title: Retrospective comparison of the Low Risk Ankle Rules and the Ottawa Ankle Rules in a pediatric population.
abstract: BACKGROUND
  A recent multicenter prospective Canadian study presented prospective evidence supporting the Low Risk Ankle Rules (LRAR) as a means of reducing the number of ankle radiographs ordered for children presenting with an ankle injury while maintaining nearly 100% sensitivity. This is in contrast to a previous prospective study which showed that this rule yielded only 87% sensitivity.
  
  
  OBJECTIVE
  It is important to further investigate the LRAR and compare them with the already validated Ottawa Ankle Rules (OAR) to potentially curb healthcare costs and decrease unnecessary radiation exposure without compromising diagnostic accuracy.
  
  
  METHODS
  We conducted a retrospective chart review of 980 qualifying patients ages 12months to 18years presenting with ankle injury to a commonly staffed 310 bed children's hospital and auxiliary site pediatric emergency department.
  
  
  RESULTS
  There were 28 high-risk fractures identified. The Ottawa Ankle Rules had a sensitivity of 100% (95% CI 87.7-100), specificity of 33.1% (95% CI 30.1-36.2), and would have reduced the number of ankle radiographs ordered by 32.1%. The Low Risk Ankle Rules had a sensitivity of 85.7% (95% CI 85.7-96), specificity of 64.9% (95% CI 61.8-68), and would have reduced the number of ankle radiographs ordered by 63.1%. The latter rule missed 4 high-risk fractures.
  
  
  CONCLUSIONS
  The Low Risk Ankle Rules may not be sensitive enough for use in Pediatric Emergency Departments, while the Ottawa Ankle Rules again demonstrated 100% sensitivity. Further research on ways to implement the Ottawa Ankle Rules and maximize its ability to decrease wait times, healthcare costs, and improve patient satisfaction are needed.
authors.affiliation: Department of Radiology, George Washington University Hospital, Washington, DC 20037, United States. Electronic address: ale2t@virginia.edu.
authors.forename: Amy L
authors.initials: AL
authors.lastname: Ellenbogen
authors.affiliation: Independent Consultant (Biostatistics), Chevy Chase, MD 20815, United States.
authors.forename: Amy L
authors.initials: AL
authors.lastname: Rice
authors.affiliation: Department of Radiology, Children's National Medical Center, Washington, DC 20010, United States.
authors.forename: Pranav
authors.initials: P
authors.lastname: Vyas
mesh_terms: D000293:Adolescent; D016512:Ankle Injuries / Q000000981:diagnostic imaging*; D000843:Ankle Joint / Q000000981:diagnostic imaging*; D002648:Child; D002675:Child, Preschool; D004636:Emergency Service, Hospital / Q000592:standards*; D005260:Female; D050723:Fractures, Bone / Q000000981:diagnostic imaging*; D017048:Health Care Costs; D006776:Hospitals, Pediatric; D006801:Humans; D007223:Infant; D008297:Male; D011859:Radiography; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D012720:Severity of Illness Index; D014481:United States
keywords: Ankle fracture; Ankle trauma; Ankle x-ray; Clinical decision rules; Pediatric emergency medicine; Pediatric radiology