Quantification of Three-Dimensional Computed Tomography (Q3DCT) is a reliable and reproducible technique to quantify and characterise ankle fractures with a posterior malleolar fragment ( Fixation of posterior malleolar fractures of the ankle is subject of ongoing debate1. Fracture fixation is recommended for fragments involving 25–30% of articular surface1. However, these measurements -and this recommendation- are based on plain lateral radiographs only. A reliable and reproducible method for measurements of fragment size and articular involvement of posterior malleolar fractures has not been described. The aim of this study is to assess the inter-observer reliability of Quantification using Three-Dimensional Computed Tomography (Q3DCT) –modelling2,3,4,5 for fragment size and articular involvement of posterior malleolar fractures. We hypothesize that Q3DCT-modelling for posterior malleolar fractures has good to excellent reliability.Summary
Introduction
posteromedial shear fracture; coronal plane fracture; lateral condylar impaction; medial condylar impaction; tibial spine involvement; separation of tibial tubercle necessitating anteroposterior lag screw fixation. In addition, fractures were classified according to the AO/OTA Comprehensive Classification of Fractures, the Schatzker classification system and the Hohl and Moore system. Two rounds of evaluation were performed and then compared. First, a combination of plain radiographs and two-dimensional computed tomography scans (2D) were evaluated, and then, four weeks later, a combination of radiographs, two-dimensional computed tomography scans, and three-dimensional reconstructions of computed tomography scans (3D) were assessed.
Three-dimensional computed tomography reconstructions also improved the average intraobserver reliability for all fracture characteristics, from κ2D = 0.624 (substantial agreement) to κ3D = 0.687 (substantial agreement). The addition of three-dimensional images had limited infiuence on the average interobserver reliability for the recognition of specific fracture characteristics (κ2D = 0.488 versus κ3D = 0.485, both moderate agreement). Three-dimensional computed tomography images improved interobserver reliability for the recognition of coronal plane fractures from fair (κ2D = 0.398) to moderate (κ3D = 0.418) but this difference was not statistically significant.
individual orthopaedic surgeons for preoperative planning (improves intraobserver reliability for the recognition of fracture characteristics), and for comparison of clinical outcomes in the orthopaedic literature (improves interobserver reliability of classification systems).
