title: A comprehensive classification of proximal humeral fractures: HGLS system.
abstract: BACKGROUND
  This study assessed the intraobserver and interobserver reliability of a binary classification system using an easy-to-remember acronym (the HGLS system--based on the reappraisal of Codman's description by Hertel et al) and compared it with the AO and Neer systems.
  
  
  METHODS
  Forty-seven proximal humeral fractures in 47 patients treated at the Department of Orthopaedics and Trauma, Royal Adelaide Hospital, Adelaide, Australia, were identified in the period from July 2007 until January 2008. Fractures of the proximal humerus were examined with anteroposterior, lateral, and axillary radiographs. Three independent reviewers classified the fractures using the AO, Neer, and HGLS systems. Reclassification of the same fractures was undertaken after a 6-month interval, and interobserver and intraobserver correlation, by use of the κ statistic, was calculated for all 3 classification systems.
  
  
  RESULTS
  The mean age of patients was 64.5 years (range, 16-95 years). The interobserver correlations for the AO system (κ value, 0.47) and Neer system (κ value, 0.44) were graded as poor and were consistent with the values of previously published studies. The HGLS classification showed good interobserver agreement for all 3 examiners at the first interpretation (κ value, 0.73) and second interpretation (κ value, 0.61). Good intraobserver agreement after a 6-month period was also seen for the HGLS classification (κ values, 0.87-0.92) compared with the AO system (κ, 0.61-0.71) and Neer system (κ, 0.42-0.77).
  
  
  CONCLUSIONS
  The HGLS system provided a more reliable description of fractures of the proximal humerus compared with the Neer and AO systems. Further studies are necessary to assess the validity of the HGLS system.
authors: Department of Orthopaedics, University of Balgrist, Zurich, Switzerland.
authors: Atul V
authors: AV
authors: Sukthankar
authors: Domenic T
authors: DT
authors: Leonello
authors: Ralph W
authors: RW
authors: Hertel
authors: Gordon S
authors: GS
authors: Ding
authors: Michael J
authors: MJ
authors: Sandow
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001315:Australia; D015331:Cohort Studies; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D015601:Injury Severity Score; D008297:Male; D008875:Middle Aged; D015588:Observer Variation; D015203:Reproducibility of Results; D012784:Shoulder Fractures / Q000145:classification* / Q000000981:diagnostic imaging*; D014057:Tomography, X-Ray Computed / Q000379:methods; D055815:Young Adult