Relationship between the ossification center and cartilaginous anlage in the normal hindfoot in children: study with MR imaging.

Abstract

Our results show that early ossification in the talus, calcaneus, and navicular bones does not begin in the center of the bones' cartilaginous anlagen. The orientations of the long axis of the talar ossification center and the long mid axis of its cartilaginous anlage are different. Therefore, part of the changes in the alignment of the tarsals seen on radiographs with growth is due to ossification beginning and proceeding eccentrically within the cartilaginous anlage and not to a true change in the alignment of the tarsals. These data provide new information about the normal development of the child's hindfoot and midfoot.