Outcomes in Fibula Free Flap Reconstruction for Treatment of Mandibular Osteonecrosis

Background: Osteoradionecrosis (ORN) of the mandible is an unfortunate possible sequela of radiotherapy for head and neck cancer. In advanced cases of ORN, mandibulectomy and free fibula flap reconstruction is required. We hypothesized that patients undergoing fibula free flap reconstruction of ORN mandibulectomy pose unique challenges and experience more complications than patients undergoing fibula free flaps after oncologic mandibulectomy. Methods: After IRB approval, we created a database of all free fibula flaps for mandible reconstruction from April 2005 through October 2019. Medical records were retrospectively reviewed for patient and surgical characteristics and post-operative outcomes. Results: 549 patients met inclusion criteria (173 ORN versus 376 non-ORN patients). Average age was 61.8±13.7 years. Mean follow-up was 35.0±29.5 months. ORN patients received more double-skin-island fibula flaps compared to non-OR patients (21.4% vs. 5.9%, p<0.001). Recipient artery other than the facial artery was utilized more commonly in ORN patients (41.0% vs. 19.1%, p <0.001). ORN patients had higher rates of delayed wound healing (27.2% vs. 17.3%, p=0.006) and surgical site infections (22.0% vs. 16.0%, p=0.058). Rates of flap loss, return to operating room, hematoma, operative time, and length of stay were similar between the groups. Conclusion: Mandibular reconstruction with fibula flaps for osteoradionecrosis is a more complicated procedure, often requiring two skin islands for both intraoral and extraoral resurfacing as well as utilization of unconventional recipient vessels due to previous history of neck dissection and radiotherapy. ORN patients also experience more complications such as delayed wound healing and infection compared to non-ORN patients.