Outcomes of free vascularized iliac bone flap for severe traumatic osteonecrosis of femoral head in young adults.

PURPOSE
To explore the clinical and radiological effects of the free vascularized iliac bone flap (FVIBF) based on deep iliac circumflex vessels for Association Research Circulation Osseous (ARCO) stage 3 traumatic osteonecrosis of the femoral head (TONFH) in young adults.


METHODS
From February 2017 to August 2020, a total of 29 (29 hips) TONFH patients with ARCO stage 3 were enrolled in this study. Following the FVIBF standard procedure, the necrotic area of the femoral head was removed and a free vascularized iliac bone flap was harvested and grafted. X-rays were performed at 1, 3, 6, 9, and 12 months and every 6 months thereafter postoperatively for evaluation of the degree of femoral head collapse. The Beijing University of Chinese Medicine X-ray Evaluation Method (BUCMXE) was used to evaluate the hip preservation effects based on anteroposterior hip radiographs. Hip functions were evaluated using the Harris hip score (HHS) every 6 months and annually after 24 months, and the quality of life was assessed using the SF-36 questionnaire at 18 months postoperatively.


RESULTS
The mean follow-up time was 30 months (range 12-54 months). None of the patients was lost to follow-up, and the wounds healed primarily without infection and deep venous thrombosis of lower limbs. The HHS at 12 months postoperatively was significantly improved than that before surgery (83.4 ± 7.4 vs. 64.8 ± 14.1; p < 0.05). The BUCMXE radiographic score at 12 months postoperatively did not reveal any significant differences in femoral head morphology and osteonecrotic lesion, when compared to preoperation. The SF-36 questionnaire showed significant improvements in social functioning, role physical, bodily pain, and general health (p < 0.05). However, eight patients had varying degrees of femoral head collapse after surgery, and only one of them underwent THA due to pain and collapse aggravation. BUCMXE-Osteoarthritis scores showed that 23 hips were stable and six hips were advanced, among which five hips staged ARCO 3B and one staged ARCO 3A preoperatively, with statistically significant differences (p < 0.05).


CONCLUSION
Although some patients showed no improvement of radiological outcomes, most patients with severe TONFH could still benefit from the FVIBF procedure. Further studies should attempt to improve this surgical procedure and explore its long-term efficacy.