Outcomes of free vascularized fibular graft for post-traumatic osteonecrosis of the femoral head.

INTRODUCTION

Osteonecrosis of the femoral head (ONFH) can occur after traumatic injuries of the hip. Surgical treatment with total hip arthroplasty (THA) may not produce lifelong viability in younger patients. Free vascularized fibular graft (FVFG) has become a reliable method to delay or even avoid THA in this patient population by aiming to correct loss of viable bone through vascularized autologous bone transfer. The purpose of this study was to evaluate the longevity and outcomes of FVFG for traumatic hip injuries resulting in ONFH.

METHODS

We performed a retrospective review of our institutional database of patients who had undergone FVFG from 1980-2006 for post-traumatic ONFH and had a minimum follow-up of 5 years. Data collected included demographics, pre-operative Urbaniak ONFH staging, Harris Hip scores (HHS), SF-12 scores, and conversion to THA.

RESULTS

Seventy-two hips in 68 patients met inclusion criteria. Mean follow-up was 11.6 years (range 5.1-33.2 years). Etiology included femoral neck fracture in 36 patients (61%), hip dislocation in 7 (12%), trauma without fracture or dislocation in 11 (19%), and femoral neck nonunion in 5 (8%). The most common stage at presentation was stage IV (48 patients). Graft survival at final follow-up (mean 10.9 years) was 64%, with mean time to conversion to THA of 8.4 years in those that did not survive (36%). There was no difference between THA conversion rates in hips with pre-collapse (Stage I and II) versus impending or post-collapse (Stage III or IV) lesions (p = 0.227). In hips with surviving grafts at final follow-up, mean HHS improved from 56.7 to 77.3 (SD 24.57, range 69-93), a mean improvement of 20.6 (p < 0.001).

CONCLUSIONS

Our study reveals improvement in HHS in surviving FVFG and an acceptable overall THA conversion rate at mid to long term follow-up in Urbaniak stage I through IV hips. FVFG remains a viable option for treatment in younger patients with pre- and post-collapse (stage IV) ONFH lesions secondary to hip trauma.