Metacarpophalangeal joint dislocation.

Traumatic dislocation of the metacarpophalangeal joint is a relatively uncommon injury. The dislocation may be easily reducible (ie, simple) or require surgical intervention (ie, complex). The flexor tendons, lumbrical muscle, natatory ligament, and superficial transverse metacarpal ligament combine with the displaced volar plate to create a tight noose, preventing reduction. Surgical approach may be dorsal or volar; however, the radial digital nerve to the index finger is especially at risk through the volar approach. Reported complications include stiffness, arthritis, osteonecrosis of the metacarpal head, and even premature closure of the physis.