Fever in the foot after root bone fracture surgery is caused by the following reasons: 1. Postoperative infection, which is one of the most common reasons, begins to appear 3-5 days after surgery, and the symptoms will gradually worsen, and will be accompanied by redness and swelling of the wound, heat in the skin of the foot, painful pressure, wound pain, discharge from the wound, as well as routine blood tests suggesting elevated white blood cells and neutrophils, and abnormal elevation of C-reactive protein. 2. Poor blood circulation is caused by the swelling after fracture surgery, thus producing compression of the surrounding small blood vessels and causing sterile inflammation caused by the accumulation of local inflammatory substances due to poor blood circulation, as well as the feeling of fever caused by abnormal peripheral nerve sensation due to ischemia and hypoxia, but the local skin temperature does not increase on examination. Fever in the foot after heel fracture surgery is an important symptom that needs to be actively treated, especially if the infection is not treated in time, which can easily form osteomyelitis.