title: Intraosseous rotation of the scaphoid: assessment by using a 3D CT model--an anatomic study.
abstract: OBJECTIVE
  The purpose of this study was to assess intraosseous rotation as the third dimension of scaphoid anatomy on a 3D CT model using common volume rendering software to impact anatomical reconstruction of scaphoid fractures.
  
  
  METHODS
  CT images of 13 cadaver wrist pairs were acquired. Reference axes for the alignment of distal and proximal scaphoid poles were defined three-dimensionally. Two methods for rotation measurement-the reference axis method (RAM) and the scapho-trapezio-trapezoidal joint method (STTM)-were developed and compared by three independent observers.
  
  
  RESULTS
  Rotation measured by the RAM averaged 66.9° ± 7 for the right and 67.2° ± 5.8 for the left wrists. Using the STTM there was a mean rotation of 68.6° ± 6.6 for the right and 68.6° ± 6.8 for the left wrists. The overall results showed a significant variability of the measured values between different specimens (P < 0.05). There was no significant difference between left and right wrists of the same specimen, neither for the RAM (P = 0.268) nor for the STTM (P = 0.774). Repeatability coefficients between the observers were low, indicating good repeatability.
  
  
  CONCLUSIONS
  The presented methods are practical tools to quantify intraosseous rotation between distal and proximal scaphoid poles using common volume rendering software. For clinical application the opposite side provides the best reference values to assess malrotation in scaphoid fracture cases.
  
  
  CONCLUSIONS
  Scaphoid intraosseous rotation can be measured using common volume rendering software. The opposite uninjured side provides good reference values for rotation measurement. Assessment of malrotation may impact anatomical reconstruction of scaphoid fractures.
authors.affiliation: Department of Trauma Surgery, Medical University Innsbruck, Anichstraße 35, 6020, Innsbruck, Austria, gernot.schmidle@uki.at.
authors.forename: Gernot
authors.initials: G
authors.lastname: Schmidle
authors.forename: Michael
authors.initials: M
authors.lastname: Rieger
authors.forename: Andrea Sabine
authors.initials: AS
authors.lastname: Klauser
authors.forename: Michael
authors.initials: M
authors.lastname: Thauerer
authors.forename: Romed
authors.initials: R
authors.lastname: Hoermann
authors.forename: Markus
authors.initials: M
authors.lastname: Gabl
mesh_terms: D059925:Anatomic Landmarks; D001696:Biomechanical Phenomena; D002102:Cadaver; D050723:Fractures, Bone / Q000000981:diagnostic imaging / Q000473:pathology / Q000503:physiopathology; D006801:Humans; D021621:Imaging, Three-Dimensional / Q000379:methods / Q000592:standards / Q000706:statistics & numerical data; D015588:Observer Variation; D012015:Reference Standards; D012399:Rotation; D021361:Scaphoid Bone / Q000033:anatomy & histology* / Q000000981:diagnostic imaging* / Q000502:physiology; D012984:Software; D014057:Tomography, X-Ray Computed / Q000379:methods* / Q000592:standards / Q000706:statistics & numerical data; D014954:Wrist Injuries / Q000000981:diagnostic imaging / Q000473:pathology / Q000503:physiopathology; D014955:Wrist Joint / Q000033:anatomy & histology* / Q000000981:diagnostic imaging* / Q000502:physiology