RESUMEN
BACKGROUND: The surgical treatment of femur shaft fractures in children is changing, and the time spent in hospital is shorter than before. The purpose of this nationwide epidemiology study is to report incidence of pediatric femur shaft fractures in Sweden during 1987 to 2005 by age, sex, cause of injury, severity of injury, and seasonal variation, and to analyze the change in incidence, treatment modalities, and length of hospital stay over time. METHODS: Children (N = 4984) with a diagnostic code for femur shaft fracture in Sweden 1987 to 2005 were selected from the Swedish National Hospital Discharge Registry. RESULTS: The overall annual incidence per 100,000 children was 22.9 in boys and 9.5 in girls. The incidence declined by 42%, on average 3% per year, from 19.4 to 11.8 between 1987 and 2005 (P < 0.001). The most common cause of injury in children younger than 4 years of age was fall of < 1 m; in children 4 to 12 years of age, sports accidents were the most frequent cause of injury; and in children 13 to 14 years of age, traffic accidents. The month of occurrence for femur shaft fractures had a bimodal seasonal variation with a peak in March and in August. Treatment modalities were changing during the study period from the use of traction to an increased use of external fixation and elastic intramedullary nailing. The length of hospital stay decreased by 81%, from 26 days in 1987 to 5 days in 2005 (P < 0.001), but had no correlation to the introduction of new surgical treatment methods. CONCLUSIONS: The present nationwide study of femur shaft fractures shows a decrease of fracture incidence, a shift in the treatment modalities, and shorter length of hospital stay. LEVEL OF EVIDENCE: Level III, retrospective comparative study.