Distribution of posterior malleolus fracture lines in ankle fracture of supination-external rotation / 中华创伤骨科杂志

ABSTRACT

Objective To study the distribution of intra-articular posterior malleolus fracture lines in ankle fracture of supination-external rotation.Methods Computed tomography scans of a consecutive series of 70 ankle fractures of supination-external rotation were used for this study.The DICOM files were loaded into Mimics 16.0 for 3D reconstruction of distal tibial articular surface.The intra-articular posterior malleolus fracture lines were identified after virtual fracture reduction.All the fracture lines were drawn on one picture of distal tibial articular surface after standardization before a heat map was created based on the frequency of fracture lines.Results Although the distribution of posterior malleolus intra-articular fracture lines varied,most of them were concentrated in an arcuate zone.The ratios of the area of posterior fracture fragment to the total area of articular surface averaged 14.96％ (range,from 2.23％ to 38.45％).They were most likely to enter the articular surface at 20.4％ of the tangent of the posterior edge in a standardized image and exit at 58.7％ of the tangent of the lateral edge.Conclusion In ankle fractures of supination-external rotation,most intra-articular posterior malleolus fracture lines may be distributed regularly in an arcuate zone of the articular surface.