Keystone perforator island flap: A simple and reliable solution for small limb defects with bone or hardware exposure—A prospective case series

Soft-tissue defects of the limbs with exposed bone or orthopedic hardware remain a major reconstructive challenge, particularly in patients in whom free tissue transfer is not feasible. The keystone perforator island flap (KPIF) provides a simple, reliable, and resource-efficient local flap option based on perforator preservation and tension redistribution, and can be safely performed under local anesthesia. This prospective clinical study included 12 patients (8 men and 4 women) with small-to moderate-sized limb soft-tissue defects with exposed bone or orthopedic hardware who underwent reconstruction using the KPIF between January 2021 and June 2025. Preoperative perforator mapping was performed using a handheld Doppler, and all dominant perforators were preserved during flap elevation. Wound beds were prepared using preoperative negative pressure wound therapy (NPWT) for contaminated or poorly granulating wounds. KPIF reconstruction was performed predominantly under epinephrine-free local anesthesia with or without tumescent infiltration, following a standardized surgical protocol. Complete flap survival was achieved in all patients with small defects (7/7), whereas one patient in the moderate defect group (1/5) developed minor distal partial flap necrosis that healed conservatively without additional surgical intervention. Most procedures were performed under epinephrine-free local anesthesia, with no need for conversion to general anesthesia and no anesthesia-related complications. No total flap loss, postoperative infection, or donor-site morbidity was observed. The mean operative time was 45 min and all donor sites were closed primarily. During a mean follow-up of 6 months, all patients achieved stable soft-tissue coverage with favorable patient-reported functional and aesthetic outcomes (mean patient-reported outcome measures-visual analog scale (PROM-VAS): 8.6 and 8.4 for small defects; 7.9 and 7.8 for moderate defects, respectively). KPIF provides reliable coverage for small limb defects with exposed bone or hardware, and can be safely and effectively performed under local anesthesia, offering a practical alternative to microsurgical reconstruction in appropriately selected patients.