Malrotation of extra-articular distal radial fractures: comparison of radiographic prediction and CT scan measurement.

Abstract

Axial malrotation may contribute to the high prevalence of malunion in distal radial fractures. Assessment of the clinical implications requires the recognition of axial malrotation. The aims of this study were to validate published radiological characteristics and to assess the frequency of axial malrotation in acute extra-articular distal radial fractures. All consecutive patients treated for an extra-articular distal radial fracture between January 2015 and December 2023 in a level II trauma centre were screened. Post-reduction radiographs and CT scans were reviewed. Axial malrotation on radiographs was identified by the characteristics reported by Giddins and Sassi. As there is no verified method to measure malrotation on CT scans, we used two CT scan measurement methods: the first, a new method (the 'Fracture level method'); and the second, a modification of a previously described method (Filer's method). Fifty patients with 51 extra-articular distal radial fractures were included. Based on the fracture level and Filer's methods applied to CT scans, respectively, 35-41% of the wrists had a rotated distal radial fracture fragment. Using Giddins' malrotation characteristics, malrotation was predicted with a sensitivity of 100% and a specificity of 70% using the fracture level method as the reference standard. This study confirms that residual fracture malrotation following reduction of a distal radial fracture is common. The ability to predict this malrotation with a 100% sensitivity using Giddins' malrotation characteristics suggests that these characteristics may be helpful for malrotation recognition on radiographs. III.