Disharmonic skeletal maturation in the congenital malformation syndromes

Skeletal maturation can be defined as the degree of progression of the bony skeleton towards maturity. Assessment of skeletal maturation can be accomplished by giving a 'bone age' as in the Greulich Pyle system or a score as in the TW2 system, or it may simply be considered as a percentage of the total maturity. Maturation differs from size of the bone in that it determines to some degree what proportion of the final size may have been reached, while size alone can only be used retrospectively. For example, a child who is very tall for his age and has a correspondingly great increase in skeletal maturity has progressed further towards maturity than would be estimated from his height alone so that he may reach only an average height. The concept of skeletal maturation may be extended to the fetus where sequences of mesenchymal condensation, chondrification, and primary ossification are in effect stages of maturation. Deviation from these fetal sequences may well result in some congenital malformation involving the skeleton. Although most maturational events occur in specific sequences this is by no means universal - sequences of onset of ossification of certain hand centers are very dependent on sex and race. We have recently published standards for the hand that give the frequency with which certain ossification sequences occur in American blacks, whites, and in both males and females. For example, the distal epiphysis of the ulna ossifies before the scaphoid and trapezium much more frequently in males than in females while the lunate ossifies after the scaphoid, trapezium, and trapezoid much more commonly in black females than in white females.