Anterior interosseous nerve palsy. A review of 16 cases.

Sixteen patients with paralysis of the anterior interosseous nerve (AIN) in 19 limbs who were treated in a single unit were reviewed at a mean of 6.4 years (range 2-14 years) following onset of the paralysis. There was a high incidence of incomplete lesions (seven limbs) and of associated neurological lesions (six limbs) in the same or opposite upper extremity. Patients treated conservatively and with surgical exploration showed no difference in the time of onset of recovery, the time taken to achieve complete recovery or the extent of recovery. Those with incomplete lesions recovered well irrespective of the type of treatment. A distinct cause of compression of the AIN or visible changes in the AIN were seen in just three of the eight limbs that were explored. Surgery is indicated in complete lesions with no evidence of recovery for at least 6 months; incomplete lesions and other neurological signs are indications for conservative management in the first instance.