title: "Duplicate calcaneus": a rare developmental defect observed in several skeletal dysplasias.
abstract: Duplication of the calcaneus is a rarely observed radiographic finding that probably results from delayed coalescence of two primary calcaneal centers of ossification. We performed a review of 2,500 computerized cases of skeletal dysplasias and syndromes with bone involvement in the International Skeletal Dysplasia Registry, searching for those cases in which a duplicate calcaneus had been recorded. We found that it was a non-random feature of three skeletal dysplasias and groups comprising thanatophoric dysplasia and the chondrodysplasia punctata and short rib (polydactyly) groups. We conclude that duplication of the calcaneus should be considered a consistent feature of these entities and may reflect a more generalized developmental defect.
authors.affiliation: Cedars-Sinai Medical Center and UCLA School of Medicine, Los Angeles, California 90048, USA.
authors.forename: V
authors.initials: V
authors.lastname: Cormier-Daire
authors.forename: R
authors.initials: R
authors.lastname: Savarirayan
authors.forename: S
authors.initials: S
authors.lastname: Unger
authors.forename: D L
authors.initials: DL
authors.lastname: Rimoin
authors.forename: R S
authors.initials: RS
authors.lastname: Lachman
mesh_terms: D001848:Bone Diseases, Developmental / Q000150:complications* / Q000000981:diagnostic imaging*; D002111:Calcaneus / Q000002:abnormalities* / Q000000981:diagnostic imaging*; D002648:Child; D006801:Humans; D011859:Radiography; D012042:Registries