Transfer of a branch of the anterior interosseus nerve to the motor branch of the median nerve and ulnar nerve.

OBJECTIVE: To explore the applied microsurgical anatomy of the intrinsic hand muscles and related nerves after nerve injuries in the wrist region and to report the results of new technique for the restoration of motor functions of the injured nerves.

METHODS: Seven fresh forearm amputation specimens were employed for studying the anatomical and microsurgical characteristics of the relevant tissues. Transfer of the pronator quadratus branch of the anterior interosseous nerve (PBAN) to the recurrent branch of the median nerve (RBMN) and the deep branch of the ulnar nerve (DBUN) to restore the functions of the intrinsic hand muscles was performed on 20 patients from April 1979 to January 1994. Fourteen patients were followed up for 3-9 years with an average of 5 years and 8 months.

RESULTS: The RBMN, DBUN and PBAN had approximately the same lengths of diameter and similar amounts of fascicles and nerve fibers so that after nerve transfer, the possibilities of misdirected connections were greatly reduced. In the latest follow-up, normal muscle strength was regained in 3 patients, grade VI strength in 6, grade III strength in 3 and grade II strength in 2.

CONCLUSION: This new technique is able to restore the intrinsic hand muscular functions after median or ulnar nerve injuries in the wrist region or distal forearm.