Total talar fracture – Inter- and intra-observer reproducibility of two classification systems (Hawkins and AO) for central talar fractures

SummaryIntroductionWe evaluated the inter- and intra-observer reproducibility of two classification systems for central talar fractures (Hawkins, as modified by Canal and Kelly and then by us; AO/AOT).HypothesisThe analysis and classification of these fractures will be better with CT scans than with X-rays.Material and MethodsFour observers evaluated 39 X-ray and CT scan files twice in the span of six weeks; each evaluation entailed classifying the fractures and describing their main features. Cohen's Kappa coefficient for inter-rater agreement was calculated and analysed.ResultsThe inter- and intra-observer reproducibility with CT scans was better with X-rays for most of the parameters evaluated. The modified Hawkins classification provided better reproducibility than the AO/AOT one. However, this classification system was not perfect, even after modifications and use of CT scans.DiscussionCT scans are an essential tool for the analysis of all talar fractures. We modified the Hawkins classification (as modified by Canal and Kelly) to include a Type 0 (no displacement or less than 2 mm), include frontal body fractures that are displaced like neck fractures and take into account comminuted fractures and other trauma in the area.Level of proofIV – retrospective clinical study.