Second floating metacarpal with a combination of Kaplan’s dislocation and CMC dislocation with associated multiple carpometacarpal joint dislocation

The phenomenon of a floating metacarpal pertains to the concurrent dislocation of both the metacarpophalangeal (MCP) and carpometacarpal (CMC) joints. Literature addressing such dislocations in the absence of accompanying fractures is quite sparse. In this report, we describe a notable case involving a floating second metacarpal, accompanied by dislocations of the third, fourth and fifth CMC joints. The diagnosis was made promptly, and the patient underwent successful treatment by closed reduction of all dislocations followed by K-wire fixation of the CMC joints. Remarkably, the patient demonstrated an excellent functional outcome within a 3 month period. This case report aims to elucidate this atypical presentation, delve into the underlying mechanisms of injury and detail our management approach, which ultimately resulted in a favourable prognosis despite the severity of the injury.