Transfer of the Platysma Motor Branch to the Accessory Nerve in a Patient With Trapezius Muscle Palsy and Total Avulsion of the Brachial Plexus: Case Report

Abstract

To report on the successful use of a platysma motor nerve transfer to the accessory nerve in a patient with concomitant trapezius and brachial plexus palsy. A 20-year-old man presented with total avulsion of the right brachial plexus combined with palsies of the accessory and phrenic nerve. The patient was operated on 4 months after his injury. The accessory nerve was repaired via direct transfer of the platysma motor branch. The contralateral C7 root was connected to the musculocutaneous nerve, and the hemihypoglossal nerve was grafted to the suprascapular nerve. Two intercostal nerves were attached to the triceps long head motor branch. Within 20 months of surgery, the patient regained full reinnervation of the upper trapezius muscle. Elbow flexion scored M3+, and 30° active shoulder abduction was observed. Triceps reinnervation was poor. Platysma motor branch transfer to the accessory nerve is a viable alternative to reinnervate the trapezius muscle.