The medial cord to musculocutaneous (MCMc) nerve transfer: a new method to reanimate elbow flexion after C5-C6-C7-(C8) avulsive injuries of the brachial plexus—technique and results

Abstract

The aim of this paper is to report on our ample experience with the medial cord to musculocutaneous (MCMc) nerve transfer. The MCMc technique is a new type of neurotization which is able to reanimate the elbow flexion in multilevel avulsive injuries of the brachial plexus provided that at least the T1 root is intact. A series of 180 consecutive patients, divided into four classes according to the quality of hand function, is available for a long-term follow-up after brachial plexus surgery. The patients enrolled for the study have in common a brachial plexus palsy showing multiple cervical root avulsive injuries at two (C5-C6), three (C5-C6-C7) and four (C5-C6-C7-C8) levels. The reinnervation of the musculocutaneous nerve is obtained via an end-to-end transfer from two donor fascicles located in the medial cord. The selected fascicles are those directed principally to the flexor carpi radialis, ulnaris and, to a lesser degree, the flexor digitorum profundus. Under normal anatomic conditions, they are located in the medial cord, and their site corresponds to the inverted V-shaped bifurcation between the internal contribution of the median nerve and the ulnar nerve. The technique has no failure and no complications when the hand shows a normal wrist and finger flexion and a normal intrinsic function. In case of suboptimal conditions of the hand, the technique has proved technically more challenging, but still with 67% satisfactory results. In the four-root avulsive injuries, however, this method shows its limitations and an alternative strategy should be preferred when possible. EMG analysis shows a reinnervation in both the biceps and the brachialis muscles, explaining the high quality of the observed results. Moreover, this technique theoretically offers the possibility of a "second attempt" at a more distal level in case of failure of the first surgery. This procedure is quick, safe, extremely effective and easily feasible by an experienced plexus surgeon. The ideal candidate is a patient harbouring a C5-C6 avulsive injury of the upper brachial plexus with a normally functioning hand.

Brachial Plexus Injuries in Sport Medicine: Clinical Evaluation, Diagnostic Approaches, Treatment Options, and Rehabilitative Interventions

“…In the large part of BPIs, the mechanism of lesion is mainly due to excessive traction along the peripheral nerve with axonal damage and a variable amount of neuroapraxia is commonly present [91]. In this case, the surgical approach is often delayed for 3-4 months.…”

“…Therefore, a "strategy" of priority in recovery is necessary. Restoring the function of elbow flexors and shoulder stabilizers is often considered as priority [91]. Several peripheral nerve procedures have been proposed during recent years.…”

Brachial Plexus Injuries in Adults: Guidelines and Management in our Experience

“…In upper BPIs, the aim is to re-innervate spinati, deltoid and biceps (Garozzo et al 2013;Ferraresi et al 2014;Garozzo 2017). We perform a spinal accessory to suprascapular (XI-SS) nerve transfer to regain spinati muscles.…”

Transferência de nervos (neurotizações) no tratamento das lesões traumáticas do plexo braquial

“…Assim, não se acarreta prejuízo importante para fletir o punho, no entanto parestesias provisórias ocorrem com frequência. 7 Outro procedimento que pode ser empregado para restaurar a flexão do cotovelo é a utilização de dois fascículos do nervo mediano, os quais originalmente se dirigem aos músculos flexores do carpo (flexor radial do carpo e palmar longo) e, nesse caso, são conectados ao ramo motor do músculo braquial, que também é do nervo musculocutâneo. Essas duas técnicas podem ser associadas (Figura 3).…”

“…B evitar o excesso de tensão caso os nervos intercostais sejam conectados diretamente com os do plexo braquial. 1,7 Nas lesões por avulsão de todas as raízes do plexo braquial, algum tipo de preensão precisa ser restaurado. Como a preensão pelo uso da mão é muito difícil de ser obtida, a cirurgia está voltada à reconstrução de uma pinça toracobraquial (para segurar objetos entre o braço e o tórax).…”