Anatomical relationships between the deep palmar arch and the deep branch of the ulnar nerve.

The relationship between the deep palmar arch (DPA) and the deep branch of the ulnar nerve (dbUN) was analysed in 60 hands from 30 formaldehyde treated cadavers of adult individuals, of both sexes, with age ranging from 21 to 70 years, in the Division of Descriptive and Topographic Anatomy of the Federal University of São Paulo (UNIFESP). The arteries were injected with neoprene latex and dissections were performed under a magnifying glass. DPA was ventral to dbUN in 50% of the cases (type I) and dorsal in 45% (type). In type I dbUN crossed the arterial arch at the following levels: in the 4th interosseous space in 17.9% of the cases, in the 3rd interosseous space in 21.4% and in the 3rd metacarpal bone in 39.3%. In type II dbUN crossed the arterial arch in the 4th metacarpal bone in 25.9% and in the 3rd intersseous space in 37%. The relationship between the nerve and the palmar metacarpal arteries was also studied. The data obtained may be of practical use in the surgery of the palmar region.