Importance and accuracy of bone age ratings in a computerized growth evaluation system.

Bone age ratings according to Greulich and Pyle and to Tanner and co-workers (RUS) of 88 children from two pediatric endocrine centers were compared with ratings from 2 trained technicians and independent ratings from a consulting pediatric endocrinologist. Considering the mean of all ratings as 'true bone age', the mean errors of the individual estimations were small (0.15-0.38 years for the Greulich and Pyle method, 0.12-0.27 years for the method according to Tanner and co-workers). Only in 2 of 338 ratings were differences larger than 1 year observed. In these 2 cases, there was marked dissociation between the maturation of carpal and phalangeal bones. It is concluded that estimations of bone maturation can be carried out reliably by properly trained technicians.