Forensic Traumatology

Forensic Traumatology - Injury Ins & Outs

Forensic Traumatology: The study of injuries for medico-legal interpretation.

• Injury Classification:

  • Mechanical: Blunt (e.g., impact), Sharp (e.g., stab)
  • Thermal: Burns (heat), Frostbite (cold)
  • Chemical: Acids, Alkalis
  • Electrical, Firearm (GSW), Explosion

• Blunt Force Trauma (BFT):

  • Abrasions: Superficial. Types: Scratch, Graze, Pressure, Impact (patterned).

  • Contusions (Bruises): Blood extravasation.

    • Ageing: 📌 BIGRRY (approx.)
      • Blue: 0-2d
      • Bluish-Black/Dark Purple: 2-5d
      • Green: 5-7d
      • Yellow: 7-10d
      • Resolves: 10-14d

  • Lacerations: Tissue tears.

    • Features: Irregular margins, tissue bridges, bruising.
    • vs. Incised: Clean margins, no bridges.

• Key Fractures (Skull):

  • Linear, Depressed, Comminuted, Ring (fall from height).

⭐ Coup-contrecoup injuries: Brain damage at impact site (coup) & opposite (contrecoup); indicates head acceleration-deceleration, common in falls/assaults.

Forensic Traumatology - Sharp & Shot Piercing Truths

• Sharp Force Trauma:
  • Incised Wounds: Clean margins, no tissue bridges, longer than deep.
  • Stab Wounds: Deeper than long; weapon characteristics evident. Langer's lines influence gaping.

    ⭐ Hesitation marks (superficial, near fatal stab) and defense wounds (victim's hands/forearms) are crucial indicators in stab injuries.

  • Chop Wounds: Features of both sharp & blunt trauma (e.g., axe, machete); underlying bone injury common.
• Firearm Injuries (Rifled):
  • Entry Wounds: Typically smaller, circular, with an abrasion collar. May show grease collar (lubricant). Other features depend on range.
  • Exit Wounds: Usually larger, irregular, everted; no abrasion collar, soiling, or tattooing.
  • Range of Fire:
    • Contact: Muzzle imprint, charring, CO in tissues (cherry-red).
    • Close (<15cm): Burning, dense tattooing, soiling.
    • Intermediate (15-60cm): Tattooing (less dense), soiling.
    • Distant (>60-75cm): Bullet hole with abrasion collar only.
• Shotgun Wounds: Pellet pattern dispersion indicates range (Wad/pellets may be present).

Forensic Traumatology - Special Trauma Vital Deprivations

• Asphyxial Deaths: General: cyanosis, petechiae (Tardieu spots), visceral congestion.
  • Hanging: Oblique, non-continuous ligature mark above thyroid; saliva dribbling; hyoid # rare.
  • Strangulation:
    • Ligature: Horizontal, continuous mark, at/below thyroid.
    • Manual: Bruises, nail marks; hyoid # commoner.
  • Suffocation: Smothering, Choking, Traumatic asphyxia (e.g., Burking - crush).

-   Types: Wet (water in lungs), Dry (laryngospasm).
> ⭐ Diatom test (diatoms in bone marrow) confirms drowning by water inhalation.

• Burns:

  • Depth: 1st (epidermis), 2nd (dermis), 3rd (full-thickness), 4th (deeper tissues).
  • Antemortem: Vital reaction (redness, protein-rich blisters), soot in airway.
  • Postmortem: No vital reaction; Pugilistic attitude (heat stiffening).

• Electrocution: Joule burn/electric mark (entry/exit).

• Explosion Injuries: Blast lung, eardrum rupture.

High‑Yield Points - ⚡ Biggest Takeaways

• Abrasion types: Scratches (linear), grazes (tangential), pressure (crushing), impact (imprint).
• Bruise ageing: Red/blue (fresh) → green (5-7d, Biliverdin) → yellow (7-10d, Bilirubin) → normal (2wks).
• Lacerations: By blunt force; show irregular margins, tissue bridges, bruising.
• Stab wounds: Sharp edges, deeper than long. Hesitation marks suggest suicide.
• Firearm entry wounds: Smaller, round, with abrasion collar. Contact wounds: muzzle imprint, soot.
• Head injuries: Coup (impact), contrecoup (opposite). Lucid interval classic for EDH (Extradural Hemorrhage).