A biomechanical evaluation of lateral plating of distal radial shaft fractures.
OBJECTIVE
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 degrees +/- 13 degrees vs 23 degrees +/- 10 degrees ) or in torsional stiffness (0.6 +/- 0.2 N-m/ degrees vs 0. 6 +/- 0.2 N-m/ degrees ) 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.
Eglseder
W Andrew
WA
Orthopaedic Biomechanics Laboratory, Baltimore, MD, Department of Orthopaedic Surgery, The Johns Hopkins University, Johns Hopkins Bayview Medical Center, and Department of Orthopaedic Surgery, University of Maryland Medical Center, USA
Jasper
Louis E
LE
Davis
Charles W
CW
Belkoff
Stephen M
SM
D001696:Biomechanical Phenomena; D001860:Bone Plates; D019544:Equipment Failure Analysis; D006801:Humans; D011885:Radius Fractures / Q000601:surgery*; D013314:Stress, Mechanical