Transfer of the Distal Terminal Motor Branch of the Extensor Carpi Radialis Brevis to the Nerve of the Flexor Pollicis Longus

Abstract

Transfer of the ECRB distal branch to the FPL is a viable option to reconstruct thumb flexion.

The Use of Nerve Transfers to Restore Upper Extremity Function in Cervical Spinal Cord Injury

“…Candidacy for nerve transfer surgery has yet to be definitively outlined. Our previous work [9,10,24], as well as contributions from others [6][7][8][11][12][13]25,26], suggest that results after nerve transfer surgery are promising, although studies [27,28] show variable outcomes. This emphasizes the need for careful and comprehensive preoperative patient evaluation using standardized functional assessments to better define surgical candidacy and outcomes of nerve transfer surgery in patients with SCI.…”

Results of wrist extension reconstruction in C5–8 brachial plexus palsy by transferring the pronator quadratus motor branch to the extensor carpi radialis brevis muscle

“…7,8 Preoperatively, direct PQ palpation to determine function preservation is not possible. However, because of palsy of the PT in C5-8 root injury, any active pronation should originate from the contraction of the PQ.…”

Tendon palpation during agonist contraction and antagonist co-contraction to assess wrist flexor and extensor muscle function

“…It is particularly relevant to determine which wrist muscles are functional in brachial plexus injuries and spinal cord lesion in the following situations: the need to correctly identify the roots involved in partial brachial plexus trauma; radial wrist extensors are paralyzed in extended upper-type lesions, whereas the ECU is consistently preserved; meanwhile, the FCR is consistently paralyzed in upper-type lesions affecting C5-C7, whereas the FCU is functional; and the PL is consistently innervated by the T1 root and preserved in C5-C8 root injuries; a few patients have wrist extension produced by finger extension; however, when grasping objects, their fingers do not extend further and their wrist drops, leading to decreased grip strength; such patients warrant a tendon or nerve transfer to strengthen their ECRB; when the FCU is being considered as an axon donor for reinnervation of the biceps [20], the anterior interosseous nerve [21], or the triceps [22]; when the FCU is being considered as a standard tendon transfer for thumb and finger extension [23]; before harvesting the FCU, PL integrity should be demonstrated, as the FCR is routinely paralyzed in extended upper-type lesions of the brachial plexus; in the absence of a strong FCU, wrist extension should be reconstructed by transferring the pronator quadratus motor branch to the ECRB motor branch [5], or to a free gracilis; we do not recommend transferring the flexor digitorum superficialis motor nerves to wrist extensors in extended brachial plexus palsy cases [24]; in lower-type injuries of the brachial plexus or in spinal cord injuries, the ECRL tendon is used to reconstruct finger flexion; before removing the ECRL, ECRB function must be demonstrated in order to preserve wrist extension [25]; also, a distal terminal branch of the nerve to the ECRB can be used to reinnervate the flexor pollicis longus or the anterior interosseous nerve [26,27]; in lower-type injuries of the brachial plexus and in midcervical spinal cord trauma, the nerve to the supinator muscle can be transferred to the posterior interosseous nerve to reconstruct thumb and finger extension; however, assessment of supinator muscle function is difficult. The nerve to the supinator shares the same spinal cord level innervation as the ECRB; consequently, if the ECRB is functional, the nerve to the supinator should also be preserved [28].…”