Forensic examination of injuries and in cases of violent death.
Vehicular trauma.
The situation on Ukrainian roads recently has got extraordinary sharpness. If, beginning from 1985, every year happened about 40 th. of vehicle accidents and traumatized 40-42 th. persons, then in 1990 it was registered 51 th. of traffic accidents, by reason of which almost 10 th. men died and 53 thousands were wounded. For period of 1991-1995 on Ukrainian highways 220 th. of road accidents were registered. At that 40 th. men was killed and almost 236 th. of road motion participants got different traumas. Level of transport traumatism in our country yearly increases on 8-10 %. Only from motor-car transport in
About severity of road traumatism testifies the fact, that although among all kinds of traumatism it takes only 7 %, among traumas with mortal end it increases to 32,5 %. Transport trauma is divided in generally into follow groups:
The most safe is a railway transport, but people die here, too. For example, for the period of 1980-1988 years on railways of post-USSR countries in passenger trains accidents yearly died nearly 46 men, not taking into account amount of railway traumas from knocking down, crossing by train on stations, stages, crossroads, etc. In 1988 on railways 6537 men hit under trains, 3669 from them died. Correlation of died to traumatized at railway trauma is 1:2, for its consequences railway trauma is considerably more terrible, than motor-car one. In not sober state were 25 % of all perished. Train, which runs with speed of
In Ternopil region from railway trauma yearly perish nearly 8-12 men, from motorcycle one – 5-10 men, from cartage –3-5 men.
The transport (motor-car, motorcycle, railway, cartage and other) trauma is not only accidents or violence of traffic rules. In practice rarely, but happen suicide cases and even murder by means of transport facilities.
Any transport accident is subjected to investigation, especially in cases, when due to it people die or become cripple. Article 215 of UCC provides punishment for breaking of safety and transport exploitation rules by persons, which drive carrier: at infliction to victim light or of middle severity corporal damages – imprisonment up to 3 years, or correctional works up to two years, or fine; at causing heavy corporal damages or victim’s death – imprisonment up to 10 years; at death of several persons – imprisonment from 3 to 15 years. In all cases – with deprivation of right to drive a carrier up to 3-5 years or without it.
Investigation of transport accidents with human victims ordinary is complicated and difficult, that is explained by their sudden beginning and swiftness. By this reason, attention of witnesses (if they are) is fixed chiefly on results, and not on that, who, what and how has done. Frequently road accident takes place in conditions of witnessless. That’s why for last years the circle of questions, which are for solving by forensic-medical examination at investigation of transport accident, has considerably broadened, and the demands to it rise with each year.
Vehicle accident is an aggregate of mechanical action on parts of man body of a carrier, that moves, and damages formed by it, which caused health discord or death.
A kind of trauma is an aggregate of mechanical influence on man body and damages formed in it by reason of some action of a carrier, that moves.
The kinds of motor-car trauma will be: from action of external parts of car – knocking down, (blow by prominent parts), crossing, dragging, combination of two or three kinds; from action of inner parts – trauma of persons, that ride on front seat of a car or in truck cab, trauma of persons driving on back sit of a car, trauma in persons riding in lorry basket.
Types of motorcycle trauma: collisions with other kinds of transport, falls from motor-cycle, that rides, collisions with immovable barrier, knocking down a pedestrian, combined and non-typical kinds.
Types of railway trauma: knocking down – blow by prominent parts), crossing, dragging, compression of a body by parts of mechanism linking carriages, combinations of knocking down and crossing, crossing with dragging – attached to trauma from external parts of a train, damages inside engine or carriage – at trauma inside a train.
A mechanism of trauma is some sequence of mechanical action of transport vehicle on man body, of methods of its shift under influence of such action and phenomena appearing in body bringing to formation of damages. For example, trauma mechanism at knocking down by a car, as a rule, consists of blow external parts of a car, that moves, or of fall on it, blow with the road or some objects on it in fall moment after knocking away by car, friction at surface of road at further body sliding on it.
One should mark, that mechanism of damages formation at separate kinds of motor-car trauma is different. To motor-car trauma such four basic mechanisms of damages formation are peculiar:
1.damage by reason of blow by parts of a car, at parts of a car, at soil or a road, that was already mentioned before;
2.damage by reason of general concussion of a body, called by one of blows, listed in paragraph 1;
3.damage from squeezing of body between car wheel and a road, between parts of a car and other immovable objects, or between parts of car and other carrier;
4.damage by reason of body friction by car, by road attached to its dragging by parts of a car or attached to sliding of a body by soil.
Knocking down is an aggregate of mechanical action on man body and damages formed in it by reason of blow by external parts of moving carrier.
Crossing over is an aggregate of mechanical action on a body and damages formed in it by reason of rolling wheel or caterpillar track of a carrier over the body.
Dragging is an aggregate of mechanical action on a body and damages formed in it by reason of dragging a man by moving transport vehicle.
Falling from truck basket or train, and also falling out of a car are not considered as one of kinds of transport trauma, because they do not subject to its determination and are kinds of road accident. During this damages are generated by falling from height attached to outstanding circumstances.
Depending on peculiarities of transport vehicle, trauma from its action is subdivided on trauma by ground transport (tyre, rail, caterpillar, cartage), air and water carriage. Into its turn in trauma by tyre transport distinguish a tractor, trolleybus, motorcycle, motor-car traumas. Rail trauma subdivides on railway, tramway, and in conditions of some production – also on a tub one. Most frequently happen the motor-car, motorcycle and railway traumas.
Trauma — a bodily harm with or without structural alterations resulting from interaction with physicochemical agents, imparting energy to tissues.
It can cause morphologically apparent damage (wound) or produce physiological imbalance (e.g. reflex cardiac arrest by neural stimulation) and secondary effects (e.g. thrombosis, infection, obstruction of tubular organs)
Transportation trauma — an association of mechanical actions of a moving vehicle to human body with the injuries that formed resulting in health disorder or death. video
Classification of transportation trauma — depends on the kind of a vehicle:
Classification of vehicular trauma (according to А.I.Мukhanov, Ternopil, 1974, 2008)
· Knock down
· Run over a body
· Dragging
· Association of them
II. Inside of the vehicle (inflicted by internal parts of a carrier):
· Driver’s trauma
· Passenger’s trauma
Forensic diagnostics of vehicular trauma. The diagnostics of a vehicular trauma is based on two main expert features (signs): specific injuries and typical injuries.
Specific injuries are termed also as patterned injuries. They may correspond to some parts of a moving vehicle involved into the traffic accident and their shape, size, outline, surface of the bottom commonly represent a definite traumatic part or detail of the car: patterned abrasion of car light in pedestrian trauma, imprint of a steering wheel or dash board on the skin in driver’s trauma, tyre mark on outer clothes in run over a body etc. If such injuries are found on the body they directly suggest vehicular trauma therefore they are so important for forensic diagnostics and must be firstly detected by the expert.
Unfortunately, specific injuries can be rarely revealed (nearly 7-8 % among all cases of transportation trauma). Thus, the basic forensic medical diagnostics is connected with typical signs of motor-vehicle trauma. The origin of trauma from car action, that moves, as also its kinds, are diagnosed basing on specific and typical signs.
The specific (or quite typical, straight, indisputable, absolutely sufficient) signs are the contact traces, which appear from immediate action of concrete part of transport vehicle and are characterized by some form, size or relief, that coincide with operating part, which into trauma moment collided with clothes or man body. These damages give an opportunity to confront them with object, by which they are made, for establishment of their likeness. Damages’ specificity is in that they appear and meet only attached to specified, given kind of motor-car trauma and is not observed at other ones, as motor-car, as other traumas. They form not frequently – into 5-10% of cases.
Specific signs of motor-car trauma: impress of headlight, over- or underlighter, radiator grate, hook, bolt head, wheel protector, part of steering wheel, parts of turning glass, details of device panel etc. They can be in appearance of originally form dirtying or in appearance of damages (grazes, bruises).
An imprint of hexagonal bolt on the skin of dead pedestrian
Typical (conditionally or in common sufficient) signs are such signs, which meet most frequently at certain kinds of motor-car trauma, but can happen also during action of other means or at other circumstances.
The typical signs ourselves do not yet indicate on a car or its parts action on victim, do not indicate on a transport trauma kind, however in their aggregate, and also at accident circumstances evidence, become sufficient for basing of expert deductions.
Totally, the following appearences are typical in road traffic accidents (RTA):
multiplicity, magnitude and damages’ variety;
deformation of body parts (head, chest, pelvis allotment, extremities);
impresses on skin of clothes folds relief;
cracks, tears or skin ruptures from its excessive tension;
damages spreading on two and more body allotments;
contamination and damages presence on two contrary body (clothes) surfaces;
disparity of skin, bones and internal organs damages localization;
stratification of damaged soft tissues;
traces of friction (dragging) of obtuse objects by clothes, body, or clothes or body by obtuse objects;
contamination of clothes or body by engine oil;
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stratification or dip from damage of paint or car glass particles, and so on.
Ukrainian expert practice meets as a rule the followings:
Typical injuries of vehicular trauma:
· Numerous and various injuries
· Deformation of the body
· Imprints of the clothes on the skin
· Ruptures of the skin
· Location of the injuries in more than 2 anatomic regions
· Presence of the injuries on the opposite sides of the body
· Great abrasions on the skin
· Internal injuries are more severe than external
Knock down by a car. It is a knock down of a pedestrian by external parts of a moving motor-car. In other words it is termed as pedestrian trauma in forensic medicine. A moving car strikes a victim as a rule due to the follow phases:
1. previous impact.
2. falling down on a car.
3. falling down on the ground.
4. friction against the road.
The first phase is characterized by formation of contact (patterned) injuries at the site of collision of the body with definite (as a rule — prominent) parts of a moving car. They may be rings of headlights, radiator, bumper, fender etc. The most prominent part of a vehicle is a bumper which blows a victim at first. As a result of this bumper fractures of lower extremities are formed.
Bumper-injury
They are usually fractures of the tibia and fibula or femur. The localization of a fracture depends on the height of the bumper (if a lorry — great, a light motor vehicle — less) and height of the victim (child or adult). It is very important for an expert to measure the distance between the heel of the victim and the level of his fracture. Generally a bumper fracture is spiral shaped. In the latter, the base of the triangular fragment of the bone indicates the site of an impact and the apex points the direction in which the vehicle was moving. In foreign forensic literature patterned and bumper injuries are often termed as primary impact injuries. During another phases (2nd-4th) secondary injuries are formed. Due to a contact with a windshield, severe head, spinal injuries, fractures of ribs, lacerations may occur. Injuries due to a contact with the ground include abrasions, lacerations and bruises over the face, hands, hips, legs or bony prominences. They are often marked with traces of dirt. Huge internal injuries (ruptures and fragmentations of inner organs) may be inflicted too.
Thus, a mechanism of a knock down is rather difficult and generally in medico-legal practice may be confirmed by the following expert features: specificе — an imprint over the clothes or skin any external details of the vehicle; typical — bumper injuries, locality of the injuries, morphological appearances of general contusion of the body, sliding marks over the body, friction marks on soles of victim’s boots. The typical signs acquire a special value at combination of them (not less 3-4) and with specific signs.
The Indistinctive or simulating traffic trauma signs are all the rest damages, which are not included in signs, described above. They don’t have an independent diagnostic sense, because on them it is impossible to confirm a fact of motor-car trauma or its kind.
Knocking down is factually man blow by prominent parts of a car, that moves. In majority of cases it is made by parts of front car surface – by bumper, revetment of radiator, headlight, bonnet, fender (up to 60% of cases), considerably more rare – by lateral machinery surface: by lateral fender side, footboard, by basket (by 30% of cases) and rarely – by back surface: by back bumper, basket and etc. (10 %).
The trauma mechanism at blow (knocking down) by car can include three or four phases:
§ 1. previous impact
§ 2. falling down to a car
§ 3. falling down to the ground
§ 4. sliding on the road
the first phase characterizes by pedestrian blow by some part of a car, that moves, the second – by pedestrian fall on car, third – by throwing him off on the ground and the fourth – by sliding of body along road surface. In each from these phases certain damages can appear.
At frontal blow by anterior car surface the pedestrian is accorded the trauma by most prominent part of a car – bumper, by headlight etc. In blow moment takes place a transmission of kinetic energy from car to victim. In man appear contact damages from blow on level of that parts of a car, by which they are stroked (in allotment of lower extremities at car blow, and in allotment of lower extremities, pelvis or chest – at strike by a truck). Simultaneously with it appear damage from general shock of the body, caused by this blow. On car are generated dents and friction traces.
Very specific for blow by parts of a car are damages, caused by headlight and its rim. They dispose in thighs allotment, lower part of a body and display in appearance of grazes, bruises, considerable in size, fully or partially repeating a form of this part of a car. They can have round or arched form.
To specific at knocking down by a car refer also damages from blow by revetment of radiator, hook, bolt head and other parts having an original form.
At frontal knocking down damage most frequently is made by a bumper. Externally these damages display in appearance of grazes, bruises and more rarely by wounds. They localize in top third of a calf or on different levels of one or both thighs and not always accord for size with bumper width. A blow by car bumper (buffer) frequently causes so-called “bumper-fracture” of lower extremities bones in places named above.
From blow by bonnet or car fender appear big bruises without typical form, with localization in allotment of top third of thighs, pelvis or buttocks.
At blow by corner of lorry, bus, trolleybus, on body, except big bruises, sometimes appear contact damages in appearance of grazes and contuse wounds, caused by bolts, hooks connecting basket sides, and other parts, which have a typical form. All these damages are specific.
In second, third and fourth phases from car knocking on pedestrian specific damages of soft tissues don’t happen. Typical for final phase of this trauma are damages of skin – grases from dragging, which happen during body sliding along soil surface. They are parallel scratches of gutter form, red in colour, with exfoliated epidermis, more deep and wide in place of their beginning, and superficial and more narrow near their end.
The rest damages, which happen during this kind of trauma, can be either typical, or indistinctive. Damages of internal organs, that frequently form during body blow by a car, that moves, more frequent manifest themselves by result of general body shock and more rare by straight blow by parts of a car.
These are all the knocking down signs with dominance of blow by a car. Still pick out knocking down with pressing (A.I.Mukhanov, 1974), for which typical are chest and (or) abdomen squeezing signs (“ekchimotic mask”, carmine lungs oedema), folds or clothes contours impresses on skin, symmetric ribs fractures, pelvis bones, various damages of internal organs, absence of sliding traces on footwear, closes and skin.
Run over a body. It is such type of a vehicular trauma when injuries are formed when a moving wheel runs over a victim’s body. As a separate type of a traffic trauma it takes place seldom in medico-legal practice and it usually is associated with a knock down. In other words it follows after a knock down, when a pedestrian is firstly knocked and then he is run over by a car. The mechanism of this trauma consists of 3 main factors: 1.impact with a moving wheel; 2. squeezing of the body between a wheel and road; 3.friction against the ground and wheel. The severity of this trauma depends upon the part of the body run-over, the weight of the car and its speed.
Forensic diagnostics in cases of run-over must be directed for the detection of specific and typical signs of this trauma. So, there is only one specific expert sign of run-over — tyre marks upon the skin and clothes.
Tire mark on the clothes
When a limb is run over by the wheel of a motor-vehicle the skin and subcutaneous fat may be dragged away from the deeper muscles with or without any break in the continuity of the skin. This is known as degloving — one of the most important of typical sign of run-over. The followings should be assumed by the expert as typical medico-legal signs of run-over a body by a car:
· Imprints of the clothes on the skin
· Deformation of limbs
· Bilateral (symmetric) fractures of the ribs and pelvis
· Displacement of abdominal viscera to the chest or vice versa
· Avulsion, crushing or extrusion of internal organs
· Longitudinal parallel tears of the skin above the bony prominences (wings of ilium)
· Ecchymoses in the eyes.
As usual these typical morphological features may be easiely found during medico-legal autopsy and help an expert exactly define this type of a motor-vehicle trauma.
There is definite specific sign of run over a body. First of all injuries are formed due to the action of moving tires of a car. According to this tire mark at the upper clothes or on the skin of pedestrian are found. This sign may be as numerous abrasions, bruises etc. and suggests exactly than run over a body took place.
So, tire mark is a main forensic appearance of run over a body.
They can be positive, that reflect a texture of prominent parts of protector, and negative, that reflect texture of its depressions. Positive impresses on skin can be in appearance of different substances stratification – dust, dirt. paint, or in appearance of damages – grazes or bruises. They accord for size with protector texture elements size, which have left them.
Typical trauma signs, that indicate on crossing:
deformation (flatting) of body parts;
impresses of relief or clothes folds on body;
clothes ruptures, cracks, tears or skin ruptures from their excessive tension;
striped scratch or the bruises – the pressure stripes from wheels;
spacious pocket-like exfoliation of skin, filled by blood;
plural two-sided symmetric fractures of ribs, scapula, pelvis bones (of Malgen type );
numerous fractures of vertebra spines;
disparity of external damages to internal;
tearing off, smashing of internal organs, diaphragm ruptures, shifts of chest, stomach, cerebrum organs from one cavity into other, or squeezing them out from cavities;
chest and (or) stomach squeezing signs, other.
Dragging. It refers to the type of a vehicular trauma when a victim is caught by a moving motor-vehicle and is dragged against the ground «road rash». The distance of such dragging may be so long (tens and hundreds of meters). Because of this a victim slides against the road and multiple elongated abrasions and grazes are formed. They are accompanied by numerous linear parallel scratches. These are termed in forensic practice as «drag marks». All these injuries are observed upon the huge surface of the skin. «Sawing» of the soft tissues may be revealed too.
Association refers to a combination of some kinds of motor-vehicle trauma: knock down with run-over, run-over together with dragging etc.
Driver’s or passenger trauma. When a vehicle is involved in a road accident a driver or passenger may sustain serious multiple injuries. Such a type of an automobile trauma is known in forensic medicine as driver’s or passenger trauma. Most of vehicular accidents are frontal (collision with other vehicle or fixed object) and occur in about 80 % of all vehicular accidents. Here, we can distinguish typical mechanism of a trauma. The occupants of the car continue to move forward, even though the vehicle stops. The driver first slides forward so that his legs strike the lower surface of a dash-board and his abdomen or lower chest strikes the edge of the steering wheel.
An imprint of dash-board on the skin
Then the body flexes across the steering wheel and begins to rise. The head goes forward and there is severe flexion of cervical and thoracic spines. When the car suddenly stops due to the collision, the head comes back with great force and great extension of the spine is formed (whip-like fracture). The head strikes the windscreen, upper windscreen rim or the side pillar (on the left for the driver, on the right in case of front seat passenger or when right traffic order). The windscreen may break and the person may be ejected trough the broken glass on the bonnet or to the ground. The front seat passenger sustains the same impact except injuries from the steering wheel. The back seat passenger impacts on the back of the front seat.
Forensic diagnostics of the trauma inside the vehicle. As stated above, the occupants of the motor-vehicle sustain definite injuries — both specific and typical. Any patterned injuries (bruises, abrasions, lacerations) due to the impact on the internal automobile details: dash-board, windscreen rim, side pillar etc. Steering-wheel injuries (an imprint abrasions of the steering-wheel on the skin, fractures of sternal portions of the ribs, fractures of the sternum) are specific only for driver’s trauma. All these injuries are specific for the trauma inside a vehicle.
The following medico-legal features are typical for a driver’s or passenger trauma:
· Location on the anterior parts of the body
· Cervical fractures of the spinal cord
· Fractures of the facial bones
· Fractures of the legs and pelvis due to the pressure against the foot pedals (in driver’s trauma)
· Fractures of the tibia, fibula, hips and knees due to impact against the dashboard
· Numerous small cuts caused by broken windscreen on the back surfaces of the hands or on the face (driver’s trauma only). Note, tiny pieces of windscreen glass may be seen inside these injuries.
· Ruptures of m. recti of the abdomen.
· Ruptures, fragmentations, displacements of internal organs (liver, spleen, kidneys, diaphragm, aorta etc.)
Basilar skull fractures, closed head injuries, dislocation of the atlanto-axial joint.
antemortem fractures of the ribs in driver’s trauma
Forensic-medical expert has to take into account that injuries that are seen on the left side of the body refer to drivers trauma and the location of the injuries on the right side usually refers to passenger trauma.
FORENSIC CLASSIFICATION OF INJURIES
The forensic classification of injuries may be separated into the following categories:
Abrasions
Lacerations
Bruises
Incised and stab injuries
Fractures and ligamentous injuries
Burns
Definition and Overview
An abrasion may be defined as an injury resulting from blunt force that removes the surface epidermal layer of the skin.
The position of an abrasion on the skin surface indicates a site of the application of blunt force. The characteristics of the injury may provide information with respect to the direction of the impact force and occasionally information regarding the shape and nature of the object that caused the injury.
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Following death from a traumatic event that resulted in abraded injuries, it is not uncommon for the affected skin surface to develop a tan-coloured leathery appearance (Figure 4.1). This parchment effect is due to drying of the tissues and does not indicate the injuries were sustained postmortem. Subcutaneous dissection may demonstrate the presence of bruising, which confirms the injuries were sustained during life, although some parchmentlike abraded injuries that had clearly occurred in life do not show subcutaneous bruising.
Direction of Impact
Skin tags can indicate the relative movement of an object and the skin. Skin tags are small, raised pieces of skin produced when an object moves across the skin surface and point toward differential blunt force contact. Thus if a broad metallic object impacted the lower limbs at the knee joint and travelled down the leg toward the foot, the skin tags produced from contact with the skin would tend to be located at the distal aspect of the abraded injuries. It is important to note that such injuries do not indicate which object was moving and which was stationary.
Surface and Nature of the Object
Examination of an abrasion can provide information regarding the surface of the object that impacted with the skin surface. Scratches or linear abrasions are injuries to the skin that occur from contact with a fine point. Broad abraded injuries result from contact with a relatively wide surface. It is not uncommon for large abrasions to have areas of uninvolved intact skin that correspond to recessed regions of the body that are protected from the impacting object.
Depending upon the nature of the object that abrades the skin, there may be foreign material derived from the object embedded or adherent to the surface of the skin. The most common materials associated with the skin of the pedestrian victim of a collision are flecks of paint, fine particles of glass, and grease.
Examination of the abrasion may provide information regarding the shape of the object that impacted with the skin surface. The majority of abraded injuries to the skin are nonspecific; however, some have distinct shapes called patterned, abraded injuries An analogy is a stamp producing its image on a sheet of white paper. If the process is repeated with the paper placed on a firm and irregular surface, only portions of the stamp surface might be seen on the paper. Because the human body has numerous curves, is covered with various layers of clothing, and may come into contact with a small portion of a larger object, patterned injuries usually do not reproduce the complete mirror image of the object. There may even be disagreement between observers as to whether an injury is patterned and whether a given patterned abraded is significant.
The classic patterned abraded injury is the seat belt abrasion (Figure 4.3). Patterned abrasions are also caused from contact with objects within the vehicle cabin in occupants of motor vehicles. Peculiar shapes and patterns are becoming less common with improved restraint systems and vehicle designers producing rounded edges to instrument and door panels.
Figure 4.4 Creases to inguinal skin from stretching associated with an open book fracture of the pelvis.
Pedestrians may suffer patterned, abraded injuries from contact with various external regions of a motor vehicle. These include grill components, headlight and windshield surrounds and wiper assemblies, and wheels. The identification of a patterned, abraded injury in a pedestrian may aid in determining the pedestrian’s position at impact.
Abrasions from Indirect Forces
Incidents involving extreme forces that cause marked deformation to the body may result in superficial stretch marks to the skin. These marks may develop anywhere in the body, but tend to occur iatural creases such as the groin and axillae. A common setting in which this injury is seen is in cases in which the torso is run over by a motor vehicle resulting in a fractured pelvis with wide separation of the pubic rami. Stretch-type injuries may then be seen in the inguinal creases (Figure 4.4).
Definition
A laceration may be defined as an injury resulting from blunt force that results in tearing of the skin.
A laceration usually has irregular margins with so-called skin bridges within the depths of the wound. Skin bridges are connective tissues, nerves, and blood vessels beneath the skin in subcutaneous tissue that extend across the opposing edges of the laceration (Figure 4.5).
Figure 4.5 Lacerated injury to the scalp showing surrounding abrasion and connective tissues forming “skin bridges” within the depths of the wound.
Because lacerations are due to the application of blunt force, there is usually an associated abraded injury surrounding the laceration.
Direction and Nature of the Impact
A laceration indicates a site of the application of blunt force. A tangential impact can result in undermining of the laceration in the direction of the force. Degloving-type lacerated injuries refer to extreme undermining with separation of the skin from the underlying deeper tissues. These injuries are especially prominent in runover incidents from the action of a rotating tire, but may also be seen in tangential impacts involving considerable force.
Definition
A bruise may be defined as the extravasation of blood from the blood vessels into surrounding tissues. A bruise results from the application of blunt force. The haemorrhage may involve subcutaneous fat or deep soft tissues including muscle.
Point of Impact
The site of bruising to the skin surface does not always correlate with the point of impact. A fractured base of skull may lead to bruising behind the ears or bilateral periorbital hematomas. These bruises result from blood tracking between tissue planes from a distant point to the surface of the skin.
Examination of a bruise to the surface of the skin does not allow a determination of the direction of the impact. In a postmortem examination, subcutaneous and deeper dissection may reveal varied degrees of bruising in sequentially deeper tissues with a directional component. In these circumstances, one may provide a guarded opinion as to the direction of force.
Macroscopic and microscopic examination of fatty tissue may shed light on the origin of a bruise. Bruising that occurs from blood tracking from a distant site will travel along tissue planes. Direct trauma of a mild degree results in perilobular haemorrhage. As the degree of force increases, there is additional intralobular haemorrhage and then rupture and destruction of supporting connective tissues, ultimately leading to a fluid-filled cavity.
Surface and Shape of the Object
Because bruising is caused by haemorrhage from blood vessels into the soft tissues, there is a tendency for the bruise to be larger than the object that impacted the skin. For the same reason, the shape of the bruise is usually not well defined. Intradermal bruises may be viewed as analogous to a patterned abrasion, and the production of such patterned injuries is often due to a combination of abrasion of the skin and localised haemorrhage into the dermis (Figure 4.6).
Degree of Bruising
The amount of bruising that occurs from impact by a particular object with a certain degree of force can vary considerably between different individuals. The bruising produced does not necessarily reflect the degree of force in a particular incident. Bruising varies with extremes of age, the site of injury, and the presence of underlying medical conditions. Regions of the body with a rich vascular supply or abundant subcutaneous fatty tissue tend to develop a greater amount of bruising. Facial trauma will tend to develop a greater degree of bruising than a chest injury of identical force. Disease processes such as bleeding disorders and severe chronic liver and kidney disease are examples of the many conditions that can lead to excess bruising. Several medical therapies, such as anticoagulant medications and corticosteroids, are associated with a bleeding tendency.
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Petechial Haemorrhages
Petechial haemorrhages may be defined as small extravasations of blood from capillaries and venules resulting in minute, pinpoint haemorrhage. Petechial haemorrhages are most commonly seen on skin and mucous membranes. On the skin, they often involve periorbital and retroauricular skin. The mucosal surfaces often affected include the conjunctivae, sclera, and buccal mucosa. During an autopsy examination, petechiae may be visible over many organs.
Petechial haemorrhages are nonspecific but classically seen in asphyxial deaths. Deaths from mechanical asphyxia usually have widespread and often confluent petechiae.
Incised and Stab Injuries Definition
Incised and stab injuries may be defined as injuries that result from the application of sharp force. An incised injury is wider than it is deep whereas a stab injury is deeper than it is wide.
Sharp force injuries differ from lacerations in that the edges are clean and well defined with no surrounding abrasions unless there is an associated blunt force injury. Compared with lacerations, there are no skin bridges as the sharp implement also divides the deeper connective tissues. In motor vehicle incidents, sharp-force injuries may result from contact with glass and metal edges (Figure 4.7).
Figure 4.7 Incised injury from partial penetration of the windshield with surrounding abraded injuries.
Contact from broken tempered glass from windows typically causes punctate, dicing, incised injuries.
Fractures and Ligament Injuries
Definition
A fracture is a disruption of bone that occurs from the application of direct or transmitted force. Ligaments are connective tissues that maintain the structural integrity of joints. A ligamentous tear may be partial or complete and lead to varying laxity of the joint.
Fractures
Bone is a highly specialised connective tissue that generally has an inner spongy trabecular region surrounded by dense cortical bone. Long bones are composed of a central portion called the diaphysis, which expands toward its opposing ends at the metaphysis, and two opposing cartilage capped ends adjacent to joints called the epiphyses. Fractures may occur at any of these points. A fracture may extend transversely across the bone, spiral around the bone, or shatter into numerous fragments in comminuted fractures (Figure 4.8). A fracture may be closed or compound. Different mechanisms of injury tend to result in certain types of fracture. Rotational forces tend to cause spiral fractures, axial loads tend to cause compression fractures, and direct perpendicular forces tend to cause transverse fractures.
Bone is stronger in compression than it is in tension. Thus when one considers an upright pedestrian in which a force is applied to the anterior aspect of the tibia, the fracture begins at the posterior aspect of the bone where the tensile forces are acting. The fracture then extends to the anterior part of the bone that is under compression force.
Figure 4.8 Radiograph showing fracture to left femur. Angulation of distal fractured portion of femur with displacement of bone fragment suggests impact from medial aspect of thigh
Ligament Injury
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Joints are complex structures that in varying degrees depend on ligaments and muscles to maintain anatomic and functional integrity. The importance of different ligaments to joint stability varies with the particular type and position of the joint. The ball-and-socket joint of the hip has far greater stability from its bony configuration than the rolling type joint of the knee.
Each different ligament around a particular joint prevents excessive movement in a particular direction. The lateral collateral ligament of the knee resists adduction of the joint. Severe force that leads to excessive adduction of the knee may result in a partial or complete tear of the lateral collateral ligament or avulsion of the ligament’s attachment to bone (Figure 4.9).
Figure 4.9 Knee joint opened anteriorly to demonstrate the femoral condyles and show ruptured anterior cruciate ligament.
Identification of ligament injuries may thus provide information regarding the direction of the application of force.
Demonstration of Fractures and Ligament Injuries
In the clinical setting and at postmortem radiographs, computed tomography scans and magnetic resonance imaging can demonstrate fractures and soft- tissue injury.
At the postmortem examination, conventional radiographs, computed tomography, and magnetic resonance imaging images provide a permanent objective record of the fracture that can be reviewed by interested parties at a later date (Figures 4.8 and 4.9).
Burns in motor vehicle incidents occur most commonly when a fire results from a collision and an occupant is unable to extricate himself or herself from the vehicle. This may be due to injuries sustained in the incident, from the effects of natural disease, or from being trapped by parts of the vehicle.
Definition
A burn may occur from contact with chemicals, electricity, or friction; however, in the context of a motor vehicle collision, radiant heat and direct contact with flames are the two important causes. Burns may be superficial or full thickness and involve the skin, soft tissues, bone, or airway. Occasionally, ejected occupants of a motor vehicle and motorcycle riders may suffer contact burns from hot segments of the vehicle’s exhaust system.
INJURIES SUSTAINED BY MOTOR VEHICLE OCCUPANTS
Introduction
The severity and distribution of injuries sustained in a motor vehicle collision depends on a number of factors, including the site of impact to the particular vehicle, the speeds and mass of the vehicles involved, and the use of restraint systems. In addition, the seating position of a vehicle occupant determines his or her risk of injury. It has been shown that the rear seat position, and in children the centre rear seat position, carries a lower risk of injury and death compared with the front seat in motor vehicle crashes. It has been estimated that sitting in the rear seat results in a 39% reduction in the risk of death.1
For a collision with a change in velocity (delta V) of 60 Kph (
The major types of vehicle collisions may be classified as:
Frontal collisions
Side impact collisions
Rear impact collisions
Rollover incidents
The impact that results from two cars that had been travelling in opposite directions is often severe (Figure 5.1). Head on collisions may be offset, with
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Figure 5.1 Lateral photograph showing the degree of front end damage. Note the integrity of the vehicle cabin and deployed airbags. |
a metre or less of vehicle width coming into contact. The design of vehicle safety features, in particular restraint systems and frontal crush zones, were largely developed to address the forces involved in frontal impacts.
Frontal collisions are common in rural locations. Driver drowsiness and inattention on two-lane highways may be a contributing factor when cars drift onto the wrong side of the road. Overtaking maneuvers are a further important issue in some cases of frontal collisions. Less commonly, an incident that occurred in the correct lane leads to the vehicle crossing onto the wrong side of the road, resulting in a frontal collision.
Oblique frontal collisions (OFCs) are defined as collisions involving the left or right front quarters of a motor vehicle in which the impact is angled. OFCs cause approximately 6% of all road crashes that lead to injury. OFCs are more common in elderly drivers.
OFCs occur most commonly when a vehicle is turning at an intersection and moves into the path of an oncoming vehicle. OFCs have a higher incidence of significant injury and death compared with true frontal collisions of a given severity and is partly related to increased cabin intrusion.
Contact with the interior of the vehicle cabin introduces consequences of
Unrestrained drivers in frontal crashes impact with the steering wheel and assembly, the windshield and surrounds, instrument panel, and floor pan (Figure 5.2). The major injury associated with direct impact is head injury.4 Unrestrained rear seat passengers have been shown to pose a significant threat to drivers and front seat passengers in frontal collisions.
The passenger does not have the steering column directly in front, so initial contact is with the windshield and dashboard. Head impact tends to be frontal, leading to forced hyperextension of the upper cervical spine, and fracture dislocation of the atlanto-occipital joint is a common injury and cause of death (Figure 5.3). Subsequent blunt force trauma leads to further chest, abdominal, pelvic, and upper and lower leg injuries.
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Figure 5.2 Lacerated and abraded injuries to the left and right knees from impact with the dashboard. |
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Figure 5.3 Schematic diagram of cervical spine. A common cervical spine injury is fractured odontoid process. |
Head impact usually occurs from contact with the A-pillar, side of the vehicle roof, door frame, B-pillar and windows and surrounds, and, in the case of rollover, the vehicle roof and other occupants.6 Rapid death at the incident scene caused by blunt head injury is usually due to diffuse axonal injury. This brain injury is from rotational forces causing differential movement within different regions of the brain, leading to damage to nerve axons and small blood vessels.
Subdural haemorrhage is classically caused by rotational forces acting on the head resulting in differential movement between the skull and relatively adherent dura, and brain leading to division of perforating small venous channels. Subdural haemorrhage is often associated with diffuse axonal injury. A subdural haemorrhage can accumulate rapidly to a volume (50 to 100 mL), resulting in compression of the underlying brain.
Traumatic subarachnoid haemorrhage over the cerebral hemispheres is caused by division of innumerable small blood vessels and, if extensive, is a marker of a significant underlying brain injury. Basal traumatic subarachnoid haemorrhage suggests rupture of the intracranial vertebral or basilar arteries or rupture of a vertebral artery within the cervical spine.
An extradural haemorrhage is classically caused by rupture of the middle meningeal artery within the squamous temporal bone. The bone shows an associated fracture in about 30% of cases. It is uncommon for an isolated extradural haemorrhage to be the sole cause of death in a motor vehicle incident. The haemorrhage has to strip the densely adherent dura from the skull and form a collection such that the underlying brain is compressed and distorted. This usually takes some hours and provides enough time for surgical evacuation of the blood clot. Extradural haemorrhage in a motor vehicle collision is usually associated with other significant forms of head injury.
A cause of death in head injury that may have subtle changes at postmortem is a tear at the pontomedullary junction in the brainstem.
Secondary Brain Injury
Secondary brain injury is common and can be as important to the survival and functional recovery of a crash victim as the primary insult. Secondary brain injury refers to brain swelling and haemorrhage that occurs as a consequence of a number of factors including, but not limited to, hypoxia, hypotension, and coagulopathy. Head injury is a recognised cause of apnea. Experimental evidence suggests the magnitude of the brain impact is directly proportional to the onset and persistence of apnea.7
Clinical observations have recorded an instance of life-saving artificial respiration followed by complete recovery in a motor vehicle crash victim who was observed by a medical practitioner to be apneic at the scene.8 The absence of immediate resuscitative efforts will contribute to hypoxic secondary brain injury.
In many cases secondary injury is inevitable because of the isolated location of the motor vehicle incident.
The uncontrolled deceleration that occurs in unrestrained vehicle occupants, primarily but not exclusive to frontal collisions, can lead to rapidly fatal deceleration injuries to the cardiovascular system. Deceleration injury is typically seen in unrestrained vehicle occupants, ejected vehicle occupants, motorcyclists, and pedestrians, but may be seen in anyone involved in collisions at speeds of greater than 60 km/hr The typical deceleration injury that leads to death is transection of the descending thoracic aorta (Figure 5.4).
Figure 5.4 Region of traumatic rupture of the descending thoracic aorta resulting from deceleration.
Complete rupture of the aorta results in rapid haemothorax and death in approximately 85% of cases.9 The differential movement between the ascending aorta and arch, and the relatively fixed descending thoracic aorta, results in injuries beginning at the endothelium and extending varying degrees through the artery wall. The injury classically occurs at the level of the isthmus. An alternate explanation in the causation of the injury is a “water hammer” effect. Tears may also occur in the ascending thoracic aorta and vascular branches from the arch. Rupture of an atrial appendage is a further significant traumatic injury.
Pulmonary haemorrhage of varying severity can occur secondary to deceleration. Avulsion of major thoracic and intra-abdominal viscera including the liver, kidneys, lungs, and heart from vascular attachments are further catastrophic injuries. Tracheobronchial disruption is a further deceleration injury, which may be seen in the absence of other significant chest injuries, and may be the sole cause of death.
The introduction of crush zones to the front of cars, seat belts with energy management systems and front airbags have been designed to lengthen the duration of deceleration and subsequently reduce deceleration injury.
The motor vehicle occupant wearing a seat belt involved in a frontal collision will also move forward following frontal impact, although obviously to a far lesser degree than unrestrained occupants. Vehicles fitted with seat belt preten- sioners will have even less forward movement. Significant forces still apply to the upper cervical spine as a result of rapid movement of the victim’s head. Direct blunt force is transmitted to the chest, abdomen and pelvis by the
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Figure 5.5 Compound fracture of the left ankle associated with floor pan intrusion in a frontal motor vehicle collision. |
seatbelt. Vehicle intrusion is a further cause of blunt force injury. Direct impact between the knee and the dashboard is decreased in the restrained occupant. Floor pan intrusion is a major cause of lower limb injury (Figure 5.5).
Restrained occupants in motor vehicle collisions most commonly die as a result of head injury or deceleration injury. Other significant injuries result from the injuries described below.
Chest injury from direct blunt trauma can lead directly to death, but more commonly contributes to death in association with other injuries. Massive pulmonary contusions, ruptured pulmonary vein, ruptured heart with pericardial tamponade, and widespread rib fractures sometimes associated with lung and cardiac lacerations are injuries seen with severe chest trauma. The presence of fractures of the first and second ribs is indicative of severe blunt force to the chest, and should be a stimulus for investigation of other significant chest and abdominal injuries.
Multiple fractured ribs or fractured sternum is a significant injury in the elderly and crash victims with other major medical conditions. In these subgroups, a fractured sternum or multiple fractured ribs especially with a flail segment, there is a high morbidity and mortality rate and often a requirement for a period of ventilation in an intensive care unit with appropriate pain management. When death occurs, it is often the result of a combination of respiratory failure and bronchopneumonia.
Tension pneumothorax is a medical emergency that can lead to rapid death. Tension pneumothorax occurs when air is able to enter the potential space between the lung and chest wall during inspiration, and is subsequently trapped during expiration. Hence the lungs and heart are increasingly compressed from the expanding volume of air, eventually leading to external compression of the heart and lungs with eventual cardiovascular collapse (Figure 5.6). The pressure can be relieved by the insertion of a cannula into the chest.
Figure 5.6 Chest radiograph showing a tension pneumothorax. Radiolucent right chest from accumulation of air within the right pleural space and showing mediastinal shift to the left side.
Blunt trauma to the abdomen can cause ruptures to abdominal viscera including the liver, spleen, bowel, and mesenteries leading to hemoperito- neum. Blunt trauma to the right side of the abdomen tends to cause liver damage, whereas trauma to the left side of the abdomen tends to cause splenic injury. Young, previously healthy trauma victims may compensate for massive abdominal injury for a significant period before the onset of cardiovascular collapse.
Abdominal trauma and haemorrhage from ruptured pelvic vessels secondary to a pelvic fracture can cause massive retroperitoneal haemorrhage. Traumatic acute pancreatitis is a relatively uncommon sequela of abdominal trauma.
Pelvic fractures tend to occur along the direction of the application of force, though there are numerous exceptions to this general rule (Figure 5.7).
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Figure 5.7 Pelvic radiograph showing fractures involving both ischiopubic rami with left sacroiliac joint dislocation. |
Axial forces transmitted along the femur from a frontal impact may cause posterior dislocation of the hip joint. Posterior hip dislocation may occur from direct impact to the knee from the dashboard, though others have postulated the mechanism of injury usually results from hip flexion, adduction, and internal rotation as occurs when the driver presses hard on the brake pedal just prior to the impact.10
Compressive load to the femur from direct impact with the dashboard can lead to significant bending and fracture. Another common femoral fracture from direct knee impact is a longitudinal splitting fracture between the femoral condyles when the patella impacts directly with the dashboard. Forces applied to the femur from muscle contraction may contribute to femoral shaft fracture.
The tibia may undergo longitudinal compression or transverse loads from contact with the floor pan and dashboard, respectively.11 Tibial and fibula shaft fractures occur principally from direct forces. Ankle joint and foot fractures are seen with intrusion from the floor pan, which usually causes forced dorsiflexion. A study in
A later study of 480 individuals with at least moderate ankle and foot injury showed that 75% were drivers and the right ankle was most often injured, suggesting the pedals were a significant factor in the injury causa- tion.13 Otte and colleagues reviewed 140 cases of restrained drivers with foot and ankle injuries and found no difference in injury rate between either side.14
Forced inversion and eversion associated with floor pan intrusion is a prominent fracture mechanism in malleolar fractures.
Forced dorsiflexion may lead to navicular fracture and talar fracture from primary direct axial compression with floor pan intrusion.15
Upper arm fractures in restrained front seat vehicle occupants in the absence of airbag deployment occur most commonly from direct impact and result in hand (25%), wrist (23%), and forearm (23%) injury. The elbow (9%), upper arm, and shoulder (both 10%) were injured less frequently.16
Airbag deployment is associated with an increased incidence of extremity injury.
Spinal injuries occur in about one third of all fatalities from road incidents. Motor vehicle collisions cause the majority (43%) of traumatic spinal cord injury in Australia.17 Spinal cord injury is especially common in crashes in rural regions, in incidents involving four-wheel drive (4WD)/sports utility vehicles (SUV), in cases of rollover and occupant ejection.18 The cervical spine is the most common site of spinal cord injury (61%) in occupants injured in motor vehicle incidents.19
Side impact collisions most commonly occur at road intersections. Side impact collisions caused 31% of all collisions leading to injury fatalities in the
The probability of injury and death varies with respect to the side and region of the vehicle that is struck, the velocity of the impacting vehicle, the mass and type of bullet and target vehicles, and the age of the target vehicle occupants.22 The rigid body shell provides more protection from intrusion than the more yielding door structures although door reinforcement is addressing this issue.
A side impact crash results in movement of occupants toward the point of contact leading most commonly to head, neck, and thoracic injury. The target vehicle’s occupants may sustain injuries from contact with their own vehicle’s interior or from the impacting vehicle. The latter is a particular problem with collisions from SUV/4WD vehicles in which the bullet vehicle’s bumper may override the window of the target vehicle.
Injuries in Side Impact Collisions
In side impact collisions, the vehicle occupant may sustain skin injuries from contact with shattered tempered glass. This results in typical “dicing” type punctate incised and abraded injuries (Figure 5.8).
These injuries will tend to be more prominent to the nearside occupant. A shadow effect can occur from the glass impacting another occupant or object. Direct impact with intact glass may cause lacerations or broad abrasions that may show directionality from its linear components.
Blunt force injury to the head occurs most commonly from impact with the B pillar, doors, and windows. Significant vehicle intrusion may also lead to head injury (Figure 5.9). Blunt force injury to the chest and abdomen results from impact with the door panel causing rib, lung, liver, and splenic injury.23
Although seat belts generally do not provide the same protection to an occupant in a side impact collision compared with a frontal collision, the use of restraints has been shown to be associated with lower rates of splenic injury in side impacts. Iearly all cases of splenic injury, the left vehicle interior is the source of injury.24 The presence of an occupant on the near side in a side impact collision has been shown to change the injury pattern for the far side occupant, whereby injuries from contact with the opposite side interior of the vehicle are mitigated.2
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Figure 5.8 Punctate abraded injuries to the left side of the face from contact with shattered tempered glass. |
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Figure 5.9 Marked vehicle intrusion from side impact into pole. Injuries to the rear seat occupants may be correlated with seating position. |
Side impacts causing lateral application of force may lead to transverse pelvic fractures. These fractures are seen mostly to the nearside (70.4%) occupants of the target vehicle compared with the far side (38.3%) occupants.25 Transverse fractures of the femoral diaphysis (shaft) can occur with transverse impact from a side-on collision. Side impacts lead to an increased incidence of thigh, knee, leg, and foot/ankle injuries to the far side occupants compared with the near side occupants in a retrospective study.25 The mechanism of injury may reflect rotation of the lower limbs toward the point of impact for far side occupant, whereas direct trauma leads to pelvic/hip injury to the near side occupants.
Children in side impact crashes suffer injuries from contact with internal cabin features and from cabin intrusion by the bullet vehicle. A combination of head, cervical spine, chest, and extremity injuries has been described.26 The pattern of injuries to children iear side collisions is similar to the pattern observed in pediatric pedestrian incidents.27 The injuries sustained by children who were seated near side in a side impact collision occur irrespective of the use of seat belts.
Most studies have suggested that the majority of rear end collisions occur during daytime in clear weather and on straight roads. In most cases, the lead vehicle had stopped or was slowing. The vast majority of rear end collisions occurs at low speeds and is associated with minor injuries. However, collisions that occur at high speeds can lead to significant vehicle intrusion and subsequent severe
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Figure 5.10 “High- speed” rear end impacts showing significant vehicle intrusion. |
blunt trauma to the head, neck, and thorax (Figure 5.10). A study that corrected for exposure level showed that rear end collisions were twice as frequent in darkness when compared with daylight.28 Approximately two thirds of rear end collisions result from inattention of the driver of the following vehicle. The contribution of environmental factors such as wet or icy roads occurs in less than 4% of cases.28
Passenger vehicle crashes into parked vehicles are an important subset of rear end crashes. Underlying causes include driver intoxication with alcohol and other drugs and driver inattention.29 A particularly lethal type of rear end collision is the underrun incident in which a passenger vehicle strikes the back of a truck resulting in significant impact to the windscreen and vehicle cabin.30 The instillation of underrun barriers to the rear of tray type trucks and trailers has decreased the severity of these crashes.
Injuries from Rear Impact
Neck injury from hyperextension in rear crashes has increased over the past two decades. Although severe trauma is uncommon in rear impacts, relatively low-speed collisions can lead to rapid neck extension especially for out of position occupants.
Recent seat design changes include high-strength designs, with “all belts to seat” configurations that have necessitated stiffer seat backs.31 The trend toward stiffer seats has lead to increased neck displacements and may be a significant factor in the pathogenesis of flexion/extension neck injury.32 A study by Burnett suggested that seats of mid-range seat back stiffness minimised neck loading and thus decreased the potential for neck injury. There is evidence to suggest that seats which yield in a rear end collision may also afford greater protection from hyperextension injury.
A rollover event may be defined as a collision in which the vehicle rotates at least a one-quarter turn, irrespective of the resting position of the motor vehicle. The vast majority of rollover incidents occur after the motor vehicle has left the roadway.
Figures in the
A rollover event may be the only factor in a particular motor vehicle incident or may be part of a more complex multiple incident event. In either case, rollover is associated with significant injury to the vehicle’s occupants and is associated with an increased risk of occupant ejection. Injury severity and death is far more likely when a seat belt is not worn. Occasionally, some seat belt latches can disengage during a rollover and, in the absence of a prior frontal collision, additional restraint systems such as seat belt pretensioners do not function.
Rollovers are a particular issue in vehicles with a high centre of gravity such as SUV/4WD and semitrailer trucks that leave the roadway (Figure 5.11). A study on the risk of rollover in cars and light trucks after accounting for driver and environmental factors showed that some light trucks have up to twice the risk of rollover compared with cars.34 Semitrailers with a high payload are at risk of rollover. Incidents of rollover by semitrailers are more prone to occur on roads that fall away to the shoulder, on very tight corners, and in high winds.
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Figure 5.11 Truck rollover associated with sharp off-ramp from freeway. |
Rollovers have been categorised into a number of subtypes, the most common of which is the tripover, which composes 57% of rollovers in passenger vehicles.35 The next most common type of event is the fallover.
Subtypes of rollover are:
Tipover — Occurs when the lateral movement of the vehicle is rapidly impeded (e.g., when the wheels/tires contact the curb, or gouge into soft ground)
Fallover — Occurs when the vehicle is moving down an incline such that the vehicle’s centre of gravity is beyond the outside wheels
Flipover — Occurs when a vehicle has a rotational force imparted along its longitudinal axis; this is usually from contact with a “ramplike” structure
Turnover — Occurs from frictional forces from a tire on a vehicle that has rapid rotation from a sharp turn
Postcollision — Occurs when the rollover is secondary to a motor vehicle collision
End over end — Occurs when vehicle rotation is along its lateral axis
Injuries in Rollover Incidents
Rollover incidents lead to complicated kinematics for occupants during the vehicle’s rotation. Interestingly, as the vehicle comes to rest over a longer period than in a frontal or side on collision, the vehicle occupant is somewhat protected from the effects of rapid deceleration.36 However, because there are often multiple episodes of contact between the occupant and the vehicle’s interior, blunt force injury to the head and torso is common. The frequent sources of injury include the A and B pillars, side interior and roof (Figure 5.12).
Severe injury ionejected victims in rollover incidents have been shown to be associated with vehicle intrusion, and especially roof rail or B-pillar intrusion of greater than
A major risk of injury for unrestrained occupants of motor vehicles involved in a collision is ejection from the cabin.37 It is clear that morbidity and mortality rates are markedly increased when ejection occurs. Data from the General Estimate System and the Fatality Analysis Reporting System estimated that, in
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Figure 5.12 Rollover of a four-wheel drive vehicle showing roof indentation and distortion resulting in close proximity between the roof and head of the occupant. |
a collision. The most common exit point from the cabin is via the side or rear window following impact damage to the tempered glass.
Injuries Associated with Seat Belts
Forensically important injuries occur from the force applied from the seat belt to the occupant.
The classical “seat belt mark” is an abrasion/intradermal bruise that extends from the region of the clavicle diagonally across the chest toward the opposite hip reflecting the path and shape of the seatbelt. A further transverse abrasion/bruised injury may be seen across the abdomen.
However, far more commonly the seatbelt/occupant interaction results in either no injury or a nonspecific bruise or abraded injury. The location and orientation of such an injury may suggest the use of a seat belt as the anterior clavicular region is not commonly injured in a motor vehicle collision. The latch mechanism overlying the lateral hip region can result ionspecific skin injuries or rectangular, right angled, or linear abraded and bruised injuries.
Rib and sternal fractures may be caused by seat belts in a motor vehicle collision. Fractures are more likely in older females because of osteoporosis. Fractures tend to occur along the path of the seat belt, reflecting the force applied during the collision.38 The fourth through to the ninth ribs are often fractured. A study in the 1970s showed that the ribs are fractured in an anterior location with the sixth rib the most frequently involved.39 In surviving occupants of a motor vehicle collision, bone scintigraphy has demonstrated different patterns of rib and sternal injury to the driver and front seat passenger.40 The imaging study showed a diagonal orientation to the rib fractures and the sternal fracture.
Incorrectly fastened and inappropriate use of seat belts is far more common in children than adults. It has been observed that in a population of children who should be restrained in a child restraint system, up to 25% were wearing seat belts that did not fit properly. Incorrectly fastened seat belts may result in submarining. Submarining refers to the situation in which the occupant is propelled underneath the seat belt during a frontal collision. Submarining commonly results when there is insufficient contact between the lap belt and the anterior lateral pelvic region. Submarining may cause significant intraabdominal trauma including rupture of the liver, spleen and hollow viscera.41 Wedge fractures of the lower thoracic/lumbar vertebrae (Chance fractures) occur from hyperflexion of the vertebral bodies when the occupant pivots around the lap belt. These fractures are more common in children.42
A clinical study evaluated the location and severity of brain injury and functional outcome with respect to seat belt use. Restrained vehicle occupants were more likely to suffer damage to the basal ganglia, corpus callosum, thalamus, and hypothalamus, whereas unrestrained vehicle occupants were more likely to sustain posterior brain lesions.43 The use of clinical cases excludes those victims who died as a result of a head injury, and the use of seat belts probably allowed individuals to survive a severe crash that would have proved fatal in an unrestrained occupant. However, it is possible that the different anatomic locations of the head injury may reflect different mechanisms (i.e., direct blunt trauma in unrestrained individuals and flexion/hyperextension in restrained occupants).
Injuries Associated with Front Airbag Deployment
Airbag deployment is associated with a variety of injuries to victims of a motor vehicle collision. The injuries are usually minor, but may occasionally be life-threatening. Children exposed to front airbags have an increased risk of minor injuries that include facial and chest abrasions and upper extremity fractures.44
The types of minor injuries associated with airbag deployment are, in decreasing order of frequency, minor abrasions, bruises, lacerations, and burns. A study by Antosia and colleagues in the mid-1990s showed that the body regions most commonly injured were the face (42%), wrist (17%), forearm (16%), and chest (10%).45 The body regions injured reflect proximity with the airbag module at the time of deployment. Abrasions, bruises, and lacerated injuries occur primarily from blunt force contact with the module cover and the airbag.
Burns have occurred from chemicals such as sodium azide or sodium hydroxide or thermal burns from hot gases liberated from vents or breaks in the airbag, though with more recent airbags these injuries are less common.46
Facial injuries are not unexpected in frontal crashes associated with airbag deployment because the inflated airbag is designed to extend across the face and chest. Airbags have been shown to cause eye injury including corneal abrasions, vitreous and retinal haemorrhage, chemical retinitis and traumatic cataract, retinal tears, and detachment.47 Wearing eye glasses has been shown to present a problem in motor vehicle crashes that result in airbag deployment because the incidence of facial and eye injuries is increased in these occupants.47
Mouzakes and colleagues showed that the rate and severity of facial fractures decreased when drivers and passengers were protected by both seat belts and frontal airbags. A later study demonstrated that the incidence of facial fractures in motor vehicle collisions were reduced from 17% to 8% with the use of seat belts alone and reduced from 17% to 11% with the use of airbags alone. Airbags were least effective in preventing zygomaticomaxillary fractures.48
Airbags are associated with a reduction in hyperflexion/hyperextension injuries to the neck. The mechanism is most probably a more diffuse application of force across the head and chest, with a reduction in hyperflexion of the cervical spine. The pattern of rib fractures caused by contact from an airbag is somewhat different when compared with contact from a seatbelt in a frontal collision. Whereas rib fractures tend to follow the diagonal line of the seatbelt, the more diffuse frontal force applied to the chest by an airbag tends to cause bilateral and symmetrical lateral rib fractures.37 The overall effect of airbag deployment in a motor vehicle collision is a reduction of fractures to the ribs, sternum, and clavicle.
Extremity injuries are increased with airbag deployment. Upper limb injuries are increased when compared with seat belts alone or wheo restraining devices are used. McGovern suggested the upper limbs are not in the zone designed for protection by airbags and may be propelled around the bag, resulting in injury.49 Front and side airbags do not protect vehicle occupants from lower extremity injuries. Burgess and colleagues showed that the use of seat belts, airbags, or combined airbag and seat belt restraints did not prevent lower extremity injuries in drivers.50
Fatal injury in airbag deployment occurs predominantly in children and small adults who are “out of position” because they are physically too close to the airbag at the time of deployment.52
Significant and lethal injuries may involve the head, neck, and chest. Head injuries reported to occur from airbag contact include intracranial haemorrhage, cerebral contusions, brainstem laceration, and transection. Ring fracture of the base of the skull and severe cervical spine injuries including atlanto-occipital dislocation have been described.52-54 Lethal chest injury includes cardiovascular trauma with cardiac contusions, ruptured heart, valve injury, and laceration or transection of the aorta.55-57
In side collisions, the occupant’s head may impact with the B pillar, side window, and surrounds. Impact of the chest may occur with the door. Intrusion of the cabin by the bullet vehicle is a further possible source of head and chest injury. Side airbags were introduced as a specific safety system for vehicle occupants in side impact collisions to protect the head and thorax.
The introduction of side airbags may be associated with fractures to the upper limbs, especially when the hand is in situ within the hand rest of the side door. A number of cadaver, anthropomorphic, and real-world investigations have demonstrated a significant risk of entrapment injuries from the hand grip in such cases.58 Risk of fracture increases with osteoporosis. The presence of these injuries may aid in the forensic identification of a driver in a particular incident.
The probability of vehicle occupant injury is increased for the occupants of a smaller car that collides with a larger vehicle. Differences in vehicle configuration have also been shown to affect the risk of occupant injury. SUVs have a higher road clearance than average passenger cars and collisions between these vehicles leads to greater injury for the passenger car occupants even when the mass of the passenger car exceeds that of the SUV.59,60
Side impact from a SUV to a passenger car is particularly dangerous. Injuries to the head and upper chest are common to passenger vehicle occupants because of override of the SUV bumper above the side door reinforcement.61 Bumper override is also a major factor in frontal collisions with passenger cars. These collisions can result in instrument panel and steering column intrusion leading to head and chest injury and a high incidence of upper extremity fractures. Bumper underride of the
SUV with the passenger vehicle can lead to marked floor pan intrusion to the passenger car, resulting in a high incidence of lower extremity fractures.
Motor vehicle trauma is a leading cause of hospitalisation of pregnant women in Western societies and a major cause of fetal death.62 Motor vehicle collisions involving pregnant women have similar rates of restraint use and seat position.
Injuries sustained by pregnant women in motor vehicle incidents are similar to those ionpregnant women. Fetal injury and death in utero can be related to direct trauma transmitted through the mother’s abdomen or from an ischaemic insult if placental function is compromised from systemic maternal factors such as blood loss or accidental haemorrhage.63
The lap belt worn by pregnant women should be positioned beneath the abdomen and across the anterior superior iliac spines to minimise direct force to the gravid uterus. Airbag deployment has not been reported to cause fetal injury or death.
Injury Differences between Drivers and Passengers
The classical seat belt abraded/bruised injury is an important feature in differentiating between driver and passenger in serious motor vehicle collisions (Figure 5.13). The distribution of cutaneous injuries, soft-tissue bruises, and fractures sustained by a trauma victim with respect to
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Figure 5.13 Intradermal bruise from forceful contact with seat belt. |
the damage to the vehicle may allow a guarded opinion on the seating position within the vehicle. In these circumstances, all of the available information pertaining to the case should be used when offering an opinion and should include a comparison between the injuries sustained by the injured parties.
A study by Daffner and colleagues published in 1988 described the difference in the pattern of bone injuries to 250 unrestrained drivers and passengers.64 They reported that 39 of the passengers had clavicular fractures compared with only 1 of the 250 drivers. The postulated mechanism was that the passengers raised their arms in a reflex action prior to impact. Humeral fractures were also twice as common in the passenger group.
Drivers were found to have a high incidence of hand, wrist, and elbow injuries. Of the drivers, 22 had hand fractures, 58 had wrist fractures, and 115 had fractures of the shaft of the radius or ulna.
Passengers had no hand fractures. There were 2 wrist fractures and 44 fractures of the radius or ulna. A suggested mechanism was that the driver braced his hands on the steering wheel prior to impact. The force of impact was transmitted to the hand, wrist, and forearm.
The incidence of pelvic fractures and hip dislocation were similar. Femoral fractures were less common in passengers because of a more upward component of the forward movement because of the absence of the steering wheel. Ankle and foot injuries in unrestrained drivers and passengers in highspeed collisions were generally similar to restrained vehicle occupants and were most severe when there was significant floor pan intrusion.
The Injury Severity Score (ISS) was created in 1974 as an indicator of anatomic injury severity based on the Abbreviated Injury Score.65 The ISS is calculated from the most severe injury in each body region and is extensively used in hospital review committees as an objective measure in evaluating outcomes of trauma management.66 More recently the New Injury Severity Score (NISS) has been introduced as a more accurate measure of injury severity.67 The NISS is believed to be superior to the ISS because the calculation more accurately reflects the presence of more than one severe injury to a given body region, and the greater importance assigned to severe head and neck, chest, and abdominal injuries as opposed to extremity injury.
The Trauma and Injury Severity Score (TRISS) evaluates the severity of anatomic injury (ISS) and physiologic effect of trauma to provide a probability of survival in the trauma patient.68,69 The documentation of injury is based on hospital investigations and autopsy reports in deceased victims of motor vehicle incidents.
Motor vehicle fires are uncommon in gas-powered vehicles and rare in diesel vehicles. A fire requires heat, oxygen, and an ignition source. A fire may commence as a result of a fuel line fault, in which case the fire usually commences in the engine bay or as a consequence of a motor vehicle collision.
The most frequent types of collision associated with a vehicle fire are high-speed rear impact and rollover incidents. These impacts are associated with a high incidence of fuel leaks and rupture of the fuel tank.70
Fires are more common in older vehicles. Vehicle size is not a risk factor. Deaths from a crash with a fire may result directly from trauma or from the fire. In cases in which the fire has caused death, the victim may have been incapacitated by the collision or unable to escape because of collapse of vehicle structures or intrusion.
Railway trauma. It signifies an association of mechanical actions of the moving train to human body together with the injuries that formed resulting in health disorder or death.
Classification of railway trauma (according to А.I.Мukhanov, Ternopil, 2008)
· Knock down
· Run over a body
· Dragging
· Squeezing between the vehicle projections
II. Inside of the train (by internal parts of a train):
Forensic diagnostics of railway trauma. Railway injuries may be suicidal or accidental. A simple decapitation is commonly an indication of a suicide and rarely of an accident. Traumatic amputation of the extremities or trunk is typically for accidents or rarely of a suicidal person. The nature of the injuries will depend upon the position of the victim when struck.
In general the diagnostics of railway trauma is based on two main expert features (signs): specific injuries and typical injuries.
Specific railway injuries are the following: Squeezing bands — the imprints of the rolling wheel on the skin like striated abrasions near 8-14 sm. in width. Dirt bands — are located on the skin, along the periphery of the squeezing bands. They are smeared with lubricant and soil. Dissection of the body. It depends on which part of the decedent was located on the rails or which part of the body was run over. Separation of limbs. Wedge-shaped defect of the tissues in the area of railway wheel rolling. Striated ruptures of the skin in the zone of separation. Imprints of any prominent details of the train etc.
Typical railway injuries:
· Injuries are multiple, extensive and various
· Deformation of the body and limbs
· Signs of general concussion of the body
· Tires of the skin
· Superficial smearing of clothes and skin with ballast bed particles
· Presence of the injuries on the opposite sides of the body
· Dragging marks upon the skin
· Internal injuries are more severe than external
Therefore multiple severe injuries formed simultaneously in many regions of the body commonly characterize this type of transportation trauma.
Railway trauma is characterized by numerous considerable injuries, which localize simultaneously in several, and sometimes in all parts of the body. Except the classification mentioned above in railway trauma distinguish (S.S.Muntyan, 1977): blow by railway transport, that moves; crossing by wheels, falling from the train; squeezing of body by parts of transport; trauma inside carriages at railway catastrophe; combined kinds.
The following specific signs of railway trauma are met in forensic medical practice:
separation of the body;
stripes if abrasion from pressure by wheel surface, that rolls,
or ribbons of abrasion on the edge of dismembered body part;
original scratch of certain form from primary “pinch ” by a wheel;
angled skin parts (in appearance of big saw indents) on dismemberment edge;
wedge-shaped tissues’ defect in crossing zone;
“plicated smoothing” of clothes material with metallic brilliance;
rubbed allotments and stripes of side-slip;
impresses of certain parts of the train, in that number of buffer plates or the mechanism, that connects carriages;
exfoliating of skin on considerable region and repeated skin pieces kink;
polishes in bones
and some other.
For railway traumas typical are:
multiplicity, magnitude and variety of damages;
deformation of body parts;
cracks, tears and skin ruptures from its excessive tension;
numerous traces of body dragging and sliding by the road surface;
ballast dusty of clothes and body;
damage of calves by locomotive, that reminds bumper-damage at autotrauma;
striped clothes ruptures, which localize on trouser-legs or sleeves.
Damages from knocking down by a train form from double action: blow by parts of transport, that runs, and blow by body during following fall. It is not easy to distinguish them at railway trauma. Dominating damage from blow by a train are the wounds, which have considerably grazed edges, are more clearly expressed comparing with those, that appear in the moment of secondary body blow. On body side, which has experienced a primary blow, bone fractures and damages of internal organs are more expressed, considerably more massive damages on contrary side, lungs are torn by ribs parts, effusions of blood into soft tissues is more intensive. Sometimes a blow leaves impresses of some prominent part of a vehicle.
Crossing by train wheels is diagnosed for specific signs: body is divided on parts or dismemberment of body parts; stripes of grazing or pressure or ribbons of grazing on dismembered parts of a body; scratch from primary “ pinch” by wheel of typical longitudinality, Т-like form or inflammation mark form; angular big skin pieces on dismemberment edge; wedge-shaped defect of tissues in wheel action zone; “plicated smoothing of clothes” and its contamination by black substance with metallic brilliance; rubbing allotments and stripes of side-slip; filings in bones from long friction of their lateral surface by wheel or rail during considerable body dislocation; are well expressed traces of body dragging along the railway etc.
Stripe of grazing or pressure, i.e. impress on wheel surface on skin, appear by reason of scratching of skin epidermis, that has a great resistance to pressure comparing with soft tissues, , organs or bones situated under it, which appear to be mashed or crushed. At once after trauma stripe (or pressure ribbon on the edge of divided part of body) is soft, pink or pale-red. Afterwards it gets dry and to the end of the first day acquires crimson or livery colour and parchment density. The pressure stripe width on average composes 10-
The scratch from primary “pinch” by the wheel is situated before grazing stripe beginning and indicates on place of primary train wheels contact with victim’s body and on his position on rails in accident moment.
The wedge-shaped tissue defect appear in all cases of train wheels crossing over the victim’s body. Morphologically it is full destruction of soft tissues and bones in crossing place. In tie with more intensive body traumatizing by wheel this defect in profile has a wedge form, always facing its wide side to the wheels. Wedge-shaped defect appears both on extremities and on the body. It is diagnosed by comparison of dismembered parts of the body. During this wound parts of body surface, which were found in dismemberment moment on the rail, compare, and facing the wheel are found on distance 5-
Rubbing allotments or stripes of side-slip form near stripes or pressure ribbons by reason of fleecing of skin by lateral wheels’ surfaces. Unlike stripes or pressure ribbons, rubbing allotments have uneven edges and unequal width, which vacillates from 2-
Polishes in bones are generated rarely, in that cases, when body during crossing by wheels of railway transport dismembers on several parts. Some part of dismembered body can be grasped by train details, pressed to lateral wheel surface, that twists, or to rail head and to drag in such state for a long time. During long friction soft tissues are fully erased, and in bone appear polished area with longitudinal lines. On their surface frequently remain parts of black grease. Polished allotments from friction by lateral surface of wheel dispose, as a rule, on arc. Polishes in bones are the specific sign of railway trauma.
To setting the fact of crossing by train wheels contribute row of typical signs, namely: massiveness and variety of damages; deformation of body parts; cracks and. skin ruptures from its excessive tension; breaks of hypodermic base from within, of aponeuroses, fascia, muscles; diaphragm ruptures, neck skin, perineum and other parts and pressing out damaged internal organs through them; ballast dusty of clothes and damages by sand or slag particles etc.
Ballast dustiness of clothes, body, wound surfaces – the considerable contamination of them by ballast, i.e. by particles of road-metal, gravel, sand, which fill up railway groundwork and on which lay the sleepers. At railway trauma because of big train speed or displacement of body by ballast groundwork layer, parts of ballast get on clothes, into their folds, to pocket, between clothes layers, into natural concavities and body holes, and also into damages. Presence of ballast parts on body, closes and in damages – almost permanent sign of railway trauma, in that number – of crossing over.
Crossing by railway transport frequently is attended with dragging of the victim along road groundwork. During this from blows by sleepers, rails and friction by ballast large grazes, numerous scratches, wounds, fractures of some bones are generated, which are dusted with considerable amount of grease and particles of way ballast layer. Long dragging can be attended with displacement, turning inside out and even full tearing away of clothes from the body.
At body squeezing between carriages on chest and back skin usually form the impresses of buffer plates contours or locking parts of autoconnector in appearance of grazes or bruises. Appear damages, typical for strong squeezing of a body. Other types of railway trauma, as a rule, do not have typical peculiarities.
Trauma by cartage, caterpillar, air and water-carriage meets more rare, its properties and possibilities of forensic-medical diagnostics are contained in special manuals, monographs or scientific articles.
Motorcycle injuries. Motorcycles are very unsafe because they have less stability than four wheeled vehicles, their speed is high, their size is relatively small and a motorcyclist does not have any protection from an accident. When an accident happens, the injuries are often severe as there is very little crushable material to absorb the impact. A driver and passengers are thrown off usually. All types of injuries may be present. Primary injuries are mostly open fractures of the tibia and fibula. Secondary injuries are mostly fractures of the skull and cervical spine, as well as contusions of the brain.
Motor-cycle trauma is an independent and separate group of vehicle trauma. It happens most frequently by reason of motor-cycle collision with other transport vehicle (43-49 %), in result of fall from motor-cycle (23-37 %) and knocking down a pedestrian by motor-cycle (12-13 %). Considerably more rare happen: motor-cycle collision with immovable barrier (8-10 %), crossing through the victim by wheels and non-typical cases.
At bike trauma meet specific damages, incident to only it – concrete traces, which reproduce the motor-cycle details: traces-impresses, contamination traces, metallization traces, which coincide with a form, size or texture of certain part of a vehicle.
For motor-cycle trauma typical are combinations of severe cranial-cerebral trauma with damages (fractures) of extremities, damage from general shock of body etc. Knocking down the pedestrian by motor-cycle frequently is followed by damages of lower extremities – fractures of one or both bones of the calf, and also by cranial trauma by reason of secondary blow at pedestrian fall, sometimes – by one-sided ribs’ fractures.
During motor-cycle collision with other transport vehicle mortal damages usually receive bikers, trauma in which is combined. Typical is combination of cranial-cerebral trauma with damage of extremities, chest and organs of abdominal cavity. Isolated cranial-cerebral trauma meets rarely. The last is most typical for falling down from motor-cycle: numerous face scratches and bruises, wounds with exfoliating of edges from bones, pressed bone fractures of anterior skull surface with distribution of cracks on skull base, blood effusions under envelopes, nto ventricles and brain substance. Also combined trauma of chest and stomach takes place.
Making forensic-medical examination in cases of motor-cycle trauma, one should have in mind also typical data. At motor-cycle trauma the biker frequently dies, at it many of light damages are observed, trauma from primary blow more frequently localizes in lower and middle third of calves, it can never be situated above pelvic allotment, does not cause exfoliating of skin, damage of head and skeleton, always one-sided, do not meet signs of body squeezing video .
A fracture of the skull with the associated brain injury is the most common cause of death but multiple injuries usually lead to fatal motorcycle accidents.
Bicycle trauma. Because of the speed of this vehicle is lower, usual fatal injuries can be inflicted due to another motor vehicle striking the rider. Primary impact injuries of the legs with secondary injuries to the head, shoulder and trunk are commonly seen. The majority of fatal bicycle accidents are collisions between a bike and a motor vehicle. Among all these kinds of trauma head injuries, trunk injuries and contusions, distortions and fractures of the lower part of tibia and fibula may be mainly revealed.
A motor-car trauma. This kind of transport trauma are occurred the most often. Particularly 80 % of all forensic investigation in cases of transport trauma is connected with road accident. among all cases of is classified differently. For practical aims most useful is dividing them into 2 groups damage by external parts (outside a car) and by inner parts of a car (inside it), their kinds are listed above. So, modern forensic medicine distinguishes follow kinds of vehicular (motor-car ) trauma (according to classification of ass.-prof. A.I. Muhanov., 1974)
Forensic autopsy in cases of vehicular trauma
Proceeding to necropsy of a man, which probably has died from vehicle (motor-car, motorcycle, railway or other) trauma, for the first turn one should view clothes and footwear with aim of search on them specific and typical traces of transport parts action, and also driveway coverage, in that number by means of magnifier or stereomicroscope (operation microscope).
Describing damages, it is necessary to determine their localization, direction concerning body axis, form, size, colour, edges properties, walls, ends and bottom, state of surrounding tissues, correlation of damages, and also contamination inside them, presence of foreign inclusions and particles (last withdraw for giving to investigator). It is important to measure the distance from damages to sole surfaces with taking into account sole thickness and footwear heel, because these data will help to specify victim’s and transport method interposition in accident moment.
To obligatory photographing according to rules of scientific photography subject specific and typical damages or contamination of skin, internal organs and bones. If it is impossible to do, one should copy them on polyethylene film by ball-pen.
It is important to find hidden damages, for example, effusions of blood into deep back muscles, extremities, etc. For this is expediently to employ a circulation cut at the front on clavicles level, behind – in suprascapular region with following skin cut along middle line at the front and behind, continuing the cuts on upper and lower extremities.
During internal examination it is necessary to have a careful view of organs and tissues in places of their withdrawal with view of topography comparison of external and internal damages, finding signs of general body shock and displacement of damaged organs. During this obligatorily examine all internal organs, ribs, scapulas, spine, pelvis bone, tubular bones, joints and bones of facial skeleton. After examination of damaged bone in the corpse it is desirable to withdraw them fully or their fragments for laboratory examination with the aim of fractures mechanism determination and specification of vehicle trauma mechanism. The fractures depict on contour schemes, photograph.
To speak about man’s health state, during necropsy is obligatorily needed to exclude, and at presence – to estimate organic diseases, which could be a cause of traffic accident (illness of cardiac-vascular system, eyesight organs, hearing etc). Obligatory is determination of presence and quantitative contents of alcohol in organism of dead man. For this for forensic-chemical examination take from the corpse and direct into laboratory 20 ml of blood (from large veins or sines of dura mater ), and urine in glassware, filled to the cork.
For direction into forensic-medical laboratory obligatorily subject also blood (not less then 10 ml) for determination of its antigen belonging in cases of external damages or bleeding presence, hair from 5 head allotments for comparative examination, about what a suitable record at the back of protocol part of the act (expert conclusions) is made. Other types of laboratory research foresee depending on tasks of concrete examination. Employ histological method for determination of lifetime and remoteness of damages, and also for specification of pathological changes in organs or for exclusion of them; stereomicroscopy – for finding damages’ details, signs of tissues’ destruction, small foreign objects; rontgenography – for search of foreign objects, bone fractures, etc.
PRACTICAL CLASS № 7
FORENSIC-MEDICAL EXAMINATION OF INJURIES AND CAUSES OF DEATH INFLICTED BY MECHANICAL FACTORS. FORENSIC-MEDICAL EXAMINATION IN CASES OF TRANSPORTATION TRAUMA
Тhemes: 1. Transportation trauma.
2. Forensic-medical examination in cases of motor vehicle trauma.
3. Forensic-medical examination in cases of railway collisions, other traffic accidents.
Objectives: to know the properties of the injuries caused by moving vehicles, the particularities of medicolegal examination in cases of vehicular trauma and to be able to make forensic conclusions in typical cases of motor vehicle, motorcycle and railway trauma.
Introduction. Injuries caused by moving vehicles – motor vehicle trauma and railway trauma have the first place among all the causes of violent traumatic death. Traffic traumatism is common all over the world. Thus, almost 5 thousand of Ukrainians died in 2010 y. in result of traffic accidents. The ratio of disable persons to the deceased is 1:5. Therefore, it is necessary for a forensic expert to be able to assess the injuries, the mechanisms by which they are caused, the cause of death, and if alcohol or drugs intoxication takes place. Investigation of transport accidents with victims is often difficult. The injuries as a rule assume a definite and distinguishing pattern in the cases of a pedestrian, and driver or a passenger, depending on the type of impact. Forensic expert should not be content with an accurate description of the injuries, but should continually give thought throughout the examination as to the possible mechanisms of their cause. His ideas, albeit tentative at the time, may be of considerable value to the police in the early stages of the investigation of unexplained death.
As far as the number of vehicles and vehicle-related trauma increases the theme is so important for medical students.
Basic level of knowledge and skills (before the practical class)
• The notion of a trauma and traumatism
• Morphological features of inflammation, reparation, bleeding etc.
• Clinical and morphological characteristics of abrasions, scratches, bruises, wounds, fractures.
Visual Aids and Material Tools.
Different museum specimens (human skin with abrasions, wounds, lacerations, internal organs, fractured bones, injured due to road accident) are the objects of the investigation. Tables, photos, video are demonstrated too.
I. Students’ Independent Study Program
Тheme № 1 of the practical class.
1. Trauma and traumatism, transportation trauma.
2. Kinds of transportation trauma.
3. Меdical classification of injuries, clinical manifistations of abrasions, bruises, wounds, bone fractures, internal injuries. Patterned injuries.
4. Basic roles, scheme and content of autopsy report.
Тheme № 2 of the practical class.
1. Motor vehicle trauma, its classification.
2. Specific and typical signs of motor vehicle trauma.
3. Forensic diagnostics of knock down by a car, run over a body, sliding across the road.
4. Еxpert appearances of driver’s trauma.
Тheme № 3 of the practical class.
1. Railway trauma, its classification.
2. Specific and typical signs of railway trauma.
3. Forensic diagnostics of motor cycle injuries.
4. Motocycle and bicycle injuries.
Block of Information (Terminology)
Trauma – a bodily harm with or without structural alterations resulting from interaction with physicochemical agents, imparting energy to tissues.
It can cause morphologically apparent damage (wound) or produce physiological imbalance (e.g. reflex cardiac arrest by neural stimulation) and secondary effects (e.g. thrombosis, infection, obstruction of tubular organs)
Transportation trauma – an association of mechanical actions of a moving vehicle to human body with the injuries that formed resulting in health disorder or death.
Classification of transportation trauma – depends on the kind of a vehicle: I. Ground – rail (railway, tram etc.); non-rail (automobile, motorcycle etc.); caterpillar (tractors). II. Air (aircraft, helicopter etc.). III. Water – above-water and underwater (both propeller, motorless vehicles).
Vehicular trauma (forensic definition) – an association of mechanical actions of a moving vehicle (lorry, track) to human body together with the injuries that formed resulting in health disorder or death.
Classification of vehicular trauma ( according to А.I.Мukhanov, Ternopil, 2008)
• Knock down
• Run over a body
• Dragging
• Association of them
II. Inside of the vehicle (inflicted by internal parts of a carrier):
• Driver’s trauma
• Passenger’s trauma
Forensic diagnostics of vehicular trauma. The diagnostics of a vehicular trauma is based on two main expert features (signs): specific injuries and typical injuries.
Specific injuries are termed also as patterned injuries. They may correspond to some parts of a moving vehicle involved into the traffic accident and their shape, size, outline, surface of the bottom commonly represent a definite traumatic part or detail of the car: patterned abrasion of car light in pedestrian trauma, imprint of a steering wheel or dash board on the skin in driver’s trauma, tyre mark on outer clothes in run over a body etc. If such injuries are found on the body they directly suggest vehicular trauma therefore they are so important for forensic diagnostics and must be firstly detected by the expert. Unfortunately, specific injuries can be rarely revealed (nearly 7-8% among all cases of transportation trauma). Thus, the basic forensic medical diagnostics is connected with typical signs of motor-vehicle trauma.
Typical injuries of vehicular trauma:
• Numerous and various injuries
• Deformation of the body
• Imprints of the clothes on the skin
• Ruptures of the skin
• Location of the injuries in more than 2 anatomic regions
• Presence of the injuries on the opposite sides of the body
• Great abrasions on the skin
• Internal injuries are more severe than external
Knock down by a car. It is a knock down of a pedestrian by external parts of a moving motor-car. In other words it is termed as pedestrian trauma in forensic medicine. A moving car strikes a victim as a rule due to the follow phases:
1. previous impact .
2. falling down on a car.
3. falling down on the ground.
4. friction against the road.
The first phase is characterized by formation of contact (patterned) injuries at the site of collision of the body with definite (as a rule – prominent) parts of a moving car. They may be rings of headlights, radiator, bumper, fender etc. The most prominent part of a vehicle is a bumper which blows a victim at first. As a result of this bumper fractures of lower extremities are formed. They are usually fractures of the tibia and fibula or femur. The localization of a fracture depends on the height of the bumper (if a lorry – great, a light motor vehicle – less) and height of the victim (child or adult). It is very important for an expert to measure the distance between the heel of the victim and the level of his fracture. Generally a bumper fracture is spiral shaped. In the latter, the base of the triangular fragment of the bone indicates the site of an impact and the apex points the direction in which the vehicle was moving. In foreign forensic literature patterned and bumper injuries are often termed as primary impact injuries. During another phases (2nd-4th) secondary injuries are formed. Due to a contact with a windshield, severe head, spinal injuries, fractures of ribs, lacerations may occur. Injuries due to a contact with the ground include abrasions, lacerations and bruises over the face, hands, hips, legs or bony prominences. They are often marked with traces of dirt. Huge internal injuries (ruptures and fragmentations of inner organs) may be inflicted too.
Thus, a mechanism of a knock down is rather difficult and generally in medico-legal practice may be confirmed by the following expert features: specific – an imprint over the clothes or skin any external details of the vehicle; typical – bumper injuries, locality of the injuries, morphological appearances of general contusion of the body, sliding marks over the body, friction marks on soles of victim’s boots.
Run over a body. It is such type of a vehicular trauma when injuries are formed when a moving wheel runs over a victim’s body. As a separate type of a traffic trauma it takes place seldom in medico-legal practice and it usually is associated with a knock down. In other words it follows after a knock down, when a pedestrian is firstly knocked and then he is run over by a car. The mechanism of this trauma consists of 3 main factors: 1.impact with a moving wheel; 2. squeezing of the body between a wheel and road; 3.friction against the ground and wheel. The severity of this trauma depends upon the part of the body run-over, the weight of the car and its speed.
Forensic diagnostics in cases of run-over must be directed for the detection of specific and typical signs of this trauma. So, there is only one specific expert sign of run-over – tyre marks upon the skin and clothes. When a limb is run over by the wheel of a motor-vehicle the skin and subcutaneous fat may be dragged away from the deeper muscles with or without any break in the continuity of the skin. This is known as degloving – one of the most important of typical sign of run-over. The followings should be assumed by the expert as typical medico-legal signs of run-over a body by a car:
• Imprints of the clothes on the skin
• Deformation of limbs
• Bilateral (symmetric) fractures of the ribs and pelvis
• Displacement of abdominal viscera to the chest or vice versa
• Avulsion, crushing or extrusion of internal organs
• Longitudinal parallel tears of the skin above the bony prominences (wings of ilium)
• Ecchymoses in the eyes.
As usual these typical morphological features may be easiely found during medico-legal autopsy and help an expert exactly define this type of a motor-vehicle trauma.
Dragging. It refers to the type of a vehicular trauma when a victim is caught by a moving motor-vehicle and is dragged against the ground “road rash”. The distance of such dragging may be so long (tens and hundreds of meters). Because of this a victim slides against the road and multiple elongated abrasions and grazes are formed. They are accompanied by numerous linear parallel scratches. These are termed in forensic practice as “drag marks”. All these injuries are observed upon the huge surface of the skin. “Sawing” of the soft tissues may be revealed too.
Association refers to a combination of some kinds of motor-vehicle trauma: knock down with run-over, run-over together with dragging etc.
Driver’s or passenger trauma. When a vehicle is involved in a road accident a driver or passenger may sustain serious multiple injuries. Such a type of an automobile trauma is known in forensic medicine as driver’s or passenger trauma. Most of vehicular accidents are frontal (collision with other vehicle or fixed object) and occur in about 80% of all vehicular accidents. Here, we can distinguish typical mechanism of a trauma. The occupants of the car continue to move forward, even though the vehicle stops. The driver first slides forward so that his legs strike the lower surface of a dash-board and his abdomen or lower chest strikes the edge of the steering wheel. Then the body flexes across the steering wheel and begins to rise. The head goes forward and there is severe flexion of cervical and thoracic spines. When the car suddenly stops due to the collision, the head comes back with great force and great extension of the spine is formed (whip-like fracture). The head strikes the windscreen, upper windscreen rim or the side pillar (on the left for the driver, on the right in case of front seat passenger or when right traffic order). The windscreen may break and the person may be ejected trough the broken glass on the bonnet or to the ground. The front seat passenger sustains the same impact except injuries from the steering wheel. The back seat passenger impacts on the back of the front seat.
Forensic diagnostics of the trauma inside the vehicle. As stated above, the occupants of the motor-vehicle sustain definite injuries – both specific and typical. Any patterned injuries (bruises, abrasions, lacerations) due to the impact on the internal automobile details: dash-board, windscreen rim, side pillar etc. Steering-wheel injuries (an imprint abrasions of the steering-wheel on the skin, fractures of sternal portions of the ribs, fractures of the sternum) are specific only for driver’s trauma. All these injuries are specific for the trauma inside a vehicle.
The following medico-legal features are typical for a driver’s or passenger trauma:
• Location on the anterior parts of the body
• Cervical fractures of the spinal cord
• Fractures of the facial bones
• Fractures of the legs and pelvis due to the pressure against the foot pedals (in driver’s trauma)
• Fractures of the tibia, fibula, hips and knees due to impact against the dashboard
• Numerous small cuts caused by broken windscreen on the back surfaces of the hands or on the face (driver’s trauma only). Note, tiny pieces of windscreen glass may be seen inside these injuries.
• Ruptures of m. recti of the abdomen.
• Ruptures, fragmentations, displacements of internal organs (liver, spleen, kidneys, diaphragm, aorta etc.)
• Basilar skull fractures, closed head injuries, dislocation of the atlanto-axial joint.
Forensic-medical expert has to take into account that injuries that are seen on the left side of the body refer to drivers trauma and the location of the injuries on the right side usually refers to passenger trauma.
Railway trauma. It signifies an association of mechanical actions of the moving train to human body together with the injuries that formed resulting in health disorder or death.
Classification of railway trauma ( according to А.I.Мukhanov, Ternopil, 2008)
• Knock down
• Run over a body
• Dragging
• Squeezing between the vehicle projections
II. Inside of the train (by internal parts of a train):
Forensic diagnostics of railway trauma. Railway injuries may be suicidal or accidental. A simple decapitation is commonly an indication of a suicide and rarely of an accident. Traumatic amputation of the extremities or trunk is typically for accidents or rarely of a suicidal person. The nature of the injuries will depend upon the position of the victim when struck.
In general the diagnostics of railway trauma is based on two main expert features (signs): specific injuries and typical injuries.
Specific railway injuries are the following: Squeezing bands – the imprints of the rolling wheel on the skin like striated abrasions near 8-14 sm. in width. Dirt bands – are located on the skin, along the periphery of the squeezing bands. They are smeared with lubricant and soil. Dissection of the body. It depends on which part of the decedent was located on the rails or which part of the body was run over. Separation of limbs. Wedge-shaped defect of the tissues in the area of railway wheel rolling. Striated ruptures of the skin in the zone of separation. Imprints of any prominent details of the train etc.
Typical railway injuries:
• Injuries are multiple, extensive and various
• Deformation of the body and limbs
• Signs of general concussion of the body
• Tires of the skin
• Superficial smearing of clothes and skin with ballast bed particles
• Presence of the injuries on the opposite sides of the body
• Dragging marks upon the skin
• Internal injuries are more severe than external
Therefore multiple severe injuries formed simultaneously in many regions of the body commonly characterize this type of transportation trauma.
Motorcycle injuries. Motorcycles are very unsafe because they have less stability than four wheeled vehicles, their speed is high, their size is relatively small and a motorcyclist does not have any protection from an accident. When an accident happens, the injuries are often severe as there is very little crushable material to absorb the impact. A driver and passengers are thrown off usually. All types of injuries may be present. Primary injuries are mostly open fractures of the tibia and fibula. Secondary injuries are mostly fractures of the skull and cervical spine, as well as contusions of the brain.
A fracture of the skull with the associated brain injury is the most common cause of death but multiple injuries usually lead to fatal motorcycle accidents.
Bicycle trauma. Because of the speed of this vehicle is lower, usual fatal injuries can be inflicted due to another motor vehicle striking the rider. Primary impact injuries of the legs with secondary injuries to the head, shoulder and trunk are commonly seen. The majority of fatal bicycle accidents are collisions between a bike and a motor vehicle. Among all these kinds of trauma head injuries, trunk injuries and contusions, distortions and fractures of the lower part of tibia and fibula may be mainly revealed.
II. Меthodology of the practical activity (9.00-
If a dead body is present in the autopsy room (road accident has occurred), forensic investigation is performed according to the methodology to lesson № 2.
In other cases practical activity is performed in the studying rooms of the course. All the themes of the class are inter-connected and students must investigate great volume of case materials, that’s why they perform only one practical work.
Тopics № 1-3 of the practical class.
Рractical activity 1-3.
Every student receives a sample of the «Report of forensic investigation of сase materials» of the person who died as a result of a vehicular trauma. They must rewrite the report in their exercise-books and make forensic conclusions taking into account the following investigator’s questions:
1. What is the cause of Mr. Н.’ death and the probable mechanism of its development?
2. Which objects caused the injuries?
3. Did the moving motor vehicle inflict the injuries?
4. Which kind of a vehicular trauma occurred?
5. Which morphological signs may suggest knock down by a car and run over a body?
6. Which degree of severity is revealed?
Practical activity starts while the protocol part of the report is filled in. The date, city, name and surname of the physician, number and date of investigator’s requirement, place of investigation, examined object and investigator’s questions are noted in the introduction. The next chapter of the report is called «Previous information» which includes the main information about the accident; «Investigation part» is the last and the most important chapter of the report where students rewrite in details all morphological features of the injuries which were found in deceased. They note such properties of the injuries: localization, their kinds, shapes, sizes, characteristics of edges, ends and surfaces, their color, signs of healing, properties of surrounding tissues are also marked. The description should be accompanied by a schematic picture of the injuries on the body.
Discussion of theoretical questions and practical activity (11.45a.m.-02.00 p.m.):
At the end of the lesson forensic conclusions are discussed with active participation of all the students of the group. The teacher corrects the answers and helps to create forensic conclusions.
Exit level of knowledge and abilities. (2.15 – 3.00 p.m.)
It is checking by tests.
Tests and real-life situations for self-assessment:
1. An association of mechanical actions of a moving vehicle to a human body with certain injuries that formed is known in forensic medicine as…
A. vehicular trauma
B. railway trauma
C. aircraft accident
D. road accident
E. all are correct
2. Which kinds of a vehicular trauma (inflicted by external parts of vehicle) do you know?
A. Knock down
B. Run over a body
C. Sliding
D. Association of this all
E. All are correct
3. Injuries that are formed only in road accidents cases and can be never seen in another cases are termed as
A. Pattern-injuries (specific signs)
B. Typical signs
C. Common signs
injuries
E. Vehicular injuries
4. Definite injuries that directly suggest vehicular trauma are termed as
A. Pattern-injuries (specific signs)
B. Typical signs
C. Common signs
injuries
E. Vehicular injuries
5. Find the correct answer: specific signs of a vehicular trauma are…
A. Pattern-injuries
B. Bumper fractures
C. Grazes of the face
D. Scratches of the back
E. Lacerations of the knee
6. An imprint-abrasion of the radiator on the chest of a pedestrian directly suggests a vehicular trauma because it is
A. Pattern-injury (specific sign)
B. Typical sign
C. Common sign
injury
E. Vehicular injury
7. Try to find the typical signs of knock-down by a car:
A. Sliding marks over the body
B. Locality of the injuries
C. Morphological appearances of general contusion of the body
D. Friction marks on soles of victim’s boots
E. All are true
8. One of the following is mainly correct about typical railway injuries:
A. Injuries are multiple, extensive and various
B. Deformation of the body and limbs
C. Superficial smearing of clothes and skin with ballast bed particles
D. Tires of the skin
E. All are true
9. Mr. V. had injuries as a result of the collision between motor vehicles. In 30 minutes he was delivered to the hospital with the diagnosis “contusion of the cervical part of the spine, abrasions and bruises of the upper extremities, multiple lacerations of the face”. The X-ray examination revealed the displacement of the 3-4 cervical vertebrae forward without a trauma of the spinal cord. Determine the type of an automobile trauma.
A. Driver’s.
B. Front seat passenger.
C. Back seat passenger.
D. Run-over.
E. Knock down.
10. An unknown old man was found next to the rails. His body was examined by an expert at the scene of death. The body was decapitated, with numerous fractures of the limbs and extensive blood stains covered a large area around. Forensic expert considered that …probably took place.
A. An assault
B. A murder
C. Railway trauma.
D. Falling from height
E. An accident
Answers to the tests:
1-A; 2 – E; 3 – A; 4 – A; 5 – A; 6 – A; 7 – E; 8 – E; 9- A; 10 – C.
After the practical class every student
must know:
1. Kinds and types of vehicular trauma in traffic accidents.
2. Modern classification of motor-car trauma and railway trauma.
3. Specific and typical forensic signs of definite kinds of vehicular trauma.
4. Particularities of medicolegal examination in vehicular trauma and the main principles of the construction of forensic conclusions.
must be able to:
1. To reveal, describe and estimate morphological appearances of injuries in all the cases of transportation trauma.
2. To create the section (morphological) diagnosis in traffic accident cases.
3. To make complete forensic conclusions in typical cases of an motor-vehicle, motorcycle or railway trauma.
