Supplementary Fixation Improves Stability of Intra-Articular Distal Radius Fractures Managed With a Spanning Plate.

Purpose: Previous studies evaluating weight bearing of distal radius fractures treated through dorsal spanning bridge plates used extra-articular fracture models, and have not evaluated the role of supplementary fixation. We hypothesized that supplementary fixation with a spanning dorsal bridge plate for an intra-articular wrist fracture would decrease the displacement of individual articular pieces with cyclic axial loading and allow for walker or crutch weight bearing.

Methods: Thirty cadaveric forearms were matched into 3 cohorts, controlling for age, sex, and bone mineral density. An intra-articular fracture model was fixed with the following 3 techniques: (1) cohort A with a dorsal bridge plate, (2) cohort B with a dorsal bridge plate and two 1.6-mm k-wires, and (3) cohort C with a dorsal bridge plate and a radial pin plate. Specimens were axially loaded cyclically with escalating weights consistent with walker and crutch weight-bearing with failure defined as 2-mm displacement.

Results: No specimens failed at 2- or 5-kg weights, but cohort A had significantly more displacement at these weights compared with cohort B. Cohort A had significantly more failure than cohort C. Both cohort A and cohort B had significantly more displacement at crutch weight bearing compared with cohort C. The supplementary fixation group had significantly lower displacement at crutch weight-bearing compared with cohort A in all gaps. Survival curves demonstrated the fixation cohort to survive higher loads than the nonfixation group.

Conclusion: There was significantly less displacement and less failure of intra-articular distal radius fractures treated with a spanning dorsal bridge plate and supplementary fixation. Our model showed that either type of fixation was superior to the nonfixation group.

Clinical significance: When considering early weight-bearing for intra-articular distal radius fractures treated with a spanning dorsal bridge plate, supplementary fixation may be considered as an augmentation to prevent fracture displacement.