The Small Finger Reverse Ulnar Digital Artery Hypothenar Palmar Perforator Flap: An Anatomical Study With Clinical Examples.

Background: Local flaps are commonly used for reconstruction of digital soft-tissue defects. There remains a paucity of options available for small finger volar and dorsal soft-tissue defects distal to the proximal interphalangeal joint. The purpose of this study was to analyze perforators along the hypothenar palmar region arising from the artery of the ulnar side of the small finger as it comes off the superficial palmar arch for consistency and potential to be used for perforator-based flap reconstruction of soft-tissue defects and joint coverage of the small finger.

Methods: Four cadaveric upper extremities were injected with Microfil silicone injection compound. Dissection was performed from the superficial palmar arch to the ulnar digital artery of the small finger, and perforators were identified and analyzed for consistency and utility. Flap elevation was performed based on these perforators in a small finger reverse ulnar digital artery fashion.

Results: All cadaveric dissections showed a suitable perforator pattern along the hypothenar palmar region with a minimum of 5 perforators available from which to base a flap to address dorsal and volar defects of the small finger. Two clinical examples are presented confirming the viability and utility of this flap.

Conclusions: A detailed anatomic study with 2 clinical examples of this retrograde pedicle island flap is presented. The small finger reverse ulnar digital artery hypothenar palmar-based perforator flaps are a viable option with a reliable perforator pattern, providing a functional solution for reconstruction of soft-tissue defects and joint coverage of the small finger.