title: Estimation of pretraumatic femoral antetorsion in bilateral femoral shaft fractures.
abstract: OBJECTIVE
  To describe a system for measurement of the pretraumatic femoral antetorsion angle post-bilateral femoral shaft fracture with the use of new imaging software which allows segmentation and three dimensional (3D) reconstruction of DICOM (digital imaging and communications in medicine) images.
  
  
  METHODS
  This case involved a 20-year-old patient with bilateral femoral shaft fractures. Following initial clinical examination, CT scans of both femurs were performed. Subsequently, the DICOM datasets were uploaded to the new software tool. Following segmentation and 3D reconstruction, pretraumatic femoral antetorsion angles were determined.
  
  
  RESULTS
  Femoral antetorsion was described and assessed in two ways by referring to the intersection of the posterior condylar plane and (1) a line drawn between the center of the femoral head and femoral neck, (2) a line drawn between the centers of the femoral head and greater trochanter. Using these definitions, values for femoral antetorsion were found to be, respectively, 20 degrees at the right fracture site and 19 degrees on the left site, and 33 degrees bilaterally.
  
  
  CONCLUSIONS
  The investigators describe in this current technical report the use of new imaging software which enables the calculation of femoral AV following reduction of virtual fracture fragments which are created from standard DICOM images. We believe that this 3D reconstruction method of measuring the antetorsion angle can be integrated into a regular treatment algorithm and may potentially optimize clinical outcomes.
authors.affiliation: Trauma Department, Hannover Medical School, Carl-Neuberg-Str. 1, 30625 Hannover, Germany. citak.musa@mh-hannover.de
authors.forename: Musa
authors.initials: M
authors.lastname: Citak
authors.forename: Mustafa
authors.initials: M
authors.lastname: Citak
authors.forename: Daniel
authors.initials: D
authors.lastname: Kendoff
authors.forename: Padhraig F
authors.initials: PF
authors.lastname: O'Loughlin
authors.forename: Frank
authors.initials: F
authors.lastname: Tavassol
authors.forename: Michael
authors.initials: M
authors.lastname: Jagodzinski
authors.forename: Christian
authors.initials: C
authors.lastname: Krettek
authors.forename: Tobias
authors.initials: T
authors.lastname: Hüfner
mesh_terms: D000328:Adult; D000465:Algorithms; D005264:Femoral Fractures / Q000000981:diagnostic imaging*; D006801:Humans; D021621:Imaging, Three-Dimensional / Q000379:methods*; D008297:Male; D011856:Radiographic Image Enhancement / Q000379:methods; D011857:Radiographic Image Interpretation, Computer-Assisted / Q000379:methods*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D014057:Tomography, X-Ray Computed / Q000379:methods*; D014102:Torsion Abnormality / Q000000981:diagnostic imaging*