Objective skull fracture evaluation by using the postmortem 3D-CT skull fracture score in fatal falls

Abstract

PurposeWe evaluated the usefulness of skull fracture analysis using three-dimensional computed tomography skull fracture scores (3DCT-SFs) in cases of fatal falls. Materials and MethodsFrom April 2016 to September 2020, 46 cases of fatal falls from great heights (33 males, 13 females; mean age: 52.7 (range: 18–89) years) were examined using routine postmortem CT. The 3DCT-SFs were determined as the sum of the fracture line lengths measured on a volume rendering image. Skull fracture severity was classified into four stages according to the 3DCT-SFs. These stages were compared by macroscopic evaluation of skull fracture severity (injury level 0: no fracture; injury level I: fracture without deviation; injury level II: fracture with deviation; injury level III: comminuted open skull fracture). The relationship between 3DCT-SFs values, the fall distance, and the hardness of the landing surface was also examined. ResultsSkull fractures occurred in 26 cases (56.5%). The mean 3DCT-SFs of the cases that were classified as stages I, Ⅱ, and III were 86.6 (5.0–187.0), 832.0 (235.1–1865.8), and 3582.5 (2171.6–4787.6), respectively. Upon macroscopic evaluation of fracture severity, there were 8, 10, and 8 cases of injury levels I, II, and III, respectively. The 3DCT-SFs-based stages correlated significantly with the macroscopic skull fracture severity levels (R2 = 0.936). Solid-surface fall points resulted in significantly higher 3DCT-SFs than soft surfaces. Comminuted open fracture of the skull (stage III) occurred with fall distances ≥ 24 m. ConclusionThe 3DCT-SFs correlate well with macroscopic findings and are useful as an objective skull fracture index.