Carpometacarpal dislocation: report of three cases.

: The case reports of three patients with carpometacarpal dislocations are described. The diagnosis of this condition may be difficult and is often missed. Swelling, dislocation and a palpable lump are the main clinical findings. X-ray findings, the key to the diagnosis, are loss of parallelism, interruption of the so-called M-line and overlapping of articular surfaces. Additional X-rays in different planes are to be recommended if carpometacarpal dislocation is suspected.