Head and neck injuries in fatal motorcycle collisions as determined by detailed autopsy

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.

The transversoclasiotome: a novel instrument for examining the vertebral artery

Opening the foramen transversarium of the cervical vertebrae is necessary for accessing the vertebral vessels. There are no specialist tools for cutting the anterior lamina of the transverse processes, and alternatives lead to questionable results. A novel tool, the transversoclasiotome, is described and tested. The literature and patent databases were systematically reviewed. A blueprint of the transversoclasiotome was created, and the prototype was tested through autopsy on ten fresh-frozen cadavers within our Body Donation Program. The transversoclasiotome consists of two delicate branches mounted as a scissor, one a cutting jaw and the other a knocker with a rounded tip, both angled 30° to the principal axis. The jaws shut, facing each other in parallel. The cutting jaw corresponds to a slit on the knocker profile without protruding beyond it even when entirely closed. It acts by cutting and wedging. The testing autopsies demonstrated its suitability for its purpose, with an adequate response to the pressure exerted on the bone lamina. The section cut cleanly, without sliding off while closing on the bone. The vertebral vessels were not injured either during instrument insertion or cutting. Their morphological features are described. The transversoclasiotome has been proven appropriate for sectioning the anterior lamina of transverse processes of the cervical vertebrae. It meets the needs of clinical anatomy in teaching and training clinicians or surgeons, forensic clinical anatomy during medico-legal investigation, and research.

Numerical Reconstruction of Cyclist Impact Accidents: Can Helmets Protect the Head-Neck of Cyclists?

Cyclists are vulnerable road users and often suffer head-neck injuries in car-cyclist accidents. Wearing a helmet is currently the most prevalent protection method against such injuries. Today, there is an ongoing debate about the ability of helmets to protect the cyclists' head-neck from injury. In the current study, we numerically reconstructed five real-world car-cyclist impact accidents, incorporating previously developed finite element models of four cyclist helmets to evaluate their protective performances. We made comparative head-neck injury predictions for unhelmeted and helmeted cyclists. The results show that helmets could clearly lower the risk of severe (AIS 4+) brain injury and skull fracture, as assessed by the predicted head injury criterion (HIC), while a relatively limited decrease in AIS 4+ brain injury risk can be achieved in terms of the analysis of CSDM0.25. Assessment using the maximum principal strain (MPS0.98) and head impact power (HIP) criteria suggests that helmets could lower the risk of diffuse axonal injury and subdural hematoma of the cyclist. The helmet efficacy in neck protection depends on the impact scenario. Therefore, wearing a helmet does not seem to cause a significant neck injury risk level increase to the cyclist. Our work presents important insights into the helmet's efficacy in protecting the head-neck of cyclists and motivates further optimization of protective equipment.

Estimating the health burden of road traffic injuries in Malawi using an individual-based model

BACKGROUND

Road traffic injuries are a significant cause of death and disability globally. However, in some countries the exact health burden caused by road traffic injuries is unknown. In Malawi, there is no central reporting mechanism for road traffic injuries and so the exact extent of the health burden caused by road traffic injuries is hard to determine. A limited number of models predict the incidence of mortality due to road traffic injury in Malawi. These estimates vary greatly, owing to differences in assumptions, and so the health burden caused on the population by road traffic injuries remains unclear.

METHODS

We use an individual-based model and combine an epidemiological model of road traffic injuries with a health seeking behaviour and health system model. We provide a detailed representation of road traffic injuries in Malawi, from the onset of the injury through to the final health outcome. We also investigate the effects of an assumption made by other models that multiple injuries do not contribute to health burden caused by road accidents.

RESULTS

Our model estimates an overall average incidence of mortality between 23.5 and 29.8 per 100,000 person years due to road traffic injuries and an average of 180,000 to 225,000 disability-adjusted life years (DALYs) per year between 2010 and 2020 in an estimated average population size of 1,364,000 over the 10-year period. Our estimated incidence of mortality falls within the range of other estimates currently available for Malawi, whereas our estimated number of DALYs is greater than the only other estimate available for Malawi, the GBD estimate predicting and average of 126,200 DALYs per year over the same time period. Our estimates, which account for multiple injuries, predict a 22-58% increase in overall health burden compared to the model ran as a single injury model.

CONCLUSIONS

Road traffic injuries are difficult to model with conventional modelling methods, owing to the numerous types of injuries that occur. Using an individual-based model framework, we can provide a detailed representation of road traffic injuries. Our results indicate a higher health burden caused by road traffic injuries than previously estimated.

Forensic and Clinical Issues in a Case of Motorcycle Blunt Trauma and Bilateral Carotid Artery Dissection

Internal carotid artery dissection (ICAD) after motorcycle accidents is unusual but life threatening if not promptly diagnosed and treated. We report the case of a motorcyclist involved in a frontal collision with a car, suffering injuries due to direct blunt trauma and indirect trauma by sudden deceleration force. Bilateral ICAD was diagnosed by computed tomography angiogram 5 days after the accident. Here in, starting from a medicolegal case, we emphasized some clinical criteria to make a prompt diagnosis to prevent permanent neurological deficit in this pathology whose best management is still under the debate. An unusual case of ICAD is described with regard to both forensic and promptly diagnostic therapeutic management.

Analysis of rider and child pillion passenger kinematics along with injury mechanisms during motorcycle crash

Objective: Traffic fatalities among motorcycle users are intolerably high in Thailand. They account for 73% of the total number of road fatalities. Children are also among these victims. To improve countermeasures and design of protection equipment, understanding the biomechanics of motorcycle users under impact conditions is necessary. The objective of this work is to analyze the overall kinematics and injuries sustained by riders and child pillion passengers in various accident configurations. Methods: Motorcycle accident data were analyzed. Common accident scenarios and impact parameters were identified. Two numerical approaches were employed. The multibody model was validated with a motorcycle crash test and used to generate possible accident cases for various impact conditions specified to cover all common accident scenarios. Specific impact conditions were selected for detailed finite element analysis. The finite element simulations of motorcycle-to-car collisions were conducted to provide insight into kinematics and injury mechanisms. Results: Global kinematics found when the motorcycle's front wheel impacts a car (config-MC) highlighted the translation motion of both the rider and passenger toward the impact position. The rider's trunk impacted the handlebar and the head either impacted the car or missed. The hood constituted the highest head impact occurrence for this configuration. The child mostly impacted the rider's back. Different kinematics were found when car impacted the lateral side of the motorcycle (config-CM). Upper bodies of both rider and child were laterally projected toward the car front. The windshield constituted the highest proportion of head impacts. The hood and A-pillar recorded a moderate proportion. The rider in finite element simulations with config-MC experienced high rib stress, lung strain, and pressure beyond the injury limit. A high head injury criterion was observed when the head hit the car. However, the simulation with config-CM exhibited high lower extremities stress and lung pressure in both occupants. Hyperextension of the rider's neck was observed. The cumulative strain damage measure of the child's brain was higher than the threshold for diffuse axonal injury (DAI). Conclusions: This study revealed 2 kinematics patterns and injury mechanisms. Simulations with config-MC manifested a high risk of head and thorax injury to the rider but a low risk of severe injury to the child. Thorax injury to the rider due to handlebar impact was only found in simulations with config-MC. However, a high risk of skull, lower extremity, brain, and neck injuries were more pronounced for cases with config-CM. A high risk of DAI was also noticed for the child. In simulations with config-CM the child exhibited a higher risk of severe injury.

Autopsy Cases of Motorcyclists Dying of Trauma or Disease

We aimed to provide a better estimation of health-related motorcycle fatalities by comparing the backgrounds, mechanisms of injuries, and injury severity of victims who died of collision versus those who died of disease. We retrospectively analyzed autopsy records of 29 motorcyclists (mean age, 61.0 ± 21.0 years), none of whom had been driving under the influence of alcohol. Altogether, 22 (75.9%) had died of trauma, and 7 had died of disease. The disease-death victims were significantly older and had a significantly higher prevalence of a medical history compared with those with trauma-related death (100% vs 45.5%, P = 0.01), especially of lifestyle diseases (100% vs 13.6%, P < 0.001) and heart or cerebrovascular disease (57.1% vs 13.6%, P = 0.02). All of the victims who were affected by disease and 50% of trauma-death victims had fallen on the road without a vehicle collision (P = 0.02). Mean Injury Severity Score of the trauma-death group was significantly higher than that of the disease-death group (48.1 vs 9.1, P < 0.001). A forensic autopsy should be performed for all motorcyclist fatalities to diagnose a disease-related death during motorcycle riding. To reduce the incidence of these accidents, motorcyclists should maintain a good physical status.

Road Safety Practices among Commercial Motorcyclists in a Rural Town in Nigeria: Implications for Health Education

This cross-sectional, community-based study was carried out among commercial motorcyclists in Igboora. All the commercial motor parks in Igboora were visited and all the commercial motorcyclists who consented to participate in the study were interviewed. Information on the respondents' socio-demographic characteristics, and the practice of road safety measures was collected using an interviewer administered questionnaire. A total of 299 motorcyclists were interviewed. All (100%) of them were males. The mean age of the respondents was 27.4 ± 7.4 years. One hundred eighty-two (60.7%) of the motorcyclists had the correct knowledge of the purpose of Highway Code. Only 70 (23.3%) could recognize more than half of the currently used road safety codes and 47 (15.7%) obey these road safety codes more than half of the time they see it. Only 183 (61.2%) of them had a driving license and 72 (24.1%) were able to produce these licenses on demand. All (100%) of the respondents did not use any protective helmet. Those who have longer years of working experience, higher level of education and higher knowledge of the safety codes practice it more regularly ( r = 0.198, p = 0.001, χ2 = 9.31, p = 0.025, and r = 0.28, p = 0.001 respectively). One hundred thirty-six (45.5%) have been involved in at least one accident in the preceding year. The overall incidence of road traffic accident was 2.16 per 1,000. There was however on statistically significant association between the practice of road safety codes and the occurrence of road traffic accidents (χ2 = 0.176, p = 0.916). The study shows that the practice of road safety measures was low in this rural Nigerian community and was not associated with the incidence of road traffic accidents. Introducing road safety education particularly targeted at educating the motorcyclists on the importance and practice of road safety measures would lead to an increase in the practice of the safety measures and hopefully a reduction in the incidence of road traffic accidents.

Motorcycle-related spinal injury: crash characteristics

This study presents an analysis of crash characteristics of motorcyclists who sustained spinal injuries in motorcycle crashes. The aim of the study is to identify the salient crash characteristics that would help explain spinal injury risks for motorcyclists. Data were retrospectively collected from police case reports that were archived at MIROS from year 2005 to 2007. The data were categorized into two subcategories; the first group was motorcycle crashes with spinal injury (case) and the second group was motorcycle crashes without spinal injury (control). A total of 363 motorcyclists with spinal injury and 873 motorcyclists without spinal injury were identified and analyzed. Descriptive analysis and multivariate analysis were performed in order to determine the odds of each characteristic in contributing to spinal injury. Single vehicle crash, collision with fixed objects and crash configuration were found to have significant influence on motorcyclists in sustaining spinal injury (p<0.05). Although relatively few than other impact configurations, the rear-end impacted motorcyclist shows the highest risk of spinal injury. Helmets have helped to reduce head injury but they did not seem to offer corresponding protection for the spine in the study. With a growing number of young motorcyclists, further efforts are needed to find effective measures to help reduce the crash incidents and severity of spinal injury. In sum, the study provides some insights on some vital crash characteristics associated with spinal injury that can be further investigated to determine the appropriate counter-measures and prevention strategies to reduce spinal injury.

Investigation of motorcyclist cervical spine trauma using HUMOS model

OBJECTIVE

With 16 percent of the total road user fatalities, motorcyclists represent the second highest rate of road fatalities in France after car occupants. Regarding road accidents, a large proportion of trauma was on the lower cervical spine. According to different clinical studies, it is postulated that the cervical spine fragility areas are located on the upper and lower cervical spine. In motorcycle crashes, impact conditions occur on the head segment with various orientations and impact directions, leading to a combination of rotations and compression. Hence, motorcyclist vulnerability was investigated considering many impact conditions.

METHOD

Using the human model for safety (HUMOS), a finite element model, this work aims to provide an evaluation of the cervical spine weaknesses based on an evaluation of injury mechanisms. This evaluation consisted of defining 2 injury risk factors (joint injury and bone fracture) using a design of experiment including various velocities, impact directions, and impact orientations.

RESULTS

The results confirmed previously reported clinical and epidemiological work on the fragility of the lower cervical spine and the upper cervical spine segments. Joint injuries appeared before bone fractures on both the upper and lower cervical spine. Bone fracture risk was greater on the lower cervical spine than on the upper cervical spine. The compression induced by a high impact angle was identified as an important injury severity factor. It significantly increased the injury incidence for both joint injuries and bone fractures. It also induced a shift in injury location from the lower to the upper cervical spine. The impact velocity exhibited a linear relationship with injury risks and severity. It also shifted the bone fracture risk from the lower to upper spinal segments.

The influence of seatbelts on the types of operated brachial plexus lesions caused by car accidents

PURPOSE

To determine whether there is a relationship between seatbelt use and type of brachial plexus injury seen in automobile accidents. Knowledge of such a relationship may help guide the surgical management of these patients.

METHODS

We retrospectively evaluated 43 surgical patients with brachial plexus palsy caused by car accidents. We recorded sex, age, and type of injury for each case. We also obtained data regarding the patients' position in the car at the time of the accident and whether they were wearing a seatbelt.

RESULTS

We obtained data on 39 men and 4 women. Of the seatbelted patients, 24 (100%) had upper plexus palsy on the side where the seatbelt crossed the shoulder. Of those who were not wearing seatbelts, 17 (86%) had complete plexus injuries. We also found 1 upper and 1 lower plexus injury in the unbelted group.

CONCLUSIONS

We found a relationship between the type of brachial plexus injury sustained by the accident victim and the use and position of the seatbelt. Complete plexus injuries were more common in those who were not wearing seatbelts. We saw upper plexus injuries for those wearing seatbelts. Information about seatbelt use may be useful in clinical practice. When treating an unbelted car accident victim with a brachial plexus injury, it is reasonable to anticipate a more serious form of the injury.

TYPE OF STUDY/LEVEL OF EVIDENCE

Prognostic IV.

Types and severity of operated supraclavicular brachial plexus injuries caused by traffic accidents

BACKGROUND

Brachial plexus injuries occur in up to 5% of polytrauma cases involving motorcycle accidents and in approximately 4% of severe winter sports injuries. One of the criteria for a successful operative therapy is the type of lesion. Upper plexus palsy has the best prognosis, whereas lower plexus palsy is surgically untreatable. The aim of this study was to evaluate a group of patients with brachial plexus injury caused by traffic accidents, categorize the injuries according to type of accident, and look for correlations between type of palsy (injury) and specific accidents.

METHODS

A total of 441 brachial plexus reconstruction patients from our department were evaluated retrospectively(1993 to 2011). Sex, age, neurological status, and the type and cause of injury were recorded for each case. Patients with BPI caused by a traffic accident were assessed in detail.

RESULTS

Traffic accidents were the cause of brachial plexus injury in most cases (80.7%). The most common type of injury was avulsion of upper root(s) (45.7%) followed by rupture (28.2%), complete avulsion (16.9%) and avulsion of lower root(s) (9.2%). Of the patients, 73.9% had an upper,22.7% had a complete and only 3.4% had a lower brachial plexus palsy. The main cause was motorcycle accidents(63.2%) followed by car accidents (23.5%), bicycle accidents(10.7%) and pedestrian collisions (3.1%) (p<0.001).Patients involved in car accidents had a higher percentage of lower avulsion (22.7%) and a lower percentage of upper avulsion (29.3%), whereas cyclists had a higher percentage of upper avulsion (68.6%) based on the data from the entire group of patients (p<0.001). Lower plexus palsy was significantly increased in patients after car accidents (9.3%,p<0.05). In the two main groups (car and motorcycle accidents),significantly more upper and fewer lower palsies were present. In the bicycle accident group, upper palsy was the most common (89%).

CONCLUSION

Study results indicate that the most common injury was an upper plexus palsy. It was characteristic of bicycle accidents, and significantly more common in car and motorcycle accidents. The results also indicate that it is important to consider the potential of a brachial plexus injury after serious traffic accidents and to examine both upper extremities in detail even if some motor function is preserved.

A proposed dissection procedure for vertebral arteries in forensic pathology

Vertebral artery removing constitutes a significant forensic pathology challenge. Dissection techniques during head-neck autopsy are based on anterior approach, a difficult method, which is unable to assess the transverse part of the artery. This work presents an original and simple method for dissecting vertebral arteries by a posterior approach, opening the vertebroarterial canal through the spinal canal without any special equipment. Once the spinal cord is removed, the transversarium foramens are opened by an internal cut at the pedicle and an external cut at the transverse process. This enables us to visualize vertebral arteries in its entirety. The method improves both the examination of the upper extracranial segment of the vertebral artery and the neuropathological study when arterial injury is suspected. Applying this method routinely is both feasible and useful in suspected cases of vertebral artery trauma and could contribute to assess more precisely the actual incidence of this injury.

Motorcyclist rear brake simple perception-response times in rear-end collision situations

OBJECTIVE

The purpose of this study was to determine the baseline motorcycle riders' perception-response times (PRTs) in an expected object braking task and to determine the significant difference between PRTs of older and younger riders.

METHODS

Fifty-nine participants sat on their motorcycles in exactly the same way as they would when riding and then they awaited activation of the taillights of the passenger car (parked) in front of them. PRTs of the motorcyclists were transcribed from the camcorder when the riders hit the brakes as quickly as possible following the activation of the car's brake lights.

RESULTS

Results of PRT were calculated by taking the average of both male and female older and younger riders. The study demonstrates that the mean and standard deviation of the motorcycle baseline PRTs are 0.44 and 0.11 s, respectively. Riders' age and gender were not found to be significant variables for PRT.

CONCLUSION

The mean of baseline perception-reaction time of motorcycle riders is smaller than that of passenger car drivers. If traffic facilities are designed based on passenger car drivers' simple perception-reaction times where drivers are generally more alert (for example, in traffic signal design), they can provide the required PRT for motorcyclists. This suggests that the utilization of more powerful brake lights on motorcycles could be highly effective for preventing rear-end motorcycle collisions.

Motorcycle helmets save lives, but not limbs: a National Trauma Data Bank analysis of functional outcomes after motorcycle crash

BACKGROUND

The incidence of motorcycle fatalities over the last 10 y has nearly doubled. There is considerable evidence that motorcycle helmets save lives, but there are little data regarding the impact that helmets have on functional outcomes after a motorcycle crash. The objective of this study was to determine the difference between helmeted and non-helmeted motorcyclists in the odds of developing a functional deficit at discharge in three domains: speech, locomotion, and feeding.

METHODS

Reviewed cases in the National Trauma Databank v7.0 involved in motorcycle collisions. Multiple logistic regression was used to analyze the effect of helmets on mortality and functional outcomes, adjusting for age, race, gender, insurance status, anatomic and physiologic injury severity, and head injury.

RESULTS

The adjusted odds of mortality (0.75; 95% CI 0.65-0.86) and functional deficits in speech (0.82; 95% CI 0.69-0.97), locomotion (1.19; 95% CI 1.11-1.29), and feeding (0.96 95% CI 0.84-1.08) among helmeted riders was compared with non-helmeted motorcyclists with equivalent injuries.

CONCLUSION

Helmeted motorcyclists are less likely to die and develop a deficit in speech after a motorcycle collision. These data support that motorcycle helmets are important in preventing functional deficits related to head injury.

Motorcycle helmet effect on a per-crash basis in Thailand and the United States

OBJECTIVE

To compare the effectiveness of motorcycle helmets seen in prospective on-the-street motorcycle accident investigations. The data are drawn from two detailed, in-depth studies of motorcycle accidents, in which trained investigators collected extensive accident evidence on-scene immediately after the crash. This article compares helmeted and unhelmeted motorcycle riders on a per-accident basis for fatality rates, the rate of serious (AIS > 2) brain injuries among survivors, or an outcome that involved either of the two.

METHODS

Nine hundred motorcycle crashes in Los Angeles and 969 crashes in Thailand were investigated in detail at the accident scenes, including photos of vehicles, skids, damage, and sometimes the rider. Helmets were collected and injury information was obtained from riders and care providers. This evidence was then used to reconstruct collision events to identify speeds, precrash motions, collision contacts, injury causation, and helmet performance.

RESULTS

In both studies, approximately 6% of riders were killed and 20-25% were hospitalized. Overall, unhelmeted riders were two to three times as likely to be killed, and three times as likely to suffer either death or survival with AIS > 2 brain injury. Unhelmeted survivors had three to four times as many AIS > 2 brain injuries as helmeted riders on a per-crash basis. Nearly 100% of riders with AIS > 4 somatic injuries died. Such injuries were 30% of Thailand fatalities and 57% of L.A. fatalities, but only about 2-3% of the overall accident population. Among the 97-98% of riders with AIS < 5 somatic injuries, helmet use could prevent about three-fourths of fatalities and brain injuries.

CONCLUSIONS

Helmets were extremely effective in preventing brain injury and death in 97% of the accident population in less-than-extreme crashes. Helmet use cannot prevent all fatalities because many of those killed succumb to below-the-neck injuries that a helmet cannot prevent.

Imaging of Traumatic Neurovascular Injury

Traumatic injury to the major vessels of the head and neck can result in potentially devastating neurologic sequelae. Until recently, conventional angiography was the primary imaging modality used to evaluate these often challenging patients. Advances in cross-sectional imaging have improved the ability to screen for these lesions, which have been found to be more common than previously thought; however, accepted protocols of imaging evaluation have not yet been fully established. This article presents a general approach to the patient with suspected neurovascular injury. This includes a discussion of the histopathologic spectrum, clinical presentation, mechanisms, radiologic work-up, pertinent issues of the most common lesions, and some of the endovascular techniques used in their management.