2.1. Study design and setting
This study was conducted at the following 3 hospitals in Sichuan, China: Sichuan Province Orthopedic Hospital, Meishan Traditional Chinese Medicine Hospital, and Sichuan Electric Power Hospital. All subjects gave their informed consent before they participated in the study. The study was conducted in accordance with the Helsinki Declaration for human studies and was approved by the Ethics Committee of Sichuan Province Orthopedic Hospital (KY2020-037-01). Only data from eligible patients were used to minimize bias in this research.