title: Evaluation of complex joint motion with computer-based analysis of fluoroscopic sequences.
abstract: OBJECTIVE
  To develop a computer-assisted analysis of complex joint motion based on standard fluoroscopic sequences.
  
  
  METHODS
  Fluoroscopic sequences of 10 normal shoulders and 20 patients after total shoulder arthroplasty were recorded during abduction and adduction. The analysis of the shoulder motion was based on automated tracking of selected components (models) of the shoulder joint. After processing the digitized images with an edge-detection procedure, visible edges were defined as base models. These models were tracked frame by frame. Several automated postprocessing evaluation procedures were developed and tested.
  
  
  RESULTS
  The amounts of rotation and translation of the glenohumeral joint can be quantified and related. The mean translation parallel to the glenoid in the normal shoulder joints was 2.8 mm and 1.9 mm in joints after shoulder arthroplasty. The mean translation perpendicular to the glenoid was 0.9 mm and 0.8 mm, respectively. In complex motion patterns (ie, combined glenohumeral and thoracoscapular motion), electronic stabilization of an object (ie, stabilization of scapula) and, thus, separate analysis of each component.
  
  
  CONCLUSIONS
  Computer assisted analysis allows automated evaluation of complex joint motion based on standard fluoroscopic sequences.
authors.affiliation: Department of Radiology, Orthopedic University Hospital Balgrist, Zurich, Switzerland. christian@pfirrmann.ch
authors.forename: Christian W A
authors.initials: CW
authors.lastname: Pfirrmann
authors.forename: Marius
authors.initials: M
authors.lastname: Huser
authors.forename: Gábor
authors.initials: G
authors.lastname: Székely
authors.forename: Juerg
authors.initials: J
authors.lastname: Hodler
authors.forename: Christian
authors.initials: C
authors.lastname: Gerber
mesh_terms: D000465:Algorithms; D016022:Case-Control Studies; D005471:Fluoroscopy; D006801:Humans; D007091:Image Processing, Computer-Assisted; D016059:Range of Motion, Articular / Q000502:physiology; D012785:Shoulder Joint / Q000000981:diagnostic imaging / Q000502:physiology*