Comparison of free vascularized iliac bone flap grafting versus pedicled iliac bone flap grafting for treatment of osteonecrosis of the femoral head

Summary Background A high incidence of osteonecrosis of the femoral head (ONFH), a commonly seen and intractable disease, has been reported. This retrospective study aims to compare the reconstructive outcomes by free vascularized iliac bone flap (FVIBF) with those by vascularized pedicled iliac bone flap (PIBF) to determine which one is better for ONFH patients. Methods From January 2010 to December 2017, 35 patients (40 hips) were treated by PIBF grafting, and 32 patients (36 hips) were treated by FVIBF grafting. The two groups were then compared in terms of the preoperative baseline conditions, intraoperative data, and postoperative Harris hip score (HHS). Results In the PIBF group, the operating time was significantly longer than the FVIBF group (195.5 ± 26.4 vs 147.2 ± 17.7 min, respectively), and the intra-operative blood loss was significantly heavier (330.0 ± 63.9 vs 240.3 ± 37.5 ml, respectively). Meanwhile, the recipient site morbidity rate in the PIBF group outnumbered that in the FVIBF group (27.5% vs 8.3%, respectively), and a higher rate of lateral femoral cutaneous nerve (LFCN) injury was observed in the PIBF group than in the FVIBF group (27.5% vs 8.3%, respectively). No difference was found in postoperative HHS score between the two groups. In both groups, the recovery effect of the patients in stage II was better than that in stage III. Conclusion While maintaining a similar clinical effect, the FVIBF grafting exhibited a distinct advantage over the PIBF grafting, in terms of shorter operative time, less blood loss, and lower risk of LFCN injury.