3D-CT-Based Assessment of Total Cranial Fracture Length in Relation to Fall Height and Manner of Death in Fatal Free Falls

Fatal free falls (FFF) represent a distinct form of blunt force trauma and pose a significant challenge in forensic investigations, particularly in estimating fall height and differentiating between accidental and suicidal events. Postmortem computed tomography (PMCT) enables detailed assessment of skeletal injuries, including quantitative evaluation of skull fracture patterns. Total Cranial Fracture Length (TCFL), derived from three-dimensional CT skull fracture scoring (3D-CT-SF), has been proposed as an objective indicator of impact severity; however, available evidence remains limited. This study aimed to assess the relationship between TCFL and fall height in fatal free falls and to evaluate the influence of selected anthropometric and biomechanical variables on cranial fracture severity. A retrospective analysis of 76 fatal free-fall cases examined between 2016 and 2024 was conducted using PMCT and autopsy data. TCFL was measured on three-dimensional volume-rendered CT reconstructions of calvarial fractures. Statistical analyses were performed for the entire cohort and separately for accidental and suicidal falls. No significant correlation between TCFL and fall height was observed in the overall cohort or among suicide cases. In contrast, a significant negative correlation between TCFL and fall height category was identified in accidental falls. TCFL showed significant positive correlations with body mass, body mass index (BMI), and kinetic energy, particularly in the suicide subgroup. TCFL is a promising objective parameter for assessing the severity of cranial injury in fatal free-fall cases. While its utility in estimating fall height appears limited in suicidal falls, TCFL may support forensic interpretation of fall dynamics and contribute to distinguishing the manner of death, especially in accidental cases. Further studies in larger, more diverse populations are warranted.