Is Bigger Better? The Effect of Obesity on Pelvic Fractures After Side Impact Motor Vehicle Crashes

Background: Previous research has identified nearside impacts, intrusion, gender, age, and body mass index (BMI) as associated with pelvic fractures in motor vehicle crashes. This study assesses the role of BMI in predicting pelvic fracture and whether BMI modifies the effect of other potential risk factors. Methods: The Crash Injury Research and Engineering Network data were queried to study occupant, vehicle, and crash factors predicting pelvic injury in occupants of nearside crashes. Occupants in different BMI categories were compared with assess odds of pelvic fracture during nearside impacts. Logistic regression was used to identify predictive variables for pelvic fracture controlling for age, gender, delta V, intrusion, side airbag deployment, seat position, vehicle curb weight, and safety belt use. Results: Two hundred forty-four (57.5%) occupants in nearside impacts sustained pelvic fractures., Occupants with a normal BMI were more likely (unadjusted odds ratio = 1.80, adjusted odds ratio = 1.98) to have a pelvis fracture compared with overweight and obese occupants. Door panel intrusion >15 cm, female gender, and delta V were associated with pelvic fracture in univariate analyses. BMI was a predictor of pelvic fracture when controlling for potential confounding factors. Conclusions: BMI status influences other variables associated with pelvic fracture. Redesign of interior door panels, hardware, armrests, and the center console may be appropriate for motor vehicle manufacturers to consider ill prevention of pelvic fracture during nearside impacts.