Cranial repair surgery is a very routine, common and classic procedure in neurosurgery. Many patients undergo craniotomy due to trauma or cerebral hemorrhage or some intracranial diseases, and after decompression of the bone flap, cranial defects are left behind, which require timely cranial repair surgery. The material that is widely used in hospitals around the world for skull repair surgery is titanium mesh material. Many patients may know some defects or shortcomings of titanium mesh, for example, the histocompatibility of titanium mesh is not too good, and infection and rejection may occur after surgery; for example, the heat insulation of titanium mesh is not good, and it may be sensitive to the external hot and cold environment after surgery, resulting in many discomforts; for example, titanium mesh as a metal will affect the radiation projection, which will affect the acceptance of CT, MRI and other medical examinations after surgery; and for example, the hardness of titanium mesh is not good. There are also many problems such as the titanium mesh is not too hard, so if it is subjected to external force, it will be easily deformed by depression, etc. So is it really that easy to concave the titanium mesh skull repair surgery? Titanium mesh cranial repair surgery, if no special circumstances occur after surgery, pay attention to protection, generally will not be dangerous, but if once subjected to strong external impact, then his hardness is not too high, the chances of deformation and concavity are still very large, we have seen many such examples in the clinic. For example, there is a patient in Jiangxi, he is also using too late for road repair, 6 years of time, no problems. But recently, he was hit by another impact on the area covered by the titanium mesh, and the deformation and depression occurred, and the scalp was obviously depressed by a small piece, causing him a lot of discomfort, frequent headaches and dizziness. The titanium mesh was removed and PEEK was placed in the skull, and he had a very good result. Another example is a 26-year-old young man who also underwent titanium mesh repair surgery, but later on, during a basketball game, the basketball hit his head, which also had a deep depression. Therefore, it is not recommended to use titanium mesh for skull repair surgery because it is easily deformed by external force.