Comparison of 4 fluoroscopic views for dorsal cortex screw penetration after volar plating of the distal radius.

ABSTRACT

PURPOSE: To determine whether use of the dorsal tangential view improves the diagnostic accuracy of intraoperative fluoroscopy compared with conventional views in detecting dorsal screw penetrations during volar distal radius plating. METHODS: Dorsal cortices of 10 cadaveric distal radii were penetrated in each of the second, third, and fourth dorsal extensor compartments at 0, 1, 2, and 3 mm penetration. We obtained 4 standardized fluoroscopic images of the wrist lateral, supination, pronation, and dorsal tangential views. Using high-definition digital images, 2 observers blinded to the experimental paradigm determined whether screws were penetrating the dorsal cortex. RESULTS: For screws that penetrated the floor of the second dorsal compartment, the 45° supination view was 92% sensitive for detecting screw penetration of 2 mm, and 98% for 3 mm. For screws that penetrated the third dorsal compartment, the lateral view was 68% and 80% sensitive in detecting screw penetrations of 1 and 2 mm, respectively. However, the dorsal tangential view showed 95% sensitivity for 1 mm and 98% for 2 mm penetrations. On the floor of the fourth dorsal compartment, pronation and dorsal tangential views were both 88% sensitive for 1 mm screw penetration and 90% and 93% for 2 mm, respectively. CONCLUSIONS: The standard lateral view of the wrist failed to detect all screw penetrations. The dorsal tangential view increased the accuracy of detecting screw penetrations on the floor of the third dorsal compartment, whereas we needed oblique views to detect screw penetrations on the floors of second and fourth dorsal compartments. CLINICAL RELEVANCE Routine clinical use of the dorsal tangential view has the potential to increase accuracy in detecting dorsal screw penetration during volar plating of the distal radius.