Open Fracture of the Tibia & Fibula Caused by an Airbag: A Case Report & Review of the Literature Regarding Lower Extremity Injuries Secondary to Airbags

摘要

This is a case report of an open fracture of the tibia and fibula caused by the deployment of an airbag in a motor vehicle collision, unreported in the literature to date. A review of the literature regarding tibia and fibula fractures secondary to airbags was performed.It has been demonstrated in the literature that airbags can produce significant upper and lower extremity injuries when no other restraining devices are employed. Introduction and Review Motor vehicle collisions (MVC) are a significant cause of morbidity and mortality. Seat belt use has been identified as a significant factor in declining rates of MVC related morbidity and mortality since their introduction in the 1960s1,2. Frontal airbags, mandated since the early 1990s, were introduced to help reduce the risk of injury secondary to frontal collisions. The effectiveness of airbags as lifesaving devices and a means of preventing or minimizing injury to the head, neck, and torso have been documented3,4,5. However, the possible effect on the lower extremities has received less attention. As a group, restraining devices decrease the incidence of upper and lower extremity trauma sustained by patients injured in motor vehicle collisions6,7,8. 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. In fact combined restraint use was associated with an increased fracture risk for tibia and fibula fractures1. Studies have shown that injuries to the lower extremity secondary to motor vehicle crashes are frequent and disabling. Burgess et al. studied the lower extremity injuries of 10 drivers of airbag equipped cars involved in MVCs and found that air bags do not prevent injuries of the lower extremity9. McGovern et al. reported an association between airbag restraint alone and an increased incidence of upper and lower extremity fractures10. There is support in the literature that airbags can cause significant injuries to both the upper and lower extremities. This case report demonstrates an unusual presentation of a lower extremity injury due to airbag deployment in an MVC. Case Report A 25 year old man, as a belted front seat passenger, was involved in a MVC resulting in an open right tibia and fibula fracture with disruption of a previous plate. Two months earlier he had fallen from a height causing isolated closed tibia and fibula fractures requiring open reduction and internal fixation with a plate and screws at a nearby peripheral hospital. Subsequently, prior to the collision the patient was resting his leg on the front dashboard to keep his leg elevated. The vehicle was traveling approximately 110 km/h when it collided with a deer causing the airbags to deploy in both the driver and passenger compartments. The passenger-sided airbag deployed in an upward direction forcing his right leg into the windshield causing an open fracture of the long bones as disruption of the plate construct. He presented to a regional hospital where he was initially assessed and imaging studies were taken (Fig. 1). Figure 1: AP, Mortise, & Lateral views of the right tibia and fibula demonstrating significant malalignment as well as bent plate preventing further reduction.