Treatment of Fourth and Fifth Carpometacarpal Fracture-Dislocations in Punching Injuries With Motion-Sparing Hamate Fixation Spring Plates: "Rabbit Ears" Plating.

Punching injuries to the hand are frequent and can result in fourth and fifth carpometacarpal (CMC) fracture-dislocations. Fourth and fifth CMC fracture-dislocations are unstable, and dorsal metacarpal dislocations are most common. Operative management for maintaining reduction of the unstable fracture-dislocation was closed reduction and percutaneous pinning; however, in delayed fractures, open reduction is necessary. We report on a plating technique used for acute and delayed, unstable fourth and/or fifth CMC fracture-dislocations. This method of plating is novel and allows for physiological motion at the CMC joint through a dorsal buttressing mechanism while maintaining joint reduction. The range of motion begins within the first week postoperatively, and full composite fist formation and digital extension occur 4 to 6 weeks postoperatively. This novel technique affords an alternative effective surgical treatment option with excellent outcomes for patients presenting with fourth and fifth CMC fracture-dislocations up to 12 weeks following the injury.