Three-dimensional Computed Tomography Mapping of Talar Body Fractures.

Background: Three-dimensional (3D) fracture mapping has improved the ability to understand and classify complex orthopaedic injuries including scapula body and tibial plafond fractures. Talar body fractures are another complex injury. The most used classification of talar body fractures is based on a series of 51 patients, using radiographs alone. The purpose of this study was to use modern techniques to further understand the morphology of talar body fractures. Methods: All skeletally mature patients with operatively treated isolated shear-type talar body fractures and preoperative computed tomography (CT) scans from 2008 to 2020 at a single level 1 academic trauma center were eligible for inclusion. 3D fracture lines and intact bone fragments were identified and subsequently mapped onto a common template talus model to generate 3D fracture maps depicting the spatial distribution and relative frequency of fractures and comminution. Results: A total of 124 talar body fractures were included. The average age was 37 years (SD 10, range 17-69). Eighty-eight patients (71%) were male. There was a dominant oblique fracture pattern originating from the anteromedial talar body and extending posterolaterally, involving a variable amount of the talar dome and posterior facet. This fracture pattern was present in 71% of cases, whereas the typical coronal shear pattern was present in only 18% and the classic sagittal shear pattern was present in only 8% of cases. Ninety percent of fractures had the presence of comminution or articular impaction, which typically occurred at the plantar-medial talus and involved the medial subtalar joint. Conclusions: This CT-based 3D fracture mapping study of 124 talar body fractures demonstrated that these fractures occur in certain patterns with high frequency. An obliquely oriented, anteromedial-to-posterolateral fracture line involving a variable amount of the posterior facet and talar dome was present in the majority of cases. These results may help guide treatment planning including surgical approach and fixation strategies. Level of Evidence: Level IV, prognostic. See Instructions for Authors for a complete description of levels of evidence.