title: Reproducibility of classifications for olecranon fractures.
abstract: BACKGROUND
  Fractures of the olecranon are relatively common injuries in adults and are of great clinical importance. Classification systems have been developed as tools to assist surgeons in grouping different types of fractures, to facilitate communication and to standardise treatment, but none of the systems used today is universally accepted for olecranon fractures.
  
  
  METHODS
  Fifty-nine olecranon fractures were classified according to the Schatzker, Colton, Mayo and AO/ASIF systems by four observers with different levels of expertise. Intra- and inter-observer agreement was assessed. Each observer analysed the images at three different times; the images were randomised and presented in a different sequence at each assessment.
  
  
  RESULTS
  There was higher mean intra-observer agreement in the AO/ASIF (0.60) and Mayo (0.64) classifications compared with the Schatzker (0.49) and Colton (0.38) classifications. Inter-observer agreement was better with AO/ASIF and Mayo (0.35 and 0.32, respectively) than with Schatzker and Colton (0.29 and 0.12, respectively).
  
  
  CONCLUSIONS
  The results of this study indicate that the most commonly used classifications for olecranon fractures are associated with low reproducibility.
authors.affiliation: Department of Orthopaedics and Traumatology, Universidade Federal de São Paulo - Escola Paulista de Medicina (Unifesp-EPM), São Paulo, Brazil.
authors.forename: Marcel Jun Sugawara
authors.initials: MJ
authors.lastname: Tamaoki
authors.affiliation: Department of Orthopaedics and Traumatology, Universidade Federal de São Paulo - Escola Paulista de Medicina (Unifesp-EPM), São Paulo, Brazil. Electronic address: fteruo@gmail.com.
authors.forename: Fabio Teruo
authors.initials: FT
authors.lastname: Matsunaga
authors.affiliation: Department of Orthopaedics and Traumatology, Universidade Federal de São Paulo - Escola Paulista de Medicina (Unifesp-EPM), São Paulo, Brazil.
authors.forename: Juliana Doering
authors.initials: JD
authors.lastname: Silveira
authors.affiliation: Department of Orthopaedics and Traumatology, Universidade Federal de São Paulo - Escola Paulista de Medicina (Unifesp-EPM), São Paulo, Brazil.
authors.forename: Daniel
authors.initials: D
authors.lastname: Balbachevsky
authors.affiliation: Department of Orthopaedics and Traumatology, Universidade Federal de São Paulo - Escola Paulista de Medicina (Unifesp-EPM), São Paulo, Brazil.
authors.forename: Marcelo Hide
authors.initials: MH
authors.lastname: Matsumoto
authors.affiliation: Department of Orthopaedics and Traumatology, Universidade Federal de São Paulo - Escola Paulista de Medicina (Unifesp-EPM), São Paulo, Brazil.
authors.forename: João Carlos
authors.initials: JC
authors.lastname: Belloti
mesh_terms: D005593:Fracture Fixation, Internal / Q000379:methods*; D006801:Humans; D057072:Intra-Articular Fractures / Q000145:classification* / Q000000981:diagnostic imaging; D015588:Observer Variation; D056740:Olecranon Process / Q000000981:diagnostic imaging / Q000293:injuries*; D015203:Reproducibility of Results; D012720:Severity of Illness Index; D014057:Tomography, X-Ray Computed
keywords: Olecranon process; Reproducibility of results; Ulna fractures; Validation studies