1\. Patients between the ages of 40-75, who meet the indications for total knee arthroplasty(TKA) surgery, plan to undergo unilateral TKA surgery, can tolerate surgical trauma, and have no surgical contraindications;
2\. Patients who have good medical obedience and can cooperate to complete the evaluation of various indicators after the operation and continue to receive follow-up;
3\. There is no contraindications to combined spinal-epidural anesthesia;
4\. Agree to accept this trial and sign an informed consent form.
You may not be if
1\. Allergic to test drugs;
2\. Abnormal liver, kidney or heart function;
3\. People who have chronic pain symptoms in other parts of the body other than the knee joint;
4\. Patients with a history of multiple operations on the knee joint, or patients with abnormal anatomical structures;
5\. Patients who cannot perform early functional exercise after unconventional knee replacement or other systemic diseases;
