Effects of postoperative administration of celecoxib on postoperative pain management in patients after total knee arthroplasty. A randomized controlled study

INTERVENTION: Administration of celecoxib from 2 hours after TKA surgery Administration of celecoxib from 2 days after TKA surgery CONDITION: Osteoarthritis, Rheumatoid arthritis PRIMARY OUTCOME: VAS pain score on the second day after TKA SECONDARY OUTCOME: 1. Fentanyl consumption through PCA; 2. VAS pain score through the following day to the seventh day after surgery; 3. Range of motion of the knee joint; 4. Evaluation of sleep quality using VAS sleep disturbance; 5. Evaluation of sleep quality including sleep latency, sleep efficacy, nocturnal awakening, sleep depth, body motion and the time it takes to deep sleep monitored by SLEEPSCAN.; 6. The overall patient satisfaction during the period of medication.; 7. The overall evaluation by physician during the period of medication.; 8. Incidence rate of postoperative nausea and vomiting, and frequency of taking anti‐nausea pills; 9. Rescue analgesic consumption (a diclofenac sodium suppository) after the removal of PCA fentanyl. INCLUSION CRITERIA: 1) Patient can understand and comply with the protocol and has signed the informed consent document at screening. 2) Patient is over 20 years old at the time of informed consent. 3) Patient undergoing unilateral total knee arthroplasty 4) Patient undergoing TKA surgery in the morning 5) Patient assessed by principal and/or co‐investigator for eligibility as pain control with multimodal analgesia including femoral and sciatic nerve blocks and PCA fentanyl after TKA surgery.