Background: We have clinically encountered children with fibrodysplasia ossificans progressiva who had abnormal calcaneal ossification.
Objective: To evaluate whether calcaneal ossification variants are significant radiographic findings in children with fibrodysplasia ossificans progressiva.
Materials and methods: Lateral feet radiographs in nine children who fulfilled the diagnostic criteria of fibrodysplasia ossificans progressiva were reviewed. The studies were obtained during infancy or early childhood.
Results: Fourteen lateral foot radiographs of fibrodysplasia ossificans progressiva were available for this study (ages at examination: 1-104 months). Four children ages 2 months to 11 months showed double calcaneal ossification centers; 7 children had plantar calcaneal spurs that decreased in size with age. Overall, eight of nine children with fibrodysplasia ossificans progressiva demonstrated double calcaneal ossifications and/or plantar calcaneal spurs in infancy or childhood.
Conclusion: Double calcaneal ossification centers in early infancy and plantar calcaneal spurs in childhood are frequently seen in children with fibrodysplasia ossificans progressiva and may be a useful radiologic indicator for early diagnosis.
Keywords: Calcaneal spur; Children; Double calcaneal ossification center; Early diagnosis; Fibrodysplasia ossificans progressiva; Radiography.