The Effects of Motorcycle Helmet Legislation on Craniomaxillofacial Injuries

https://goo.gl/2F1aOe

Motorcyclists are 30 times more likely to die and five times more likely to be injured when compared mile for mile to passenger car occupants.1 Motorcycle helmets have been shown to prevent nearly 40 percent of fatal injuries and 13 percent of nonfatal serious injuries.1–3 However, as many as one-third of motorcycle riders still do not wear helmets, with a larger percentage riding unhelmeted in states without universal helmet laws.3 The effects of motorcycle helmet legislation on helmet use, patient injuries, and outcomes have been demonstrated.2–9 However, few to no data are available evaluating the effects of motorcycle helmet laws on craniomaxillofacial trauma.

Complex facial injuries are common among motorcycle trauma patients and are over twice as likely in unhelmeted patients.10–12 Although most facial injuries are not immediately life threatening, patients sustaining complex facial injuries have been shown to have poorer health outcomes and greater injury-related disability preventing employment.13

The National Highway Safety Act was signed into law in 1966 mandating that all states enact specific safety standards to continue receiving federal highway funding. Included in the legislation was the requirement for universal motorcycle helmet laws. In 1976, Congress amended the act, allowing states more flexibility in the implementation of helmet regulations.9 On April 13, 2012, the state of Michigan repealed their universal helmet law in favor of a partial law.

We hypothesized that the repeal of universal helmet laws would lead to increased rates of craniomaxillofacial trauma. To test our hypothesis, we analyzed motorcycle trauma patients presenting to trauma centers in the state of Michigan. This article describes the rates and patterns of craniomaxillofacial injuries in patients presenting before and after repeal of Michigan’s universal helmet law. In addition, we assessed the craniomaxillofacial injuries in helmeted and nonhelmeted riders.

Several studies have shown an increased incidence of craniomaxillofacial injuries in unhelmeted riders, but none have shown the correlation between weakened motorcycle helmet laws and increased craniomaxillofacial injuries.10–12

Dramatic decreases in helmet use have been described following helmet law repeal.2,3,8,14 This study confirms these findings, showing a greater than two-fold increase in unhelmeted motorcycle trauma patients. Moreover, our data identify a substantial increased risk of craniomaxillofacial injuries in unhelmeted patients, providing a likely cause for the increase in facial injuries after the repeal. This finding is well documented in the literature.10–12 The risk for alcohol intoxication acting as a confounder remains a concern. We did note a higher blood alcohol content in unhelmeted patients compared with helmeted riders. However, no difference was seen when comparing patients presenting before and after the universal helmet law was rescinded. Furthermore, other large series have found an increase in injuries in unhelmeted patients even after controlling for multiple confounding variables, such as alcohol and drug use.12,15

The results from this study also indicate an increase in certain patterns of facial injuries following the change in Michigan’s helmet law. We noted a significant increase in malar fractures and facial soft-tissue injuries, including lacerations, contusions, and abrasions. Other studies have shown increases in multiple injury patterns in unhelmeted patients, including fractures and soft-tissue injuries. Christian et al. reported similar findings to ours, with a higher proportion of unhelmeted motorcyclists sustaining malar fractures and soft-tissue injuries. They also noted an increase in orbital fractures within their series.10 Crompton et al. evaluated 46,362 motorcycle trauma patients for facial injuries using the National Trauma Data Bank. They reported a significant increase in mandibular, malar, nasal, and orbital fractures in addition to increased soft-tissue injuries.12