The distribution of the radial and musculocutaneous nerves in the brachialis muscle

Abstract

Few have examined the distribution of the radial nerve branch to brachialis, generally believed to be motor, within the muscle. We examined the right brachialis muscles of six dissecting room cadavers and found that four received a supply from the radial nerve. The radial nerve branch(es) supplied the inferolateral region of the muscle and was overlapped proximodistally and mediolaterally by the intramuscular branches of the musculocutaneous nerve, which lay on a more superficial plane. The results have implications for the anterolateral approach to the humerus for orthopedic surgery. Anterior splitting of the muscle will almost certainly damage the most lateral branches of the musculocutaneous nerve.

Subbrachial approach to humeral shaft fractures: new surgical technique and retrospective case series study

“…After the motor branch has been separated, the musculocutaneous nerve goes out of the brachialis muscle and enters the intermuscular sulcus. [19][20][21][22] With the anterior approach, the musculocutaneous nerve can be damaged during operative manipulation. Considering that the nerve is placed near or within the operative field, the best way to avoid damage is to move its covering structures away to expose the whole nerve in the operative field.…”

“…When isolating the muscle distally the musculocutaneous nerve stays by the brachialis muscle. [20][21][22] There are conflicting opinions about treating the radial nerve during the surgery; however, most authors agree that if the radial nerve is not exposed, there is a risk of iatrogenic injury. 4,10,14,27,28 The occurrence of an intraoperative lesion of the radial nerve is also emphasized with the anterolateral and anterior approaches; injury rates of 5%-20% have been recorded.…”

“…20,21 It comes from the radial and the musculocutaneous nerves, with some variations in the involvement of those nerves. The innervation from the musculocutaneous nerve is 70%-90% and that from the radial nerve is 10%-30%.…”

Doble Inervación del Músculo Braquial en la Población Chilena

“…La presencia de ramos del nervio radial que abordan el músculo braquial se haya también descrita en numerosos trabajos científicos (Ip & Chang, 1968;Yan et al, 1998;Ji & Chung, 2002;Mahakkanukrauh & Somsarp, 2002;Spinner et al, 2003;Pacha Vicente et al, 2005;Blackburn et al, 2007;Park et al, 2007;Frazer et al, 2007;Oh et al, 2009;Prakash et al, 2009). Estos trabajos, sin embargo, difieren en los resultados encontrados, reportando entre un 67% y un 100% los casos la doble inervación del músculo braquial.…”

“…La inervación de este músculo está dada por el nervio musculocutáneo como lo describen algunos textos anatómicos (Feneis & Dauber, 2000;Moore & Dalley, 2006; Latarjet & Ruiz Liard, 2008;Gray & Standring, 2005). Sin embargo, textos anatómicos antiguos (Cloquet, 1830; Hirschfeld, 1866; Testut, 1884; Le Double, 1897; Poirer et al., 1901; Testut & Latarjet 1944;Lewis, 1944; Brash & Jamieson, 1949;Lockhart & Hamilton, 1959;Williams & Warwick, 1975) y modernos (Jenkins & Hollinshead, 2002; Rouvière, 2007) dan cuenta de una doble inervación del músculo braquial caracterizada por la contribución del nervio radial en la inervación de este músculo, pero sin detallar su frecuencia de aparición.La presencia de ramos del nervio radial que abordan el músculo braquial se haya también descrita en numerosos trabajos científicos (Ip & Chang, 1968;Yan et al, 1998;Ji & Chung, 2002;Mahakkanukrauh & Somsarp, 2002;Spinner et al, 2003;Pacha Vicente et al, 2005;Blackburn et al, 2007;Park et al, 2007;Frazer et al, 2007;Oh et al, 2009;Prakash et al, 2009). Estos trabajos, sin embargo, difieren en los resultados encontrados, reportando entre un 67% y un 100% los casos la doble inervación del músculo braquial.…”