Effect of Timing of Weight-Bearing Training on Postoperative Recovery After Hip-Preserving Surgery for Femoral Head Necrosis: A Retrospective Analysis

Background: There is currently no clear consensus regarding whether and when weight-bearing should be initiated following hip-preserving surgery for osteonecrosis of the femoral head (ONFH). This study aimed to investigate the impact of the timing of weight-bearing training on postoperative recovery outcomes in patients undergoing hip-preserving procedures for ONFH. Methods: A retrospective analysis was conducted on 42 ONFH patients (78 hips) who underwent hip-preserving treatment at the Fourth Medical Center of PLA General Hospital in 2023. Twenty patients (38 hips) were assigned to the control group (no weight-bearing for 8 months postoperatively, followed by partial weight-bearing), and 22 patients (38 hips) were assigned to the weight-bearing (WB) group (non-weight-bearing for 6 weeks postoperatively, then partial weight-bearing, progressing to full weight-bearing at 3 months). Radiographic progression and clinical outcomes were assessed over a minimum follow-up period of 16 months using the Association Research Circulation Osseous (ARCO) classification system. Results: At 8 months postoperatively, the control group had a significantly lower radiographic progression rate compared to the WB group ( P  < 0.05). However, by the final follow-up, no statistically significant difference in progression rate was observed between the two groups ( P  > 0.05). All progressed hips were classified as Japan Investigation Committee (JIC) type C2. Kaplan–Meier survival analysis showed superior hip survival in the control group at 8 months ( P  < 0.05), though the difference became nonsignificant over time ( P  > 0.05). Functional assessment revealed better hip range of motion in the control group at 8 and 16 months postoperatively ( P  < 0.05), while the WB group demonstrated superior Harris Hip Score (HHS), general health, social function, and health change scores at 16 months ( P  < 0.05). Conclusion: For patients with ARCO stage IIIA and JIC type C2 ONFH, postoperative weight-bearing should be avoided. In contrast, for patients with JIC types B and C1, appropriately timed weight-bearing training may enhance functional recovery.