Comparison of computed tomography, traction, and inverted grayscale radiographs for understanding pilon fracture morphology

Abstract

Background: There have been no studies evaluating the usefulness of grayscale radiographs in extremity fractures. We aimed to compare the ability and reliability of traction radiographs vs traction grayscale inversion radiographs to detect fracture fragment and comminution zones in comminuted tibia pilon fractures. Methods: Plain radiographs and grayscale inversion images of 60 patients with Orthopaedic Trauma Association/AO Foundation type C3 fracture were evaluated by 20 observers (15 orthopedic surgeons and 5 radiologists) after traction had been applied. The anterolateral, posterolateral, and medial malleolar fragments, as well as the lateral, central, and medial column comminution zones, were identified by all physicians. Computed tomography scan images were used as the "gold standard" against which plain radiographs and grayscale inversion image interpretation were measured. Intra- and interobserver reliability and correct identification of fracture fragments and comminution zones were evaluated. Results: The interobserver reliability for 3 of the fracture fragments and comminution zones on the traction plain radiographs was moderate, whereas it was substantial on traction grayscale inversion radiographs. The lateral comminution zones (P = .001) and presence or absence of posterolateral fragments (P < .001) were significantly better identified in grayscale inversion radiographs compared to standard radiographs. Conclusion: After traction was applied, we found grayscale inversion radiographs are superior to plain radiographs in the identification of posterolateral fragment and lateral zone of comminution in comminuted intraarticular pilon fractures.