Posterior forearm flap survival despite inability to identify the posterior interosseous artery: A clinical observation.

BACKGROUND

The posterior interosseous flap is commonly based on the posterior interosseous artery (PIA), but anatomical variability and intraoperative compromise may challenge its reliability. Alternative microvascular networks may contribute to flap survival beyond named axial vessels.

CASE: A 68-year-old woman presented with a dorsal hand defect with exposed extensor tendons following a grade V extravasation injury. A posterior interosseous artery (PIA)-based flap design was initially planned for coverage. Intraoperatively, however, the PIA pedicle could not be clearly identified. The flap was elevated with preservation of a wide (2cm) adipofascial pedicle. Postoperatively, limited distal epidermolysis (∼15%) occurred, while the majority of the flap remained viable and healed with conservative management.

CONCLUSION

This case suggests that posterior forearm flap survival may occur despite inability to identify the PIA, likely supported by capillary perforator and perforasome networks, although this mechanism cannot be directly confirmed in the absence of vascular imaging. Preservation of a wide adipofascial pedicle may facilitate ischemic tolerance and recovery.