Analysis of the Risk Factors for Free Flap Necrosis in Soft Tissue Reconstruction of the Lower Limbs.

The risk of flap necrosis was significantly increased when the soft tissue defect was located in the proximal leg, the time from injury to flap coverage was >7 days, and the patient had a moderate-to-severe smoking history. These three risk factors have an increased influence on flap necrosis and have guiding significance in predicting flap prognosis.