"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 ..