ROAD TRAFFIC INJURYby

Dr Mohd Kaleem Khan

Assistant ProfessorDepartment Of Forensic Medicine

JNMCH AMU Aligarh

• 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. Impact Injuries- when vehicle strike the victim

2. Secondary Injuries- due to victim falling on ground or striking any other stationary object

3. Run-over Injuries- d/t vehicle running over some part of victim

Impact Injuries• Primary Impact Injuries:

d/t initial impact of vehicleProjections of vehicle may cause specific injuries

e.g. bumper fracture (# of tibia & fibula of one or both the legs)

Height of pedestrian often determines site of injury

• Secondary impact injuries:Subsequent impact with the same vehicle

Secondary Injuries– Usually found on parts opposite to primary impact– Most pronounced over the unclothed areas of the

body

Run-over Injuries– Severity of injury will depend upon the part of body

run over and weight of the vehicle.– E.g. degloving injury, tyre marks, burns, avulsion etc.

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. Bumper

2. Wing

3. Grill

4. Head Light

5. 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 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:1. 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.

2. 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• 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

The common causes of motorcycle accidents are 1. Alcohol, 2. Drugs, 3. Environmental factors,4. 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 but regions 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 injuries depend upon the type of impact crash it

can be:-

1. Front impact crash: tThis 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.

V. As well as imprint abrasions, minor bruises and

contusions of the chest or bilateral rib fracture. VI. 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.

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.

Whiplash injury:-

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.

III. Cervical spine fracture , fractured ribs, contusions,

lacerations and explosive tearing of the lung on the right side of the impact common.

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

IV. 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