Selective motor hyperreinnervation by using contralateral C-7 motor rootlets in the reconstruction of an avulsion injury of the brachial plexus

Abstract

✓ Brachial plexus avulsion injuries are a clinical challenge. In recent experimental studies the authors have demonstrated the high degree of muscle reinnervation attained when a C-4 motor rootlet was directly connected to the musculocutaneous nerve. This degree of reinnervation was attributed to the good chance that a muscle fiber can be reinnervated by a motor fiber when the number of regenerating motor neurons is increased and when competitive sensory fibers are excluded from the process. The authors present the first clinical case in which this phenomenon has been observed. This 26-year-old man, who was involved in an automobile accident, presented with an upper brachial plexus avulsion, for which he underwent operation 4 months later. The axillary and suprascapular nerves were directly surgically connected to the motor rootlets of the C-7 contralateral root by using two cables of sural nerve graft. Two years postsurgery, the patient was able to perform shoulder abduction of 120° and hold an 800-g weight at 90°. These results are encouraging, and in selected patients motor rootlet transfer might prove to be a useful surgical strategy.