Changes in injury patterns, injury severity and hospital mortality in motorized vehicle accidents: a retrospective, cross-sectional, multicenter study with 19,225 cases derived from the TraumaRegister DGU.

Purpose: In the last 20 years, the number of fatalities due to road traffic accidents (RTA) in Germany has steadily decreased from 7503 to 2724 per year. Due to legal regulations, educational measures and the continuous development of safety technology the number of severe traumatic injuries and injury patterns are most likely to change. The aim of the study was to analyse severely injured motorcyclists (MC) and car occupants (CO) that were involved in RTAs in the last 15 years and investigate the development and changes of injury patterns, injury severity and hospital mortality.

Methods: We retrospectively evaluated data from the TraumaRegister DGU (TR-DGU) considering all RTA-related injured MCs and COs (n = 19,225) that were registered in the TR-DGU from 2006 to 2020 with a primary admission to a trauma center with continuous participation (14 of 15 years) in the TR-DGU, an Injury Severity Score (ISS) ≥ 16 and aged between 16 and 79 years. The observation period was divided into three 5-year interval subgroups for further analysis.

Results: The mean age increased by 6.9 years and the ratio of severely injured MCs to COs changed from 1:1.92 to 1:1.45. COs were in 65.8% male and more often severely injured in the age groups under 30, while the majority of severely injured MCs were in the age group around 50 years and in 90.1% male. The ISS (- 3.1 points) as well as the mortality of both groups (CO: 14.4% vs. 11.8%; MC: 13.2% vs. 10.2%) steadily decreased over time. Nevertheless, the standardized mortality ratio (SMR) hardly changed and stayed < 1. Regarding the injury patterns, the greatest decline of injuries with AIS 3 + were to the head (CO: - 11.3%; MC: - 7.1%), in addition, a decrease of injuries to extremities (CO: - 1.5%; MC: - 3.3%), to the abdomen (CO: - 2.6%; MC: - 3.6%), to the pelvis in COs (- 4.7%) and to the spine (CO: + 0.1%; MC: - 2.4%) were observed. Thoracic injuries increased in both groups (CO: + 1.6%; MC: + 3.2%) and, furthermore, pelvic injuries in MCs (+ 1.7%). Another finding was the increase of the utilization of whole body CTs from 76.6 to 95.15%.

Conclusion: The severity of injuries and their incidence, especially head injuries, have decreased over the years and seem to contribute to a decreasing hospital mortality of polytraumatized MCs and COs injured in traffic accidents. Young drivers and an increasing number of seniors are the age groups at risk and require special attention and treatment.