To assess the qualitative variables, we calculated absolute and relative frequencies; for quantitative variables, we calculated summary measurements. A comparison of the differences between chronological and bone age was performed using the Student’s t test or variance analysis, and the comparison between the bone ages of affected and unaffected sides in hemiparetic patients was performed using except the Student’s t test for paired data. Assessment of inter-observer matching was made through the intra-class correlation coefficient. The level of significance adopted was 5 % (p < 0,05). The software used was SPSS (Statistical Package for the Social Sciences) version 13.0 for Windows. RESULTS Assessment of inter-observer matching resulted in high correlation coefficients with values of 0.995 and 0.

994 on the right and left sides, respectively. Given this result, it was possible to confirm the reproducibility of the method to obtain bone age in patients with cerebral palsy between different observers and correlate them with several factors. (Table 2) Table 2 Analysis of matching between observers. When comparing chronological age with the average bone age between the right and left wrist, according to the gender, we observed a delay in males of 13.59 months and in females of 9.63 months, showing only a tendency to a greater difference in males, without statistical significance (p = 0.54). (Table 3) Table 3 Comparison of bone age and chronological age (in months) distributed by gender. Regarding the topographic distribution of the CP there was a significant delay (p <0.

005) in tetraparetic (17.7 months), hemiparetic (10.1 months) and diparetic (7.9 months) patients. It was also evident a shorter delay in diparetic than in hemiparetic. (Table 4) Table 4 Difference between chronological and bone age (in months) distribution by type of cerebral palsy. In the hemiparetic group, the mean bone age in the affected side was 96.88 months and in the unaffected side 101.13 months. The difference between both sides is statistically significant (p <0.005). (Table 5) Table 5 Comparison of bone age (in months) between the compromised and non-compromised sides on hemiparetic patients group. Regarding the functional status, the non-ambulating demonstrated a significant delay in bone age over the chronological age of 18.73 months (p <0.005). The delay in community-ambulating was 6.

72 months and in the home-ambulating 6.93 months, both showing no statistically significant difference (p=1 in both). (Table 6) Table 6 Difference between chronological age and bone age (in months) by ambulating status. DISCUSSION Analyzing the results obtained, we observe that patients with spastic CP showed delayed bone age compared with chronological age. However, these data were based on the book from Greulich and Pyle, 10 which could assume that our healthy population could also present this Brefeldin_A delay due to the socio-economic and cultural reasons.