Enhancing postoperative analgesia in open orthopedic surgery through acupoint catgut embedding

The study protocol received approvals from the Ethics Committee of the Shanghai Fourth People’s Hospital (No. 2019112-001) and were registered at the Chinese Clinical Trial Registry (ChiCTR2000034008, https://www.chictr.org.cn/). The study included the patients aged 18–80 years, with an American Society of Anesthesiologists score of I or II, body mass index (BMI) between 18 kg/m2 and 30 kg/m2, and those who underwent open orthopedic surgery under general anesthesia at Shanghai Fourth People’s Hospital, School of Medicine, Tongji University from June 2020 to December 2021. The patients with central nervous system disease or mental illness, uncontrollable hypertension, diabetes mellitus, coronary heart disease or cardiac insufficiency, severe liver or kidney dysfunction, preoperative blood hemoglobin