Knee injuries in pedestrians and cyclists resulting from impacts with passenger cars

The WP4 paper on knee injuries – written by David Bützer, Stefan Lang, Kai-Uwe Schmitt, Bettina Zahnd, Corina Klug – was published in the IRCOBI proceedings:

Knee injuries in pedestrians and cyclists resulting from impacts with passenger cars – Frequency and associated factors based on Swiss insurance claims data

These proceedings were reviewed and approved for publication in conjunction with the 2020 IRCOBI Europe conference. The conference was not held in person, due to concerns related to the corona pandemic, but the proceedings are the official record of the conference.

Abstract & conslusion
The relevance of knee injuries in accidents involving passenger cars and pedestrians or cyclists is not clear. Past studies using different research methods and data sources came to different conclusions. This study aims to analyse the frequency of knee injuries based on a new dataset from insurance claims data in Switzerland. The study sample contains 340 real-world accidents, each representing an impact between one passenger car and one pedestrian or cyclist. Injury descriptions, accident details and vehicle information were extracted from medical and police reports and insurance data. In 123 pedestrian and 217 cyclist accidents, knee ligament injuries were sustained in eight accidents, which represents 16% of the accidents with injuries of the lower extremities (excluding superficial injuries). In total, 37 knee injuries were reported, of which 13 were knee ligament ruptures and 10 were bone fractures in the knee area. It was observed that ligament injuries were mostly diagnosed three or more days after the injury, which might explain the different prevalence of ligament injuries in different data sources. Based on this analysis, knee ligament ruptures are relevant for the assessment of modern vehicles and should therefore be considered in virtual testing procedures addressing the protection of pedestrians and cyclists.

Insurance claims from 340 accidents of pedestrians or cyclists impacted by modern passenger cars were analysed. Based on this analysis, knee injuries, and more specifically knee ligament injuries, should be considered in virtual assessment procedures. The study highlighted that the diagnosis of knee ligament injuries is often confirmed rather late in the treatment process. This was identified as a possible explanation for the varyingprevalence reported in different accident studies using different data s ources.

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