Three-Dimensional CT Mapping of Intra-articular Calcaneal Fractures

Abstract Background: Intra-articular calcaneal fracture is a challenge for surgeons, which must be understood to provide optimal treatment. The aim of this study was to define the distribution of the primary fracture line and the secondary fracture line of intra-articular calcaneal fractures. Methods: All X-rays and CT scans of intra-articular calcaneal fractures were collected from January 2014 to July 2020. According to the classification of Essex-Lopresti, these fractures were divided into tongue-fracture group and compression-fracture group. Construct 3D models of intra-articular calcaneal fractures in all patients, and record the location of all fracture lines, which were marked and integrated on the 3D model of intact calcaneus after virtual reduction. Heat mapping were created based on the occurrence frequency of fracture lines. Results: A total of 171 patients with intra-articular calcaneal fractures were included in this study, 4 of whom were bilateral. There were 87 cases in the tongue-fracture group, 37 cases (42.5%) involved 4 anterior articular surface, 16 cases (18.4%) involved middle articular surface, and 52 cases (59.8%) involved calcanecuboid articular surface. There were 88 cases in the compression-fracture group, including 43 cases (48.9%) involving anterior articular surface, 21 cases (23.9%) involving middle articular surface, and 63 cases (71.6%) involving calcanecuboid articular surface. Conclusion: The distribution of the primary fracture line and the secondary fracture line of intra-articular calcaneal fractures has a certain rule and correlation. Whether in tongue-fracture group or compression-fracture group, the fracture line is most often involves the calcanecuboid articular surface, followed by anterior articular surface, at least involves middlearticular surface. This study provides a theoretical basis for further exploration of calcaneal injury mechanism, construction of biomechanical model, and choice of surgical approach.