Fractures of the femoral shaft in children. Incidence, mechanisms, and sociodemographic risk factors.

BACKGROUND: Fractures of the femoral shaft in children are caused by major musculoskeletal trauma and result in high direct and indirect medical costs. To date, the American literature has focused on treatment options and outcomes, but the epidemiology of these injuries has been generalized from Scandinavian studies reported in the 1970s and early 1980s. The goals of the current study were (1) to determine the age, gender, and race-specific rates and mechanisms of fractures of the femoral shaft in children in a large United-States-based population and (2) to identify associations between the rates of these fractures and multiple sociodemographic indicators. Such information is vital for preventive efforts.
METHODS: The Hospital Discharge Database of the Maryland Health Services Cost Review Commission for the years 1990 through 1996 was used to obtain demographic data on 1485 cases of acute fracture of the femoral shaft in patients who were less than eighteen years old, and data from the United States Bureau of the Census for the state of Maryland for the year 1990 were used to obtain denominator data. Reliable external-cause data were available from the 1995 and 1996 databases for 472 patients. Small-area analysis was performed at the zip-code level to determine associations between numerous sociodemographic indicators and the rate of femoral shaft fracture.
RESULTS: The annual rate of femoral shaft fracture in children was 19.15 per 100,000. With regard to age, there was a bimodal distribution, with peaks at two and seventeen years. Boys had higher rates of fracture than did girls at all ages, and blacks had higher rates than did whites. The primary mechanisms of fracture were age-dependent and included falls, for children less than six years old; motor vehicle-pedestrian accidents, for those six to nine years old; and motor-vehicle accidents, for teenagers. Firearm-related injuries accounted for 15 percent of the fractures among black adolescents. Adverse socioeconomic conditions were significantly associated with higher rates of fracture.
CONCLUSIONS: The rates and mechanisms of femoral shaft fractures in children depend on age, gender, and race. For children living in the United States today, the epidemiology of these fractures is different than that described in earlier, Scandinavian reports.