Acute distal radioulnar joint instability.

The distal radioulnar joint (DRUJ) is critical for pronosupination of the forearm and for upper extremity function in general. Because of its critical role in tool handling, some authors place the human DRUJ on par with the opposable thumb in the evolution of man. This seemingly simple cylindrical joint is stabilized by a complex network of soft tissue constraints, primarily components of the triangular fibrocartilage complex. Chief among these are the dorsal and palmar radioulnar ligaments. Any injury that disrupts these stabilizers, their balanced tension, or the bony congruity of the joint will have a major deleterious effect on hand function. Although they can occur in isolation, injuries causing acute DRUJ instability generally are associated with other trauma to the forearm-wrist complex. When managing these associated injuries, it is paramount to have a high index of suspicion for associated acute DRUJ instability. If the DRUJ is evaluated and stabilized in the acute setting, the more difficult clinical problem of chronic DRUJ instability can be avoided.