Methods

A database search was performed in the Institute of Legal Medicine from 1 January 2011 to 31 July 2023 using World Health Organization codes from the Tenth Revision of the International Statistical Classification of Diseases and Related Health Problems (ICD-10) for traffic accidents (codes V01-V99). Patients identified this way were searched for the presence of a postmortem CT in the radiological picture archiving and communication system (PACS). Archiving in the PACS is anonymous and identified only by the autopsy registration number. The patients were reevaluated for the presence of a TAWH in the non-enhanced postmortem CT scan defined as the disruption of muscle and/or fascial layers. The images were also screened for the protrusion of intra-abdominal content without skin breakage. The majority of CT scanning from 2011 to 2019 was done on a Aquillion 64 CT-scanner (Toshiba, Japan) in 2020 on a Somatom Go.All CT-scanner (Siemens, Germany) and from 2021 to 2023 on a Somatom Force CT-scanner (Siemens, Germany). Due to the long time period and the variety of scanner types, various protocols based on the DGRM guidelines [15] were used. The most recent protocol for the Somatom Force CT scanner (Siemens, Germany) had the following parameters: tube current of 250 mAs, tube voltage of 140 kV, and a pitch factor of 0.6. Reconstruction was performed using hard (Br59) and soft (Bf40) kernels with the following parameters: slice thickness of 0.6 mm and an increment of 0.4 mm in a small field of view of 240 mm for the head and neck, and a large field of view of 500 mm for the whole body spiral.

Exclusion criteria was severe thermic abdominal wall damage. The single reader (a radiologist with 20 years’ experience of postmortem CT scans) was blinded to the accident mechanism. Additional parameters were either retrieved from the database of the forensic department (age, sex, height, weight, position in the vehicle, and seatbelt usage) or evaluated in the CT scans. The presence of fractures of the spine, pelvis, ribs or sternum was recorded as well as sacroiliac joint dislocation, hematoma in the subcutaneous fatty tissue, presence of gas or blood in the abdomen. In addition, the implementation of resuscitation measures (defined as chest compressions) was documented if there were indications of this in the case records.

We analysed the accident procedure of all patients with TAWH in a subgroup of motor vehicle occupants (MVOs). Speed, road and collision type were documented.

Statistical analysis was done using SPSS 28.0 (IBM, USA) using Chi-square- and Mann-Whitney U test.

We acknowledge the use of Google’s AI tools (Gemini pro 2.5) for assistance with language editing and manuscript formatting and DEEPL for the translation of several German terms.