Pontomedullary lacerations in unhelmeted motorcyclists and bicyclists: a retrospective autopsy study

Motorcycle injuries: a systematic review for forensic evaluation

The intricate interplay of exposure and speed leave motorcyclists vulnerable, leading to high mortality rates. During the collision, the driver and the passenger are usually projected away from the motorcycle, with variable trajectories or final positions. Injuries resulting from the crash can exhibit distinct and specific characteristics depending on the circumstances of the occurrence.The aim of this study is to provide a systematic review of the literature on injuries sustained by motorcyclists involved in road accidents describing and analyzing elements that are useful for forensic assessment.The literature search was performed using PubMed, Scopus and Web of Science from January 1970 to June 2023. Eligible studies have investigated issues of interest to forensic medicine about during traffic accidents involving motorcycle. A total of 142 studies met the inclusion criteria and were classified and analyzed based on the anatomical regions of the body affected (head, neck, thoraco-abdominal, pelvis, and limb injuries). Moreover, also the strategies for preventing lesions and assessing injuries in the reconstruction of motorcycle accidents were examined and discussed.This review highlights that, beyond injuries commonly associated with motorcycle accidents, such as head injuries, there are also unique lesions linked to the specific dynamics of accidents. These include factors like the seating position of the passenger or impact with the helmet or motorbike components. The forensic assessment of injury distribution could serve as support in reconstructing the sequence of events leading to the crash and defining the cause of death in trauma fatalities.

Pontomedullary lacerations and concomitant head and neck injuries: their underlying mechanism. A prospective autopsy study

It is a well-documented fact that pontomedullary lacerations (PML) occur as a result of severe craniocervical injury, but their underlying mechanism has yet to be fully clarified. The aim of this prospective study has been to give greater insight into the underlying mechanism of PML through determining the site of blunt head-impact, as well as the presence of concomitant head and neck injuries in cases of brainstem PML. A total of 56 cases with partial PML have been analysed for this study. The case group was composed of 40 men and 16 women, averaging in age 44.2 ± 19.2 years and consisting of 7 motorcyclists, 4 bicyclists, 18 car occupants, 16 pedestrians, and 10 victims of falls from a height, as well as 1 victim of a fall from standing height. The presented study has shown that there are several possible mechanisms of PML. Impact to the chin, with or without a skull base fracture, most often leads to this fatal injury, due to the impact force transmission either through the jawbone or vertebral column; most likely in combination with a fronto-posterior hyperextension of the head. Additionally, lateral head-impacts with subsequent hinge fractures and PML may also be a possible mechanism. The jawbone and other facial bones are able to act as shock absorbers, and their fracture may diminish the energy transfer towards the skull and protect the brain and brainstem from injury. The upper cervical spine can act as damper and energy absorber as well, and may prevent any occurrence of fracture to the base of the skull.