Metaphyseal (Chondro) Dysplasia in SDS is characterised by short stature, delayed appearance but subsequent normal development of secondary ossification centres. And by variable metaphyseal widening and irregularity that is most often seen in the ribs in early childhood and in the proximal and distal femora later in childhood and adolescence. Rarely, skeletal involvement may be extremely severe with generalized bone abnormalities.
Radiographic features of SDS:
X thorax : marked cupping and widening of the anterior ends
X pelvis : short iliac notches, valgus position of femoral neck,
X long bones: widening of metaphysis