A rare anatomical variation of the Berrettini anastomosis and third common palmar digital branch of the median nerve.

Variations in the origin and distribution of Berrettini anastomosis between the digital branches of the ulnar and median nerves exist and are well described in the literature. During regular dissections by medical students, we encountered a rare variation in the left hand of an approximately 50-year-old male cadaver. Berrettini anastomosis connecting the third common palmar digital branch of the median nerve with the fourth common palmar and proper palmar digital branches of the ulnar nerve presented a plexiform nature. This communicating branch and the third common palmar digital branch of the median nerve were perforated by the superficial palmar arch. Further, the superficial palmar arch was incomplete, and it was solely formed by the superficial branch of the ulnar artery. The unusual relationship of Berrettini anastomosis with the superficial palmar arch is very rare, and knowledge about such a variation is important when performing carpal tunnel release, flexor tendon surgery, and Dupuytren's fasciectomy and when dealing with arterial repairs and vascular graft applications in the hand.