The three main application options of the posterior tibial artery supra-ankle skin flap are: 1. covering the ipsilateral trauma in the form of an island flap; 2. covering the contralateral trauma in the form of an island flap; 3. covering the distant trauma in the form of a free graft. Advantages of the posterior tibial artery epicutaneous branch flap: 1, no or less damage to the main artery. 2, long vascular tip. 3, thin calf skin, etc.