The extraneural and intraneural arterial anatomy of the ulnar nerve at the elbow.

The purpose of this report was to investigate the vascular anatomy of the ulnar nerve at the elbow with a technique of combined India ink and latex injection followed by nondissection chemical debridement. Twenty-two fresh human cadaveric arms were injected with India ink to stain the intraneural microcirculation followed immediately by latex injection and chemical debridement for study of the extraneural vascularization. After clearing with a modified Spalteholtz technique, the intraneural blood supply was studied in 10 of the specimens. The findings demonstrated a consistent but segmental extraneural and intraneural vascular supply from the superior ulnar collateral, inferior ulnar collateral, and posterior ulnar recurrent arteries. No identifiable direct anastomosis was seen between the superior ulnar collateral and posterior ulnar recurrent arteries in 20 of 22 arms. The inferior ulnar collateral artery provided the only direct vascularization to the nerve in the region just proximal to the cubital tunnel. Although the clinical importance of maintaining specific arterial sources to the ulnar nerve has not been determined, these anatomic findings indicate that the arterial contribution from the inferior ulnar collateral artery may be more important than appreciated previously.