[Free Full Text] Growth of the Foramen Magnum in Achondroplasia
This is an old study, but it is still relevant when it comes to foramen magnum size and growth in individuals with achondroplasia.
It presents growth curves for individuals with achondroplasia and compares them with the growth curves for individuals without achondroplasia. It shows big differences, but it also shows that there is no reliable connection between the relative size of the foramen magnum and the presence of symptoms or their severity.
Hecht, J.T., et al., Growth of the foramen magnum in achondroplasia. Am J Med Genet, 1989. 32(4): p. 528-35.
Abstract
"Foramen magnum growth curves in achondroplasia and in the general population are presented. The achondroplastic foramen magnum is small at birth, and during the first year it has a severely impaired rate of growth especially in the transverse dimension. This markedly diminished growth results not only from abnormal endochondral bone growth but also because of abnormal placement and premature fusion of the synchondroses. Evaluation of the foramen magnum in achondroplasia should address absolute size of the transverse and sagittal dimensions, shape, and growth centers to determine growth potential of this area."