Superficial Communication Between Ulnar and Media Nerves in the Hand. An Anatomical Study

The objective of this study was to characterize the communication between ulnar and the median nerve in the superficial palmar region from a sample of mestizo-raced population predominant in Latin America. The superficial palmar regions of 53 fresh cadaveric specimens were evaluated, whom of which underwent necropsy procedure at the Institute of Legal Medicine. Dissection was performed by planes until visualizing the presence of the Communicating Branch (CB) between the digital branches of the ulnar nerve (UN) and the median nerve (MN). Qualitative and morphometric evaluation of the CB was carried out.A CB were observed in 82/ 106 (77.4 %) of the cadaveric specimens studied, of which, 38/53 (71.7 %) were bilateral, 15/53 (28.3 %) unilateral; this being a statistically significant difference (p <0.002). Oblique trajectory of the CB between the fourth and third common digital nerve was observed in 70 (85.4 %) specimens, while the CB with transverse trajectory was found in 7 (8.5 %) regions and in a plexiform form in 5 (6.1 %) cases. The length of the CB was 20.2 +/- 5.1 mm and the distances from the upper edge of the flexor retinaculum to the proximal and distal points of the CB were 25 +/- 6 mm and 37.4 +/- 8.3 mm respectively. The anatomical characteristics of the CB patterns, as well as the morphometric CB findings and their points of reference from the carpal flexor retinaculum, make it possible to delimit a safe area of surgical access in the first-fifth proximal of the palmar region, during the surgical approach of carpal tunnel syndrome.

Automated summary

The study aimed to characterize the communication between the ulnar and median nerve in the superficial palmar region of a mestizo-raced population predominant in Latin America. The presence of Communicating Branch (CB) between the digital branches of the ulnar and median nerve was observed in a significant number of cadaveric specimens, with variations in trajectory and length noted.