Comparison of plain radiography and CT in postoperative evaluation of ankle fractures

To compare postoperative plain radiographs with computed tomography (CT) post-processing images in evaluating the quality of anatomical reduction and internal fixation of ankle fractures.

A total of 168 patients who sustained closed ankle fracture and were treated with open reduction and internal fixation in East Hospital were reviewed. Postoperative plain radiographs and CT post-processing images were evaluated. The observation was performed under volume-rendering mode and multiplanar reconstruction mode. The assessment was performed by two independent orthopaedic surgeons. The inter- and intra-observer variations were analysed by kappa statistics. The differences between plain radiographs and CT post-processing images were compared using χ(2) test (McNemar's test).

Inter- and intra-observer agreement was almost perfect (0.813-1.000) using CT post-processing images, which was higher than that using plain radiographs (0.323-0.848). More non-anatomical reduction could be recognised in the supination-external rotation (SER), supination-adduction (SAD), pronation-external rotation (PER), and overall groups (p<0.05) and more poor internal fixation could be recognised in the SER, SAD, and overall groups (p<0.05) using CT post-processing images than using radiographs.

More residual articular step, fracture fragment displacement, and poor internal fixation could be detected by CT post-processing images than plain radiographs.