Ulnar dislocation of the trapeziometacarpal joint: a case report.

An ulnar dislocation of the trapeziometacarpal joint is reported. On the posteroanterior radiograph of the wrist, the boney alignment appeared normal, and the only sign indicating a dislocation was a slight widening of the joint. By contrast, a true posteroanterior view of the trapezium clearly demonstrated the metacarpal ulnarly displaced. A late tendon reconstruction of the damaged palmar and medial ligaments produced a satisfactory result.