Penetration of the digital nerves by the common palmar digital arteries in human cadavers

To investigate the incidence of digital nerve loop penetration by digital arteries (neural loops) in cadaver palms and to classify these neural loops according to their topography and morphology.

In total, 121 palms (from 57 right and 64 left hands) were dissected from 70 preserved cadavers (50 male and 20 female; mean age 66.1 y).

Of the 121 palms, 98 had neural loops; 184 cases of neural loop were observed in total. The neural loops could be classified into 4 topographical types, according to their position relative to the digital arteries: ulnar (in which the ulnar proper palmar digital nerve of the finger is penetrated), radial (in which the radial proper palmar digital nerve of the finger is penetrated), common (in which the common palmar digital nerve of the finger is penetrated), and bridge (in which the neural loop is formed by connecting the ulnar and radial proper palmar digital nerves). The neural loops were also classified morphologically according to their size: form A (≥10 mm), form B (4.0-9.9 mm), and form C (≤3.9 mm). The mean lengths in these groups were 16.1, 7.2, and 3.0 mm, respectively, and the overall mean length of all neural loops was 10.8 mm.

It was confirmed that neural loops are a common occurrence in humans; hence, it is surprising that it is a little-known variation in the palm.