title: AST classification of proximal humeral fractures: introduction and interobserver reliability assessment.
abstract: BACKGROUND
  This article introduces an alphanumeric AST (Articular, Surgical neck, Tuberosities) classification of proximal humeral fractures, based on the number, localization, and displacement of articular and extra-articular fragments. All possible cases of proximal humeral fractures can be assessed from a single figure using this classification. The aim of the study was thus to describe the AST classification and to assess interobserver reliability.
  
  
  METHODS
  This classification is based on a single figure, allowing an easy description of the anatomic variants of different proximal humeral fractures. The severity of the fracture is determined by the fragment displacement in angular degrees and the major linear displacement in millimeters. AST reproducibility was assessed and compared with Neer, AO, and Duparc classifications, commonly used in clinical practice. The interobserver agreement was measured with Cohen's kappa coefficients and their 95% confidence intervals.
  
  
  RESULTS
  Thirteen independent observers analyzed a total of 64 X-rays. Overall kappa coefficients were 0.34, 0.29, 0.24, and 0.25 for AST, Neer, AO, and Duparc classifications, respectively.
  
  
  CONCLUSIONS
  The AST classification, which is easier to use because it is based on only one figure, is at least as reproducible as other proximal humeral fracture classifications.
authors: Department of Orthopaedics and Traumatology, CHR Metz Bon-Secours, 57038, Metz Cedex, France. c.cuny@chr-metz-thionville.fr
authors: Christian
authors: C
authors: Cuny
authors: Cedric
authors: C
authors: Baumann
authors: Julien
authors: J
authors: Mayer
authors: Didier
authors: D
authors: Guignand
authors: M'barek
authors: M
authors: Irrazi
authors: Aboubekr
authors: A
authors: Berrichi
authors: Nicolas
authors: N
authors: Ionescu
authors: Francis
authors: F
authors: Guillemin
mesh_terms: D006801:Humans; D015588:Observer Variation; D011859:Radiography; D015203:Reproducibility of Results; D012784:Shoulder Fractures / Q000145:classification* / Q000000981:diagnostic imaging