This study investigated sex-specific differences in thoracic injury prevalence,
causation, and rib fracture patterns among seriously injured occupants in
frontal motor vehicle collisions. Crash Injury Research and Engineering Network
(CIREN) data from 2005 to 2022 included 793 front-seat occupants aged 16 years
and older with Abbreviated Injury Scale 2+ thorax injury, representing 1802
thoracic injuries. Injuries were grouped as rib fracture, sternum fracture,
hemo/pneumothorax, lung injury, heart injury, and other. A weighted scoring
system captured contributions of involved physical components to each injury.
Logistic and linear regression with generalized estimating equations assessed
sex associations with injury presence and causation. Two models were estimated:
a comprehensively adjusted model including demographic, crash, vehicle,
restraint, and airbag deployment, and a simplified model adjusting for age, body
mass index, delta-V, and occupant role.
Among occupants with AIS 2+ thoracic injuries, sex-specific differences were
observed in injury patterns and causation. Females were less likely than males
to sustain lung injuries (OR = 0.70, p = 0.038) and more likely to sustain rib
fractures (OR = 1.25, p = 0.006). Females had higher odds of rib fractures
attributed to seatbelt loading in both models (Full: OR = 2.20, p = 0.005;
Simplified: OR = 1.55, p = 0.021). Females were less likely than males to
sustain lung injuries (OR = 0.17, p = 0.042) and hemo/pneumothoraces (OR = 0.15,
p = 0.044) from instrument panel loading. Steering wheel, airbag, and other
components showed no significant sex-specific associations with thoracic injury.
Rib fracture patterns showed clusters along the seatbelt path in belted
occupants and a more diffuse pattern in unbelted occupants, with minimal
significant findings of differences between sexes. These findings contribute to
the growing evidence of sex-specific injury patterns and may inform future
research on injury prediction and prevention strategies. However, this dataset
includes only occupants with AIS 2+ thoracic injuries and therefore cannot be
extrapolated to the general population or to collisions outside those
represented in the sample.
