Air bags: reducing the toll of brain trauma

Motor vehicle crashes account for approximately one-half of all hospitalized patients with brain injury. Therefore, measures to reduce the frequency and severity of injuries from motor vehicle crashes have the potential for making a substantial impact on the incidence and severity of brain trauma. Occupant restraints, including seat belts and air bags, have been proven highly effective in preventing injuries, yet the specific benefits for the brain, the face, and the cervical spine provided by air bags have not been widely publicized. Air bags prevent the violent whiplash motion of the head in a frontal crash, resulting in a more controlled deceleration of the brain. Wrenching forces exerted on the cervical spine are attenuated, and the face is protected from contact with hard or lacerating surfaces. Furthermore, compliance is not a problem with air bags. When a car is equipped with air bags, they are in effect 100% of the time, which is important for the protection of high risk groups, such a teenage boys, who tend to wear seat belts less often than other groups. It is estimated from national data and from epidemiological studies that air bags could have prevented or reduced brain injury for 25% of the hospitalized, brain-injured population. If provided as standard equipment on both the driver and the passenger side, air bags could do more to reduce the toll of brain trauma than any other available intervention. Air bags were ready for introduction into the marketplace 15 years ago. Since then, approximately 150,000 preventable deaths and more than 1,500,000 preventable brain injuries have occurred.(ABSTRACT TRUNCATED AT 250 WORDS)     

Eye injuries in patients with major trauma

BACKGROUND: A study was performed to determine the type and frequency of ocular injuries in patients with major trauma. METHODS: All patients with ocular and adnexal injuries (n = 178) among 1,119 patients admitted with major trauma (Injury Severity Score >15) to the Royal Prince Alfred Hospital from July 1990 to December 1997 were analyzed. RESULTS: Sixteen percent of the major trauma cohort had ocular or orbital trauma. Fifty-five percent of patients with injuries involving the face had ocular or orbital injuries. A range of ocular injuries was seen. Analysis of the major trauma cohort showed that motor vehicle drivers, orbital and base of skull fractures, eyelid lacerations, and superficial eye injuries were strongly associated with vision-threatening injury. CONCLUSION: Patients with major trauma and facial injuries have a high risk of vision-threatening injury. Patients with orbital fractures, base of skull fracture, eyelid lacerations, and superficial eye injuries should be assessed by an ophthalmologist as part of the early management of their trauma to determine whether an ocular injury is present.     

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.     

Protection against head injuries should not be optional: a case for mandatory installation of side-curtain air bags

Background

More than 9,000 vehicle occupants die each year in side-impact vehicle collisions, primarily from head injuries. The authors hypothesized that side-curtain air bags significantly improve head and neck safety in side-impact crash testing.

Methods

Side-impact crash-test data were obtained from the Insurance Institute for Highway Safety, which ranks occupant protection as good, acceptable, marginal, or poor. Vehicles of the same make and model that underwent side-impact crash testing both with and without side-curtain air bags were compared, as well as the protective effect of these air bags on occupants' risk for head and neck injury.

Results

Of all the passenger vehicles, 25 models have undergone side-impact crash testing with and without side-curtain air bags by the Insurance Institute for Highway Safety. Only 3 models without side-curtain air bags (12%) provided good head and neck protection for drivers, while 21 cars with side-curtain air bags (84%) provided good protection (P < .001). For rear passengers, the added protection from side-curtain air bags was less dramatic but significant (84% without vs 100% with side-curtain air bags, P = .04).

Conclusion

Side-curtain air bags significantly improve vehicle occupant safety in side-impact crash tests. Installation of these air bags should be federally mandated in all passenger vehicles.     

Invalidity of speculated injury mechanism in autopsy reports

Postmortem and crash investigation reports were examined for 35 cases of belted automotive crash fatalities. This paper highlights those cases with speculation of the injury mechanism in the post mortem report. In two cases, the medical examiner made specific reference to a 'whiplash' mechanism of brain injury, which refers to an inertial loading of the neck without head contact. Examination of the car interior in one case indicated evidence of head contact with transfer of hair, and the other facial contact with transfer of teeth. Death was more likely due to direct head impact. In another case, the vehicle was struck laterally by another car on the far side of the driver. The medical examiner stated that the driver incurred typical 'steering wheel type' injury, while examination of the car interior indicated no consequential contact between the driver and the steering wheel. Instead, the intruding passenger door probably impacted the driver at a velocity high enough to induce fatal chest injuries. These cases demonstrate the necessity of a thorough examination of contact points in the crashed car to discern the mechanism of injury and to reconstruct the kinematics of injured occupants in a crash. They also demonstrate how 'popular' misunderstanding of mechanisms of fatal injury may be introduced and perpetuated.     

Pediatric temporal bone fractures in a rural population.

OBJECTIVE: To examine pediatric temporal bone fractures in a rural population. STUDY DESIGN AND SETTING: A retrospective chart review of pediatric temporal bone fractures between January 1, 1996, and December 31, 2000, at a rural academic medical center. RESULTS: A total of 108 patients were identified. Common etiologies include falls, bicycle-related injuries, and motor vehicle accidents. Animal-related injuries were identified primarily in patients under 5. Facial nerve injuries were noted in 7%, hearing loss in 16%, additional skull base fractures in 65%, and intracranial injuries in 75%. CONCLUSIONS: Temporal bone fracture etiology in the rural pediatric population is associated with age. Young children may suffer fractures secondary to animal-related accidents. Patterns of injury differ little between rural and urban settings. SIGNIFICANCE: Animal-related accidents may be a significant cause of temporal bone trauma in rural young children. Our data remain unique in that we report additional skull base fractures as well as intracranial injuries in this population.     

Spectrum of ocular injuries in children with major trauma

BACKGROUND: Few studies document the variety of ocular injuries encountered in children after major trauma. This study was performed to determine the type and frequency of ocular injuries in a large population of children with major trauma. METHODS: All children with ocular and adnexal injuries (n = 7497) among 96,879 children registered in the National Pediatric Trauma Registry (NPTR) were analyzed. Children were stratified for Injury Severity Score (ISS is a method for categorizing patients with multiple injuries in which an ISS > 15 is considered major trauma), age, sex, injury, protective restraint, vision threatening injury, and basilar skull fracture. RESULTS: Nearly 8% of the children in the NPTR sustained an ocular injury. These children had one or more injuries to one or both eyes and/or the ocular adnexa for an average of 1.3 ocular injuries per child. Three-fourths (75%) of the children with an ocular injury had an ISS < or = 15 and one-fourth (25%) had an ISS > 15. Among children with an ISS > 15 the most common injuries were orbital wall fracture (59%) and contusion of the eye and ocular adnexa (18%). Among these same children with an ISS > 15, the percent of orbital wall fractures, injuries to the optic nerve, and injuries to the other ocular cranial nerves doubled while the percent of basilar skull fractures tripled when compared with children with an ISS < or = 15. Penetrating injuries of the globe were significantly lower in children with an ISS > 15 than in children with an ISS < or = 15. Over 70% of the children with an eye injury and an ISS > 15 sustained injury in an accident involving a motorized or non motorized vehicle, and over 75% of those who could have been restrained, were not restrained. CONCLUSIONS: Children with an ocular injury sustained during major trauma (ISS > 15) are more likely to have a basilar skull fracture, orbital wall fracture, and a contusion of the eye and/or the ocular adnexa as compared with children with ISS < or = 15. Children with any of these injuries sustained during major trauma should be afforded prompt ophthalmologic evaluation to uncover injury to components of the visual system.     

Do Concomitant Cranium and Axis Injuries Predict Worse Outcome? A Trauma Database Quantitative Analysis

We performed a trauma database analysis to identify the effect of concomitant cranial injuries on outcome in patients with fractures of the axis. We identified patients with axis fractures over a 14-year period. A binary outcome measure was used. Univariate and multiple logistic regression analysis were performed. There were 259 cases with axis fractures. Closed head injury was noted in 57% and skull base trauma in 14%. Death occurred in 17 cases (6%). Seventy-two percent had good outcome. Presence of abnormal computed tomography head findings, skull base fractures, and visceral injury was significantly associated with poor outcome. Skull base injury in association with fractures of the axis is a significant independent predictor of worse outcomes, irrespective of the severity of the head injury. We propose that presence of concomitant cranial and upper vertebral injuries require careful evaluation in view of the associated poor prognosis.     

Bitemporal compression injury caused by static loading mechanism. Report of two cases

The authors report two cases of bitemporal compression injury caused by a static loading mechanism. These head injuries resulted from gradual bitemporal compression of the head. Plain skull films showed multiple skull fractures, and carotid angiography revealed internal carotid artery obstruction at the base of the skull. Neurological examination disclosed a slight disturbance of consciousness, hemiparesis, multiple cranial nerve injuries, and Horner's syndrome. In comparison with impact head injury, the energy from this type of trauma tends to be transmitted to the foramina and hiati of the middle cranial fossa and results in multiple injuries to the cranial nerves, sympathetic nerves, and blood vessels.     

Management of Minor Head Injuries: Admission Criteria, Radiological Evaluation and Treatment of Complications

Summary The clincal course of patients admitted following minor head injuries (Glasgow Coma Score [GCS] 13–15) has been studied less extensively than in severely head injured patients. Admission criteria, methods and indications for radiological evaluation are controversial. To study this further, a retrospective review of 633 patients admitted following such injuries to King Khalid University Hospital between 1986 and 1993 was undertaken. Their ages ranged from one month to 80 years (average 17 years). The mechanisms of injury were mainly falls in 339 (53.5%) cases and road traffic accidents in 234 (37%). None of the cases resulted from a non-accidental injury. Radiological evaluation was by skull radiography in 616 (97.3%) cases followed by CT scan in 131 (20.7%). These studies revealed a skull fracture in 78 (12.7%) cases. Six of these 78 patients with skull fracture required a neurosurgical procedure during the first week post injury. These represented 0.97% of the cases who had skull radiographs. A base of skull fracture was an ominous sign, since 3 of the 5 cases with such fractures required ventilation of which one resulted in the only mortality of this series, the fourth developed meningitis. Of the cases studied, 3 (0.5%) developed growing skull fractures all had the initial injury during their first year of life. Other complications were as follows: 25 (3.9%) early post-traumatic seizures, 10 (1.6%) chronic subdural haematomas, 9 (1.4%) extradural haematomas, 2 (0.3%) post-traumatic hydrocephalus and one (0.2%) cerebral abscess. We conclude that patients who have an abnormal GCS, a neurological deficit, post-traumatic seizure, signs or suspicion of basal or depressed skull fracture should be admitted for observation because of the risk of deterioration. Patients with a history of loss of consciousness or amnesia without any of the previous may be discharged to be observed at home by a competent observer, otherwise, will need admission for observation. Radiological evaluation once indicated must be by CT scan. There is no benefit from immediate skull radiography in the initial evaluation of minor head injuries. The indications for CT are an abnormal GCS, presence of neurological deficit, signs of basilar or depressed fracture and persistent or progressive headache or vomiting. Infants with minor injuries should be followed up at least once after two to three months for possible growing fractures.     

The influence of air bags and restraining devices on extremity injuries in motor vehicle collisions

The influence of air bags and other restraining devices on injury after motor vehicle collisions is not well defined. This study examined the relationship between the use of restraining devices and the incidence of extremity injuries in motor vehicle collisions. A retrospective analysis was performed on motor vehicle collision data submitted to the Pennsylvania Trauma Outcome Study database from 1990 through 1995. Criteria for submission included trauma patients who were admitted to the intensive care unit, who died during hospitalization, who were hospitalized for more than 72 hours, or who were transferred in or out of the receiving hospital. A total of 21,875 patients met these criteria. These patients were analyzed for the presence or absence of upper and lower extremity injuries and were compared based on their use of restraining devices. Restraining devices were categorized into four groups: air bag alone, air bag and seat belt, seat belt or carseat without air bag, and no restraining device. Statistical analysis was performed using the chi-squared test of association. For contingency tables with small expected frequencies, Fisher's exact test was used. Study participants included 11,688 men and 10,185 women with a mean age of 38 +/- 20 years. There were 16,033 drivers and 5,842 passengers. Air bags were deployed in 472 instances. In 297 of these cases, additional restraint was provided with a seat belt. In 6,632 cases, air bags were not deployed; however, patients were restrained with either a seat belt or a carseat. In 14,771 cases, patients were not restrained. When comparing restraining devices as a group vs. no restraint, there was a significant decrease in the incidence of upper (p = 0.018) and lower (p < 0.001) extremity injuries. Air bags, however, were associated with an increased incidence of both upper (p = 0.033) and lower (p = 0.002) extremity injuries when compared with no restraint or when compared among patients who were restrained. As a group, restraining devices decrease the incidence of upper and lower extremity trauma sustained by patients injured in motor vehicle collisions. Air bags, however, are associated with an increased incidence of upper and lower extremity injuries when compared with seat belts alone or when no restraining devices are used.     

Association of head trauma with cervical spine injury, spinal cord injury, or both

BACKGROUND: Links between cervical spine and/or spinal cord injuries and head trauma have not been reported in detail. METHODS: 188 patients with cervical spine and/or spinal cord injury were divided into two groups, i.e., with upper cervical and mid-lower cervical injury, and compared for head injury. RESULTS: Associated head trauma was investigated in 188 patients with cervical spine and/or spinal cord injuries; 35% had moderate or severe injuries. Brain damage was more frequently observed in patients with upper cervical injury than in those with mid to lower cervical injury. Those patients with upper cervical injury appeared to have an elevated risk of suffering skull base fractures, traumatic subarachnoid hemorrhage, and contusional hemotoma. CONCLUSIONS: Approximately one third of patients with cervical spine and/or spinal cord injuries had moderate or severe head injuries. Brain damage was more frequently associated with upper cervical injury. Those patients with upper cervical injury are at greater risk of suffering from skull base fractures and severe intracranial hematomas than those with mid to lower cervical injury.     

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.     

Acute cervical spinal cord injury secondary to air bag deployment without proper use of lap or shoulder harnesses

The authors present a case report of a patient with cervical central spinal cord syndrome caused by a hyperextension injury after a motor vehicle collision in which the air bag deployed in the absence of shoulder or lap belt harnesses. The potential for cervical spine and spinal cord hyperextension injuries in passengers positioned in front of air bags without proper use of shoulder or lap belt harnesses is discussed. Cervical central spinal cord quadriplegia occurred with cervical spondylosis and kyphosis that was managed by early three-level cervical corpectomy in a 58-year-old patient. Early improvement in the patient's neurological status occurred but was incomplete at the time of this report. Cervical hyperextension injuries are possible in passengers positioned in the front seat of cars with air bags when shoulder or lap belt harnesses are not used properly. Previous biomechanical studies have documented the potential for these types of injuries.     

Harvey Cushing's Early Operative Treatment of Skull Base Fractures

Objectives To review Dr. Harvey Cushing''s early surgical cases at the Johns Hopkins Hospital, revealing details of his operative approaches to fractures of the skull base. Design Following institutional review board approval and through the courtesy of the Alan Mason Chesney Archives, we reviewed the Johns Hopkins Hospital surgical files. Setting The Johns Hopkins Hospital, 1896 to 1912. Participants A total of 24 patients underwent operative treatment for suspected fractures of the skull base. Main Outcome Measures The main outcome measure was operative approach, postoperative mortality, and condition recorded at the time of discharge. Results Overall, 23 patients underwent operative treatment for suspected skull base fractures. The mechanisms of injury were known for 22 patients and included work-related injuries (41%), falls (23%), vehicle injuries (32%), and other trauma (5%). One patient had no mechanism of injury specified in the file. The outcome at the time of discharge from the hospital was “well” or “improved” in 12 patients (52%). The remaining 11 patients died during their admission. Conclusions Although Cushing''s experience with selected skull base pathology has been previously reported, the breadth of his contributions to operative approaches to the skull base has been neglected.     

One-year experience in a regional pediatric trauma center

During 1982, 267 children with life-threatening injuries were admitted to the Maryland Regional Pediatric Trauma Center at the Johns Hopkins Hospital. Seventy-three percent of patients arrived directly from the injury scene by helicopter (46%), ambulance (50%), or other (4%). Mechanisms of injury included motor vehicle accidents (MVA; 55%), falls (27%), assaults (8%), and sports and other injuries (10%). In 75% of MVA the child was a pedestrian. Fifty-one percent of injuries were single organ system, 29% involved two systems, and 20% involved three or more systems. Remarkably, the mortality of 6.7% was not affected by the number of organ systems involved, but was directly related to the presence or absence of head injury. Fourteen of seventeen deaths resulted from head injury. Eighty percent of documented liver and spleen injuries were managed nonoperatively. This nonoperative plan of management simplified the optimal treatment of head injury. The high frequency of head injury has mandated a more aggressive approach to the management of brain trauma including intracranial monitoring to facilitate control of cerebral edema. Our data demonstrate that an excellent quality of life may be anticipated even in children with severe head injury.     

Children in crashes: mechanisms of injury and restraint systems.

OBJECTIVES: To explore the levels of protection offered to children involved in motor vehicle collisions. DESIGN: A joint study by the Children's Hospital of Eastern Ontario (CHEO) and Transport Canada, Ottawa, conducted in 2 phases: retrospective from 1990 to 1997 and prospective from 1998 to 2000. SETTING: CHEO, a university affiliated tertiary care centre. PATIENTS: Children admitted to CHEO between 1990 and 2000 with spinal trauma due to motor vehical crashes (MVCs). Phase I of the study involved analysis, in a series of 45 children after MVAs, by location of spinal injury versus belt type. Phase 2 was a prospective study of 22 children injured in 15 MVAs. INTERVENTIONS: A biomechanical assessment of the vehicle and its influence on the injuries sustained. MAIN OUTCOME MEASURES: The nature and extent of the injuries sustained, and the vehicle dynamics and associated occupant kinematics. RESULTS: The odds ratio of sustaining a spinal injury while wearing a 2-point belt versus a 3-point belt was 24 (95% confidence interval 2.0-2.45, p < 0.1), indicating a much higher incidence with a lap belt than a shoulder strap. CONCLUSIONS: Proper seat-belt restraint reduces the morbidity in children involved in MVCs. Children under the age of 12 years should not be front-seat passengers until the sensitivity of air bags has been improved. Three-point pediatric seat belts should be available for family automobiles to reduce childhood trauma in MVCs.     

Incidence and pattern of direct blunt neurovascular injury associated with trauma to the skull base

OBJECT: Skull base fractures are often associated with potentially devastating injuries to major neural arteries in the head and neck, but the incidence and pattern of this association are unknown. METHODS: Between April and September 2002, 1738 Level 1 trauma patients were admitted to St. Joseph's Hospital and Medical Center in Phoenix, Arizona. Among them, a skull base fracture was diagnosed in 78 patients following computed tomography (CT) scans. Seven patients had no neurovascular imaging performed and were excluded. Altogether, 71 patients who received a diagnosis of skull base fractures after CT and who also underwent a neurovascular imaging study were included (54 men and 17 women, mean age 29 years, range 1-83 years). Patients underwent CT angiography, magnetic resonance angiography, or digital subtraction angiography of the head and craniovertebral junction, or combinations thereof. RESULTS: Nine neurovascular injuries were identified in six (8.5%) of the 71 patients. Fractures of the clivus were very likely to be associated with neurovascular injury (p < 0.001). A high risk of neurovascular injury showed a strong tendency to be associated with fractures of the sella turcica-sphenoid sinus complex (p = 0.07). CONCLUSIONS: The risk of associated blunt neurovascular injury appears to be significant in Level 1 trauma patients in whom a diagnosis of skull base fracture has been made using CT. The incidence of neurovascular trauma is particularly high in patients with clival fractures. The authors recommend neurovascular imaging for Level 1 trauma patients with a high-risk fracture pattern of the central skull base to rule out cerebrovascular injuries.     

Evaluation of Skull Cortical Thickness Changes With Age and Sex From Computed Tomography Scans

Head injuries resulting from motor vehicle crashes (MVC) are extremely common, yet the details of the mechanism of injury remain to be well characterized. Skull deformation is believed to be a contributing factor to some types of traumatic brain injury (TBI). Understanding biomechanical contributors to skull deformation would provide further insight into the mechanism of head injury resulting from blunt trauma. In particular, skull thickness is thought be a very important factor governing deformation of the skull and its propensity for fracture. Previously, age‐ and sex‐based skull cortical thickness changes were difficult to evaluate based on the need for cadaveric skulls. In this cross‐sectional study, skull thickness changes with age and sex have been evaluated at homologous locations using a validated cortical density‐based algorithm to accurately quantify cortical thickness from 123 high‐resolution clinical computed tomography (CT) scans. The flat bones of the skull have a sandwich structure; therefore, skull thickness was evaluated for the inner and outer tables as well the full thickness. General trends indicated an increase in the full skull thickness, mostly attributed to an increase in the thickness of the diploic layer; however, these trends were not found to be statistically significant. There was a significant relationship between cortical thinning and age for both tables of the frontal, occipital, and parietal bones ranging between a 36% and 60% decrease from ages 20 to 100 years in females, whereas males exhibited no significant changes. Understanding how cortical and full skull thickness changes with age from a wide range of subjects can have implications in improving the biofidelity of age‐ and sex‐specific finite element models and therefore aid in the prediction and understanding of TBI from impact and blast injuries. © 2015 American Society for Bone and Mineral Research.