Radiographic Evaluation of the Distal Radius Using Two Novel Biplanar “Pitch-and-Roll” Views: A Preliminary Cadaveric Study

Abstract

This study's objective was to compare the use of two biplanar angled radiographs versus standard posterioanterior (PA) and lateral radiographs in determining preservation of the articular space with regard to pin placement in the distal radius. Various combinations of inclination (pitch) and clockwise/counterclockwise rotation (roll) were used to determine the best view of the distal radius articular surface. Optimum visualization of the articular surface presented at 12° inclination plus 15° counterclockwise rotation for the PA view and 22° inclination and 15° counterclockwise rotation for the lateral view. Ten cadaveric forearms were dissected, and ten Kirschner wires (K-wires) were placed at specific surfaces of the distal radius. Each K-wire was countersunk 2 mm below the chondral surface so all K-wires resided within the subchondral bone. Each forearm was radiographed in four views; PA, lateral, pitch-and-roll PA (PR-PA), and pitch-and-roll lateral (PR-lateral). Four blinded reviewers evaluated the radiographs and marked whether they were certain, relatively certain, or uncertain that the K-wires did not penetrate into the articular space. Reviewers demonstrated significantly less uncertainty about intraarticular penetration (p<0.005) with both the PR-PA and PR-lateral views compared with standard PA and lateral views. The biconcave nature of the distal radius makes it extremely difficult to visualize placement of hardware with respect to the articular surface using standard radiographs. The use of PR-PA and PR-lateral views significantly improves the surgeon's ability to judge the position of hardware in the distal radius compared to standard radiographic views, thus allowing for more meaningful clinical decision in postoperative radiographs.