The reanimation of the elbow functions in avulsive injuries of the upper brachial plexus using the medial cord transfer: nuances of the technique and update.

OBJECTIVES

Report on a new transfer for the reinnervation of biceps and brachialis muscles after multilevel avulsive injuries of brachial plexus provided at least T1 is viable: the Medial Cord to Musculocutaneous (MCMc) and its variant, the Medial Cord to anterior Upper Trunk (MC-aUT). The MC-aUT is indicated in agenesia of musculocutaneous nerve and when a residual function in the biceps is present. The MCMc transfer would be unfeasible in the former and contraindicated in the latter.

METHODS

Three hundred and five consecutive patients, classified according to the quality of hand function, are available for a long-term follow-up after reconstructive surgery. They had multiple cervical root avulsive injuries at two (C5-C6), three (C5-C6-C7) and four (C5-C6-C7-C8) levels. The reinnervation was obtained via an end-to-end transfer from two donor fascicles located in the medial cord (MC) and aimed at the flexor carpi ulnaris or the flexor digitorum profundus.

RESULTS

These transfers have no failures and no complications when the hand shows a normal function. In the case of suboptimal conditions of the hand, the technique is more challenging, but still has many satisfactory results. In the four-root avulsive injuries, on the contrary, strong limitations suggest that different strategies should be preferred. EMG shows a reinnervation in both biceps and brachialis muscles and this accounts for the quality of results. Tendon transfers for wrist and finger dorsiflexion, when required, remain unencumbered.

DISCUSSION: The procedures are safe, effective and easily feasible. The ideal candidate has a C5-C6 injury and a normal hand function.