Numbness of the lower limbs after lumbar spine surgery may be caused by preoperative nerve injury, surgical trauma and so on. 1. Preoperative nerve injury: The purpose of lumbar spine surgery is to reduce the pressure of the spinal canal and restore the stability of the spine. If the patient has already had nerve compression before surgery, it is normal for the patient to still have numbness in the lower limbs after surgery, because it takes a long time to recover from nerve injury, and most of the patients need a recovery period of about 3~6 months to relieve the numbness symptoms. 2. Surgical trauma: Surgery itself is a kind of trauma to the organism, if the patient does not have the manifestation of nerve compression before the operation, and the numbness of the lower limbs occurs after the operation, it may be caused by mistakenly damaging the nerves during the operation or excessively pulling the nerve tissues; if there is no error in the operation, and the above mentioned symptoms occur after the operation, it is considered to be related to the adhesion of the nerve tissues after the operation. Numbness of the lower limbs after lumbar spine surgery may also have other causes, it is recommended to go to the hospital in time, improve the examination to clarify the cause of the disease, and then give targeted treatment or treatment under the guidance of the doctor.