Clinical assessment and risk stratification

There are certain injury patterns common to specific mechanisms of injury that can be useful in guiding trauma assessment.

**In trauma patients who are sedated, have received significant prehospital opiate or hypnotic medication, or who are not cognitively intact (GCS<15) a thorough secondary survey must be completed so as not to miss injuries which while not immediately life threatening may result in significant morbidity later e.g. scaphoid fracture. It is important to note such injuries may not show up on a trauma CT. If handing over care of a patient to a colleague or in patient specialty team it is important that this is conveyed e.g. primary survey complete, secondary/tertiary survey still outstanding.

Fall from height (>2 storeys)

• Skull base fracture
• Spinal compression fractures
• Hip injury
• Tibial plateau fracture
• Pilon ankle fracture- (distal tibia fracture with intraarticular component, and often multiple fragments seen in high energy mechanism)
• Calcaneal fractures

Axial loading [e.g. diving into shallow pool or heavy load falling on head from height]

• Intracranial injury (e.g. subdural, extradural subarachnoid bleeds or contusions)
• Cervical spine injury

Motor vehicle crash (MVC)

Frontal impact

If unrestrained

• Craniofacial injuries
• Hyperextension of the cervical spine
• Atlanto-occipital dislocation
• Rib and sternal fractures
• Deceleration injuries (aortic injury, pedicle injury)
• Posterior hip dislocation
• Femoral fracture + knee dislocation.

In restrained occupants, the pattern of injury will be determined by the pattern and location of the seat restraints.

Lateral

• Craniofacial injuries
• Lateral rotation/flexion of c spine
• Humeral fractures
• Lateral flail chest and lung contusion
• Lateral abdominal compression (liver/splenic lacerations)
• Lateral pelvic compression fracture
• Fractured femur

Rear

• Neck injury from rapid hyper-extension.
• Lower back injury

Injuries will be more severe if the vehicle is fitted with a tow bar and force is transmitted to the passenger shell avoiding rear crumple zones.

Pedestrians

There are typically three impact phases when a pedestrian is hit by a car:

1. Bumper impact: in an adult who is upright, initial impact is usually on the lower limbs causing injuries such as bilateral tib/fib fractures.

2. Windscreen impact: torso and head injuries occur when a pedestrian impacts the body of the vehicle. Adults are more likely to get thrown up onto bonnet of the car due to their height whereas children/shorter patients can get knocked onto the floor.

3. Ground impact: further injuries occur as the pedestrian hits the ground.

Waddells triad: pattern of injury which appears in children hit by motor vehicles

• Contralateral head injury
• Ipsilateral intrathoracic or intra-abdominal injury
• Ipsilateral fracture of the femoral shaft.

Motorcyclists

• Posterior fossa fractures (caused when force impacts the chin-piece of a helmet)
• Cervical spine injuries
• Bilateral mid-shaft femoral fractures
• Pelvic fractures
• Bilateral wrist fractures
• Shoulder girdle injuries
• Bladder rupture
• Maxillofacial fractures

Mechanism of injury

While assessing the mechanism of injury, gathering information from sources such as witnesses, bystanders, and the surrounding environment is important while concomitantly clinically assessing the patient.

Police have often gained collateral history at the scene and will interview bystanders and therefore a potential source of information to inform mechanism of injury.