Volar plating of distal radius fractures does not restore the anatomy

INTRODUCTION: The objective of this study was to evaluate whether volar locking plating can restore the anatomical volar tilt of 12 degrees and the, anatomical length of the radius relative to the ulna. We retrospectively reviewed the radiographic outcome of distal radius fractures treated with two different first-generation locking plate systems; VariAx (Stryker) and ACU-LOC (Acumed). METHODS: Three independent observers evaluated radial volar tilt and ulnar variance (> 2 mm) on radiographs taken preoperatively, immediately after the operation and five weeks later. In addition, the radial inclination, distal radio-ulnar joint incongruity and articular step-off were assessed in order to describe the personality of the fracture. RESULTS: A total of 576 fracture cases were included in the study. Preoperatively, the, mean volar tilt was 18 +/- 6 degrees and -15 +/- 11 degrees for volarly and dorsally displaced fractures, respectively. After operation, the mean volar tilt was 4.5 +/- 6 degrees without any significant changes after five weeks, p = 0.79 and no significant differences with respect to fracture type or type of plate. Thus, the anatomical angulation of 12 degrees was not achieved at any point in time after surgery (p < 0.001). Shortening of the radius (> 2 mm ulnar variance) was still seen in 9% of the cases immediately after surgery and in 22% after five weeks. CONCLUSIONS: Volar locking plating did not restore the anatomy after distal radius fractures. The clinical implication of these findings is unclear because the, functional outcome of the patients was not available.