Distal posterior interosseous nerve syndrome.

Five patients presenting with chronic dorsal wrist pain and diagnosed as distal posterior interosseous nerve syndrome are reported. Clinical examination revealed point tenderness of the fourth extensor compartment. The symptoms were reproduced by extreme wrist extension in all patients and by extreme flexion in three of the patients. The pain was relieved in all patients by a selective lidocaine block of the terminal branch of the posterior interosseous nerve at the wrist joint. All the patients failed to respond to nonoperative treatment and underwent surgical exploration of the nerve. The operative findings were an enlarged nerve in three patients and adhesion of the nerve to the joint capsule in five patients. A 2 cm section of the nerve proximal to the extensor retinaculum was resected. Four of the five patients had excellent pain relief and returned to full asymptomatic activity. One patient had improvement in pain and was satisfied with the outcome. A diagnosis of distal posterior interosseous nerve syndrome should be considered if the usual sources of dorsal wrist pain are eliminated.