Fluoroscopic evaluation of intra-articular screw placement during locked volar plating of the distal radius: a cadaveric study.

PURPOSE

To evaluate specific fluoroscopic views for assessment of intra-articular screw placement during locked volar plating of the distal radius.

METHODS

The distal radius of a cadaver forearm was plated with a fixed-angle volar plate according to the surgical technique guide of the manufacturer. A goniometer was used to place the specimen at various described angles in the fluoroscope including standard posteroanterior (PA), tilt PA (11 degrees ), standard lateral, and tilt lateral (15 degrees , 23 degrees , 30 degrees ) views. Radiographic images of each screw individually and in various combinations were digitally captured.

RESULTS

Only the tilt PA view correctly showed all 4 screws to be extra-articular. On the standard PA view, the 2 ulnar screws appeared intra-articular. Lower angle tilt lateral views (15 degrees and 23 degrees ) correctly visualized the ulnar screws but not the styloid screw. The highest angle lateral view (30 degrees ) correctly visualized the radial screws but not the sigmoid (most ulnar) screw. The styloid screw appeared to be intra-articular on every lateral view except at 30 degrees and was correctly visualized on both the PA and tilt PA views.

CONCLUSIONS

Multiple oblique views are required for evaluation of intra-articular screw placement during locked volar plating of the distal radius. Lower angle tilt lateral views are more specific for the ulnar screws, and higher angle views are more specific for the radial screws. We suggest first placing the ulnar screws whenever possible, using lower angle tilt lateral views (15 degrees to 23 degrees ) to evaluate for intra-articular placement. The styloid screw may be placed last and can then be evaluated on the PA and tilt PA views.