Edie Benedito Caetano; Luiz Angelo Vieira; Vinicius Santos Bueno; Tulio Stefanin Volpiani; Giovanni Caetano Padilha & Vinicius Parron Keller

The objective of this study was to analyze the potential for compression of the median nerve (MN) caused by the bicipital aponeurosis (BA), the humeral and ulnar heads of the pronator teres muscle (PTM) and the arcade of the flexor digitorum superficialis muscle (FDS) in recently deceased cadavers. In this analysis 20 forearms of 10 recently deceased adult male cadavers were dissected. Dissections were performed in the institution's autopsy room or anatomy laboratory. The short and long heads of the biceps brachii muscle, as well as the BA were identified in all upper upper limbs. The BA received contribution from the short and long heads of the biceps brachii muscle. In 12 upper limbs the BA was wide and thickened and in 8 it was supported by the MN. In 5 upper limbs, the BA was wide but not very thick, and in 3 it was narrow and not very thick. We identified the existence of the FDS muscle arcade in all dissected upper limbs. A fibrous arcade was identified in 4 forearms, a muscular arcade in 14 and a transparent arcade in 2 upper limbs. In all of them, we recorded that the arcade was in contact with the MN. We recorded the humeral and ulnar heads of the PTM in all dissected upper limbs, with the presence of fibrous beams between them along their entire length. The MN was positioned between the humeral and ulnar heads of the PTM in all upper limbs. In eight upper limbs (40 %), we identified that the BA had thickness and contact with the MN with the potential to cause its compression. Compression between the humeral and ulnar heads of the PTM by the fibrous connections has the potential to cause nerve compression in all upper limbs (100 %). We did not identify that the anatomical structure of the FDS arcade had the potential to cause compression in the MN.

KEY WORDS: Musculoskeletal abnormalities; Nerve compression syndromes; Dissection in cadavers.

CAETANO, E. B.; VIEIRA, L. A.; BUENO, V. S.; VOLPIANI, T. S.; PADILHA, G. C. & KELLER, V. P. Compressive structures of the median nerve at the elbow. Int. J. Morphol., 42(3):623-630, 2024.