[Classification of pediatric supracondylar fractures: Gartland, AO and Holmberg: Which has the best interobserver agreement?]. 
Several classifications have been proposed for supracondylar fractures of the humerus.  The purpose of this study was to assess the reproducibility and interobserver agreement of the Holmbert, Gartland and AO classifications.  Retrospective study consisting of concurrent, blind and independent assessments of a consecutive sample of 42 elbow X-rays (AP and lateral) of pediatric patients with supracondylar fractures.  Three observers, with similar degree of training, evaluated the X-rays independently and scored each one of them using the 3 scales compared herein.  The interobserver agreement was assessed using Kendalls Tau-b ratio; the arithmetic mean was calculated and the ratios were compared with Fishers transformation.  The interpretation was made using the standards proposed by Landis Koch.  The Holmberg and Gartland classifications had a mean correlation coefficient of 0.654 and 0.706, respectively (p 0.001).  Holmbergs classification provides a better anatomical description.  The mean correlation coefficient of the AO classification was 0.491 (p = 0.001).The difference between the correlation coefficients was 0.052 for Holmbert/Gartland; 0.163 for Holmberg/AO, and 0.215 for Gartland/AO.  There were no statistically significant differences among these values, but there were epistemological differences.  According to Landis and Koch, the Holmberg and Gartland classifications show a substantial agreement, while the AO classification showed a moder ate agreement.  Holmbergs classification is the most recommendable one.