Estudio biométrico de la distribución de los ramos motores del nervio fibular superficial en el compartimiento lateral de la pierna en individuos brasileiros: implicancias clínicas y variaciones / Biometric study of the distribution of the motor branches of the superficial fibular nerve in the lateral compartment of the leg in Brazilian individuals: clinical implications and variations

El propósito del presente estudio fue conocer la distribución de los ramos motores del nervio fibular superficial (NFS) y de sus respectivas penetraciones en los músculos fibulares en relación al ápice de la cabeza de la fíbula, dividiendo el compartimiento lateral de la pierna en tres regiones a fin de hacer posible una visión más segura de sus correlaciones clínicas y quirúrgicas. A través de disección, se estudiaron 60 piernas pareadas de 30 cadáveres adultos, de ambos sexos, Brasileños, con edad promedio de 44,9 años, siendo 8 de sexo femenino y 22 del masculino. Después de la disección se registraron las distancias de los puntos de penetración de los ramos del NFS en los músculos fibular largo (mFL) y corto (mFC), localizándolos en los tercios proximal, medio o distal, según fuere el caso. Se observó que el mayor número de ramos penetraron en el mFL a nivel de la parte distal del tercio proximal de la pierna, mientras que en el mFC lo hicieron en las partes proximal y distal del tercio medio de la pierna. Los ramos motores para el mFL penetraban en el vientre muscular entre 48,06 y 141,56 mm, y los ramos para el mFC lo hicieron entre 163,34 y 209,67 mm del origen del nervio. No hubo diferencias estadísticamente significativas ni entre los lados derecho e izquierdo ni entre genéros. Independiente de las diferencias metodológicas entre los estudios disponibles, el detalle de la distribución nerviosa en este compartimiento, permitirá una mayor precisión en el momento de elegirse un área para colgajo de injerto autólogo y una menor chance de lesiones iatrogénicas durante cirugías de la región.

The purpose of the present study was to know the distribution of the motor branches of the superficial fibular nerve (SFN) and their respective motor points in the fibular muscles in relation to the apex of the head of the fibula, dividing the lateral compartment of the leg in three regions in order to make possible a safer view of your clinical and surgical correlations. Through dissection, 60 paired legs of 30 adult cadavers, of both sexes, Brazilians, with an average age of 44.9 years, 8 being female and 22 male, were studied. After the dissection, the distances of the motor points of the NFS branches in the fibularis longus (FLm) and brevis (FBm) muscles were recorded, locating them in the proximal, middle or distal thirds. It was observed that the largest number of branches penetrated the FLm at the level of the distal part of the proximal third of the leg, while in the FBm they did so in the proximal and distal parts of the middle third of the leg. The motor branches for the FLm penetrated into the muscular belly between 48.06 and 141.56 mm, and the branches for the FBm did between 163.34 and 209.67 mm of the origin of the nerve. There were no statistically significant differences between the right and left sides or between genres. Regardless of the methodological differences between the available studies, the detail of the nervous distribution in this compartment will allow a greater precision at the time of choosing an area for autologous graft flap and a lower chance of iatrogenic injuries during surgeries of the region.

Innervation of the extensor carpi radialis brevis and supinator muscles: Levels of origin and penetration of these muscular branches from the posterior interosseous nerve.

Dissections of 30 upper extremities from 15 skeletally mature cadavers were performed to identify the levels of origin and penetration of the innervation of the extensor carpi radialis brevis and supinator muscles. The humeroradial joint was used as a reference point for measurements. The most common pattern of extensor carpi radialis brevis innervation consisted of a single origin from the posterior interosseous nerve at the level of the humeroradial joint branching to penetrate the muscle at a level 30 mm to 60 mm distal to the humeroradial joint. The common innervation pattern of the supinator consisted of multiple origins from the posterior interosseous nerve at a level 0 mm to 30 mm distal to the humeroradial joint with multiple penetrations into the muscle at a level 10 mm to 40 mm distal to the humeroradial joint. Although there is variability in the innervation of the extensor carpi radialis brevis and supinator, our data provide useful patterns concerning the anatomy of these muscular branches from the posterior interosseous nerve. More complete knowledge of this anatomy allows safer approaches for the surgical exposure of the radius and improved diagnosis and localization of radial nerve lesions in the proximal forearm, with improved predictability of recovery of nerve injuries.