Most fracture surgeries require general anesthesia or lumbar hard anesthesia, and a catheter is needed because lumbar hard anesthesia can lead to urine retention after surgery, and it is not convenient to control the amount of fluid and access without a catheter during surgery, so catheterization is needed for fractures. Because of the unpredictable duration of the fracture, some surgeries may take a long time and some may take a short time, and when the surgery takes a long time, it is inevitable that there will be blood loss in the operative area, and once there is blood loss in the operative area, a lot of rehydration or blood replenishment is needed. If there is no urinary catheter to control the patient’s urine output, it is possible that the patient may suffer from overfilling of the bladder, which may cause bladder damage.