Cadaveric Study of Appropriate Screw Length for Distal Radius Stabilization Using Volar Plate Fixation

We conducted a study to highlight areas of risk with distal radius fixation to prevent occurrence of extensor tendon injury without compromising the security and stability of the fixation. Twelve cadaveric forearms were used. The volar locking plate was placed to best anatomical and radiologic fit on the distal radius of each arm. All 7 holes in the plate were drilled, and bicortical length was measured using a depth gauge under fluoroscopy to estimate screw lengths. Screws were secured into place, and dorsal prominence was measured. The central screw positions had the least dorsal screw prominence, mean (SD) of 0.50 (1.06) mm, and were considered low-risk. The radial and ulnar screw positions had more dorsal screw prominence, 3.38 (1.38) mm and 1.03 (1.30) mm, respectively. Although only radial prominence was statistically significant, both radial and ulnar screw positions were considered high-risk and in need of screw length adjustments. The data suggest that screw length for this plate should be decreased by about 3 mm for the radial positions and by 1 mm for the ulnar positions to decrease the risk for tendon rupture and irritation secondary to dorsal screw prominence.