Medial Antebrachial Cutaneous Nerve: Anatomical Relationship with the Medial Epicondyle, Basilic Vein and Brachial Artery

Medial antebrachial cutaneous nerve (MACN) courses in the medial arm to provide sensory innervation to the medial forearm. Its anatomy has been partly described since data regarding its branching pattern and distances to adjacent landmarks are still lacking. The purpose of this study was to provide morphometric anatomy of the MACN with comparisons between sides and sexes. Ninety-six upper extremities from 26 males and 22 females were dissected. We found that up to 5 branches of MACN pierced the deep fascia with the maximum of 4 reaching the interepicondylar line (IEL). Presence of 2 and 3 branches was found in the majority of cases (> 80%). The distances from these branches to the landmarks varied considerably. In case of no branch, the mean distances to the medial epicondyle (ME) and brachial artery (BA) were approximately 1.5 cm while those to the basilic vein (BV) were 0.7 cm in both sexes. Regardless of the branching pattern, the MACN could pass over or close (within 0.5 cm) to the ME, BV and BA. Asymmetry in the branching pattern was found in 50% of specimens. Sex but not side differences were observed in some measurement parameters. These data are crucial for not only localizing the MACN during nerve block and graft harvest but also avoiding the nerve injury during surgical procedures. El recorrido del nervio cutaneo antebraquial medial (NCAM) proporciona la inervacion sensorial medial del antebrazo. Su anatomia se ha descrito en parte, porque los datos relativos a su patron de ramificacion y distancias a puntos de referencia adyacentes son insuficientes. El proposito de este estudio fue proporcionar datos morfometricos sobre la anatomia del NCAM, comparando entre lados y sexos. Se disecaron 96 miembros superiores de 26 hombres y 22 mujeres. Se encontro que 5 ramos del NCAM traspasaron la fascia profunda y llegaron 4 hasta la linea interepicondilar (LIE). Presencia de 2 y 3 ramos se encontro en la mayoria de los casos (>80%). Las distancias de estos ramos a los puntos anatomicos variaron considerablemente. En caso de ausencia de ramos, la distancia medial al epicondilo medial (EM) y arteria braquial (AB) fueron de aproximadamente 1,5 cm, mientras que a la vena basilica (VB) fueron 0,7 cm en ambos sexos. Independientemente del patron de ramificacion, el NCAM podria pasar sobre o cerca (a menos de 0,5 cm ) del EM, VB y AB. Asimetria en el patron de ramificacion se encontro en 50% de las muestras. Diferencias en algunos de los parametros de medicion se observaron segun sexo, pero no por lado. Estos datos son relevantes para localizar el NCAM durante el bloqueo del nervio y la toma de injertos, sino tambien para evitar la lesion del nervio durante los procedimientos quirurgicos.