An Unlikely Case of Isolated Dorsal Fifth Carpo Metacarpal Joint Dislocation

Abstract

Introduction:
Carpometacarpal (CMC) joint dislocations are uncommon injuries that account for less than 1% of hand injuries.1 Dorsal dislocations of the CMC joints are more frequent than volar dislocations. Palmar dislocations can be either ulnopalmar or radiopalmar. Due to severe swelling and overlapping of bones on the radiograph of wrist-hand, dislocations are missed. Here we report a case of dorsal dislocation of the 5th CMC joint which was managed with K-wires.

Case Presentation:
A 16 year old male presented to the casualty following a road traffic accident with complaints of pain and swelling over dorsum of right hand extending from the wrist to the metacarpo-phalangeal (MCP) joints. Clinically, there was increased tenderness at the base of 4th& 5thmetacarpals(MC) and ulnar deviation of the 5th digit. Radiologically,there was isolated dislocation of the 5th Carpometacarpal joint(CMC) dorsally and ulnarward. Due to instability, closed reduction was done under C-Arm guidance by longitudinal traction and direct pressure over dorsal base of the 5th metacarpal and 2 K-wires were placed percutaneously. Ulnar gutter slab was applied for maintenance. Wire removal was done at 6thweek postoperatively. Regular physiotherapy was started and normal hand grip strength was restored.

Conclusion:
Isolated carpo-metacarpal dislocations are a rare phenomenon. Thorough clinical examination accompanied with appropriate radiographs followed by early stable reduction and fixation will avoid long term complications.

Keywords: Carpometacarpal joint,casualty,dislocation,K-wiring