Risk of tendon entrapment under a dorsal bridge plate in a distal radius fracture model.

PURPOSE: To determine the risk of iatrogenic damage to the extensor tendons and sensory nerves under a bridge plate along the second versus third metacarpal.

METHODS

Using 6 paired (left-right) cadaver forearms-wrists and via a volar approach, we created a distal radius fracture with metaphyseal comminution. We then applied a dorsal distraction plate to either the second or third metacarpal. We next performed dorsal dissection of the hand and wrist over the zone of injury to determine the position of the plate relative to the extensor tendons and sensory nerves.

RESULTS

The bridge plate on the third metacarpal entrapped tendons of the first and third compartment in all 6 specimens. When the plate was applied to the second metacarpal there were no cases of tendon entrapment. There were no instances of nerve entrapment in plating to either the second or third metacarpal.

CONCLUSIONS

Distraction plating has been proposed for use in the second and third metacarpals for unstable comminuted distal radius fractures. We recommend formal exposure of the extensor tendons over the zone of injury when applying a distraction bridge plate to the third metacarpal.

CLINICAL RELEVANCE: Plating to the second metacarpal decreases the risk of entrapment of extensor tendons compared with plating to the third metacarpal.