14.6 Classification Of Common Wounds Flashcards
Classification of traumatic skin injuries
SHARP FORCE INJURIES
- INCISED WOUNDS
- STAB WOUNDS
- OTHER: IATROGENIC WOUNDS
BLUNT FORCE INJURIES
- LACERATIONS
- CONTUSIONS (BRUISES)
- ABRASIONS
Combination of 2: Chop wounds
Blunt force injuries
- Instruments without a cutting edge
- Forces involved: Traction, torsion, oblique, shearing
- Results in:
• Contusions/Bruises
• Lacerations
• Abrasions
Lacerations
- caused by blunt object
- Tearing/splitting injury of the skin
- Involves the full thickness of the skin {epidermis, dermis, sometime hypodermis}
- Epidermis, dermis, may involve the subcutis
- Underlying structures
- Nerves and blood vessels
Combinations of laceration and blunt pentrating
- Considering the mechanism of injury
- Lacerations are often surrounded by bruises or abrasions
Contusions
- blunt but now injury to overlying skin (damage to internal vessels)
- A localised collection of blood in the dermis, caused by blunt trauma applied to a particular area. (Not just a bleed under the skin)
- It causes the stretching and subsequent rupture of small blood vessels in the underlying soft tissue (arterioles and venules).
- The epidermis overlying a simple bruise is usually intact, as the injuries are in the deeper tissues.
2 Events must occur:
• Damaged blood vessels
• Leakage of blood into surrounding soft tissue
- Results in skin discoloration
- Blood products under skin are broken down over time, resulting in color changes
- Superficial bruises are usually easily visible, but deep bruises, scalp bruises and bruises in dark skinned individuals may be more difficult to detect and may only become visible on incision into the affected area.
- These bruises were not visible during external examination.
- The collection of a large amount of blood in the in the area of bruising is called a haematoma.
- The size and the severity of a bruise is not always indicative of the amount of force applied; bruising might even be absent under certain circumstances.
- A bruise is generally larger than the object causing it.
- Several factors influence the prominence or severity of a bruise.
The following factors are important to keep in mind when asked to comment on the amount of the force used and the type of object used to cause certain injuries (contusions)
AGE:
- Children and the elderly bruise easier than young, fit, muscular individuals.
- Children have loose delicate skin while in the elderly there is a loss of supporting subcutaneous tissue.
SEX:
- Females, especially obese ones, generally bruise easier than males.
SKIN COLOUR:
- Bruises are hard to see in very dark- skinned individuals.
GENERAL CONDITION OF HEALTH:
- Underlying bleeding diatheses, for example:
- Chronic alcoholics with liver cirrhosis
- Clotting disorders: Haemophilia A, B, C, parahaemophilia, Von Willebrand’s Disease
- Malnutrition: Vitamin C, K, B12, B9.
THE ANATOMICAL STRUCTURE OF TISSUE:
- The absence of a visible bruise on the skin does not imply that blunt force has not been applied to a specific area.
- Bruising of the anterior abdominal wall for example might be absent with severe underlying injuries to the intra-abdominal structures.
- The reason for this is the lack of underlying supporting structures to the loose and elastic anterior abdominal wall.
- Bruises over bony prominences such as the skull or a joint will be more readily visible.
Reason for colour of bruises
- Bruises may increase in size with the passage of time, since haemorrhage under the skin may continue for a while, and red blood cells move closer to the epidermis with time.
- Colour changes within bruises as criterion to determine the exact age of a bruise should be used with caution.
Abrasions
- most superficial
- Traumatic injuries to the superficial layers{epidermis} of the skin.
- Caused by a rough object scraping over the surface of the skin, or where a body moves while in contact with such surfaces.
- It usually only involves the epidermis but may involve the dermis, which causes bleeding of the wound.
- Foreign material found on the abraded skin surface such as paint flakes, clothing fibers or gravel could be used to identify the object causing the abrasion.
Sharp force injuries
- Instrument with sharp or cutting edge
• Knife, (Sharp) axe, Glass shards, Sharp metal edge, surgery - Results in:
• Incised wound
• Stab wounds
• Iatrogenic / Therapeutic wounds
Incisions (Cuts)
- An incised wound can be defined as an injury cause by a sharp object interrupting the full thickness of the skin, with a skin wound that is longer than it is deep.
- Length of the wound is longer than its deep
- Incised wounds are usually caused by a swiping action, rather than a stabbing thrust.
- In some situations an incised wound may very closely resemble a laceration, but since the mechanism of injury is different, it is vital for the distinction to be made.
Stab wounds
- An injury cause by a sharp object interrupting the full thickness of the skin, with a tract that is deeper than the length of the skin wound. The track of the wound therefore also involves the underlying soft tissue and even bone.
- These injuries can be caused by knives, scissors, shears, and many more.
- The sharpness of the tip of the instrument is the most important factor when evaluating the amount of force needed to penetrate the skin.
- The sharper the tip, the less force is needed for skin penetration.
- The sharpness of the cutting edge is not that important (but can affect the appearance of the wound).
Description of stab wounds
- how many wounds
- length of wound
- location
- edged of wound (double or single edge knifes)
➡️one edge of wound will be sharp and other will be blunt - whether there was movement within the wound
- depth of tract (can be deeper than the length of the blade)
- direction of tract
- how much force was used
- what weapon is used
Sharp force injuries - manner of death
DEFENSE INJURIES:
- Found in cases of assault.
- These are commonly situated on the outer aspect of the forearms and hands, as the victim tried to protect his head.
- Incised wounds may also be present on the palmar aspects of the hand, if the person tried to grab the weapon.
SUICIDE INJURIES:
- Suicidal injuries are usually found in certain well described sites, i.e. the wrists, throat and thorax.
- Multiple injuries are often present, with numerous hesitation cuts surrounding the fatal lesion.
- Many potentially fatal stab wounds may, however, also occur together.
Iatrogenic sharp force injuries
DIAGNOSTIC/ THERAPEUTIC WOUNDS:
- Surgical incisions that might have the appearance of stab wounds including incisions for insertion of intercostal drains, “cut downs” for deep veins and tracheostomy incisions.
- As these wounds may be mistaken for primary traumatic injuries, therapeutic tubing should not be removed when a body is sent for a medico-legal autopsy.
- Accurate descriptions should also be made of the primary wounds and wounds caused by subsequent surgical interventions.
Chop wounds
- These wounds are caused by heavy instruments with at least one “sharp edge”.
- Axes, machetes, pangas as well as propellers.
- Although most chop wounds have an incised appearance, tearing characteristics may also be involved in the skin wound, with an underlying fracture or deep groove in the bone.
- Thus these wounds have mixed features of both sharp and blunt force injuries.
