Total Hip Arthroplasty Following Failure of Free Vascularized Fibular Graft

BACKGROUND: Many treatments for osteonecrosis of the femoral head, including the use of a free vascularized fibular graft, have been advocated in an attempt to delay the need for hip arthroplasty. The purpose of this study was to document the clinical and radiographic results of total hip arthroplasty performed following failure of a free vascularized fibular grafting procedure. METHODS: Twenty total hip arthroplasties in eighteen patients who had previously undergone a free vascularized fibular grafting procedure for the treatment of osteonecrosis were retrospectively reviewed. A straight-stem femoral component was used in twelve hips, a tapered femoral component with removal of residual fibular graft was used in five hips, and a tapered stem without graft removal was used in three hips. The twelve hips with a straight-stem femoral component and previous vascularized fibular grafting were compared with thirty-six osteonecrotic hips in thirty other patients who had undergone total hip arthroplasty but had not had previous free vascularized fibular grafting. The radiographic outcomes with respect to initial femoral component alignment and subsequent migration and the clinical outcomes were compared. RESULTS: Analysis of the immediate postoperative radiographs demonstrated significantly improved alignment of the femoral component when a high-speed burr had been used to remove residual fibular graft (p = 0.001), although doing so did significantly increase both the intraoperative blood loss (p = 0.017) and the operative time (p = 0.0002). There was no significant difference in the amount of migration of either the acetabular or the femoral component between the control and study groups at the time of the most recent follow-up. When comparing patients with or without a previous free vascularized fibular graft, the mean postoperative scores at three years were significantly worse in patients who had undergone a previous free vascularized fibular graft (p = 0.03). One revision occurred in the study group at seventy-two months due to acetabular wear, and one revision occurred in the control group at 108 months due to aseptic loosening. CONCLUSIONS: This study raises concern that the outcome of total hip arthroplasty in patients who previously underwent a free vascularized fibular graft for the treatment of osteonecrosis of the femoral head may be worse than that in patients without previous free vascularized fibular grafting. The intraoperative use of a high-speed burr can improve the alignment of the femoral component by removing more of the residual graft. However, this technique does increase intraoperative blood loss and operative time. LEVEL OF EVIDENCE: Therapeutic Level IV. See Instructions to Authors on jbjs.org for a complete description of levels of evidence.