A biomechanical evaluation of lateral plating of distal radial shaft fractures

Abstract

Purpose In this ex vivo biomechanical study we compared the maximum anterior/posterior bending moment, maximum torque, torsional stiffness, and twist angle at failure of distal radial shaft (Galeazzi) fractures stabilized with lateral plating (LP) and anterior plating (AP) and subjected to 4-point anterior/posterior bending and torsion. Methods Simulated fractures (oblique osteotomy between the middle and distal thirds of each radius) were created in 21 pairs of fresh, unembalmed, cadaver radii. One radius from each pair was stabilized with AP (n = 21); the contralateral radius was stabilized with LP (n = 21). Eleven pairs of specimens were tested to failure in torsion; the remaining 10 pairs were tested to failure in 4-point anterior/posterior bending. Differences between plating groups were checked for significance using paired t-tests. Results AP fixation was stronger in torsion (12.8 ± 5.6 N-m) and anterior/posterior bending (40.1 ± 25.7 N-m) than LP fixation (10.7 ± 5.6 N-m and 36.0 ± 30.5 N-m, respectively), although the differences were not significant. Similarly there was no significant difference in twist angle at failure (29° ± 13° vs 23° ± 10°) or in torsional stiffness (0.6 ± 0.2 N-m/° vs 0. 6 ± 0.2 N-m/°) between AP and LP fixations, respectively. Conclusions Because LP fixation was not mechanically superior to AP fixation and required additional tendon elevation and dissection of the dorsal sensory nerve and possibly of the lateral antebrachial cutaneous nerves, AP fixation appears to be the preferable treatment for Galeazzi fractures.