Forensic Aspects of Trauma 2

Question 1

Blunt force injuries are caused by impact with a blunt object – ground, fist, foot, weapon

Blunt force injuries can cause what?

Answer 1

• Contusions (bruises) - Burst blood vessels in skin
• Abrasions (graze, scratch) - Scraping of skin surface
• Lacerations (cut, tear) - Tear/split of skin due to crushing

Question 2

Sharp force injuries are injuries caused by any weapon with sharp cutting edge?

they can be superficial or penetrating

what are the different types?

Answer 2

Superficial wounds are incised wounds and deep wounds are stab wounds

Incised wounds:

• Superficial sharp force injury caused by slashing motion
• Longer on the skin surface than it is deep

Stab wounds:

• Penetrating injury resulting from thrusting motion
• Wound depth greater than length on the surface

Question 3

what is important and what are the different injury patterns?

Answer 3

Don’t story fit with pattern of injury

Anterior rib fractures due to resus

Question 4

what are defensive type injuries like?

Answer 4

Blunt and sharp force

can be passive or active

Question 5

what are passive defensive type injuries?

Answer 5

• victim raises arms and legs for protection
• Sliced, shelved often with skin flaps over backs of hands and forearms

Question 6

what are active defensive type injuries?

Answer 6

• victim tries to grab weapon or attackers hand
• Sliced shelved incised wounds on palmer aspect of hands and web spaces between fingers – particularly between thumb and index finger

Question 7

what are self inflicted injuries like and how do you recognise them?

Answer 7

• Circumstances very important!
• Commonly sharp force
• Site of election - usually wrists/forearms, chest and abdomen
• Parallel, multiple and tentative incisions (varying depths)
• Position of clothing

Question 8

what does the consequences of injury depend upon?

Answer 8

• Type of mechanical insult - blunt, sharp, homicide, suicide, accident etc
• Nature of target tissue - head, chest, abdomen, fat
• Forces involved - high speed RTC, fall from height, kicking, stamping, punch
• Number of impacts - multiple vs single

Question 9

a type of head injury is a skull fracture, what do they look like and what are the different types?

Answer 9

• Skull fractures – linear, depressed (with hammer)

Question 10

Head injuries:

Bleeding over brain – subarachnoid, subdural, extradural = amount (of haemorrhage) critical

what are the outcomes for different volumes of blood lost due to bleeding over the brain?

Answer 10

Question 11

what is shown here?

Answer 11

Extradural Haemorrhage

Arterial blood collecting due to a fracture that tears meningeal artery, collection of blood between the dura and skull in the extradural space

The source of bleeding is usually arterial, most commonly from a torn middle meningeal artery

Question 12

what is shown here?

Answer 12

Subdural Haemorrhage

Mostly due to trauma

Head thrown backwards and forwards, due to shearing of the small bridging veins that bridge between the dura and brain, rupture of veins so slower collection of blood and not under the same pressure as arterial blood and has a longer lucid interval so can be misdiagnosed and sent home then die in their sleep later

Question 13

what is shown here?

Answer 13

Subarachnoid Haemorrhage

Meningeal surface stuck on to the top of the brain

Trauma

Exclude it is not due to natural disease like rupture of cherry aneurysm which is the most common cause of these kind of haemorrhages

Question 14

what is Traumatic Subarachnoid Haemorrhage?

Answer 14

• Specific pathological entity
• Due to rapid rotational movement of head, usually as the result of a single punch to jaw/upper part of neck or side of head
• Sudden unexpected twisting movement
• Causes traumatic rupture of vessels at base of brain – most frequently distal portion of intracranial vertebral arteries at point where they cross the dura
• ? Possibly represents same twisting damage to brainstem
• Immediately unconscious and in cardiac arrest

Question 15

Head Injuries - What are the different types of Diffuse Brain Injury?

Answer 15

• Diffuse axonal injury - CLINICAL TERM - immediate and prolonged coma with no apparent mass lesion or metabolic abnormality
• Traumatic axonal injury - PATHOLOGICAL TERM - damaged axons due to trauma
• TAI - focal or diffuse (graded 1-3 depending on severity)

Question 16

what is the internal damage caused by blunt force and sharp force injuries?

Answer 16

Question 17

what are some other types of injuries?

Answer 17

• Burns
• Firearms injuries
• Explosions
• Resuscitation – bruising neck and chest, finger marks, bruising/laceration of lips and gums, damage to teeth, sternal and rib fractures, pleural cavity haemorrhage, laceration of lung, heart rupture, venepuncture and cannulation (need to distinguish from drug users)

Question 18

what are some Post Mortem Injuries?

Answer 18

• Clues = lack of vital reaction, parchmentation
• Animal predation
• Insect predation