Traumatic orthopaedic motor vehicle injuries: Are there age and sex differences in pedestrian and cyclist accidents in a major urban center?

Introduction: Injuries caused by road traffic have become the leading cause of death in people aged 5 to 29 years, with pedestrians and cyclists being disproportionately affected. Research has demonstrated age and sex differences in road accidents in European populations. The purpose of this study was to determine age and sex-specific differences in pedestrian and cyclist accidents involving passenger cars at a single Level 1 Trauma Center in a major US metropolitan area.

Methods: We performed a retrospective chart review of 1,845 patients that presented to a single level 1 trauma center from January 1, 2016 - October 1st, 2021, and were involved in a motor vehicle vs. pedestrian or motor vehicle vs. cyclist accidents. Demographics, injury pattern, abbreviated injury scores (AIS), and hospital stay were analyzed, and the data was stratified by pedestrian vs. cyclist, biological sex, and race. Chi square analysis, t tests, and binomial logistic regression was used to examine sex and age-based differences.

Results: Pedestrian vs. motor vehicle collisions (N = 1359, 74%) occurred more frequently than cyclists (N = 475, 26%) with an overall mortality rate of 6%. The mean age of pedestrians and cyclists was 39 and 42 years of age, respectively. Overall, more female than male patients had hand (mean=0.05 vs. 0.02) (p = 0.03) and pelvis fractures (mean 0.28 vs. 0.19) (p = 0.007). Females had a 1.2 times higher likelihood of getting a pelvis fracture than males (95% CI, 1.06 to 1.43). Linear regression analysis found a statistically significant relationship between older age and increased AIS severity (p < .001). Half of our sample consisted of Black patients (49.6% Black vs. 42.1% white).

Conclusion: Female pedestrians and cyclists are at increased risk of obtaining pelvis fractures when in a traumatic road accident than males, regardless of age stratification, and age is a predictor of injury severity. Our study also found that race-based differences exist, with Black patients being injured more frequently. Further research is needed to better understand demographics at risk for traumatic road accidents, as well as evaluation of city infrastructure for biking and walking.