Fig. 23.48 
Hypothyroidism in childhood: delay in skeletal maturation (with normal hand for comparison). 
This PA film (a) of the hand of a three-year-old hypothyroid boy demonstrates the characteristic retardation of skeletal growth. The bones of the hand are smaller than normal reflecting the generalised delay in growth that occurs and ossification has not yet started in any of the carpal bones or secondary epiphyses. Irregularity and increased density of the metaphyses occurs and, in this view, these changes are best seen in the distal radius and ulna. The appearances should be compared with those of the hand of a normal boy.