Airbag deployment and cervical spine injury in restrained drivers following motor vehicle collisions

Seatbelts and airbags are the most important devices protecting drivers from cervical spine injury (CSI) following motor vehicle collisions (MVCs). However, there have been few reports on the radiographic characteristics of CSI sustained by restrained, airbag-deployed drivers.

A single-center, retrospective observational study was conducted using prospectively acquired data. Between January 2011 and December 2017, 564 restrained drivers, whose vehicle had been severely damaged in MVCs, underwent whole-body computed tomography for evaluation of bodily injuries. The drivers were dichotomized into airbag (+) group (n = 218) and airbag (-) group (n = 139), after excluding 207 drivers in whom airbag deployment status was unknown.

Eight and nine drivers sustained CSIs in the airbag (+) and airbag (-) group, respectively. The frequency of CSI did not differ significantly between the two groups (3.7% vs. 6.5%, p = 0.31). All eight CSIs in the airbag (+) group were classified as hyperextension injuries, and four of them sustained concomitant spinal cord injuries caused by dislocation. Within the airbag (+) group, the drivers with CSIs were significantly older than those without CSIs (65.2 ± 18.5 vs. 44.8 ± 18.7 years, p = 0.002).

Although it is without doubt that the combination of seatbelt and airbag reduces the frequency and severity of CSIs following MVCs, the CSIs sustained in restrained, airbag (+) drivers may not always be mild, and elderly drivers may be at an elevated risk of CSI. In addition, the possibility of a causal role of airbags in CSI requires consideration in this population.