Harvesting less than 1/3 fascicles of the ulnar nerve at the upper arm level is relatively safe. However, caution mast be used when consider taking more than 1/2 of the nerve in that severe and irreversible functional deficit cam occur.

• 上臂尺神经切取少于1/3比较安全,切取1/2虽有一定程度的功能恢复但仍有较严重的不可逆功能障碍,临床上应谨慎。