The proximal ulnar perforator flap (PUPF) for hand digital reconstruction: an anatomical study

Degloving injuries of the fingers represent a reconstructive challenge. Even if poorly described in literature, the proximal ulnar perforator flap (PUPF), based on perforator of the anterior ulnar recurrent artery or directly on a perforator branch of the ulnar artery, meets the requested criteria for the ideal coverage. We performed a cadaveric study in order to clarify the anatomical basis and vascularization of the PUPF flap. Eight injected upper limb specimens were dissected for this study: perforators were followed down to their origin and classified in terms of number, length, diameters and distances between their emergence and specific pre-determined landmarks as the medial humeral epicondyle. At least one ulnar perforator in the proximal third of the forearm was identified in all the specimens. In 50% of the upper limbs, the perforator branch came directly from the ulnar artery, while in the 87.5% a perforator branch came from the anterior recurrent ulnar artery; in 3 out of 8 cases both perforator branches were described. Mean lengths of the perforator branch were 57.9 mm and 44.3 mm, respectively and the mean diameters measured at their origin were 0.99 mm and 1.17 mm respectively. Our data illustrate the consistency of at least one perforator branch from the proximal third of the ulnar artery, most commonly coming from the anterior recurrent ulnar artery. Considering our results, the PUPF could be a good alternative to the classical free flaps for the resurfacing of the finger defects.