Long-term results of thenar muscle reanimation after contralateral C7 root transfer in repair of total brachial plexus avulsion injury

Abstract

Objective To evaluate the long-term functional recovery of thenar muscles following contralateral C7 transfer in total brachial plexus root avulsion injuries. Methods Five patients treated with contralateral C7 transfer to the median nerve for brachial plexus root avulsion were follow-up for 24 to 118 months.Affected limb function,electrophysiologic evidence of recovery and the motor and sensory function of the recipient nerves in the affected limb were evaluated. Results Varied degrees of functional restorations were achieved in these 5 patients ( 2 children and 3 adults).The strength of abductor pollicis brevis (APB) muscle was M2 in four patients and M1 in one patient.The incomplete interference pattem in the APB muscle was detected by electromyogram (EMG) in two patients,while few motor unit potential (MUP) was detected in three patients.Sensory recovery reached S3 in 4 cases and S2 in one case. Conclusion Contralateral C7 nerve root transfer to the median nerve can result in thenar muscle reinnervation to certain extent in patients with brachial plexus total avulsions. Key words: Brachial plexus; Nerve transfer; Follow-up studies; Thenar muscle; Root avulsion