title: Calculation of pediatric femoral fracture rotation from direct roentgenograms.
abstract: BACKGROUND
  Radiologic determination of pediatric femoral fracture rotation has been debated. Measuring the antetorsion angle of the fractured femur by computed tomography and comparing it with the opposite side has been the method of choice for this purpose. However, no simple method for direct measurement of femoral fracture rotation exists in the literature. In this study, our aim was to test a mathematical method of measuring the axial plane malrotation from direct roentgenograms.
  
  
  METHODS
  A pediatric femoral shaft fracture model was produced. The bone was secured to a wooden frame that allowed the distal part of the fracture to rotate around an axis. Radiographs were taken at known intervals of rotation ranging from the neutral position to 60° external rotation and to 60° internal rotation in 5° increments of rotation. Five independent, blinded observers measured the radiographs and calculated the fracture rotation according to a standard formula. Calculated rotation values were compared with known rotation values.
  
  
  RESULTS
  Calculated rotation values were close to actual rotation values throughout the arc of rotation. The mean absolute error of five observers for all measurements of external and internal rotation was 3.97° (±0.83). The correlation coefficient between calculated and actual rotation values was 0.9927. The interobserver intraclass correlation coefficient for calculated rotation was 0.997.
  
  
  CONCLUSIONS
  Absolute error and correlation coefficient values indicate that this method is accurate and reliable in determining the fracture rotation.
authors: Department of Orthopaedics and Traumatology, Umraniye Education and Research Hospital, Istanbul, Turkey, msefaozel@gmail.com.
authors: M S
authors: MS
authors: Ozel
authors: I E
authors: IE
authors: Ketenci
authors: E
authors: E
authors: Kaya
authors: S
authors: S
authors: Tuna
authors: B
authors: B
authors: Saygi
mesh_terms: D002102:Cadaver; D002648:Child; D005264:Femoral Fractures / Q000000981:diagnostic imaging* / Q000601:surgery; D005269:Femur / Q000000981:diagnostic imaging* / Q000601:surgery; D005594:Fracture Fixation, Intramedullary; D006801:Humans; D008953:Models, Anatomic; D008954:Models, Biological; D009985:Orthopedics; D010372:Pediatrics; D011859:Radiography; D012399:Rotation
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