A rare case of floating fifth metacarpal and review of literature

Abstract

Background: Floating metacarpal is a rare concurrent bipolar dislocation of metacarpal at both ends. Isolated dislocations of Carpo-metacarpal (CMC) or Metacarpo-phalangeal (MCP) have been previously reported, simultaneous dislocations of both joints is scarcely reported in literature and bares high chance of diagnosis being missed on presentation. Patient: A 29-year-old male presented with pain, swelling in left hand and loss of movement in fifth and fourth finger following a motorcycle fall injury. Radiography showed floating metacarpal of fifth ray along with fracture dislocation of at base of fourth metacarpal. Diagnosis: The patient was diagnosed with floating fifth metacarpal along with fracture dislocation at base of fourth metacarpal. Intervention: Open reduction and K-wire fixation was performed across CMC for fifth and fourth metacarpal along with MCP fixation for fifth metacarpal joint. Outcomes: The patient had excellent outcome after one year with normal Range of motion and grip. Lessons: Early recognition and prompt management of these injuries are considered as hallmark of prognosis. Ideal treatment for such dislocation is controversial. However, we have noted from earlier case reports that with acute dislocation and minimal swelling closed reduction and cast immobilization could be sufficient. In case of delayed presentation or swelling along with fracture, open reduction is favorable choice of treatment. Keywords: Floating metacarpal, CMC dislocation, MCP dislocation