Classification of talocalcaneal coalitions based on 3D reconstruction of computer tomography by Rozansky et al. []. Type 1– linear: fibrocartilaginous linear coalition parallel to the subtalar joint; Type 2– linear with posterior hook: fibrocartilaginous coalition linear anteriorly, which curves into a posterior hook overlapping the sustentaculum tali medial and dorsal; Type 3– shingled: coalition with an orientation that sloped down in an overlapping fashion, with the talar portion shingled over the calcaneal; Type 4– complete osseous: complete osseous coalition of the medial facet; Type 5– posterior: small, peripheral posterior coalition.
Wähnert et al. BMC Musculoskeletal Disorders 2013 14:111 doi:10.1186/1471-2474-14-111