This study aims to ascertain the value of CT in assessing union of complex tibial fractures in patients treated with internal or external fixation.

Twenty patients who fit the above criteria were selected from a list of those sent for CT lower leg by the department of Orthopaedics and Trauma at the Royal Infirmary of Edinburgh from 2007–2012. The x-rays chronologically closest to the CTs were assessed by two observers, and the results evaluated for inter-observer agreement. The observers recorded their general impression of whether there was adequate union for fixation removal, and scored the x-rays using the Radiographic Union Scale for Tibial fractures (RUST). There was fair agreement on “general impression” (kappa 0.36, 95% CI 0.08 to 0.64), but there was good agreement using the RUST score (ICC 0.81 95CI 0.12 to 0.96). However, only 45% of the x-rays could be rated by both observers due to obstruction from metalwork. The CT scans were assessed by two orthopaedic surgeons, first giving a general impression of whether there was adequate union for fixation removal, then using a modified RUST score. The inter-observer agreement was moderate in the former (kappa 0.55, 95% CI 0.18 to 0.89) and substantial in the latter (ICC 0.78 95% CI 0.40 to 0.92); only one image was unable to be assessed due to artefact.

The author concludes that CT was useful in these patients due to the high number of x-rays in which cortices were obstructed by metalwork. Use of the RUST score improved inter-observer agreement, and would therefore be useful in both future studies and inter-departmental clinical communication. Further research is needed to relate use of the modified RUST score to clinical outcome.