Combined Nerve Grafting and Myoelectric Orthosis Bionic Approach (MOBA) for Functional Restoration After Pan-Plexus Injury.

Abstract

A variety of approaches have been described to obtain a rudimentary grasp following traumatic pan-plexus injury in the adult. The aim of this report is to present a novel reconstructive algorithm based on the combination of reconstructive surgery and the fitting of a myoelectric orthosis (Myoelectric Orthosis Bionic Approach [MOBA]), to gain grasp function after a pan-plexus injury. A 44-year-old patient presented with a pan-plexus injury after a heavy branch fell on his right shoulder during forestry operations. After 5 months without spontaneous recovery, the patient underwent a brachial plexus exploration with intraoperative neuromonitoring, neurolysis of the C5 root and the upper trunk, and spinal accessory nerve transfer to the musculocutaneous nerve using a sural nerve graft. The myoelectric orthosis was initially employed for rehabilitation purposes, with a cutaneous electromyography (EMG) sensor positioned over the trapezius muscle to activate elbow flexion. Six months after the surgery, the patient presented Grade M1 pectoral muscle contraction, strong enough to be detected by cutaneous EMG. A second separate EMG sensor was placed over the pectoralis muscle to activate the finger flexion. As soon as the patient achieved Grade M2 active elbow bending (biceps muscle) with reinnervation signs at EMG, the sensor over the trapezius muscle was transferred to the biceps muscle to augment elbow bending. One year after surgery, the patient presented with active elbow bending (biceps muscle Grade M4), and finger flexion and extension using the myoelectric orthosis through the pectoral electrical signal, being able to hold and open. In addition, the patient presented Grade S2 proprioception and sensation in all fingers. This new treatment algorithm for pan-plexus injuries is further discussed. We believe the MOBA should be considered as an alternative treatment protocol after a pan-plexus injury.