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.
- punching (most common)
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: