The vascularized fibular graft in precollapse osteonecrosis: is long-term hip preservation possible?

Background: Osteonecrosis of the femoral head (ONFH) is a debilitating condition affecting primarily young patients. Free vascularized fibular grafting (FVFG) may provide a durable means to preserve the femoral head. When used in the precollapse stages of ONFH, this treatment may alter the course of disease.

Questions/purposes: We asked: (1) In what percentage of patients does FVFG preserve the femoral head beyond 10 years? (2) When long-term preservation is not achieved, what is the duration of femoral head preservation? (3) Do demographic or etiologic factors predict FVFG survivorship? (4) What long-term improvements in function and activity can be anticipated?

Methods: We retrospectively reviewed 61 patients (65 hips) who underwent FVFG for precollapse ONFH. We calculated graft survivorship, SF-12 scores, activity levels, and Harris hip scores. Minimum followup was 10.5 years (mean, 14.4 years; range, 10.5-26 years). Results Forty-nine of 65 hips (75%) had surviving FVFG for at least 10 years. At last followup, 39 of 65 hips (60%) had surviving FVFG, with a mean graft survival time of 15 years (range, 10.5-26.1 years). Twenty-six of the 65 hips with FVFG (40%) underwent conversion to THA at a mean of 8 years postoperatively. Demographic factors, lesion size, additional procedures, and low preoperative function were not associated with changes in graft survivorship. Pain and function were similar in patients with surviving FVFG and patients who had conversion to THA. Patients with surviving FVFG were more likely to engage in impact sports or active events than were patients who had conversion to THA.

Conclusions: When patients with precollapse ONFH undergo FVFG, the majority have preservation of the hip lasting for greater than 10 years with low levels of pain and reasonable function. In patients who ultimately undergo conversion surgery to THA, the mean duration of hip preservation before conversion is 8 years. We continue to use FVFG for treating patients younger than 50 years with symptomatic, precollapse ONFH.

Level Of Evidence: Level IV, therapeutic study. See Instructions to Authors for a complete description of levels of evidence.