-handed person or vice versa. Both side & mid line. Level. Higher level above the thyroid cartilage. Lower level below the thyroid cartilage. Tentative cuts.Present at the commencement. Nil. Direction of woundObliquely down wards & medially. Transverse, upwards & laterally. Depth of wound Gradual deepening, shallowing with tailing. Bold deep cut without tailing.

Differentiate between Incised & Lacerated woundFeaturesIncised wound Lacerated wound Site Any where in the body Over bony prominencesEdges Clean cutLacerated Bruising of Margins No bruising Present Injury to blood vessels & NervesClean cutCrushed Hair BulbsClean cutCrushed BleedingMore Less

Stab wound:Definition: wound caused by a sharp pointed weapon driven in the body, the depth of wound being the greatest dimension.

Substituting words: Penetrating wound: It refers to injury when a weapon enters into the body cavity such as thorax or abdomen.

Perforating wound: It refers to the injury when a weapon after penetrating the tissues comes out from the other side making an exit wound.- Flat, pointed objects_____ knife, dagger, . Sharp, rounded objects____needles, ice picks.

DIAGNOSTIC FEATURES: HAVING ALL THE FEATURES OF INCISED WOUND, BUT DEPTH IS MORE THAN OTHER DIMENSIONS.

EXAMPLE:

WOUND OF EXIT: SMALLER WITH EVERTED MARGINS. CLOTH FIBERS ARE DIRECTED OUT WARDS. WEAPONSHAPE OF WOUNDSingle sharpEdged weapon.Wedge shapeDouble sharp edged weaponElliptical shapeRounded pointedCircularPointed squareCruciateDouble edged blunt Circular with bruisingInstrument twisted before with drawl. Triangular or cruciate.Or fish tail injury

DEFENSE WOUNDS. WOUNDS CAUSED AS A RESULT OF IMMEDIATE REACTION OF VICTIM TO SAVE HIM FROM THE ATTACKING WEAPON, EITHER BY RAISING THE ARM OR BY GRASPING THE WEAPON. SITES:

MEDICO LEGAL IMPORTANCE: INDICATIVE HOMICIDE.VICTIM WAS ALIVE & CONSCIOUS.

WEAPONTYPE LOCATION BLUNT BRUISEDORSUM OF HANDS, FORE ARMS SHARP EDGES. INCISED WOUNDSPALM OF HANDS, ULNER BORDER OF FOREARM.

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FABRICATED (FICTITIOUS. FORGED SELF-INFLICTED INJURIES, INVENTED WOUNDS.DEFINITION: THE WOUNDS INFLICTED ON THE BODY, BY THE PERSON HIMSELF OR BY ANOTHER PERSON TO MISGUIDE THE INVESTIGATORS, WITH SOME MALAFIDE INTENTIONS. MOTIVES: TO BRING A CHARGE AGAINST A PERSON OR TO IMPLICATE AN INNOCENT PERSON IN A FALSE CASE. TO ACCUSE POLICE OF MALTREATMENT DURING CUSTODY. POLICE/WATCHMAN/GUARDS CLAIM EFFICIENCY DURING CATCHING/ENCOUNTERS WITH CRIMINALS. MURDERER MISGUIDING THE INVESTIGATORS, THAT KILLING WAS IN SELF-DEFENSE.

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Weapons used: 1. Sharp edge light cutting weapon_____ commonly used. 2. Fire arms (shot gun)______ rarely used3. Chemicals _______ marking nut juice very rarely used. 4. Blunt weapons_______ very rarely uses Injuries sustained due to fall are claimed to be caused by blows. Tooth shed due to disease is claimed to caused by blunt trauma.

Elective sites: 1. Accessible/non vital areas. Top of head/fore head, outer side of left arm. Front of left forearm, front of chest/abdomen, front & outer part of thigh.

Examination of clothes: Clothes are spared usually. The wound:Superficial, multiple, made half heartedly. Seen on accessible, non-vital less functioning areas. Caused by light, cutting instruments. Shot guns are used. Cartridge discharging small pallets is used. Wound may be incised & pellets are kept manually.After x-ray (certificate) they are removed.