RESUMEN
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.
RESUMEN
The Load Sharing Classification (LSC) allocates one to three points to each of three different radiological characteristics of traumatic thoracolumbar fractures: the vertebral body involved in the fracture, the displacement of the fracture parts and the kyphotic deformity. Added up, a minimal score of three and a maximal score of nine can be obtained. When the LSC score is three to six, a short segment pedicle screw fixation suffices. When the LSC score is seven to nine, a high rate of failure in patients with a short segment pedicle screw fixation exists. In these cases an anterior stabilising procedure of the spine is advised. The LSC has been examined by Dai and Jin, who claim an almost perfect inter- and intraobserver agreement, according to the Landis and Koch criteria. Dai and Jin only present results for the separate three items of the LSC and for the total LSC scores. Observer agreement for the two LSC score categories (three to six and seven to nine) have not been studied. The aim of this study is to study the inter- and intraobserver agreement of the LSC for the total score, the three separate items and also for the two LSC score categories. Three observers determine twice the LSC scores of forty traumatic thoracolumbar fractures. The average standard Cohen's kappa values for the separate LSC items range between 0.06 and 0.48. For the total LSC score the average standard Cohen's kappa and weighted kappa values are 0.22 and 0.67 respectively. For the two LSC score categories, there is unanimous agreement in 55% of the cases and a majority agreement in 40%. In the remaining 5% of the fractures there is a split decision. Standard Cohen's kappa value for the two LSC score categories is 0.53. The standard Cohen's kappa values can be rated as fair to moderate. From these data it can be concluded that the inter- and intraobserver reliability of the Load Sharing Classification of Spinal fractures can be rated as fair.