The spondylometaphyseal dysplasias. A tentative classification

The spondylometaphyseal dysplasias constitute a very complex group of disorders. In addition to the Kozlowski type, three subgroups can be distinguished by the appearance of the femoral neck. In the first group (A) the changes are severe with absent ossification of the femoral neck and coxa vara. In the second group (B) the changes of the femoral neck are moderate and in the third (C) mild metaphyseal irregularities are only visible. This classification is not definitive but tries to put order in this confusing section of constitutional bone diseases.