title: Measuring femoral neck torsion angle using femoral neck oblique axial computed tomography reconstruction.
abstract: OBJECTIVE
  To propose a novel method for measuring the femoral neck torsion angle (FNTA) with femoral neck oblique axial computed tomography (CT) reconstruction.
  
  
  METHODS
  Fifty-five patients (24 females, 31 males; mean age 48.8 years [range, 20-91 years]) were included in the study. CT scans were performed on the left femurs of 27 patients and the right femurs of the remaining 28 patients. The images were analyzed independently by two observers using oblique axial femoral neck CT reconstruction. Intra-observer and inter-observer agreement was calculated as intraclass correlation coefficient (ICC).
  
  
  RESULTS
  FNTA can be measured with high intra-observer (ICC = 0.961) and high inter-observer (ICC = 0.982) agreement. Mean FNTA was slightly larger in women than in men, and the mean left FNTA was slightly larger than the right, but neither difference was statistically significant.
  
  
  CONCLUSIONS
  Femoral neck oblique axial CT reconstruction can be used to obtain accurate measurement of FNTA with good reproducibility. No significant differences were found in FNTA between sexes or sides.
authors.affiliation: Department of Orthopedic Surgery, Third Hospital of Hebei Medical University, Hebei, China.
authors.forename: Yingchao
authors.initials: Y
authors.lastname: Yin
authors.affiliation: Hebei Medical University, Hebei, China.
authors.forename: Liping
authors.initials: L
authors.lastname: Zhang
authors.affiliation: Department of Orthopedic Surgery, Third Hospital of Hebei Medical University, Hebei, China. drzyhou@gmail.com.
authors.forename: Zhiyong
authors.initials: Z
authors.lastname: Hou
authors.affiliation: Department of Orthopedic Surgery, Third Hospital of Hebei Medical University, Hebei, China.
authors.forename: Zongyou
authors.initials: Z
authors.lastname: Yang
authors.affiliation: Department of Orthopedic Surgery, Third Hospital of Hebei Medical University, Hebei, China.
authors.forename: Ruipeng
authors.initials: R
authors.lastname: Zhang
authors.affiliation: Department of Orthopedic Surgery, Third Hospital of Hebei Medical University, Hebei, China.
authors.forename: Wei
authors.initials: W
authors.lastname: Chen
authors.affiliation: Department of Orthopedic Surgery, Third Hospital of Hebei Medical University, Hebei, China.
authors.forename: Pengcheng
authors.initials: P
authors.lastname: Wang
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D005269:Femur / Q000000981:diagnostic imaging*; D005272:Femur Neck / Q000002:abnormalities* / Q000000981:diagnostic imaging; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D008297:Male; D008875:Middle Aged; D015588:Observer Variation; D015203:Reproducibility of Results; D014057:Tomography, X-Ray Computed / Q000379:methods*; D014102:Torsion Abnormality / Q000000981:diagnostic imaging*; D055815:Young Adult
keywords: CT; Femoral neck axial; Femoral neck torsion angle; Oblique reconstruction