title: Determination of Femoral Neck Angle and Torsion Angle Utilizing a Novel Three-Dimensional Modeling and Analytical Technology Based on CT Datasets.
abstract: BACKGROUND
  Exact knowledge of femoral neck inclination and torsion angles is important in recognizing, understanding and treating pathologic conditions in the hip joint. However, published results vary widely between different studies, which indicates that there are persistent difficulties in carrying out exact measurements.
  
  
  METHODS
  A three dimensional modeling and analytical technology was used for the analysis of 1070 CT datasets of skeletally mature femurs. Individual femoral neck angles and torsion angles were precisely computed, in order to establish whether gender, age, body mass index and ethnicity influence femoral neck angles and torsion angles.
  
  
  RESULTS
  The median femoral neck angle was 122.2° (range 100.1-146.2°, IQR 117.9-125.6°). There are significant gender (female 123.0° vs. male 121.5°; p = 0.007) and ethnic (Asian 123.2° vs. Caucasian 121.9°; p = 0.0009) differences. The median femoral torsion angle was 14.2° (-23.6-48.7°, IQR 7.4-20.4°). There are significant gender differences (female 16.4° vs. male 12.1°; p = 0.0001). Femoral retroversion was found in 7.8% of the subjects.
  
  
  CONCLUSIONS
  Precise femoral neck and torsion angles were obtained in over one thousand cases. Systematic deviations in measurement due to human error were eliminated by using automated high accuracy morphometric analysis. Small but significant gender and ethnic differences were found in femoral neck and torsion angles.
authors.affiliation: Department of Trauma, Hand and Reconstructive Surgery, University Medical Center Hamburg-Eppendorf, Germany.
authors.forename: Maximilian J
authors.initials: MJ
authors.lastname: Hartel
authors.affiliation: Stryker Trauma GmbH, Kiel-Schönkirchen, Germany.
authors.forename: Andreas
authors.initials: A
authors.lastname: Petersik
authors.affiliation: Stryker Trauma GmbH, Kiel-Schönkirchen, Germany.
authors.forename: Anne
authors.initials: A
authors.lastname: Schmidt
authors.affiliation: HELIOS ENDO-Klinik, Orthopedic Department, Holstenstr. 2, Hamburg, 20457, Germany.
authors.forename: Daniel
authors.initials: D
authors.lastname: Kendoff
authors.affiliation: Department of Trauma, Hand and Reconstructive Surgery, University Medical Center Hamburg-Eppendorf, Germany.
authors.forename: Jakob
authors.initials: J
authors.lastname: Nüchtern
authors.affiliation: Department of Trauma, Hand and Reconstructive Surgery, University Medical Center Hamburg-Eppendorf, Germany.
authors.forename: Johannes M
authors.initials: JM
authors.lastname: Rueger
authors.affiliation: Department of Trauma, Hand and Reconstructive Surgery, University Medical Center Hamburg-Eppendorf, Germany.
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Lehmann
authors.affiliation: Department of Trauma, Hand and Reconstructive Surgery, University Medical Center Hamburg-Eppendorf, Germany.
authors.forename: Lars G
authors.initials: LG
authors.lastname: Grossterlinden
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015992:Body Mass Index; D005260:Female; D005272:Femur Neck / Q000000981:diagnostic imaging* / Q000502:physiology*; D006621:Hip Joint / Q000000981:diagnostic imaging; D006801:Humans; D008297:Male; D008875:Middle Aged; D013223:Statistics as Topic / Q000379:methods; D014057:Tomography, X-Ray Computed / Q000379:methods; D055815:Young Adult