Background

Though MCP dislocations are less common than PIP/DIP dislocations, the joint is susceptible to dislocation due to joint shape/mobility and relatively loose collateral ligaments. The structural support of the MCP joint is provided by the volar plate and collateral ligaments. The most common mechanisms are high-energy axial loads or hyperextension of the joint. Dorsal dislocation of the joint is most common and results from disruption of the volar plate. Lateral dislocation may occur from collateral ligament tear.