Reliability of the Modified Radiographic Union Score for Tibia Fractures (mRUST) for Femoral Shaft Fractures.

Objectives: To evaluate the interobserver and intraobserver reliability of the modified Radiographic Union Score for Tibia Fractures (mRUST) and the effect of rater experience in evaluation of femoral fractures.

Design: Retrospective cohort study.

Setting: Single Level 1 trauma center.

Patients/participants: Patients 18-55 years of age with a femur shaft fracture.

Intervention: Intramedullary nail fixation.

Main Outcome Measurement: Interobserver and intraobserver reliability using the intraclass correlation coefficient.

Results: The overall interobserver reliability was 0.96. Among fellowship-trained evaluators, the interobserver reliability was 0.94, and it was 0.92 among trainees. The overall intraobserver reliability was 0.98. The intraobserver reliability was 0.97 among fellowship-trained evaluators and 0.96 for trainees.

Conclusions: These results show high interobserver and intraobserver reliability of mRUST in the evaluation of radiographic healing for femur shaft fractures treated with intramedullary nail. This high reliability was further demonstrated throughout different postoperative healing time frames. In addition, mRUST appears to be reliable when used both by trainees and experienced surgeons for the evaluation of femur shaft fractures.

Level Of Evidence: Diagnostic Level I. See Instructions for Authors for a complete description of levels of evidence.