title: Inter- and intra-observer agreement of the AO classification for operatively treated distal radius fractures.
abstract: The reproducibility of the AO classification for distal radius fractures remains a topic of debate. Previous studies showed variable reproducibility results. Important treatment decisions depend on correct classification, especially in comminuted, intra-articular fractures. Therefore, reliable reproducibility results need to be undisputedly determined. Hence, the study objective was to assess inter- and intra-observer agreement of the AO classification for operatively treated distal radius fractures. A database of 54 radiographs of all AO types (A, B and C) and groups (A2-3, B1-3, and C1-3) of distal radius fractures was assessed in twofold. Likewise, a subset of 152 radiographs of solely C-type groups (C1-3) was assessed. All fractures were classified by six observers with different experience levels: three consultant trauma surgeons, one sixth-year trauma surgery resident, a consultant trauma radiologist, and an intern with limited experienced. The inter-observer agreement of both main types and groups was moderate (κ = 0.49 resp. κ = 0.48) in combination with a good intra-observer agreement (κ = 0.68 resp. κ = 0.70). The inter-observer agreement of the subset C-type fractures group was fair (κ = 0.27) with moderate intra-observer agreement (κ = 0.43). According to these results, the reproducibility of the AO classification of main types and groups of distal radius fractures based on conventional radiographs is insufficient (κ < 0.50), especially at group level of C-type fractures.
authors.affiliation: Department of Surgery, VU University Medical Centre, 1007 MB, Amsterdam, The Netherlands. jessevb@gmail.com.
authors.forename: Jesse M
authors.initials: JM
authors.lastname: van Buijtenen
authors.affiliation: Department of Surgery, VU University Medical Centre, 1007 MB, Amsterdam, The Netherlands.
authors.forename: Mischa L C
authors.initials: ML
authors.lastname: van Tunen
authors.affiliation: Department of Surgery, VU University Medical Centre, 1007 MB, Amsterdam, The Netherlands.
authors.forename: Wietse P
authors.initials: WP
authors.lastname: Zuidema
authors.affiliation: Department of Radiology, VU University Medical Centre, Amsterdam, The Netherlands.
authors.forename: Emile A
authors.initials: EA
authors.lastname: Heilbron
authors.affiliation: Department of Surgery, Westfriesgasthuis, Hoorn, The Netherlands.
authors.forename: Jeroen
authors.initials: J
authors.lastname: de Haan
authors.affiliation: Department of Epidemiology and Biostatistics and the EMGO Institute for Health and Care Research, VU University Medical Centre, Amsterdam, The Netherlands.
authors.forename: Henrica C W
authors.initials: HC
authors.lastname: de Vet
authors.affiliation: Department of Surgery, Zaandam Medical Centre, Zaandam, The Netherlands.
authors.forename: Robert J
authors.initials: RJ
authors.lastname: Derksen
keywords: AO classification; C-type fractures; Distal radius fracture; Inter-observer agreement; Intra-observer agreement; Surgical procedures