title: Interobserver agreement of Neer and AO classifications for proximal humeral fractures.
abstract: BACKGROUND
  The classification of proximal humeral fractures remains challenging. The two main classification systems used, the Neer and the AO classification, have both been shown to have less than ideal interobserver agreement. Agreement in classification is required, however, to guide fracture management.
  
  
  METHODS
  Data from the Victorian Orthopaedic Trauma Outcomes Registry were collected and the X-rays of 104 proximal humeral fractures were reviewed by three orthopaedic consultants. They classified the fractures according to the Neer and AO classifications, as well as their simplified versions. Interobserver agreement was then assessed using kappa statistics.
  
  
  RESULTS
  Interobserver agreement was better overall in the Neer classification, which was moderate (kappa = 0.40-0.58), than the AO classification, which was fair to moderate (kappa = 0.31-0.54). When simplified, the Neer and AO classification interobserver agreement remained similar.
  
  
  CONCLUSIONS
  The classification of proximal humeral fractures with both the Neer and the AO systems remains difficult with minimal improvements seen when reducing the number of categories in each classification system. From these results, the Neer classification system would appear slightly more useful in clinical practice to guide treatment.
authors.affiliation: Department of Orthopaedics, St Vincent's Hospital, Melbourne, Victoria, Australia.
authors.forename: Maritsa K
authors.initials: MK
authors.lastname: Papakonstantinou
authors.affiliation: Victorian Orthopaedic Trauma Outcomes Registry (VOTOR), Melbourne, Victoria, Australia.|Department of Epidemiology and Preventive Medicine, School of Public Health and Preventive Medicine, Monash University, Melbourne, Victoria, Australia.
authors.forename: Melissa J
authors.initials: MJ
authors.lastname: Hart
authors.affiliation: Department of Orthopaedics, The Royal Melbourne Hospital, Melbourne, Victoria, Australia.
authors.forename: Richard
authors.initials: R
authors.lastname: Farrugia
authors.affiliation: Department of Epidemiology and Preventative Medicine, Monash University, Melbourne, Victoria, Australia.
authors.forename: Belinda J
authors.initials: BJ
authors.lastname: Gabbe
authors.affiliation: Department of Orthopaedics, The Alfred Hospital, Melbourne, Victoria, Australia.
authors.forename: Afshin
authors.initials: A
authors.lastname: Kamali Moaveni
authors.affiliation: Department of Orthopaedics, St Vincent's Hospital, Melbourne, Victoria, Australia.|Department of Orthopaedics, The Epworth Hospital, Melbourne, Victoria, Australia.
authors.forename: Dirk
authors.initials: D
authors.lastname: van Bavel
authors.affiliation: Department of Orthopaedics, University Hospital, Geelong, Victoria, Australia.|School of Medicine, Deakin University, Geelong, Victoria, Australia.
authors.forename: Richard S
authors.initials: RS
authors.lastname: Page
authors.affiliation: Department of Orthopaedics, The Epworth Hospital, Melbourne, Victoria, Australia.|Department of Surgery, The University of Melbourne, Melbourne, Victoria, Australia.
authors.forename: Martin D
authors.initials: MD
authors.lastname: Richardson
mesh_terms: D002983:Clinical Competence; D006801:Humans; D015588:Observer Variation; D000072161:Orthopedic Surgeons; D011859:Radiography / Q000379:methods; D015203:Reproducibility of Results; D012784:Shoulder Fractures / Q000145:classification* / Q000000981:diagnostic imaging*
keywords: X-rays; classification; humerus; observer variation; shoulder fractures