Extensor digiti minimi muscular flap: From a clinical case to an anatomical study

Abstract

We present a case report of a failed posterior interosseous flap with distal pedicle rescued by an extensor digiti minimi (EDM) island pedicle flap supplied by the posterior interosseous artery (PIOA) in reverse flow to cover a soft tissue defect in the hand of a 25-year-old man. We subsequently performed an anatomical study on 5 cadaver limbs to determine the EDM muscle's vascularization: it was segmental, multiple and came from the PIOA. The rotation arc reached the dorsal side of the metacarpophalangeal (MCP) joints, as well as the distal part of the thumb. The indications selected are the same as those of the distal pedicle flap: defect on dorsal side of the hand and MCP joints, coverage of carpal tunnel, failure of posterior interosseous flap. This study describes a new flap and adds to our understanding of the EDM muscle's vascularization.