Dorsal approach for isolated volar fracture-dislocation of the base of the second metacarpal: A case report

BACKGROUND: We report a case with the displacement of an articular fracture fragment of the base of the second metacarpal from the ulnar to the volar side, treated via the dorsal approach. The dorsal approach can be a good option not only because it allows direct observation of ligament damage and fixation of bone fragments but also because the thin subcutaneous tissue makes the approach easier. CASE SUMMARY: A 45-year-old man with a right hand injury visited the hospital. A small bone fragment was identified using plain radiography. Lateral radiography revealed the fragment as lying over the volar aspect of the carpometacarpal (CMC) joint. Computed tomography revealed that approximately one-third of the CMC joint surface of the second metacarpal was damaged. We provisionally diagnosed an intra-articular fracture with significant CMC joint instability and performed open reduction and internal fixation. We made a dorsal longitudinal incision over the CMC joint between the second and third metacarpals. The dorsal ligament of the third CMC joint was torn. We thought it had been dislocated to the volar side and spontaneously reduced to that position. There are only few reports of volar dislocation of CMC joint fractures, particularly of the second and third metacarpals; our report is unique as our patient had an intact interosseous ligament between the second and third metacarpals. CONCLUSION: Although past reports have used a palmar approach, the dorsal approach is a good option for these cases.