Development of the Radiographic Union Score for Tibial Fractures for the Assessment of Tibial Fracture Healing After Intramedullary Fixation

Background: The objective was to evaluate the newly developed Radiographic Union Score for Tibial fractures ( RUST). Because there is no "gold standard," it was hypothesized that the RUST score would provide substantial improvements compared with previous scores presented in the literature. Methods: Forty-five sets of X-rays of tibial shaft fractures treated with intramedullary fixation were selected. Seven orthopedic reviewers independently scored bony union using RUST. Radiographs were reassessed at 9 weeks. Intraclass correlation coefficients (ICC) with 95% confidence intervals (CI) measured agreement. Results: Overall agreement was substantial ( ICC, 0.86; 95% CI, 0.79-0.91). There was improved reliability among traumatologists compared with others ( ICC = 0.86, 0.81, and 0.83, respectively). Overall intraobserver reliability was also substantial ( ICC, 0.88; 95% CI, 0.80-0.96). Conclusions: The RUST score exhibits substantial improvements in reliability from previously published scores and produces equally reproducible results among a variety of orthopedic specialties and experience levels. Because no "gold standards" currently exist against which RUST can be compared, this study provides only the initial step in the score's full validation for use in a clinical context.