Thoracic injuries, specifically rib fractures, are prevalent in motor vehicle crashes and are a significant source of morbidity and mortality. Rib fractures present in a variety of patterns, ranging in severity from minor to severe. The number of fractures also contributes to the injury assessment; as fracture number increases, severity increases. Research regarding relationships between a rib’s structural properties and fracture characteristics is lacking; therefore, the objective of this study was to identify relationships of fracture characteristics with structural properties in human ribs subjected to anterior-posterior loading to contribute to a comprehensive understanding of thoracic injury and improving injury risk assessment. Ribs (n=347) were impacted in a dynamic bending scenario representing a frontal thoracic impact. Fracture characteristics (location, classification, number, and severity) were analyzed utilizing a new classification system. Structural properties (peak and yield force, %peak and yield displacement, linear structural stiffness, total energy, plastic energy, and ductility/brittleness) were calculated from test data for each rib and their relationships with fracture characteristics were assessed. Three structural properties (%peak displacement, total energy, and plastic energy) were found to have significant differences with all fracture characteristics except fracture location. However, the significant differences were only found in specific comparisons within each fracture characteristic. Fracture location was only found to have a significant relationship with %peak displacement.
Keywords: Fracture classification; injury risk; rib fractures; structural properties; thoracic injury