IS DELTA-V A GOOD PARAMETER TO DESCRIBE THE RISK OF CERVICAL SPINE INJURIES DUE TO WHIPLASH?

Abstract

Background: In a car-to-car collision, an adequate force has to be exerted to produce an injury of the cervical spine. This force is often described with the parameter delta-V. Limits for delta-V were defined for rear-end, frontal and side collisions on the basis of dummy experiments and volunteer crash tests under laboratory conditions, and then transformed for the road accident situation. According to this definition, an injury in a rear-end or side collision is unlikely at delta-V< 10km/h and probable at delta-V> 15km/h. For frontal collisions, the values are 20 km/h and 30km/h. To this day, there is no data to confirm these limits in the actual road accident situation.

Objective: Our objective was to compare clinical data and data from accident analyses of individuals after actual car-to-car collisions in a prospective study. We intended to check the validity of the delta-V limits on the basis of this data.

Methods: 57 individuals (25 males/32 females) were included in the study. The delta-V was calculated by a technical expert on the basis of photographs of the two cars involved. The individuals who had been in an accident were evaluated with regard to their history. Those reporting symptoms underwent a radiological and clinical examination.

Results: Rear-end collisions (n=21): The median delta-V for rear-end collisions is 13 km/h (min=3 km/h; max=58 km/h). 7 individuals reported symptoms. Both patients had delta-V values< 9km/h. Delta–V 10km/h.

• Frontal collisions (n=13): The median delta-V for frontal collisions is 24 km/h (min=8 km/h; max=50 km/h). 4 individuals reported symptoms. Under delta-V 20, one individual had a fractured cervical vertebra (QTF IV).

• Side collisions (n=19): The median delta-V for side collisions is 12 km/h (min=4 km/h; max=59,3 km/h). 9 individuals reported symptoms. Under delta-V 10 km/h, two patients had symptoms (QTF II and QTF IV (fracture).

Conclusions: The existing limits for delta-V cannot be transferred without reservation from the laboratory test situation to the actual road accident situation. Injuries and even fractures of the cervical spine can occur at a delta-V < 10km/h, particularly with side collisions. At the same time, delta-V values > 15km/h do not necessarily result in an injury of the cervical spine.