title: Femoral curvature variability in modern humans using three-dimensional quadric surface fitting.
abstract: BACKGROUND
  This study analysed femoral curvature in a population from Belgium in conjunction with other morphological characteristics by the use of three-dimensional (3D) quadric surfaces (QS) modelled from the bone surface.
  
  
  METHODS
  3D models were created from computed tomography data of 75 femoral modern human bones. Anatomical landmarks (ALs) were palpated in specific bony areas of the femur (shaft, condyles, neck and head). QS were then created from the surface vertices which enclose these ALs. The diaphyseal shaft was divided into five QS shapes to analyse curvature in different parts of the shaft.
  
  
  RESULTS
  Femoral bending differs in different parts of the diaphyseal shaft. The greatest degree of curvature was found in the distal shaft (mean 4.5° range 0.2°-10°) followed by the proximal (mean 4.4° range 1.5°-10.2°), proximal intermediate (mean 3.7° range 0.9°-7.9°) and distal intermediate (mean 1.8° range 0.2°-5.6°) shaft sections. The proximal and distal angles were significantly more bowed than the intermediate proximal and the intermediate distal angle. There was no significant difference between the proximal and distal angle. No significant correlations were found between morphological characteristics and femoral curvature. An extremely large variability of femoral curvature with several bones displaying very high or low degrees of femoral curvature was also found.
  
  
  CONCLUSIONS
  3D QS fitting enables the creation of accurate models which can discriminate between different patterns in similar curvatures and demonstrates there is a clear difference between curvature in different parts of the shaft.
authors.affiliation: Operational Direction 'Earth and History of Life', Royal Belgian Institute of Natural Sciences, Brussels, Belgium. tchapman@ulb.ac.be.|Laboratory of Anatomy, Biomechanics and Organogenesis, Faculty of Medicine, Université Libre de Bruxelles, Brussels, Belgium. tchapman@ulb.ac.be.
authors.forename: Tara
authors.initials: T
authors.lastname: Chapman
authors.affiliation: Laboratory of Anatomy, Biomechanics and Organogenesis, Faculty of Medicine, Université Libre de Bruxelles, Brussels, Belgium.|Department of Applied Mathematics, Peter the Great St. Petersburg Polytechnic University, St. Petersburg, Russia.
authors.forename: Victor
authors.initials: V
authors.lastname: Sholukha
authors.affiliation: Operational Direction 'Earth and History of Life', Royal Belgian Institute of Natural Sciences, Brussels, Belgium.
authors.forename: Patrick
authors.initials: P
authors.lastname: Semal
authors.affiliation: Laboratory of Anatomy, Biomechanics and Organogenesis, Faculty of Medicine, Université Libre de Bruxelles, Brussels, Belgium.|Department of Radiology, ULB Erasme Hospital, Brussels, Belgium.
authors.forename: Stéphane
authors.initials: S
authors.lastname: Louryan
authors.affiliation: Laboratory of Anatomy, Biomechanics and Organogenesis, Faculty of Medicine, Université Libre de Bruxelles, Brussels, Belgium.
authors.forename: Marcel
authors.initials: M
authors.lastname: Rooze
authors.affiliation: Laboratory of Anatomy, Biomechanics and Organogenesis, Faculty of Medicine, Université Libre de Bruxelles, Brussels, Belgium.
authors.forename: Serge
authors.initials: S
authors.lastname: Van Sint Jan
mesh_terms: D001530:Belgium; D002102:Cadaver; D005269:Femur / Q000000981:diagnostic imaging*; D006801:Humans; D007091:Image Processing, Computer-Assisted; D021621:Imaging, Three-Dimensional; D014057:Tomography, X-Ray Computed
keywords: Bone palpation; Curvature; Femur; Quadric surface