Intermuscular Connections in Anterior Brachium: its Implications in Radial Nerve Entrapment Neuropathy

Abstract

SUMMARY Background. Radial nerve (RN) is the largest branch arising from the brachial plexus, which supplies the extensor muscles and skin. This nerve may go for entrapment anywhere in its course. Muscular and tendinous variations have been implicated in various nerve entrapment syndromes along with other causes. The goal of this investigation was to observe for any connections between brachialis (BL) and brachioradialis (BR) muscles that may compress the radial nerve or its terminal branches. Methods. The study was performed on 84 formalin fixed human cadaveric upper limbs. Meticulous dissection in and around the cubital region was carried out to expose the BL, BR and the RN. The connections between the two muscles were noted and classified as muscular split type, muscular slip type and tendinous type. Results. Exploration of the cubital region revealed connecting bridges in 24 of the specimens (28.5% cases). 17 (20.2%) specimens exhibited split type, 6 (7.1%) specimens muscular slip type and 1 (1.2%) upper limb presented tendinous connection. In all these cases, the connecting bridge between the two muscles was oblique and crossed the RN. Conclusions. The results of our study reveal that various types of connections exist between the two muscles, contributing to the factors leading to radial nerve compression. Knowledge about this anatomical entity will be helpful in further understanding the aetiology of radial nerve compression and in devising effective treatment