There are many conditions that can cause nerve necrosis, most of which are caused by the lack of timely treatment after injury. Once nerve necrosis occurs, like other tissues in the human body, there is no possibility of recovery. Even for peripheral nerves with the ability to recover, timely and effective treatment within 6 months is required to fully recover the nerve injury or only partially recover the function. Once the nerve injury is not treated in time for more than 6 months and nerve necrosis occurs, the nerve function and structure cannot be recovered, even through nerve reconstruction surgery, the recovery effect is very limited, so it is important to actively treat the nerve before necrosis occurs.