title: 3D scapular orientation on healthy and pathologic subjects using stereoradiographs during arm elevation.
abstract: BACKGROUND
  Alterations of the scapular kinematics in different pathologic conditions have been widely studied. However, results have shown considerable discrepancies concerning the direction and the amplitude of scapular movement. The lack of consistency in the literature probably has several explanations. The purpose of this study was to analyze scapular orientation with the arm at rest and with 90° lateral elevation in healthy and pathologic subjects by use of stereoradiographs.
  
  
  METHODS
  All participants (n = 65) underwent a clinical examination and magnetic resonance imaging of the shoulder to assess rotator cuff status. Participants were separated into 3 groups: healthy, rotator cuff tear (RCT), and RCT and subacromial impingement syndrome (RCT+ SIS). A 3-dimensional model of the scapula was fitted to each low-dose stereoradiograph acquired with the arm at rest and 90° arm elevation.
  
  
  RESULTS
  Orientation of the scapula with the arm at rest was not significantly different between groups. During lateral elevation, scapular orientation was not significantly different between the healthy group and the RCT group. However, upward rotation was significantly reduced in the RCT + SIS group.
  
  
  CONCLUSIONS
  Alterations of scapular kinematics in symptomatic subjects are multifactorial. We observed a link between clinically assessed subacromial impingement and scapular orientation during lateral elevation of the arm.
authors.affiliation: Institut de Biomécanique Humaine Georges Charpak, Paris, France; CHU Maison-Blanche, Service d'Orthopédie-Traumatologie, Reims, France. Electronic address: xohl@chu-reims.fr.
authors.forename: Xavier
authors.initials: X
authors.lastname: Ohl
authors.affiliation: Laboratoire de recherche en Imagerie et Orthopédie, École de technologie supérieure, Centre de recherche du Centre hospitalier de l'Université de Montréal, Montréal, Canada.
authors.forename: Nicola
authors.initials: N
authors.lastname: Hagemeister
authors.affiliation: Institut de Biomécanique Humaine Georges Charpak, Paris, France; Laboratoire de recherche en Imagerie et Orthopédie, École de technologie supérieure, Centre de recherche du Centre hospitalier de l'Université de Montréal, Montréal, Canada.
authors.forename: Cheng
authors.initials: C
authors.lastname: Zhang
authors.affiliation: Institut de Biomécanique Humaine Georges Charpak, Paris, France.
authors.forename: Fabien
authors.initials: F
authors.lastname: Billuart
authors.affiliation: Service de Chirurgie Orthopédique, CHU de Bicêtre, Université Paris 11, Le Kremlin-Bicêtre, France.
authors.forename: Olivier
authors.initials: O
authors.lastname: Gagey
authors.affiliation: Laboratoire de recherche en Imagerie et Orthopédie, École de technologie supérieure, Centre de recherche du Centre hospitalier de l'Université de Montréal, Montréal, Canada.
authors.forename: Nathalie J
authors.initials: NJ
authors.lastname: Bureau
authors.affiliation: Institut de Biomécanique Humaine Georges Charpak, Paris, France.
authors.forename: Wafa
authors.initials: W
authors.lastname: Skalli
mesh_terms: D001132:Arm / Q000502:physiology; D005260:Female; D006801:Humans; D021621:Imaging, Three-Dimensional; D008297:Male; D008875:Middle Aged; D009068:Movement / Q000502:physiology; D011859:Radiography; D012146:Rest / Q000502:physiology; D017006:Rotator Cuff / Q000000981:diagnostic imaging / Q000503:physiopathology; D000070636:Rotator Cuff Injuries; D012540:Scapula / Q000000981:diagnostic imaging* / Q000503:physiopathology; D019534:Shoulder Impingement Syndrome / Q000000981:diagnostic imaging / Q000503:physiopathology*
keywords: Subacromial impingement syndrome; rotator cuff tear; scapula; shoulder kinematics; stereoradiography