Lunotriquetral sprains.

Injuries to the ulnar side of the carpus have not been well defined. Lunotriquetral (LT) sprains have only recently been described and are often unrecognized. They usually occur from hyperextension: and twisting of the wrist. Symptoms include pain, weakness, limitation of motion, and a "click" with lateral motions. The sprain may be associated with dorsal subluxation of the ulnar head and supination of the carpus. Physical examination discloses point tenderness, laxity, and often a snap over the LT joint. Dorsopalmar manipulation of the triquetrum on the lunate demonstrates crepitus and laxity. A radiocarpal arthrogram is helpful in confirming the diagnosis. Palmar-flexion instability patterns represent a more extensive continuation of this injury, which then may be termed an LT dissociation. Treatment with adequate immobilization for acute injuries appears to be useful if the diagnosis is established early. Chronic sprains may require stabilization of the LT joint by ligament repair, reconstruction, or LT fusion. Associated injuries, such as carpometacarpal (CMC) or hamulus fractures, have been noted. Results of treatment have varied considerably and depend in part on the severity and chronicity of the condition at the time of recognition.