Resorption of fibula bone following mandibular reconstruction for osteoradionecrosis

The free fibular flap is commonly used for mandibular reconstruction because of its length, consistent blood supply, and relative ease of harvest. The bone has been shown to maintain mass over time, which confers a potential advantage over other osseous flaps. We know of no published papers on changes in height of fibular bone in patients treated for osteoradionecrosis (ORN). We measured the change in bony height over time as an indirect measure of bone mass. We identified 17 patients (mean age 65, range 49-80 years) who had had reconstruction with a free fibular flap for mandibular ORN. Of them, 10 had fixation with a reconstruction plate, and serial radiographs were available for inclusion in the study. Three measurements were taken on at least 2 rotational tomograms for each patient. Two observers recorded measurements at 25, 50, and 75% of the distance along the bone. Mean change in fibular height (mm) and percentage change were calculated. The interval between radiographs ranged from 5 months 4 days to 20 months 14 days. There was a reduction in fibular height in 8/10 cases, with a mean reduction of 1.5mm (range 2.6-0.3), or 11%. Our results show a moderate reduction in fibular height, which is comparable with a previously published series of patients without ORN who had reconstruction with miniplates. The stress shielding effects of reconstruction plates were less evident in our patients than in previously published material.