title: Femoral bowing plane adaptation to femoral anteversion.
abstract: BACKGROUND
  Femoral bowing plane (FBP) is the unattended subject in the literature. More over the femoral shaft with its bowing is neglected in established anteversion determination methods. There is limited information about the relationship between FBP and anteversion. Thus we focused on this subject and hypothesized that there could be an adaptation of FBP to anteversion.
  
  
  METHODS
  FBP is determined on three-dimensional solid models derived from the left femoral computerized tomography data of 47 patients which were taken before for another reason and comparatively evaluated with anteversion. There were 20 women and 27 men. The mean age of patients was 56 years (range 21-84 years).
  
  
  RESULTS
  The anteversion values were found as the angle between a distal condylar axis (DCA) and femoral neck anteversion axis (FNAA) along an imaginary longitudinal femoral axis (LFA) in the true cranio-caudal view. The FBP was determined as a plane that passes through the centre-points of three pre-determinated sections on the femoral shaft. The angles between DCA, FNAA and FBP were comparatively evaluated. The independent samplest-test was used for statistical analysis. At the end, it was found that FBP lies nearly perpendicular to the anteversion axis for the mean of our sample which is around 89° in females and 93° in males (range 78-102°). On the other hand, FBP does not lie close to the sagittal femoral plane (SFP); instead, there is an average 12.5° external rotation relative to the SFP. FBP is correlated well with anteversion in terms of FBP inclination from SFP and femoral torsion (i.e., angle between FBP and femoral neck anteversion axis (P< 0.001;r= 0.680 andr= -0.682, respectively). Combined correlation is perfect (R2= 1) as the FBP, SFP, and posterior femoral plane forms a triangle in the cranio-caudal view.
  
  
  CONCLUSIONS
  We found that FBP adapts to anteversion. As FBP lies close to perpendicularity for the mean, femoral component positioning perpendicular to the FBP can be an alternate way in the replacement surgeries. In addition, it has been found that FBP lies externally rotated relative to the SFP.
authors.affiliation: Department of Orthopaedics and Traumatology, School of Medicine, Pamukkale University, Denizli, Turkey.
authors.forename: Alp
authors.initials: A
authors.lastname: Akman
authors.affiliation: Department of Orthopaedics and Traumatology, School of Medicine, Pamukkale University, Denizli, Turkey.
authors.forename: Fahir
authors.initials: F
authors.lastname: Demirkan
authors.affiliation: Department of Radiology, School of Medicine, Pamukkale University, Denizli, Turkey.
authors.forename: Nuran
authors.initials: N
authors.lastname: Sabir
authors.affiliation: Department of Orthopaedics and Traumatology, School of Medicine, Pamukkale University, Denizli, Turkey.
authors.forename: Murat
authors.initials: M
authors.lastname: Oto
authors.affiliation: Department of Orthopaedics and Traumatology, School of Medicine, Pamukkale University, Denizli, Turkey.
authors.forename: Cagdas
authors.initials: C
authors.lastname: Yorukoglu
authors.affiliation: Department of Orthopaedics and Traumatology, School of Medicine, Pamukkale University, Denizli, Turkey.
authors.forename: Esat
authors.initials: E
authors.lastname: Kiter
keywords: Anteversion; Femur; anatomy; anthropometry; bowing of femur; computerized tomography; femoral bowing plane; human; x-ray