Abstract

Floating first metacarpal has been scarcely described in the literature. Fracture dislocation of the trapezio-metacarpal joint has been reported more than the isolated form but deemed exceptional. We report a 40-year-old man consulting for an injury on his right thumb in which the described mechanism was an axial metacarpal force with both flexed trapezio-metacarpal and interphalangeal joints. X-ray findings revealed a floating metacarpal composed from a Bennet fracture dislocation of the trapezio-metacarpal joint and a fracture dislocation of the base of the proximal phalanx. A closed reduction and percutaneous fixation was achieved. After removal of pins and physiotherapy, and at 12 months of follow up, anatomical and functional outcomes were satisfied with a normal motion of the thumb. The aim of our case report is to improve the closed reduction and percutaneous fixation on fracture dislocation of the trapezio-metacarpal on contrast to the isolated dislocation form in which closed reduction must be avoided.

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