Epidemiologic Features of Facial Injuries among
Motorcyclists using Abbreviated Injury Scale (AIS)
Hamed Akhlaghi 1, Ali Adibi 2 and Mohammad Reza Zafarghandi3 Sina Trauma Research Center, Sina General Hospital
hamed.akhlaghi@gmail.com
Abstract
We want to investigate the relationships of motorcycle rider helmet, license driver and facial injuries among motorcyclists envolved a crash. Data from the questionnaire - filled when the motorcycle riders arrived to the emergency ward of Imam Khomeini, Shariati and Sina hospitals - were used to study 71 motorcycle riders. The mean age of motorcycle riders is 26.7 years old and most of them are men (97%). Although 63.8% of the motorcyclists held driver license, 38.6% of them used helmet. Compared to unhelmeted motorcycle riders, helmeted riders were more likely to have no injury after crash but equally likely to have license driver. 33.8% of the motorcyclists suffered from the head and neck injuries and the most frequent type of injury is scalp injuries followed by frontal and orbit injuries. These findings support policy and educational efforts promoting helmet use.
Keywords: Motorcyclist, facial injury, helmet use, AIS
1 Introduction
Facial injury, particularly soft tissue injury and fracture of the facial bones, is a frequent result after motor vehicle crashes, falls, and assaults and crashes during some recreational activities, such as bicycling6 and skiing [1].
Motorcycle crash injuries constitute a disproportionate number of motor vehicle crash-related deaths and hospital admissions each year in the United States [2] and elsewhere [3].
The increase in motorcycle use has resulted in an increase in the incidence of motorcycle-related injuries. Furthermore, data showed that motorcycle-related injuries ranked first among all forms of injuries in years of potential life lost [4].
Both international and national epidemiologic surveys have reported that the vast majority of serious or fatal motorcycle related injuries involve the head [5,6,7].
Among injuries sustained in motorcycle crashes, facial and head injuries contribute significantly to morbidity, mortality, disability, disfigurement, and costs of medical care. Although injuries to the brain have been studied extensively, information on clinical and epidemiologic characteristics of facial injuries is limited. Early published
1
- Medical Student of Tehran University of Medical Sciences, Correspondence Author 2
- Medical Student of Tehran University of Medical Sciences 3
- Sub-Specialty of Vascular Surgery and trauma, Chair of Department of Vascular Surgery and Traumatology, Tehran University of Medical Sciences
reports indicate that facial injuries are present in 5% to as many as 68% of injured persons treated in emergency departments of hospitals in various countries [8,9,10]. Immediate identification and management is important to reduce short- and long-term consequences of facial injuries. Although the impact of helmet use in reduction of head injuries in motorcycle crashes is well known [5,11], the effect of their use on facial injuries is not well documented.
The vulnerability of motorcyclists and bicyclists to facial injury in crashes has prompted several articles in which the role of helmets (and their design) in reducing facial injury risk was examined. All reports [3,8,10,12,13] confirm the protective role of helmets in reducing the occurrence of facial injuries in motorcycle and bicycle riders and that the full-face model, as compared with the open-face model, was superior in terms of injury attenuation. However, none of the published reports examined traumatic brain injury, facial injuries, and helmet use status simultaneously [1].
Information on the prevalence and types of facial injuries should be useful to medical specialists involved in primary, secondary, and tertiary levels of care and prevention. The objective of this study was to evaluate the prevalence, nature, type, and severity of facial injuries among riders involved in nonfatal motorcycle crashes.
2 Materials and Methods
The research design was a cohort study. A sample of nonfatally injured motorcyclists in Tehran formed the study population. In brief, the sample included nonfatally injured motorcyclist admitted to the emergency department (ED) of the three biggest teaching hospitals (Imam Khomeini, Shariati and Sina) affiliated to Tehran University of Medical Sciences (TUMS) during the first six month of 2004. All selected hospitals were level I trauma care centers. Patients dead on arrival and no hospitalized patients were excluded from the study. A questionnaire including age, sex, helmet use, diver license, Glasco Coma Score (GCS), blood pressure and respiratory rate enclosed with the 1990 Abbreviated Injury Scale (AIS) was filled for each patient by medically trained staff. The AIS classifies facial injuries under 5 different groups: whole area, vessles, nerves, internal (facial) organs and skeletal.
It ranks the severity of each injury on a scale from zero (no injury) to six (fatal injury). A head injury was defined as any injury with an AIS score in the head region, which includes all levels of severity. To determine the prevalence of severe head injuries, AIS scores greater or equal to three were used. These injuries are moderately severe to critical, and include skull fractures, intracranial damage, and prolonged loss of consciousness. Facial fractures were examined separately for each anatomic site. Hospital records were individually reviewed to obtain a complete list of injury diagnosis. Radiography and MRI results were used to verify injury diagnoses when available.
SPSS 12.0 was used to analyzed the relation between helmet wearing and injuries. The analysis compared patients with facial injuries with patients without facial injuries with respect to general characteristics, helmet use, and injury patterns.
3 Results
During the study period, 71 motorcycle riders envolved a crash were identified from the participating hospitals. Drivers constituted 81.7% and passengers 14.1% of
cases (4.2% had unknown status). Facial injuries were diagnosed in 24 cases, or 33.8% of them.
The average age of injured motorcycle riders with a facial injury was 31 years, and men constituted 95.8% of the total series. The average age of motorcyclist with facial injuries is higher than the motorcyclist without facial injuries (24.8 years old).
63.8% of cases had motorcycle driver license. The percentage of motorcycle driver license was similar between riders with and without facial injuries (approximately 50%) (Table 1).
Table 1. Number and percentage of injured motorcycle riders with and without facial injuries by sex, helmet use, rider status and having license driver.
Facial injury No facail injury Total Characteristics No % No % No % Sex Male 23 95.8 46 97.9 69 97.2 Female 1 4.2 1 2.1 2 2.8 Helmet use Yes 4 16.7 23 48.9 27 38 No 20 83.3 24 51.1 44 62 Rider status Driver 21 83.3 38 80.9 58 81.7 Passenger 2 8.3 8 17 10 14.1 Unknown 2 8.3 1 2.1 3 4.2 license holder Yes 12 50 25 53.2 37 52.1 No 7 29.2 14 29.8 21 29.6 Unknown 5 20.8 8 17 13 18.3
Data on frequency, nature, and severity of facial injuries by helmet use are given in Table 2. Injury to the facial region was diagnosed in 14.8% of helmeted and 45.5% of nonhelmeted riders, with an odds ratio (OR) indicating that helmeted riders had facial injuries only .21 times as often as nonhelmeted riders (95% confidence interval [CI], .06 to .70). Furthermore, multiple facial injuries were more frequent in riders without helmets (27.3%) than in those with hemlets (3.7%).
Tree fourths of all facial injuries were AIS 1; 12.5% of patients had moderate (AIS 2) and 12.5% had severe (AIS 3) facial injuries. All moderate and severe facial injuries were diagnosed among unhelmeted riders (Table 2).
Table 2. Number and percentage of facial injury by frequency and severity among helmeted and non helmeted riders.
Helmet Worn Helmet Not worn Total Injury No % No % No % No Facial Injury 23 85.2 24 54.4 47 66.2 Facial Injury 4 14.8 20 45.5 24 33.8 Number of Facial Injury One 3 75 8 40 11 45.8
Severity (AIS)
Mild (AIS I) 4 100 14 70 18 75
Moderate (AIS II) 0 0 3 15 3 12.5
Severe (AIS III) 0 0 3 15 3 12.5
4 Discussion
Injury to the face is a serious clinical problem among injured motorcyclists. Facial injuries pose significant physiologic and functional problems, including long-term effects on activities of daily life. Facial injuries are also important from an aesthetic point of view, because facial disfigurement can lead to long-term psychological and social sequelae. The presence of any facial injury should also be of clinical concern, because it can be a marker for substantial transfer of energy to the brain, with associated brain damage [12,14].
Early studies examined facial and head injuries under the rubric of "craniofacial trauma" or "maxillofacial trauma and head injury." The availability of the 1990 AIS contributed to the broader recognition of facial injuries separate from head trauma. With its use, it is now possible to identify and code the type, nature, anatomic location, and severity of facial injuries. Despite this advance there are still problems in researching multiple injuries to the face. The crash patterns and associated mechanisms of injury are not clearly known for facial trauma. Facial injuries resulting from single-vehicle crashes were reported in 13% of patients studied by Vaughan [8] and 37% of patients studied by Shankar et al [15] In the present study,
persons with facial injuries were more often involved in a single-vehicle crash, more often not wearing a helmet at the time of the crash. Lack of accurate information on the speed of the vehicle at impact was a limiting factor in this study, as it is in most studies of motor vehicle crashes. Because the nature, extent, type, and severity of facial injuries are determined by the nature of the collision, the force and direction of impact, the energy-absorbing characteristics of facial tissues and bones, and the use or nonuse of helmets, information on these factors is vital for identification of possible interventions [15,16]. So, this study was not able to control for the severity of the crash because detailed data on crash speed, angle of impact, and other features not available.
The reported incidence of facial trauma among motorcycle riders in crashes varies between 38% and 57%, respectively, depending on the setting, the nature of the study population, and the case identification methods [10,12,13,17]. Multiple fractures were present in 42% of patients who had a facial fracture. The energy generated during a crash is generally transmitted to the first bone contacted in the protruding area of the face [16]. Also, the anatomic composition of the maxilla, nose, and zygoma (thickness of bone and hollow interiors) makes them more susceptible to fracture compared with the mandible. Hampson [18], in a review of biomechanical studies of facial injury, reported that the tolerance of the maxilla, nasal, and zygoma to energy forces is lower than that of frontal and mandibular bones. Motorcycle helmets appear to reduce the occurrence and distribution of facial injuries. Further, riders without helmets had a greater number of multiple facial injuries and an increased number of moderate and severe injuries compared with persons using helmets. Similar increases in the odds of facial fracture among riders without helmets have been reported by Johnson et al [12] and Bachulis et al.
There were several limitations also in this study concerning using and coding existing hospital record data. The Abbreviated Injury Scale does not allow detail in diagnostic
coding; for example, supraorbital ridge is subsumed under orbit. These shortcomings and occasional small sample sizes prohibited more detailed analyses.
A major limitation of the present study was the unavailability of information on the specific type of helmet worn. The effects of different types of helmets on facial injury occurrence need to be studied in more detail. Nevertheless, the use of a helmet among injured motorcycle riders decreased the risk of facial injuries by more than 50%. This strongly suggests that, in addition to head injury protection, helmets also afford a substantial degree of protection from facial injury. Our study is based on a sample of riders who required emergency care for their injuries; it does not, therefore, reflect the entire spectrum of injuries sustained in motorcycle crashes. This study is not an incidence study of facial fractures in all crashes. Hospitals were sampled to achieve a representative population of patients, but there may be some differences between our cases and patients treated in other hospitals. The results of this study are most generalizable to more severely injured motorcycle riders who are not killed at the scene of the crash. It is these riders whom emergency physicians and other trauma care providers most frequently encounter. In this population, motorcycle helmets appear to prevent many facial injuries. This information should be incorporated into helmet promotion programs.
Continued studies on motorcycle injury-related morbidity and mortality are necessary to determine the long-term effect of the helmet use law. Effects on related medical costs, years of potential life lost, and the National Health Insurance Plan should also be evaluated.
5 Conclusion
Motorcycle riders who had at least one type of head and neck injuries in a crash are less likely to be helmeted. ED practitioners should screen all motorcyclists with facial fractures for brain injury, regardless of helmet use status. Increased use of motorcycle helmets might decrease the risk of traumatic brain injury occurrence by reducing energy transfers to the facial bones of crash-involved motorcycle riders. These findings support policy and educational efforts promoting helmet use, which seek to decrease these tragedies.
6 References
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