Carpometacarpal joint dislocation

Dr Mark Thurston and Dr Henry Knipe et al.

Carpometacarpal joint dislocations are uncommon dislocations of the hand.

There is a strong younger male predominance. These injuries are more common in the dominant hand.

Typical mechanism:

  • punching (most common)
  • fall

The patient may present with ulnar deviation of the 5th digit if just the 5th carpometacarpal joint is dislocated. A mass may be present in cases of 3rd, 4th, and 5th joint dislocation. Often the hand is so grossly swollen that these features may not be readily apparent.

Loss of the clear joint space and zigzag or M-shape pattern between the carpals and metacarpals on the PA projection, although this may be sometimes seen in normal patients. The dislocation may only clearly be shown on oblique or lateral projections.

The following injuries should raise the suspicion of in carpometacarpal joint dislocations:

Share article

Article information

rID: 23619
Synonyms or Alternate Spellings:
  • CMC dislocation
  • CMC joint dislocation
  • Carpometacarpal dislocation

Support Radiopaedia and see fewer ads

Cases and figures

  • Drag
     Case 2: fracture-dislocation of the 4th and 5th CMC joints
    Drag here to reorder.
  • Drag
    Case 3: CT with hamate fracture
    Drag here to reorder.
  • Drag
    Case 4: dislocation of 4th and 5th CMC joints
    Drag here to reorder.
  • Drag
    Case 5
    Drag here to reorder.
  • Drag
    Case 6: 5th CMC joint
    Drag here to reorder.
  • Drag
    Case 7: dislocation of all CMC joints
    Drag here to reorder.
  • Drag
    Case 8: 5th CMC with base of metacarpal fracture
    Drag here to reorder.
  • Updating… Please wait.
    Loadinganimation

    Alert accept

    Error Unable to process the form. Check for errors and try again.

    Alert accept Thank you for updating your details.