Medicolegal Aspects of Wounds PDF

MEDICOLEGAL ASPECTS OF WOUNDS :Definition A wound is a disruption of the continuity of tissues (e.g. Skin, bone…) produced by external.mechanical force :Classification :Legal classification -1 A- Simple wounds: which heal in less than 20.days leaving no permanent infirmity B- Dangerous wounds...

MEDICOLEGAL ASPECTS OF WOUNDS :Definition A wound is a disruption of the continuity of tissues (e.g. Skin, bone…) produced by external.mechanical force :Classification :Legal classification -1 A- Simple wounds: which heal in less than 20.days leaving no permanent infirmity B- Dangerous wounds: heal in more than 20.days and/or leave a permanent infirmity.C- Fatal (mortal) wounds: which lead to death 1 Permanent infirmity: can be defined as loss of functioning organ or loss of function in this organ. : Medicolegal Classification -11.Abrasions. (Scratches) -1.Contusions. (Bruises) -2.Incised (Cut) wounds -3.Contused (Lacerated) wounds -4.Stab wounds -5.Firearm wounds -6 2 :Abrasions (Scratches) -1 :Definition Abrasions are defined as destruction of the superficial layers of the skin either epidermis alone, or involves the upper dermis due to pressure or.friction with a rough blunt object Graze: is a linear abrasion produced by drawing a sharp point over the.surface 3 :Types of abrasions Pressure abrasions: Nail – 1 abrasions and ligature (rope) mark in.hanging and strangulation Sliding (dragging or friction) – 2 abrasions: e.g. Car accidents and.nail abrasions 4 :MLI Of Abrasions Abrasions take the shape of the -1 :causal object Smothering and throttling: 4 semi lunar nail abrasions on one side and the 5th on the other side. They may point to the assailant if he was.right, left handed or having a missing finger.Ligature mark: take the shape of rope used.Bite marks: - human bite: 2 curved rows.animal bite: 2 parallel rows - Car accidents: tire impression is present on the.victim 5 Abrasions denote resistance as in cases -2 :of rape and murder N.B. Finger nail abrasions are of medicolegal importance because of their high frequency in assaults. :They are of two types Sliding finger nail abrasions: -1 Are due to drawing of nails on the skin during resistance. They form.parallel grooves Pressure finger nail abrasion: -11 Due to static pressure applied to the 6 Age of abrasions can be -3 compared with the date of a :crime First 2 days: covered with a soft.scab After 3 days: covered with a dry.scab After one week: the scab falls leaving a red area which disappears in 3.weeks scab is formed by serum, red cells(.)and fibrin 7 Site of abrasions denotes the sort of -4 :the crime.Smothering : around the mouth.Throttling: around the neck.Rape: around wrists, mouth and thighs Strangulation and hanging: ligature.mark on the neck :It helps to identify the assailant -5.Shape of bite marks fit with victim's teeth Finger nail abrasions may tell if the assailant is left.handed or has a missing finger 8 Gives us an idea about the direction -6.of the assailant Abrasions differentiate cut from -7 :contused wounds.)present around contused( Abrasions differentiate hypostasis -8 from bruises: (present around.bruises) 9 A.M. abrasions must be differentiated -9 :from P.M. abrasions Due to eating by animals and dragging after.death P.M. A.M. Item abrasion abrasion s s Absent Present Redness Absent Present Bruises Absent Present Vital reaction: Healing and sepsis seen by N.E. and 10 microscope (cell infiltration and :Contusions (bruises) -2 :Definition Extravasations of blood in to tissues following rupture of blood vessels by the application.of blunt force Bruising is most commonly seen in the skin, but it can also occur in the deeper tissues, including muscle and.internal organs 11 Factors modifying the shape and degree :of bruising A- Severity of the blow (not the size of.the object) B- Onset of death: blow to the pericardium may lead to sudden death.without bruises detected at P.M C- Natural diseases: as haemophilia or purpura, high BP, vitamin deficiency and liver disease minimal blow lead to.severe bruises 12 :E- Type of tissue Vascular and lax areas (eye lids and labia major): minimal blow lead to.severe bruises Tough areas (palm and sole): minimal.bruises Underlying tissues: muscles (abdominal wall) minimal bruises,.bone (shin of tibia) severe bruises F- Age: in very young and elderly persons large bruises are produced by.minor trauma 13 Medicolegal importance of bruises 1. bruises take the shape of the causal object :  Blow by a stick: leads to two elongated parallel lines bruises [ tramline or railway bruises as the major stretching of the skin occur at the edges of contact and not directly beneath the center of the object, which is simply compressed].  Human bite: gives two curved rows of bruises that may be accompanied by abrasions. 14  Animal bite : gives two parallel rows of bruises that may be accompanied by abrasions.  Whip mark : gives curved bruise around the body. 2- Bruises denote resistance:  As in cases of rape and murder. 15 3. Site of bruises : Bruise usually occurs at the same site of force application, but sometimes it may shift under the influence of gravity e.g. blow to the forehead may appear as a black eye owing to gravitation of effused blood from tough scalp to loose tissue of the lids. A blow to the temple may find its way to the cheeks. Also a blow to the calf may find its way around the ankle. 16 The black eye looks recent because of its color. It is one week old. People bruise and heal differently. Determining the age of a bruise is difficult 17 4- Age of the bruise: This can be estimated from the color changes that occur from the periphery to the center of the bruise. Certain states of hemoglobin disintegration occur by the action of tissue enzymes and histiocytes and can be detected microscopically by applying certain stains. 18 When first formed the bruise is bright red in color [oxyhemoglobin]. Gradually , it becomes more or less blue (reduced hemoglobin). Then , to a green color (biliverdin ), and finally it becomes yellowish (bilirubin ) , N.B. hemosidrin (an iron containing pigment) is released as well giving a brown tinge to the bruise. Each change takes 2-3 days until color fades in 1-3 weeks(engulfment by phagocytes ). 19 Bruises (contusions) change color as they heal. They may progress from red/blue, green, brown to yellow, as they heal. Unfortunately, all contusions do not resolve the same. The multicolored bruise in this photograph 20 5. Traumatic or pathological ? Some disease may produce susceptibility to develop bruises after minor trauma as in case of hemophilia , chronic alcoholism, liver cirrhosis. So, these must be taken in to consideration so as not to be mistaken for traumatic bruises. 21 6- Antemortem or postmortem? Bruises can occur after death so must be differentiate A.M. from P.M. bruises: Postmortem Antemortem bruises bruises No swelling Accompanied by swelling Always small in size May be of any size No color changes May show color changes 22  Lacerations (contused wounds) -3  Definition: These are wounds where the skin and underlying tissues are torn or split as a result of compression or grinding by heavy blunt instruments (car accidents, fall from height, ….).  Characters of lacerated wounds: 1- Ragged irregular and abraded edges ( except in areas of stretched skin over a bone e.g. scalp and shin of tibia) with the presence of abrasion and bruises. 2- Tissue bridges across the edges, e.g. blood vessels, muscle fibers, nerves, thus no gapping of edges occur. 3- Crushed blood vessels and clotted blood with minimal bleeding. 4- Crushed hair stem and follicles. 5- Easily contaminated with foreign bodies and microorganisms. 6- Healing usually delayed, with secondary intention.  Subtypes of contused wounds: 1- Crushed wound: where the tissue of limb is crushed or amputated e.g. run over car accidents. 2- Torn wounds: in this types a ragged irregular flap of the skin separated in most of its contour e.g. by a revolving belt of a machine. 3- Rupture of internal organ. 4- Avulsion: separation of the skin from underlying tissue. 5- Split (cut-lacerated) by heavy edged instrument against bone. 4- Incised (cut) wounds  Definition: These are wounds caused by drawing the edge of sharp object on the skin and underlying tissues.  Characters of incised wounds: 1- Regular edges except if skin corrugated axilla or scrotum or irregular instrument′s edge (broken glass) cleanly cut edges and base, without bruising or abrasions. 2- No tissue bridges across the edges, thus edges usually gape; due to retraction of tissues. The degree of gaping depends on the direction of the wound in relation to underlying muscle fibers i.e. more crosses muscle fiber. 3- Cleanly cut blood vessels, so profuse free bleeding. 4- Cleanly cut hair stem and follicles. 5- Minimal contamination. 6- Healing is rapid, usually by primary intension. 7- They are long than deep.  Varieties of incised wounds: They are usually homicidal, but: 1- Multiple small parallel cut wounds at the beginning of incision indicate hesitation in suicidal wounds (hesitation marks). 2- Incised wounds in the palm or forearms indicate defense wounds. 3- Surgical incisions.  Postmortem cut wounds shows no gapping due to loss of elasticity of tissues together with absence of vital reactions. Shelving wounds occurs when the blade is at an angle to the surface.  Age of incised wounds: Age of incised wounds may be compared with the date of a certain crime.  First 12 hours: the edges are red and swollen.  By the end of 36 hours: new vessels start to grow towards the skin surface.  After 5 days: new vessels start obliteration.  After 10 days: the wound is healed by primary intention.  After 3 weeks: the scar is red.  After 3 month: the scar is coppery brown.  After 6 month: the scar is white. 5- Stab wounds:  Definition: These are clean edged wounds caused by forcing a sharp pointed object into the body. Example stabs in chest and abdomen.  Characters of stab wounds: 1. Stab wounds are more deep than long. 2. The edges are cleanly cut. 3. They are very dangerous due to internal injury, hemorrhage and sepsis. 4. They give an idea about the causal object; Single sharp bladed: one acute angle. Double sharp bladed: two acute angles. The length of the wound equals the breadth of the weapon and a little smaller due to retraction of the tissues unless the wound is enlarged during withdrawal of the weapon. The depth of the wound equals the length of the weapon in the presence of handle abrasion denoting complete penetration of the weapon. Differences between A.M. and P.M. wounds P.M. A.M. wounds Item wounds Edges No Present Gaping No Present Swelling and hyperemia Absent May be present Bruises Absent Present Bleeding No Bruises may show Color changes color changes No May be present Vital reaction (healing or sepsis) Fabricated/ Self-Inflicted wounds Definition:  These are simple wounds which are self inflicted (or fabricated) by the person on his body.  This may be a desire for revenge, to pretend that the crime was self defense, to avoid work in the prison, to obtain illegal compensation, and to escape military service. Characters of fabricated wounds:  Superficial and relatively harmless.  In an area readily accessible to the victim and in a safe site e.g. extremities.  They are inflicted on bare skin so no corresponding tear on clothes.  The age of the wound does not usually correlate with the date stated by the fabricator.  Defense wounds  These are injuries sustained by the victim to defend himself.  In case of punching: there will be abrasion or bruises on the outer side of the forearm, back of hands and fingers may be broken in an attempt by the victim to defend himself.  In kicking: defend bruises may occur on the outer side of the thigh as the victim tries to protect his genital region.  In attacks by knife: cut wounds may occur across the flexors of the fingers and in the palm. Causes of death in wounds:  Early: 1. Hemorrhage. 2. Traumatic shock: Primary (parasympathetic inhibition of circulation; reflex vagal inhibition (R.V.I.) Leads to cardiac arrest. Sympathetico- adrenal stimulation; painful wounds leads to adrenaline release lead to rise BP. and tachycardia leads to pulmonary edema and ventricular fibrillation). Secondary (this occur due to absorption of histamine-like substances from site of trauma which cause vasodilatation and circulatory failure and death. 3. Embolism: ( air embolism, fat embolism, and bone marrow embolism).  Late: 1. Sepsis. 2. Surgical interference. 3. Suprarenal hemorrhage. 4. Disseminated intra-vascular coagulation (DIC). 5. Adult respiratory distress syndrome. 6. Acute renal failure.