title: Incidence and trends in femur shaft fractures in Swedish children between 1987 and 2005.
abstract: 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.
  
  
  METHODS
  Level III, retrospective comparative study.
authors.affiliation: Department of Women's and Children's Health, Clinical Epidemiology Unit, Karolinska Institutet, Stockholm, Sweden. johan.von.heideken@ki.se
authors.forename: Johan von
authors.initials: Jv
authors.lastname: Heideken
authors.forename: Tobias
authors.initials: T
authors.lastname: Svensson
authors.forename: Paul
authors.initials: P
authors.lastname: Blomqvist
authors.forename: Yvonne
authors.initials: Y
authors.lastname: Haglund-Åkerlind
authors.forename: Per-Mats
authors.initials: PM
authors.lastname: Janarv
mesh_terms: D000058:Accidental Falls / Q000706:statistics & numerical data*; D000063:Accidents, Traffic / Q000706:statistics & numerical data*; D000293:Adolescent; D017677:Age Distribution; D001265:Athletic Injuries / Q000150:complications* / Q000453:epidemiology; D002648:Child; D002675:Child, Preschool; D005260:Female; D005264:Femoral Fractures / Q000453:epidemiology* / Q000209:etiology / Q000601:surgery; D005500:Follow-Up Studies; D005594:Fracture Fixation, Intramedullary / Q000379:methods*; D006801:Humans; D015994:Incidence; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D012042:Registries; D012189:Retrospective Studies; D012307:Risk Factors; D017678:Sex Distribution; D013548:Sweden / Q000453:epidemiology; D013997:Time Factors