Different types and epidemiological patterns of calcaneal fractures based on reviewing CT images of 957 fractures

Introduction Calcaneal fractures may have lifelong debilitating sequences, if not treated properly. Identifying different types of calcaneal fractures based on the computed tomography (CT) scans can increase our conception about these fractures. Methods In a cross-sectional study, the available CT images of all consecutive patients with the diagnosis of calcaneal fracture, from January 2015 to December 2018, were reviewed to determine different patterns and types of these fractures. Results CT images of 886 patients (mean age, 41.29 ± 14.9; range, 3–89 years; male/female, 4.86; pediatric: 3.7%) with 957 calcaneal fractures were evaluated. The peak incidence of calcaneal fractures was seen in patients between 30 to 39 years of age (29%). The rate of open fractures and bilateral involvements were 2.4% and 8.0%, respectively. Among 680 (71.0%) intra-articular calcaneal fractures, subtalar calcaneal fractures were the most common type (94.3%). The majority of intra-articular subtalar calcaneal fractures were displaced (95.0%) with calcaneocuboid joint (CCJ) involvement (59.9%). Fracture lines were extended to the CCJ in about 86.9% of Sanders type IV, 66.3% of type III, and 60.2% of type II. Among 261 extra-articular fractures (27.3%), calcaneal body fracture (55.6%) was the most frequent type, followed by medial tubercle fracture (24.1%), calcaneal tuberosity fracture (10.4%), Degan type I anterior process fractures (5.4%), Degan type II anterior process fracture (3.4%), and isolated lateral tubercle fracture (1.1%). Most of bilateral calcaneal fractures were intra-articular subtalar fractures with involvement of CCJ. Although majority of intra-articular calcaneal fractures were displaced; less than half of the extra-articular fractures were displaced. Conclusion Displaced intra-articular subtalar calcaneal fractures with CCJ involvement are the most frequent type of unilateral and bilateral calcaneal fractures. It appears that there is a correlation between Sanders type and the probability of CCJ involvement. Unlike intra-articular subtalar calcaneal fractures, the CCJ in the majority of extra-articular calcaneal body fractures was intact. Level of evidence Level IV.