Abstract:Objective: This study aims to explore the impact of the course of non-traumatic osteonecrosis of the femoral head (ONFH) on pain, functional recovery and quality of life after total hip arthroplasty (THA). Methods: Patients undergoing THA treatment at the First Affiliated Hospital of Nanjing Medical University from September 2022 to January 2024 due to terminal ONFH were retrospectively analyzed. Patients were divided into short course group (course of disease ≤3 years) and long course group (course of disease>3 years) according to the length of the course of disease. Compare the duration of surgery, hospital stay, total blood loss, preoperative and postoperative pain VAS scores, hip joint function Harris scores, Leg Length Discrepancy (LLD), Muscle Fat Infiltration (MFI), Pelvic Obliquity Angle (POA), and the incidence of postoperative complications between two groups of patients. Results:A total of 219 patients were included, 149 patients were in the short course group and 70 patients were in the long course group. Compared to the short disease duration group, patients in the long disease duration group exhibited longer operative times(P<0.05) and hospital stays (P<0.01), greater total blood loss (P<0.05), higher Visual Analogue Scale (VAS) pain scores preoperatively and at postoperative days 3, 5, and 1 month (P<0.05), and lower Harris hip scores at 6 weeks and 3 months postoperatively (P<0.05). Additionally, there was a greater preoperative LLD、MFI and larger preoperative and postoperative Pelvic Obliquity Angles in the long disease duration group(P<0.05). However, there was no significant difference between the two groups in pain VAS score 3 months after operation, hip Harris score 6 months after operation, leg length discrepancy and postoperative complications (P>0.05).