A retrospective study of the outcome of failed free flaps in lower limb reconstruction

Background: Microvascular free tissue transfer is a reliable reconstructive technique; however, these procedures carry inherent risks and are time-consuming. Flap failure can result in complete tissue loss and negatively impact functional outcomes. Methods: A retrospective review was conducted of all patients who underwent free flap reconstruction for acute open tibial fractures at the North Bristol NHS Trust Orthoplastic Unit between 2017 and 2021. Patients were categorized into two groups: flap success and flap failure. Results: A total of 678 patients were treated. Seventeen experienced flap loss (2.5%). Of these, 11 underwent successful secondary free flap reconstruction (64.7%), one received skin grafting, and one was managed conservatively with glycerine trinitrate (GTN) patches. Four patients proceeded to amputation (23.5%). Additionally, 11 patients underwent timely surgical intervention for vascular compromise, achieving 100% flap survival in this subgroup. Conclusion: Free flaps remain a gold standard for post-traumatic lower limb reconstruction. When free flaps fail, the amputation rate is 23.5%. The salvage rate for compromised free flaps is 52.4%. Patients who underwent salvage procedures or secondary free tissue transfer achieved functional outcomes comparable to those with primary flap success.