Reliability of the radiographic union scale in tibial fractures (RUST)

Fernando Antonio Silva de Azevedo Filho, Ricardo Britto Cotias, Matheus Lemos Azi, Armando Augusto de Almeida Teixeira

This study aimed to evaluate the inter- and intra observer reproducibility of the radiographic score of consolidation of the tibia shaft fractures. Fifty-one sets of radiographs in anteroposterior (AP) and profile (P) of the tibial shaft treated with intramedullary nail were obtained. The analysis of X-rays was performed in two stages, with a 21-day interval between assessments by a group of nine evaluators. To evaluate the reproducibility of RUST score between the evaluators, the intra-class correlation coefficient (ICC) with a 95% confidence interval was used. ICC values range from +1, representing perfect agreement, to -1, complete disagreement. There was a significant correlation among all evaluators: ICC = 0.87 (95% CI 0.81 to 0.91). The intraobserver agreement proved to be substantial with ICC = 0.88 (95% CI 0.85 to 0.91). This study confirms that the RUST scale shows a high degree of reliability and agreement.