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Vascularized compared with nonvascularized fibular grafts for large osteonecrotic lesions of the femoral head.

BACKGROUND
Many authors have reported good results with the use of vascularized fibular grafts to treat large osteonecrotic lesions of the femoral head. To our knowledge, there have been no prospective case-controlled studies comparing the effectiveness of vascularized fibular grafting with that of nonvascularized fibular grafting for the prevention of progression and collapse of the lesion.


METHODS
Nineteen patients (twenty-three hips) with a large osteonecrotic lesion of the femoral head (Stage IIC in ten hips, Stage IIIC in two, and Stage IVC in eleven, according to the classification system of Steinberg et al.) underwent vascularized fibular grafting. This group was retrospectively matched according to the etiology, stage, and size of the lesion to a group of nineteen patients (twenty-three hips) who underwent nonvascularized fibular grafting during the same time period. A prospective case-controlled study of the two groups, with a mean duration of follow-up of four years, was then performed.


RESULTS
The mean Harris hip score improved for 70% of the hips treated with a vascularized graft and 35% of the hips treated with a nonvascularized graft (p < 0.05). At the time of the final follow-up, nine of the ten hips with a Stage-IIC lesion treated with a vascularized fibular graft had not collapsed whereas seven of the thirteen hips with a larger lesion (Stage IIIC or IVC) had collapsed. Three hips (13%) were converted to a total hip replacement. The mean dome depression measured 2.8 mm. In the group treated with a nonvascularized graft, five of the ten Stage-IIC hips had not collapsed and eleven of the thirteen hips with a larger lesion had collapsed. Five (22%) of the hips were converted to a total hip replacement. The mean dome depression measured 4.3 mm. The rates of radiographic progression and collapse were significantly lower and the mean dome depression was significantly less in the group treated with a vascularized fibular graft (p < 0.05).


CONCLUSIONS
Vascularized fibular grafting was associated with better clinical results and was more effective than nonvascularized fibular grafting for the prevention of collapse of the femoral head in a matched population with a Steinberg Stage-IIC or larger osteonecrotic lesion. The results of vascularized grafting were best when the procedure was used to treat precollapse lesions (Steinberg Stage IIC).