Introduction: The Metacarpophalangeal (MCP) joint of the thumb dislocation is rare, and buttonhole dislocation is a rarer type that is often irreducible by closed reduction due to the interposition of soft tissue. In this study, we aim to report the surgical management of a case of complex MCP dislocation of the thumb. Presentation of case: A 29-year-old male presented with pain and deformity of the left thumb after a fall. Clinical and radiographic examinations revealed a dorsal dislocation of the MCP of the thumb without associated fractures. Closed reduction attempts with local and under general anesthesia was performed but turned out unsuccessful. Open reduction was performed via a dorsal approach, and the volar plate was found blocking the dorsal side of the metacarpal. After the release of the trapped structures, the reduction was successful, and joint stability was achieved by soft tissue reconstruction. Discussion: Complex dislocations are generally caused by the interposition of anatomical structures, such as the volar plate. In such cases, a surgical approach is the only option to free the trapped structures and restore the anatomical configuration of the joint. Conclusion: Thumb MCP buttonhole dislocation is a rare occurrence but should be suspected when closed reduction fails. Open reduction via dorsal approach is a safe and effective option to overcome mechanical constraints and restore anatomical joint stability.
Aprilya et al. (Mon,) studied this question.