Bone age in the 21st century: UIs Greulich and Pyle's atlas accurate for Israeli children?

Background The applicability today of Greulich and Pyle's Radiographic Atlas of Skeletal Development of the Hand and Wrist (G&P) is uncertain. Objective The purpose of this study was to determine whether G&P is accurate in Israeli children today. Materials and methods Left-hand radiographs of 679 children (375 boys) ranging in age from 1 day to 18 years old were obtained for trauma in the period 2001-2009 and were evaluated for bone age according to G&P. Individual bone age was plotted against calendar age and smoothed to obtain the association between calendar age and bone age. Any difference was assessed with Wilcoxon signed-rank test. Results In girls, there was no significant difference between bone age and calendar age (P=0.188). G&P underestimated bone age in boys <15 years old (median difference, 2.3 months; P<0.0001) and overestimated bone age in boys ≥15 years old (median difference, 2.9 months; P= 0.0043). The largest median difference (5.4 months; P= 0.0003) was seen in boys 6-10 years old. Conclusion The differences between calendar age and bone age according to G&P were relatively small compared with normal variance and are unlikely to be of clinical importance.