Anatomical analysis of the radial nerve and arcade of Frohse in the cubital fossa using human cadavers.

Background: The radial nerve (RN) is a peripheral nerve that originates from the posterior bundle of the brachial plexus and carries C5-Th1 fibers. In the cubital fossa radial nerve divides into a superficial branch of the radial nerve (SBRN) and a deep branch of the radial nerve (DBRN). Next DBRN enters under the arcade of Frohse (AF) and changes its name to posterior interosseous nerve of antebrachii (PIN). The AF was first described in 1908 by Frohs and Frankel. It is the superior proximal part of the supinator muscle, which can be tendinous or membranous.

Materials and methods: Eight dissected upper limbs were examined to measure the distances and characteristics of the RN, DBRN, SBRN and AF, utilizing precise electronic caliper.

Results: The average distance from the point of branching of the RN into its terminal branches to the AF was 54.64 mm on average. In half of the cases DBRN divided before entering the AF. The average distance from the point of branching of the DBRN to the AF in these cases was 13.88 mm. The width of the AF averaged 8.60 mm. Five tendinous AF and three membranous AF were identified.

Conclusions: A thorough understanding of the anatomy of the radial nerve and its branches in the cubital fossa, as well as the AF, is important for the development of anatomy and may also contribute to the reduction of surgical complications during procedures in this area.