bone age

Last reviewed 01/2018

Bone age is defined as the age implied in an individual by the degree of bone ossification. Thus, for a given age a certain amount of ossification will have happened in a normal population. The bone age is therefore the age that the individual would be expected to have attained to have that degree of ossification.

It is classically assessed on ossification of the carpal bones. A number of techniques are used, from comparison of the bone radiograph to a set of pictures of various stages of ossification, which is the least accurate, to a scoring system for each of the centres of ossification, which is subsequently converted to a bone age. The latter is generally felt to be the most accurate.