title: Intraoperative imaging of the shoulder: A comparison of two- and three-dimensional imaging techniques.
abstract: BACKGROUND
  Isocentric three-dimensional C-arms allow for more effective intraoperative fracture reduction control compared to two-dimensional imaging techniques. However, this design is not appropriate for shoulder scanning.
  
  
  OBJECTIVE
  To assess the feasibility of using a newer generation variable isocentric flat detector 3D C-arm for intraoperative glenohumeral and acromioclavicular joint assessment and to compare the accuracy of its intraoperative 3D imaging technology to a standard two-dimensional (2D) flat detector fluoroscope.
  
  
  METHODS
  Five whole-body human cadavers were used (ten shoulders). Native shoulder scans were obtained. A glenohumeral arthrotomy was performed and several injuries and procedures were simulated. Five independent orthopaedic surgeons reviewed each scan and filled out a questionnaire assessing the quality of the images using a visual analog scale (VAS) and a points scoring system.
  
  
  RESULTS
  The examiners rated the 3D images as very-good-to-excellent according to the established parameters: image quality; visualization of the corticalis and the spongiosa; delineation of the joint surface; presence of artifacts; and clinical assessment capability. This high quality of the images led to a higher interobserver reliability for 3D images compared to 2D images.
  
  
  CONCLUSIONS
  Variable isocentric 3D C-arm technology is feasible for intraoperative assessment of shoulder procedures. Assessment of 3D images in shoulder procedures showed better interexaminer reliability in this experiment compared to 2D images. With the aid of intraoperative 3D shoulder imaging, intraoperative 3D C-arm navigation could help improve accuracy in the clinical setting.
authors.affiliation: Trauma Department, Hannover Medical School, Hannover, Germany.
authors.forename: Eduardo M
authors.initials: EM
authors.lastname: Suero
authors.affiliation: Trauma Department, Hannover Medical School, Hannover, Germany.
authors.forename: Nael
authors.initials: N
authors.lastname: Hawi
authors.affiliation: Trauma Department, Hannover Medical School, Hannover, Germany.
authors.forename: Musa
authors.initials: M
authors.lastname: Citak
authors.affiliation: Trauma Department, Hannover Medical School, Hannover, Germany.
authors.forename: Sebastian
authors.initials: S
authors.lastname: Decker
authors.affiliation: Trauma Department, Hannover Medical School, Hannover, Germany.
authors.forename: Julia
authors.initials: J
authors.lastname: Brandes
authors.affiliation: Trauma Department, Hannover Medical School, Hannover, Germany.
authors.forename: Rupert
authors.initials: R
authors.lastname: Meller
authors.affiliation: Trauma Department, Hannover Medical School, Hannover, Germany.
authors.forename: Christian
authors.initials: C
authors.lastname: Krettek
authors.affiliation: Trauma Department, Hannover Medical School, Hannover, Germany.
authors.forename: Timo
authors.initials: T
authors.lastname: Stübig
mesh_terms: D000173:Acromioclavicular Joint / Q000473:pathology / Q000601:surgery; D005471:Fluoroscopy / Q000379:methods*; D006801:Humans; D021621:Imaging, Three-Dimensional / Q000379:methods; D007432:Intraoperative Period; D015588:Observer Variation; D000070599:Shoulder Injuries; D012785:Shoulder Joint / Q000473:pathology / Q000601:surgery*
keywords: 3D C-arm; shoulder imaging; shoulder surgery; shoulder trauma