title: The physiological range of femoral antetorsion.
abstract: BACKGROUND
  Intramedullary nailing is a common method for fixation of femoral diaphyseal shaft fractures. However, postoperative malrotation does occur in 20-30 % of patients, as intraoperative assessment of antetorsion remains difficult. The estimated average antetorsion angle is 15°. However, it is not clear whether antetorsion correlates with individual characteristics such as age, gender, or femoral length. This information may help surgeons to better estimate the correct target rotation before and during surgery.
  
  
  METHODS
  The antetorsion of 211 healthy femurs was measured using torsion difference CTs according to the technique published by Jend. Correlations with age, gender, and femoral length were calculated.
  
  
  RESULTS
  A significant negative correlation of age and antetorsion was found for women aged 0-20. Older women and men did not show any correlation between antetorsion and age. There was no correlation between antetorsion and femoral length. Mean values differed between 17.8° ± 8.9° and 22.7° ± 10.7° in women and 15.3° ± 8.0° and 21.4° ± 9.7° in men.
  
  
  CONCLUSIONS
  Antetorsion is mostly independent of body height and age, the latter except in women younger than 20. The so-far-estimated physiologic antetorsion of about 15° seems to be a little higher in most people.
authors.affiliation: Trauma Department, Hannover Medical School, Carl-Neuberg-Strasse 1, 30625, Hannover, Germany, decker.sebastian@mh-hannover.de.
authors.forename: Sebastian
authors.initials: S
authors.lastname: Decker
authors.forename: Eduardo M
authors.initials: EM
authors.lastname: Suero
authors.forename: Nael
authors.initials: N
authors.lastname: Hawi
authors.forename: Christian W
authors.initials: CW
authors.lastname: Müller
authors.forename: Christian
authors.initials: C
authors.lastname: Krettek
authors.forename: Musa
authors.initials: M
authors.lastname: Citak
mesh_terms: D000293:Adolescent; D000328:Adult; D017677:Age Distribution; D000368:Aged; D000369:Aged, 80 and over; D002648:Child; D002675:Child, Preschool; D005260:Female; D005269:Femur / Q000002:abnormalities* / Q000000981:diagnostic imaging*; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D007719:Knee Joint / Q000002:abnormalities* / Q000000981:diagnostic imaging*; D008297:Male; D008875:Middle Aged; D012016:Reference Values; D012399:Rotation; D017678:Sex Distribution; D014057:Tomography, X-Ray Computed / Q000706:statistics & numerical data*; D055815:Young Adult