The incidence of hospital-treated facial injuries from vehicles

The annual incidence rate of facial injuries from vehicle crashes, 278 per 100,000 residents, was determined from a population-based study involving all Dane County, Wisconsin, hospitals with emergency departments. Applying this figure to the U.S. population yields an estimated 625,000 hospital-treated facial injuries from vehicles occurring in the United States each year. Vehicle crashes were the source of a substantial proportion of facial injuries from all causes, and were found to be the single leading cause of the most severe facial lacerations and facial fractures. The majority of injuries were sustained by drivers and other vehicle occupants, and others by bicyclists, motorcyclists, and pedestrians struck by vehicle. Vehicle occupants' faces were most commonly injured by steering wheels and windshields. Technologies which are thought to protect occupants include airbags and nonlacerating windshields, but neither is available in vehicles currently manufactured for sale in the United States.     

Incidence and crash mechanisms of aortic injury during the past decade

BACKGROUND: Aortic injuries were traditionally thought to be the result of severe frontal crashes. Newer data has suggested other crash types such as nearside crashes may also be important in aortic injury. We hypothesized the implementation of recent safety measures would decrease the incidence of aortic injury associated with fatal motor vehicle crashes. METHODS: The autopsy reports of all traffic fatalities for motor vehicle occupants in a large urban county for the years 1993 to 2004 were examined. The demographics, impact types, safety measures used, and the presence of any aortic injury were recorded. Trends were evaluated for significance by weighted linear regression. RESULTS: The incidence of aortic injury associated with fatal motor vehicle crashes has remained unchanged during the past 12 years (r = 0.057, p = 0.45). There is a trend toward decreased aortic injuries associated with frontal crashes (r = 0.26, p = 0.089) but no change in aortic injuries associated with nearside or farside crashes (r = 0.053, p = 0.47), when the crash resulted in a fatality. This is despite an increase in seat belt use and increased presence of airbags during the same time period. CONCLUSIONS: Despite improved safety measures designed to minimize the occurrence of aortic injuries, the incidence of blunt aortic injury in fatal motor vehicle crashes has not decreased during the past decade. Although not statistically significant, there is a trend toward decreased frontal impacts in fatal motor vehicle crashes associated with aortic injuries. The nearside crash mechanism continues to play a prominent role, and efforts at improving vehicle safety should be focused on crash mechanisms as they relate to aortic injury.     

Type II odontoid fracture from frontal impact: case report and biomechanical mechanism of injury

The authors report a case of Type II odontoid fracture from a frontal impact sustained in the crash of a late-model motor vehicle. They discuss the biomechanical mechanisms of injury after considering patient demographic data, type and use of restraint systems including seatbelt and airbags, crash characteristics, and laboratory-based experimental studies. Multiple factors contributed to the Type II odontoid fracture: the patient's tall stature and intoxicated state; lack of manual three-point seat belt use; obliqueness of the frontal impact; and the most likely preflexed position of the head-neck complex at the time of impact, which led to contact of the parietal region with the A-pillar roof-rail area of the vehicle and resulted in the transfer of the dynamic compressive force associated with lateral bending. Odontoid fractures still occur in individuals involved in late-model motor vehicle frontal crashes, and because this injury occurs secondary to head impact, airbags may not play a major role in mitigating this type of trauma to an unrestrained occupant. It may be more important to use seat belts than to depend on the airbag alone for protection from injury.     

On burn injuries related to airbag deployment

Airbags have been shown as a vital, supplemental restraining device that save lives and reduce morbidity associated with motor vehicles crashes. However, as with any developing technology, airbags have also been identified in some instances, as the source of injuries which, have been well described in the literature. To a significantly lesser degree, burns due to airbag deployment (about 7-8% of these injuries) have been reported. These injuries will be seen more frequently as more vehicles are equipped with airbags and should be suspected in drivers and passengers involved in accidents in which airbags have been activated. This article, reviews the various types of burns and their pathogenesis, found in crashes involving airbag deployments.     

Kinematics of belted fatalities in frontal collisions: A new approach in deep studies of injury mechanisms

BACKGROUND: More than half of car crash fatalities are belted occupants, and the majority of these occur as a consequence of frontal crashes. In an earlier study of crash configuration characteristics, we have shown that 48% of fatalities occurred in frontal small overlap (SO) crashes in which less than 30% of the vehicle front was engaged. Only 23% of fatalities occurred in large overlap (LO) crashes engaging the drive train, similar to most barrier front crash testing procedures. The main purpose of this study was to analyze the characteristics of injury mechanisms and injuries in fatal SO and LO car crashes in Sweden. METHOD: Retrospective examination and analysis of 61 fatally injured occupants from 53 car crashes within a sample area covering 40% of the population of Sweden was conducted. RESULTS: A clear difference in injury mechanisms and injuries was found between SO and LO crashes. The major injury mechanisms in SO crashes are explained by an oblique torso movement and rotation toward the outboard side, which causes a high proportion of serious lateral chest and head injuries. In contrast, LO crashes were generally characterized by serious anterior chest injuries in elderly occupants (> or =60 years). CONCLUSION: Current government and consumer barrier crash test procedures are not designed to estimate the performance of cars and restraint systems for the type of crashes which caused the majority of occupant fatalities in this data set.     

Injuries of the pelvic ring in road traffic accidents: a medical and technical analysis

Between 1985 and 1995, 9380 traffic accidents occurring in the area of Hannover, Germany, were analysed; 12428 individuals had been injured and 387 (3.1%) had sustained a pelvic-ring injury (AIS(PELVIS)>2). In 131 cases (34%), the injuries were further classified (Pennal and Tile) and a technical reconstruction made of the accident: 52% were type A, 27% type B and 21% type C injuries; 46% were in cars, 12% on motorised two-wheelers, 10% on bicycles and 1% in utility vehicles; 31% were pedestrians. Pelvic-ring injuries occurred in restrained vehicle occupants in accidents with a (delta)V of more than 30 km/h, whereas they occurred in a considerable proportion of unrestrained vehicle occupants, pedestrians and bicyclists at lower (delta)V or collision speed. The percentage of B- and C-type injuries increased in crashes with higher (delta)v or collision speed. In addition to further improvements of the passive safety, lower collision speeds or (delta)V would reduce or prevent pelvic-ring injuries. Due to the small number of occupants protected by airbags in this study, their protective effect for the pelvis could not be assessed. The reconstruction of pelvic-ring injury mechanism in traffic accidents is possible when technical and medical factors are considered.     

The association between restraint system and upper extremity injury after motor vehicle collisions

OBJECTIVES: This study was designed to investigate the relationship between upper extremity (UE) injuries and occupant restraint systems among front seat occupants who were involved in frontal motor vehicle collisions (MVCs). DESIGN: Case-control. SETTING: The 1995 through 2002 National Automotive Sampling System (NASS) Crashworthiness Data System (CDS). PARTICIPANTS: Subjects were identified from the NASS-CDS. All cases sustained an UE injury with a > or = 2 Abbreviated Injury Scale Score. OUTCOMES: Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated comparing risk of UE in 3 mutually exclusive restraint system groups (seatbelt-only, airbag-only, seatbelt-airbag-combined) to the unrestrained group. Data analysis was adjusted for significant occupant, vehicle, and collision characteristics. RESULTS: Seatbelt-only occupants had a reduced UE injury risk (OR, 0.41; 95% CI, 0.22-0.76). Near null associations were found for airbag-only (OR, 1.1; 95% CI, 0.68-1.76) and seatbelt-airbag-combined (OR, 0.97; 95% CI, 0.56-1.69). CONCLUSION: The results of this study suggest that UE injuries may become more common as a result of MVCs as the proportion of airbags in motor vehicles increases.     

Children in side-impact motor vehicle crashes: seating positions and injury mechanisms

BACKGROUND: This study aimed to describe the injury mechanisms of children involved in side-impact car crashes, particularly as these relate to seating position, and to estimate the danger of the near-side seating position. METHODS: A prospective two-center study of children involved in severe car crashes in Canada was conducted as well as a retrospective cohort study of children involved in crashes reported in the Fatality Analysis Reporting System (FARS) and the National Automotive Sampling System: Crashworthiness Data System (NASS CDS). RESULTS: Children sitting at the side the car was struck (near-side position) sustained severe head, trunk, and limb injuries. Many of these injuries were attributable to direct intrusion, but some occurred without direct damage to the occupant compartment. Center-seat and far-side occupants had severe injuries only when unrestrained. Injury severity scores were higher for children seated on the near side, and this was statistically significant (p = 0.024) The analysis of Fatality Analysis Reporting System data showed that the risk of fatality was higher for children seated in the near-side position than for those in the center-seat position. The fatality risk ratio was 2.53 (95% confidence interval [CI], 2.08-3.07) for restrained children and 1.84 (95% CI, 1.57-2.17) for unrestrained children. Analysis of the NASS-CDS data showed that for restrained children, severe injury (ISS > or = 16) was more common among those on the near side (7 per 1,000 children) than among those in the center seat (2 per 1,000) or on the far-side seat (1 per 1,000) (p < 0.001). CONCLUSIONS: Severe injuries to near-side occupants occurred in both the presence and absence of compartment intrusion. A typical pattern of head, chest, and extremity injury similar to that seen among child pedestrians was observed among near-side child occupants in side-impact crashes. The center seat was statistically safer than the near-side seat, particularly for restrained child occupants. Scene information may be useful to trauma teams for the prediction of injury type and location. Avoiding intrusion and preventing the occupant from striking the vehicle wall are both important to side-impact protection for children. Improvement of the vehicle safety cage may protect against intrusion injuries. Seating two child occupants in inboard seating positions may provide additional protection against intrusion injuries, and also may protect against nonintrusion injuries.     

Causes of scapula fractures differ from other shoulder injuries in occupants seriously injured during motor vehicle crashes

Purpose

Current motor vehicle safety systems primarily focus on preventing life-threatening and serious injury during crashes, but occupants may still sustain less serious injury. Upper extremity injury is common in occupants involved in motor vehicle crashes. The purpose of this study was to compare occupants with scapula fractures to occupants with other shoulder injuries.

Methods

We used data from the Crash Injury Research and Engineering Network (CIREN) database (1997-2008) to compare two groups of occupants: (1) occupants with only scapula fractures and (2) occupants with shoulder injury not involving the scapula. We hypothesised that there were no differences in demographics, vehicle, crash characteristics and causes of shoulder injury in these two groups.

Results

Of the 3370 occupants studied, 54 occupants (1.6%) had only a scapula fracture in the shoulder region and 342 (10.1%) occupants had other shoulder injuries. There were significant differences between gender, height and weight, maximum Abbreviated Injury Scale (AIS) severity and the crash type. Occupants with scapula fractures were 3 times more likely to be male (odds ratio (OR) = 3.30) and were significantly taller and weighed more than occupants with other shoulder injuries. Occupants with other shoulder injuries had significantly greater injury severity (based on maximum AIS for any injury) than those with scapula fractures. There was a significant difference between scapula fractures and clavicle fractures (OR = 1.87) and joint dislocations/separations (OR = 2.79) comparing the cause of injury (vehicle side interior vs. other causes). Safety belts are the single most important safety system in motor vehicles and should always be worn. However, we found no differences in the cause of scapula fractures comparing occupants wearing their safety belt with those not wearing the belt.

Conclusion

This study provides information showing that scapula fractures occur during different types of impacts and have different causes other than shoulder injuries.     

The role of restraint and seat position in pediatric facial fractures

BACKGROUND: Recently, head and brain injuries were identified as consequences of the inappropriate use of seat belts by children. The proposed mechanism of these injuries might also place a child at risk for facial fracture. METHODS: A probability sample of children under age 16 involved in crashes were enrolled in an ongoing crash surveillance system (1998-2001) that links insurance claims data to telephone survey and crash investigation data (unweighted, n = 12,659; weighted, n = 131,717). Incidence of facial fracture was estimated and a series of cases were examined using in-depth crash investigation to identify the mechanisms of these injuries, specifically, the role of seating position and restraint use in the mechanism of injury. RESULTS: Ninety-two children suffered a fracture of the facial bones (0.07% of all children in crashes). Among restrained children with facial fractures (n = 68), those inappropriately restrained were at a 1.6-fold higher risk (95% confidence interval, 1.2-2.1; p = 0.001) of significant injury than those appropriately restrained for their age. The in-depth investigations revealed that excessive head excursion resulting from suboptimal torso restraint caused facial impact, which resulted in the facial injuries described. CONCLUSION: The potential for disfigurement associated with these facial injuries may resonate strongly with parents, and prevention of disfigurement may provide additional motivation for proper restraint, in particular, booster seats and rear seat location, for this pediatric population.     

Patterns of maxillofacial injuries in restrained and unrestrained motor vehicle crash victims

Safety belts reduce the frequency and severity of injuries sustained in motor vehicle crashes. Since the head and face are the most frequently injured anatomic regions in motor vehicle crash victims, the use of active restraints should lessen these injuries. This study was undertaken to examine the ability of safety belts to prevent and alter the pattern of maxillofacial injuries. During a 6-month period beginning February 1, 1987, 613 motor vehicle crash victims presented alive to the Trauma Center at the University of Tennessee Medical Center at Knoxville and were entered into this study. There were 254 restrained victims (R), 290 unrestrained (UR), and 69 who were excluded for lack of sufficient data regarding restraint usage. Unrestrained victims tended to be younger (mean age: UR = 27.9, R = 31.7; p less than 0.03), and more often male (UR = 65% vs. R = 51%; p less than 0.03). Irrespective of position within the vehicle, the mean number of facial lacerations per person was less in the restrained group (R = 0.31, UR = 0.76; p less than 0.03). This injury reduction was more pronounced in front seat occupants (R = 0.27, UR = 0.82; p less than 0.03). Furthermore, a smaller proportion of the lacerations in the restrained group were categorized as complex, i.e., involving more than skin and subcutaneous tissue (R = 5.0%, UR = 15.9%; p less than 0.03). The pattern of skeletal injuries was also significantly different.(ABSTRACT TRUNCATED AT 250 WORDS)     

Pelvic ring fractures: implications of vehicle design, crash type, and occupant characteristics

BACKGROUND: Pelvic ring fractures (PRFs) are a major cause of morbidity and mortality in motor vehicle collisions (MVCs). Understanding the factors leading to PRFs may help improve vehicle design and safety. This study sought to determine the vehicular, crash, and occupant characteristics that contribute to PRFs. METHODS: From 1997 to 2003, 240 adult patients involved in lateral or frontal crashes were prospectively studied. Comprehensive crash reconstructions, vehicle analysis, and occupant data were compiled and analyzed as part of the national Crash Injury Research Engineering Network project. RESULTS: Of 240 study patients, 38 had PRFs. The incidence of PRFs was significantly associated with female gender, lateral impact crashes, vehicle incompatibility, and severity of crash. Seat belts and airbags were not protective against PRFs in either lateral or frontal crashes. CONCLUSIONS: All vehicles in the current study were less than 6 years old at the time of the MVC and thus reflect newer safety designs. Compared with studies of PRFs in MVCs before the widespread adoption of modern safety standards, our series suggests there has been a modest decrease in the incidence of PRFs in newer vehicles. Current safety standards do not adequately protect against PRFs, especially in lateral MVCs involving incompatibility and female occupants. New technology needs to be developed and implemented. Our data suggest that side impact airbags, alteration of vehicle geometry, and increased reinforcement of side panels and doors may result in fewer PRFs.     

Upper extremity fracture patterns following motor vehicle crashes differ for drivers and passengers

PURPOSE: Injury patterns of occupants in motor vehicle crashes are changing, with upper extremity injury becoming more common in patients treated at trauma centres. Although not life threatening, upper extremity injuries may result in long-term disability, including chronic deformity, neurovascular compromise and degenerative arthritis. The purpose of this study was to compare upper extremity injury in drivers and passengers using the Crash Injury Research Engineering Network (CIREN) database. METHODS: CIREN data were used to compare upper extremity skeletal injury patterns and sources for drivers and passengers in frontal and side impacts. Occupant variables (age, gender, co-morbidity, avoidance maneuvers and restraint use) and crash variables (direction of impact, delta V and vehicle crush) were considered in the analysis. RESULTS: Only 24.8% of all occupants in the CIREN database had upper extremity injuries. One-half of upper extremity injuries to drivers were forearm fractures compared to one-third for passengers. Occupants in side impacts were more likely (OR=5.05) to have clavicle fractures, even while controlling for driver versus passenger status and safety belt use. Air bags were more likely to be a source of forearm fracture (OR=2.31) when controlling for driver versus passenger status, direction of force, sex and age compared to other sources. Only 10% of driver fractures with air bag deployment in frontal impacts were associated with air bag fling. CONCLUSIONS: This study found that drivers and passengers have different upper extremity injury patterns but the direction of impact also plays an important role.     

Injury in U.S. Army helicopter crashes October 1979-September 1985

All U.S. Army class A and B mishaps of four types of helicopters occurring from 1 October 1979 through 30 September 1985 were reviewed. During this 6-year period, there were 298 crashes involving 303 aircraft. There were 1,060 individuals aboard the crashed aircraft and 611 were injured, 136 fatally. The most common cause of injury was the "secondary impact" caused by collapse of structure into occupied areas, by inadequate restraint of the occupants which allowed them to flail into structure, or by a combination of both mechanisms. Injury solely related to acceleration occurred infrequently. The most frequently injured body regions in survivable crashes were the head (28%) and extremities (43%). Injury patterns are compared for different helicopter types and related to differences in design. Basic principles of crash injury protection, including individual protection by helmets, seatbelts, and airbags, and structural modifications to minimize injury potential, as well as crashworthy fuel systems, are reviewed, and recommendations are made to increase the crashworthiness of helicopters, such as adapting designs and standards on the basis of active field investigations.     

Thoracic aortic injury in motor vehicle crashes: the effect of impact direction, side of body struck, and seat belt use

BACKGROUND: Using in-depth, real-world motor vehicle crash data from the United States and the United Kingdom, we aimed to assess the incidence and risk factors associated with thoracic aorta injuries. METHODS: De-identified National Automotive Sampling System Crashworthiness Data System (U.S.) and Co-operative Crash Injury Study (U.K.) data formed the basis of this retrospective analysis. Logistic regression was used to assess the level of risk of thoracic aorta injury associated with impact direction, seat belt use and, given the asymmetry of the thoracic cavity, whether being struck toward the left side of the body was associated with increased risk in side-impact crashes. RESULTS: A total of 13,436 U.S. and 3,756 U.K. drivers and front seat passengers were analyzed. The incidence of thoracic aorta injury in the U.S. and U.K. samples was 1.5% (n = 197) and 1.9% (n = 70), respectively. The risk was higher for occupants seated on the side closest to the impact than for occupants involved in frontal impact crashes. This was the case irrespective of whether the force was applied toward the left (belted: relative risk [RR], 4.6; 95% confidence interval [CI], 2.9-7.1; p < 0.001) or the right side (belted: RR, 2.6; 95% CI, 1.4-5.1; p < 0.004) of the occupant's body. For occupants involved in side-impact crashes, there was no difference in the risk of thoracic aorta injury whether the impacting force was applied toward the left or toward the right side of the occupant's body. Seat belt use provided a protective benefit such that the risk of thoracic aorta injury among unbelted occupants was three times higher than among belted occupants (RR, 3.0; 95% CI, 2.2-4.3; p < 0.001); however, the benefit varied across impact direction. Thoracic aorta injuries were found to be associated with high impact severity, and being struck by a sports utility vehicle relative to a passenger vehicle (RR, 1.7; 95% CI, 1.2-2.3; p = 0.001). CONCLUSION: Aortic injuries have been conventionally associated with frontal impacts. However, emergency clinicians should be aware that occupants of side-impact crashes are at greater risk, particularly if the occupant was unbelted and involved in a crash of high impact severity.     

Mechanisms, pattern and treatment costs of maxillofacial injuries

Facial contact with the steering wheel was the most common source of maxillofacial injuries sustained by vehicle occupants. Maxillofacial injuries to non-restrained occupants, especially children, most commonly resulted from contact with the vehicle's seats. In contrast to previous studies, contact with the windscreen by non-restrained occupants produced only a small number of minor facial injuries. Serious fractures of the facial skeleton were rare and no maxillofacial injury was fatal. A relationship between impact speed and the severity of facial injury sustained was demonstrable. Total compliance with seat belt legislation could be expected to save the National Health Service in excess of 5 pounds million/year from the reduction in maxillofacial injuries alone.     

Air bag injuries and occupant protection.

Analysis of the investigations of crashes involving automobiles equipped with air bags verifies the estimations of the lifesaving and injury reduction benefits of this supplemental restraint system. Cases of air bag-associated injuries, primarily erythema, abrasions, and contusions of the lower face and anterior throat-upper chest, are identified as those most often observed. Corneal-scleral injuries were infrequently noted but are rarely found in crashes involving air bag deployments.     

Incidence and characteristics of motor vehicle collision-related blunt thoracic aortic injury according to age

BACKGROUND: Motor vehicle collision-related blunt thoracic aorta injury (BAI) is rare and highly lethal. Vascular disease as related to advancing age potentially subjects older adults to increased risk of BAI; the mechanisms associated with such injuries may be different as compared with younger adults. The goal of the present study is to test this hypothesis using population-based data. METHODS: The 1995 to 1999 National Automotive Sampling System data files were used. The National Automotive Sampling System is a national probability sample of passenger vehicles involved in police-reported tow-away crashes. BAI was defined according to the Abbreviated Injury Scale codes. Among those with BAI, information on occupant (age, seating position, restraint use), collision (collision type, delta-V, vehicle intrusion), and outcome characteristics were obtained and compared according to age. RESULTS: The overall incidence of BAI was 6.8 per 10,000 occupants and there was a steady increase in the BAI rate for advancing decades of life. The proportion of occupants with BAI who die at the scene of the collision is relatively consistent across all age groups ( approximately 85%). Among those who survive to receive medical care, ultimate survival is lowest among those aged 60 and older. Near-side collisions were responsible for more BAI among older adults than other age groups (50% vs. 20.6%, p < or = 0.05). Older adults sustained BAI in collisions with lower delta-V values compared with younger persons (p < or = 0.05). CONCLUSION: Older adults have the highest rate of motor vehicle collision-related BAI, and their injuries tend to occur in less severe collisions. A high level of suspicion for BAI among older adults should not be reserved for high-energy collisions only.     

Foot and ankle injuries in motor vehicle accidents.

BACKGROUND: We studied foot and ankle (F/A) injuries that occurred in motor vehicle accidents treated in a Level 1 trauma center. METHODS: The records of F/A injuries of 2248 consecutive orthopedic patients were reviewed to find foot and ankle injuries. RESULTS: Pilon fractures were common. Motor Vehicle Accident (MVA) occupants with F/A injuries had a higher injury Severity Score than those without (17.9 vs. 11.6, p <. 001). MVA F/A injury risk was higher without restraint [relative risk ratio (rrr) 1.68, p <. 0032] than with restraint except for air bagged drivers who were similar to unrestrained drivers (rrr 1.18, p > .05, NS). CONCLUSION: Patients with F/A injuries may have serious associated injuries. Air bags may not protect feet.