title: Clinical criteria for using radiography for children with acute knee injuries.
abstract: OBJECTIVE
  To evaluate clinical criteria for selective radiography for knee injuries in children.
  
  
  METHODS
  Retrospective chart review.
  
  
  METHODS
  Emergency department (ED) of a children's hospital.
  
  
  METHODS
  All patients evaluated by radiography for an isolated, acute knee injury during 12 months. Patients were excluded for injuries: >1 week; isolated to superficial lacerations/abrasions; with prior knee surgery; being reassessed.
  
  
  RESULTS
  Two hundred fifty-four patients (60% male; 12.7 years median age) were included. Twelve patients (4.7%) sustained a fracture. Evaluated criteria were point tenderness, inability to bear weight in the ED, and inability to flex the knee to 90 degrees. Point tenderness was not statistically associated with fracture, P = 0.7. Inability to bear weight in the ED (37% fracture rate, P = 0.001) and inability to flex to 90 degrees (52% fracture rate, P < 0.001) were associated with the presence of fracture.[table in text] Applying a rule combining nobearwt and noflex90 would decrease the number of x-rays by 73%, with no missed fractures.
  
  
  CONCLUSIONS
  Point tenderness was not a good predictor of knee fracture in children. Using the clinical criteria to select patients requiring knee radiography may greatly reduce the number of unnecessary x-rays.
authors.affiliation: Department of Pediatrics, Ohio State University College of Medicine, Children's Hospital, Columbus 43205-2696, USA.
authors.forename: D M
authors.initials: DM
authors.lastname: Cohen
authors.forename: J W
authors.initials: JW
authors.lastname: Jasser
authors.forename: J R
authors.initials: JR
authors.lastname: Kean
authors.forename: G A
authors.initials: GA
authors.lastname: Smith
mesh_terms: D000208:Acute Disease; D002648:Child; D005260:Female; D050723:Fractures, Bone / Q000000981:diagnostic imaging; D006801:Humans; D007718:Knee Injuries / Q000000981:diagnostic imaging* / Q000209:etiology / Q000503:physiopathology; D008297:Male; D018579:Patient Selection; D011859:Radiography / Q000706:statistics & numerical data; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D016474:Weight-Bearing