Reliability of the RUST Score for the Assessment of Union in Simple Diaphyseal Tibial Fractures

Objective: The aim of our study is to check the reliability of recently developed Radiographic Union Score for Tibial fractures (RUST Score) for determining the healing progression using X-rays of simple diaphyseal tibial fracture patients. Methods: Total sixty-five patients with a simple diaphyseal tibial fracture are enrolled. Each of them are regularly follow-up at 6th, 10th, 16th, 20th, 24th post fracture weeks as per as their routine treatment protocol. To measure inter-observer reliability, an orthopaedician and a radiologist independently scored the bony union using plain X-ray by RUST scoring method. Further to measure, intra-observer reliability, each of the radiographs was reassessed and rescored at average of 06th weeks, from the initial day of scoring, without revealing patients identity or fracture duration. Finally to check the reliability of RUST score, Intraclass correlation coefficient (ICC) with 95% confidence intervals (CI) was measured. Results: Overall agreement was statistically significant. The test-retest reliability was statistically significant, having value of 0.87, 0.95, 0.94, 0.98 and 0.97 respectively at each follow-up. The overall inter as well as intra-observer reliability of RUST score was collectively significant at each follow-up. Conclusions: The RUST score shows substantial improvements in reliability and produces reproducible results, either scored by an orthopaedican or a radiologist.