Tag Archives: mechanism


Risk factors for cervical spine injury

Data from the Crash Injury Research Engineering Network (CIREN) database were analysed to identify epidemiologic and biomechanical risk factors for  cervical spinal cord and spinal column injuries. They showed:

  • Older case occupants are at an increased risk of cervical spine injury (CSI)
  • Rollover crashes and severe crashes led to a much higher risk of CSI than other types and severity of MVCs
  • Seat belt use is very effective in preventing CSI
  • Airbag deployment may increase the risk of occupants sustaining a CSI


BACKGROUND: : Motor vehicle collisions (MVCs) are the leading cause of spine and spinal cord injuries in the United States. Traumatic cervical spine injuries (CSIs) result in significant morbidity and mortality. This study was designed to evaluate both the epidemiologic and biomechanical risk factors associated with CSI in MVCs by using a population-based database and to describe occupant and crashes characteristics for a subset of severe crashes in which a CSI was sustained as represented by the Crash Injury Research Engineering Network (CIREN) database.

METHODS: : Prospectively collected CIREN data from the eight centers were used to identify all case occupants between 1996 and November 2009. Case occupants older than 14 years and case vehicles of the four most common vehicle types were included. The National Automotive Sampling System’s Crashworthiness Data System, a probability sample of all police-reported MVCs in the United States, was queried using the same inclusion criteria between 1997 and 2008. Cervical spinal cord and spinal column injuries were identified using Abbreviated Injury Scale (AIS) score codes. Data were abstracted on all case occupants, biomechanical crash characteristics, and injuries sustained. Univariate analysis was performed using a χ analysis. Logistic regression was used to identify significant risk factors in a multivariate analysis to control for confounding associations.

RESULTS: : CSIs were identified in 11.5% of CIREN case occupants. Case occupants aged 65 years or older and those occupants involved in rollover crashes were more likely to sustain a CSI. In univariate analysis of the subset of severe crashes represented by CIREN, the use of airbag and seat belt together (reference) were more protective than seat belt alone (odds ratio [OR] = 1.73, 95% confidence interval [CI] = 1.32-2.27) or the use of neither restraint system (OR = 1.45, 95% CI = 1.02-2.07). The most frequent injury sources in CIREN crashes were roof and its components (24.8%) and noncontact sources (15.5%). In multivariate analysis, age, rollover impact, and airbag-only restraint systems were associated with an increased odds of CSI. Using the population-based National Automotive Sampling System’s Crashworthiness Data System data, 0.35% of occupants sustained a CSI. In univariate analysis, older age was noted to be a significant risk factor for CSI. Airbag-only restraint systems and both rollover and lateral crashes were also identified as risk factors for CSI. In addition, increasing delta v was highly associated with CSIs. In multivariate analysis, similar risk factors were noted. Of all the restraint systems, seat belt use without airbag deployment was found to be the most protective restraint system (OR = 0.29, 95% CI = 0.16-0.50), whereas airbag-only restraint was associated with the highest risk of CSI (OR = 3.54, 95% CI = 2.29-5.46).

CONCLUSIONS: : Despite advances in automotive safety, CSIs sustained in MVC continue to occur too often. Older case occupants are at an increased risk of CSI. Rollover crashes and severe crashes led to a much higher risk of CSI than other types and severity of MVCs. Seat belt use is very effective in preventing CSI, whereas airbag deployment may increase the risk of occupants sustaining a CSI. More protection for older occupants is needed and protection in both rollover and lateral crashes should remain a focus of the automotive industry. The design of airbag restraint systems should be evaluated so that they are not causative of serious injury. In addition, engineers should continue to focus on improving automotive design to minimize the risk of spinal injury to occupants in high severity crashes
Occupant and Crash Characteristics for Case Occupants With Cervical Spine Injuries Sustained in Motor Vehicle Collisions
J Trauma. 2011 Feb;70(2):299-309

Is cervical spine protection always necessary following penetrating neck injury?

This short cut review in the Best Bets format attempted to answer the question: “is cervical spine protection always necessary following penetrating neck injury?”

From the available evidence they draw the following conclusions:

  1. In stab wounds to the neck (with or without neurological deficit) an unstable spinal injury is very unlikely and c-spine immobilisation is not needed
  2. In gunshot wounds the value of cspine immobilisation is limited: for gunshot wounds without neurological deficit no immobilisation is required, while in cases of gunshot wounds with neurological deficit, or where the diagnosis cannot be made (ie, altered mental status), a collar or sandbag is advised once ABCs are stable, with close observation and intermittent removal to inspect and reassess.
  3. In the rare event of penetrating injury with combined blunt force trauma, a collar or sandbag is advised if possible, once ABCs are stable, with intermittent removal to reassess.

Emerg Med J. 2009 Dec;26(12):883-7

Full text at BestBets.org

Vehicle Rollover

Vehicle rollover as an indicator of mechanism of injury was investigated in a study examining accident databases and the medical literature. Only 2.4% of crashes involved rollovers but they accounted for one third of occupant deaths.

Some facts on vehicle rollover from the article:

  • Rollover is defined as a vehicle overturned by at least one quarter turn (at least onto its side).
  • Some rollovers involve many quarter turns and the final resting position may be on the vehicle’s side, roof, or back on its wheels.
  • Factors that cause a vehicle to roll over include trajectory (i.e., turning vs. straight), vehicle type, and speed (precrash velocity may be the most predictive factor)

The importance of vehicle rollover as a field triage criterion
J Trauma. 2009 Aug;67(2):350-7

High BMI and frontal crashes

In adult patients injured in front impact motor vehicle collisions, the outcomes of obese patients with a Body Mass Index greater than 30 kg/m2 was compared with those less than 30 kg/m2. Obese patients were more likely to suffer a severe head injury from a frontal collision.

J Trauma. 2009 Mar;66(3):727-9
Traumatic Brain Injury After Frontal Crashes: Relationship With Body Mass Index

Passenger Compartment Intrusion and Kids

The presence and degree of compartment intrusion (from crash investigation data) was correlated with the likelihood of serious injury in 880 children from age 0-15 years, and odds for presence of serious injury increased for each centimetre of compartment intrusion.

Passenger Compartment Intrusion as a Predictor of Significant Injury for Children in Motor Vehicle Crashes
J Trauma. 2009 Feb;66(2):504-7