Cuts, Contused, Stab, Fabricated & Defence Wounds

3- CONTUSED WOUND جرح رضى

Definition:

Full thickness tearing of the skin caused by blunt trauma with force more than the elasticity of the skin.

Mechanism:

It is due to blunt force trauma by a moving object or fall → crushing and stretching forces → splitting and tearing of tissues.

Causative instrument:

Heavy blunt instrument

Characters:

See table

Types:

1. Ordinary contused wound
2. Torn wound (Flap wound): wound produced by the running belt of a machine.
3. Crushed wound: produced by passage of a vehicle.
4. Lacerated wound: contused wound with severe damage to the tissue.
5. Cut lacerated wound: The instrument is heavy and sharp e.g., butcher knife or axe.

Medico-legal importance:

1. Not related to object shape

2. Trace evidence may be found in the wound

3. Relatively little blood loss (except scalp)

4. Rarely suicidal.

5. Dangers of contused wounds: a) Great liability to sepsis. b) Disfiguring scar. c) Injury to internal organs and internal hemorrhage.

6. It simulates incised wound if it occurs in skin stretched over bones as scalp, forehead & shin of tibia. It is distinguished from incised wound by: a) Adjacent abrasions and bruises. b) Ragged edges. c) Compressed base with tissue bridges in depth. d) Surrounding hairs are crushed.

Differences between characters of incised (cut) and contused wounds

	Incised (cut) wounds	Contused wounds
1. Shape	- Linear or elliptical often deeper at starting end.	- Any shape
2. Edges & angles	- Sharply, cleanly cut & gapping with acute angles except in redundant skin or if irregular & jagged instrument	- Ragged with no angles except when skin stretched over bone (as scalp)
3. Abrasions	- No abrasions and bruises.	- Surrounded by abrasions.
4. Base	- Sharply & cleanly cut No bridging of tissues	- Compressed with bridging of tissues across the edges (e.g., nerves, vessels, tendons) - May contain foreign bodies
5. Surrounding hairs	- Sharply & cleanly cut.	- Crushed or irregularly cut.
6. Bleeding	- Profuse bleeding due to cutting of the blood vessels.	- Minimal bleeding due to crushing and retraction of the blood vessels except in the scalp.
7. Liability to sepsis	- Less liable to sepsis due to washing of contaminations by profuse bleeding.	- Great liability to sepsis due to severe tissue destruction with minimal bleeding.
8. Healing	- Rapid healing with thin scar (primary intension).	- Delayed healing with thick scar (secondary intension).

4- INCIDED (CUT) WOUNDS

Definition:

Clean division of the full thickness of skin (or other tissue) under the pressure of a sharp-edged instrument.

Mechanism:

Drawing of a sharp instrument along the skin, therefore an incised wound is longer than it is deep.

Causative instrument:

Sharp-edged, such as: knife (linear, clean), jagged metal (irregular, jagged), broken glass.

Wounds and Their Medico-Legal Importance

Types of Wounds

1. Incised Wounds

Characters:

1. Reflect sharp edge instrument, not weapon type.
2. No trace evidence except if done by broken glass, glass particles may be found.
3. Profuse external hemorrhage and air embolism may occur in incised wound in the neck.
4. Danger to life depends on site and depth.
5. Its age can be determined to know the time of its infliction by histological examination of the wound.
6. May give an idea about the direction of cut (it is deeper at the start).
7. Incised wound simulates contused wound if:
   • The cut occurs in areas with redundant skin (axilla, scrotum, abdomen in obese persons).
   • The wound is caused by irregular jagged sharp instrument (e.g., the edge of a broken glass).
8. Incised wounds may be Self inflected, homicidal or accidental as follows:

A) Self Inflicted:

i- Suicidal:

• At sites of election (wrists, neck, cubital fossae, chest, abdomen, and groin)
• Associated with tentative marks.

ii- Fabricated: seen later

iii- Para suicidal mutilation: Of face, arms, trunk … (low self-esteem)

B) Homicidal Incisions (Assault) Characterized By:

• Occur at any site.
• Not associated with tentative cuts, all are forceful and deepen rapidly
• No repetition in same track
• Usually slope backwards and downwards
• Associated with ‘defense injuries’ to hands and arms.

C) Accidental Incisions:

• Random pattern.
• Usually single.
• Often deep and forceful.

5. Fabricated Wounds

Definition:

They are self inflicted wounds to support a false charge or to afford suspicion from oneself.

Causative Instrument:

Usually sharp or pointed.

Characters:

1. They are parallel lines or incisions.
2. The wound is usually superficial
3. Within the reach of the person unless another person helps him.
4. The tears in the clothes don’t correspond to those in the body.
5. Age of wound doesn’t coincide with the history given by the person.

6. Stab Wounds

Definition:

Stab wounds are injuries whose depth within the body is much greater than the dimensions of the wound on the body surface.

Mechanism:

• Thrusts with a weapon
• Falling upon pointed objects.

Causative Instrument:

(a) Sharp with pointed end, e.g. a knife (uni-bladed), sword (bi-bladed).

(b) Blunt with pointed end, e.g. needle (long, thin )

(c) Long with blunted end, e.g. wooden stake, poker, closed scissor, animal tooth, hayfork, protruding part of machinery or motor vehicle and broken ends of bone (as in puncture wounds of the lungs from fractured ribs)

Types:

• Puncture wound: a small hole made with a blunt pointed instrument.
• Stab wound is: a piercing made by driving in a sharp pointed instrument.
• A perforating or transfixing stab wound: is one which passes through the whole thickness of a tissue or organ (through and through injury).
• A penetrating wound: is one which reaches a body cavity as pleura, peritoneum, pericardium, dura and synovial membranes.

Characters:

1. More deep than long so the stab wound has external wound on the skin and a track inside the underlying tissue. There may be one wound and several tracks (how?)

2. The edges of the wound are affected by the character of the instrument.

   a. If the instrument is sharp pointed, it may be either bi- or uni-bladed:

   • Bi-bladed weapon:
     • The edges of the wound are sharply cut.
     • No bruises or abrasions.
     • The wound is elliptical with 2 acute angles.
   • Uni-bladed weapon:
     • The wound has one acute angle while the other angle is rounded.

   b. If the instrument is blunt pointed:

   • The edges of the wound are irregularly split and lacerated surrounded by abrasions and contusions.

3. Shape of the Wound May Indicate:

A- The cross section of the causative instrument:

• Closed scissor will produce a rhomboid wound.
• Poker will produce Satellite laceration.
• A nail will produce a circular wound.

B- Movement of instrument on withdrawal:

• Twisting → crescentic wound.

4. The Direction of Stabbing Affects the Wound Length:

• A straight in and out stab → wound slightly shorter than the width of the blade (due to the elastic recoil of the skin and subcutaneous tissues).
• Entry and withdrawal of the blade at angle → wound length is longer than the width of the blade.
• When the blade passes through bone, e.g. skull or sternum → wound length is equal to the width of the blade (the cross section of the instrument can be accurately identified).

5. Wound Track Length:

• If the blade is not fully inserted → wound track is less than length of blade
• If the blade is fully inserted and body surface is compressed e.g. abdomen → wound track is more than the length of blade

Medico-Legal Importance:

1. There may be little or no external blood loss. Internal blood loss may be profuse; stab wound may hide serious damage to vital organ.

2. Examination of the wound gives an idea about:

• Weapon size. - Shape and width. - Direction of thrust.

3. Manner of injury: Homicide stab wounds: multiple, scattered, with different directions, potentially fatal and associated with defense wounds Suicide stab wounds: single at elective sites, surrounded by tentative wounds, not involving clothes. there is only one fatal wound

7. Defence Wounds

Definition:

Homicidal wounds sustained by the victim during defending himself against an attack by trying either to grasp the weapon by hands or raise the arms towards off an attack to protect the face and the head from injury.

Mechanism:

1. Injuries sustained by grasping the weapon:

   • Such injuries are usually found on the palms of the hand and on the opposing bends of the fingers or thumb
   • As grappling the knife will loosen the skin tension → cuts produced are usually irregular and ragged.
   • Grasping the knife → cuts corresponding with the position of the edges of the weapon.

2. Injuries sustained during raising the hand or arm towards off an attack to protect his face and head:

   • In the form of cut wounds, contused wounds or contusions according to the causative instruments.

Medico-Legal Importance:

1. They indicate violence.
2. They indicate that the victim was conscious, at least partly mobile and
3. They indicate that the victim not taken completely by surprise.

Role of Physician in Case of Wounds

Do:

• Take good history.
• Examine the clothes carefully.
• Cut the clothes if necessary away from the tear due to trauma.
• Make good notes of the original appearances of the injuries before any surgical cleaning or operative interference.
• Draw the site (in relation to anatomical part), dimensions and appearance of the wound.
• Photograph of each injury (if available).
• Examine hair with a magnifying lens to differentiate cut wound from contused one when the differentiation become difficult by necked eyes.
• Photograph, take swab and cast from any bite mark (for identification).

Don’t:

• Forget that deep contusion needs time to be apparent on the skin.
• Forget that contusion may appear far from site of trauma.
• Forget to search for components of the instrument such as broken glass or tip of knife in the wound base.
• Forget to seek for surgical consultation in cases of abdominal or chest trauma for fear of internal haemorrhage.
• Push probes through loose tissue in stab or puncture wound because this may create artifactual tracks with incorrect directionality.