Reconstruction of Segmental Mandibular Defects with Use of Avascular Fibula Grafts

Abstract

IntroductionFunctional and cosmetic defects involving the maxillofacial complex may result from traumatic injury, developmental deformities, infections, and iatrogenic injury. Reconstruction of large segmental defects with the use of vascularized free flaps has been considered the gold standard in recent years. There are many logistical and economic considerations with vascularized free flaps, and therefore the authors aim to discuss an alternative. After appropriate patient selection, the use of non-vascularized reconstruction techniques has been shown to be effective. The predominance of current literature centers on the use of iliac crest harvesting, with minimal description of using non-vascularized fibula. The authors will show that a non-vascularized fibula graft should remain a viable alternative in the reconstruction of mandibular defects. Case descriptionsPatient 1 is a 49-year-old male with no significant past medical history, who presented in 2016 with left mandibular fibrous dysplasia. The patient opted for a mandibular shave as initial treatment. However, the lesion recurred in 2019. A left hemimandibulectomy and arthroplasty were performed in March 2020. A vascularized fibula flap was planned in November 2020 to address the patient's ∼13cm defect. During the harvest of the fibula, the vascular pedicle was detached from the flap and determined to be unusable. All soft tissue was then removed from the fibula and secured to the custom fabricated plate and utilized as an avascular graft. The patient underwent an uneventful postoperative course and has shown all signs that the graft is completely viable.Patient 2 is a 52-year-old male with a significant past medical history of tonsillar cancer treated by chemotherapy and radiation in 2009. The patient presented in 2019 with swelling and trismus and was found to have right mandibular chronic osteomyelitis. This was initially treated with debridement and antibiotic therapy. However, the disease process continued, and definitive treatment was performed in June 2020 with a right hemimandibulectomy and arthroplasty. The defect was ∼12cm, and a vascularized fibula flap was selected as treatment in December 2020. However, during anastomosis, there was noted to be a lack of adequate venous flow, and the flap was unable to be salvaged. The fibula was prepped as an avascular graft and fixated to the custom plate. The patient experienced an uneventful postoperative course and has shown no signs of graft failure. DiscussionThe cases presented demonstrate the viability of using a non-vascularized fibula in the reconstruction of segmental mandibular defects. Benefits of using this type of graft include the customization of segments, ease of harvest, and high cortical volume. Literature supports the viability of fibula grafts for future implants.1 Fibula has shown resistance to resorption (∼7.2% after 1 year) in comparison to some reports of ∼50% graft loss with iliac crest. These features as well as the lower failure rates in defects greater than 9cm have popularized the use of vascularized fibula flaps in large mandibular defects. However, the original literature compares vascularized fibula flaps to iliac crest and not avascular fibula. Devireddy et al2 showed the viability of fibula grafts in non-irradiated defects of 6-10cm with consistent success. However, these 2 cases performed by the authors' institution have shown that, even in circumstances of greater than 9cm defects with radiation (Patient 2), an avascular fibula graft may be a viable alternative.