Preparation procedure: first, establish the individualized ankle model according to the patient's ankle CT scan data and then prepare the implant model; second, conduct surgery rehearsal and place the implant model in the ankle model for observation; third, after confirmation, use titanium alloy in the 3D printing machine to prepare the individualized metal implant, which is in line with the Chinese National Standard "Wrought titanium and titanium alloy for surgical implants" (GB/T 13810-2007); fourth, implant the individualized metal implant into the bone defect area after sterilization.