ROAD TRAFFIC INJURY

The road traffic accidents, injuries may be sustained to.

1. Pedestrian . 2. Cyclist / motorcyclist. 3. Occupants of a vehicle.

TRAFFIC ACCIDENTS:- A large variety of injuries are

sustained by persons involved in traffic accidents..

A traffic collision, also known as a traffic accident, motor vehicle collision, motor vehicle accident, car accident, automobile accidents, road traffic collision, road traffic accident.

1. INJURIES TO PEDESTRAINS:-

Three patterns of injury are often seen.

1. Primary impact injuries.(the first part struck).

2. Secondary injuries.( further injury caused by vehicles). &

3. Tertiary injuries.(injuries caused by victim’s striking objects, such as the ground).

I. IN PRIMARY IMPACT INJURY:-

These are the injuries caused by vehicle when it first struck and Hit the person whether crossing the road from one side to the other side or walking with or against the traffic.

The importance of primary impact injury is that the body of victim may bear design / pattern of the part of vehicle in form of imprint abrasion pattern bruised.

Common parts of vehicle which may struck or hit a person includes..

1. Bumper2. Wing3. Grill4. Head Light5. Fender 6. Radiator 7. Door handle The body part which bears the

injury depends upon the position of the person such as:-

1. Was the pedestrian struck by front of Car/Vehicle?

2. Was the pedestrian struck by side of Car/Vehicle?

3. Was the pedestrian standing on road?

4. Was the pedestrian walking on road?5. Was the pedestrian lying on road? If the vehicle was braking violently

at the movement of impact, the font end of the vehicle dips down an the legs get injured at a lower level.

The injury comprises of damage to skin and fracture of bone (k/w as Bumper fracture).

The Bumper fracture usually involves Tibia. The fracture is wedge shaped with base of triangular fragment indicating the site of impact and apex pointing the direction of vehicle.

Frequently Bumper injuries are at different level of the two legs or absent on one leg, which suggest that the victim was walking or running when Struck.

Frequently Bumper injuries are at different level of the two legs or absent on one leg, which suggest that the victim was walking or running when Struck

In children the bumper usually produces fracture of the femur.

If bumper injury are at the same level on both legs then it means the person is standing.

The level of bumper injury (i.e the height of injury from ground level) varies with height of bumper of different vehicle. It means than the offending vehicle can be identified.

At impact against the headlamp or mudguard may result in fracture of the pelvis or fracture dislocation of the sacroiliac joint.

The findings of primary impact injury are important to find out the relative position of pedestrian and vehicle and kind of vehicle involved in the Incident.

II. IN SECONDARY IMPACT OF INJURY:-

After sustaining primary impact of injury, the person may be lifted off the ground and thrown of the vehicle.

thus these secondary impact injuries are resulted from the impact of body of a person and the vehicle for a second time.

Here the person strike to windshield or bonnet or placed on the top of car/ vehicle.

After the second impact injuries, the victim will be thrown on the ground.

Extensive abrasions, bruises and laceration may be seen.

Some times pedestrians are ‘run over’ if knocked down by the vehicle.

This will tend to occur if the pedestrian’s center of gravity is lower then the impact side or scooped-up victim being run over by other vehicle.

Injuries are variable, depending on the area of the body involved.

The weight of the vehicle and the surface area of the contact.There may be:

i. Tyre trade marks marks over the unclothed or clothed areas on one surface of body with graze like abrasions on the opposite side of body.

ii. The head may be crushed causing gross distortion and externalization of the brain and severe injuries my occur to the chest, pelvis & abdomen.

iii. Compression of the chest may result in multiple rib fractures, causing a ‘flail chest ’ with rupture of internal organs along with the fracture of spine, sternum & ribs.

iv. Burning and singeing of skin and hair resulting from discharge of hot exhaust

FLAIL CHEST:-

III. SECONDARY INJURIES/ TERTIARY INJURIES :-

These are the injuries that occur after second impact injuries when the victim is thrown off the vehicle on the ground .

Here the victim sustain secondary injuries from the ground. Head injury is more common though injuries to other part may occur.

Some times the victim may be run over by the same vehicle and another vehicle.

Brain damage is frequent without any associated skull fractures.

Fracture of the skull and ribs due direct contact with a surface, and fracture of spine due to hyperflexion or extension may be seen.

Fracture of the limbs are common but apart from toes of the legs.

Usually it is very difficult to classify the injuries as Primary impact, secondary impact or secondary injuries.

In pedestrian accidents, the common cause of death is head injuries and fracture dislocation of cervical spine.

Injuries to the chest and abdomen are minimal or absent.

2. INJURIES BY MOTORCYCLE & CYCLE:-

Injuries sustained by motorcyclist are much more serious then car travelers because:-

1) Inherent instability of two wheeler.

2) Unprotected and lack of protective gear.

3) Rush and negligent driving.4) The common causes of

motorcycle accidents are Alcohol, drugs, environmental factors, reckless driving and failure by drivers of

Cars to see the motorcycle.5) The most common cause of

motorcycle fatality is running of road.6) Most injuries are due to ejection from

the vehicle into the roads, due to high speed and instability of the vehicle.

7) Primary injuries are mostly open fracture of the Tibia and Fibula.

8) Secondary injuries are mostly fracture of the Skull, Ribs & cervical spine, as well as contusions of the Brain.

9) There are graze abrasions due to sliding across the road.

: Any part of body may sustain injury butregions are more affected and are:Head:- 1. Injury sustained to head is common

in motorcyclist followed by thoracic and abdominal region.

2. Fall on road surface and sustaining injury to lateral part with fracture of temporo – parietal bone is very common.

3. Fracture occurring in skull of motorcyclist can be summarized as:

Fall on side with side impact to head causes basal skull fracture especially hinge type .

Impact on face causes fracture of facial skeleton.

Impact on forehead causes sagittal fracture of base of skull.

Impact on chin causes mandibular fracture.

Impact on crow of head by fall may cause ring fracture.

4.INJURIES BY OCCUPANT OF A VEHICLE:

After pedestrians, the driver is the most frequent casually in road traffic accidents as a high proportion of vehicles are occupied by only driver.

Ejection of driver and passenger from a vehicle is associated with significantly severe injuries or fatality as the door often burst open.

Unbelted rear seat occupants are also at increased risk of serious injuries in motor vehicle accidents.

The driver and passenger injuriesdepend upon the type of impact

crash itcan be:-

1. Front impact crash: This happen when one car strikes another car head- on or strike a stationary object, like an electric pole/ tree( approx 80% of impact).

I. The driver tends to receive a different pattern of injury as compared to either the front seat or rare seat passenger.

II. Fracture of wrist and arms occur when driver brace himself against the steering wheel.

III. The fracture or dislocation of Tibia, fibula & pelvis may occur from transmission of the force of impact from pressing on the Break and Clutch pedals.

IV. An impact of the knees against the dashboard commonly causes fracture of the Tibia, Fibula, Femur & pelvis.

V. Severe impact against the windshield pillar may cause avulsion of the skin of the forehead, basilar skull fractures, closed head injury and fracture or dislocation.

VI. Steering wheel impact injury: The circular rim of the steering wheel may cause fracture of the jaws and facial bones.

VII. As well as imprint abrasions, minor bruises and contusions of the chest or bilateral rib fracture.

VIII.Laceration of spleen & Liver may be seen.

IX. Front seat passenger/ Whiplash injury: It is due to a violent acceleration or deceleration force applied to the passenger, usually front seat occupant.

X. He may not get the momentary warning of the impending collision.

XI. There may be peculiar facial lacerations due to contact with the shattered windscreen known as “Sparrow Foot marks”.

XII. Passenger of the rare seat often escape such injuries, they may be injured against internal fittings, like Doors, Handles or ejected through burst-open doors.

WHIPLASH INJURY:-

2.REAR IMPACT CRASH:-Low velocity rear impacts are relatively common.

Usually, they cause whiplash injury

Neck fractures are rare.A high velocity rare impact crash can deform and rupture the gas tank with ignition of the fuel.

3.SIDE IMPACT CRASH:-The vehicle strikes on the side of

another vehicle or skids sideways into a fixed object.

I. Injuries are often severe, because the side of a car has a thin metal wall door and no other components to absorb the force of impact.

II. Dicing injuries may occur which are superficial cuts of the skin caused by fragments of tempered glass.

III. They are linear, right angel or V- shaped laceration seen typically on the face, Forehead and arms on the right side of the driver and left or right side passenger.

IV. Cervical spine fracture , fractured ribs, contusions, lacerations and explosive tearing of the lung on the right side of the impact common.

V. In the abdomen, a lateral impact on the right side commonly causes laceration of the right lobe of the Liver and right Kidney.

VI. The pelvis may be fractured from an impact on the either side.

4.ROLL-OVER CRASH:-Although the automobiles may suffer

severe damage in a roll over crash, the occupants receive the surprisingly moderate impact, if the vehicle is not brought to a sudden stop and the impact is spread over a period of time.

The crashing of different sides of the vehicle absorbs the forces of impact. if the passenger compartments remains intact, the belted occupants frequently survive the crash.

Non belted occupants are involved into two types of injury:

Tumbling around inside and striking the interior of vehicle.

Ejection out from the vehicle.

ROLE OF SEAT BELTS AND AIR BAGS:-

Numerous safety features such as safety belts, air bags, collapsible steering columns, softened interior dashboard and anti lock breaks have contributed to the saving of lives.

The air bag system has reduced the gravity and incidence of chest and facial trauma, especially in those individuals not using seat belt.

Seat belts offer the greatest benefits in frontal and roll over crashes.

Wearing seat belts reduces the risk of fatalities to front seat occupants by 45% since.

i. Injuries are of less severity, except whiplash injury.

ii. Probability of severe head injury is lower.

iii. Probability of being ejected from the vehicle is lower.

iv. There are fewer fatal/ major injuries to head, neck, chest & abdomen.

Lap belts can produce tears of the mesentery, omentum and laceration of the bowel .

Shoulder belt may produce a linear abrasion running downward and medially on the right side of the driver and left side of front seat passenger.

Although seat belts reduce mortality, they cause a specific pattern of internal injuries.

INJURY BY SEAT BELT

Air bags alone reduce fatalities by about 14% in drivers compared with 45% of lap- Shoulder belts used alone.

Delayed Deaths:- Delayed deaths can be caused by continuing bleeding, secondary haemorrhage ,renal failure from hypertension and or extensive muscle damage, fat embolism. Local or systemic infection, myocardial or cerebral infraction.

POSTMORTEM EXAMINATION:-

Photographs of the seen, clothing and injuries should be taken routinely. Since some countries limit the damage to be recovered if the victim was not wearing a seat belt, any injuries consistent with seat belt injuries should be noted. The role of the auto mobile to commit homicide is also postulated.

HISTORY :- The history should include the condition of the

eyes (corneal opacities), blindness, if the victim was suffering from any disease e.g. Heart, epilepsy or diabetes, drugs that he was using(or abusing) and if he was depressed or under unusual stress.

Clothing:- The clothing should be described with special attention to tyre imprint marks, tears, amount of bleeding and foreign bodies especially glass particles, metal, grease, marks or oil stains and paint which may indicate the parts of the vehicle that struck the victim and provide valuable evidence with respect to the suspected vehicle (Hit and Run Case).

Similarly hair blood and other tissue can be transferred from the pedestrian to the vehicle. For this reason, autopsy surgeon should preserve hair and blood samples for comparison.

INJURIES:External injuries:- It should include.I. The nature if the wound, i.e. whether it is

a bruise abrasion or laceration. II. The wound dimensions, e.g. length, width

and depth. It is helpful to take a photograph of wound with an indication of dimension (e.g. a tape measure placed next to the wound.)

III. The position of the wound in relation to fixed anatomical land marks, e.g. distance from the midline or below the clavicle.

IV. The height of the wound from heel- this is important in case where pedestrians have been struck by motor vehicles so that the height of an impact point can be compared with any suspect vehicle.Internal injuries:- The distribution of fatal injuries is mostly related to the head and chest. Due to extraordinary resilience of the skin, serious internal injuries may be present without any evidence of a corresponding external injuries. It is there for necessary to incise suspected areas of impact.

LABORATORY SPECIMENS:-

A blood sample (of the driver and pedestrians) should be taken analyzed for the presence and amount of alcohol (taken from peripheral vein and not from viscera, if death occurred in 12-24 h of accident.) and drugs, since the question of contributory negligence may subsequently arise.

If sufficient blood is not obtainable, vitreous fluid from the eye can be analyzed for alcohol.

The urine should be screened for commonly abused drugs.

Whether the victim was the driver or the passenger?

Some times it is necessary to know who was driving the vehicle for insurance purpose.

Following can assist the autopsy surgeon in determining if a particular occupant was the

driver.Steering wheel impact abrasions may be seen

on the chest.Dicing injuries on the right side of the body.

Pattern seat belt abrasions is seen on the right side of the shoulder going diagonally across the

chest of the left.Imprint marks of the break and clutch pedals on the sole of shoe is pressed at the time of impact.

In different jurisdictions autopsy, surgeons may rule the manner of death in Hit and run pedestrian fatalities as ‘Homicide’ or ‘accident’ or ‘undetermined’ depending on the existing protocol.

Alcohol, Drugs And Trauma:- Alcohol and substance abuse are major

associated factors in all major trauma. About 10% of drivers with blood alcohol

level higher then the legal limit account of nearly 1/3rd of non fetal and half of fatal driver deaths.

Drugs tested for should include alcohol, carbon mono oxide, acid, basic and neutral drugs.

Marijuana and opiates testing are indicated in select cases .

Blood used for testing should be the one which has been drawn prior to starting of IV fluids and blood transfusion.

In case of Death, analysis of vitreous fluid is valuable as it reflects the alcohol and drug levels 1-2 h prior of Death.

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