The nail of lumbar fusion surgery will not be loosened in general, but it may occur under special circumstances. After lumbar spine fusion surgery, patients generally need to rest in bed for a short period of time, and carry out active rehabilitation training for all four limbs in bed. 1-2 months later, they can carry out activities on the ground under the protection of the support, but weight bearing is not allowed, and the vertebrae of lumbar spine fusion have basically completed the process of bony fusion in about 3 months, and the internal fixation such as the screws will be connected tightly with the adjacent tissues, and they will not be loosened under normal circumstances. However, if the patient goes down to the ground relatively early, premature rehabilitation training, or down to the ground in the process of training, premature weight-bearing, excessive bending and strenuous exercise, as well as elderly patients combined with osteoporosis, etc. can cause bony fusion part of the instability, resulting in the internal fixation of the friction repeatedly by the external force, the surrounding tissues on the internal fixation of the holding force decreases, there may be a screw loosening of the situation. Patients with lumbar spine fusion surgery should actively cooperate with the doctor’s treatment, and carry out rehabilitation training under the doctor’s guidance, and practice step by step, do not rush, so as not to cause adverse consequences.