Anterior Fusion using a Vascularized Fibular Graft for Cervical Kyphosis Associated with Neurofibromatosis Type 1: A Report of Two Cases with Long-term Follow-up

INTRODUCTION: Vascularized fibular grafts (VFG) in the cervicothoracic spine have been used for patients with progressive neurofibromatosis (NF) type-1-related kyphosis, but the long-term outcomes of VFG with NF-1 are not well described. We describe the long-term follow-up of two cases of cervical kyphosis related to NF-1 treated with VFG in the cervical spine. CASE REPORT: Case 1 was that of a 33-year-old man with a large neurofibroma at the back of his neck and an arteriovenous malformation at C2–7. The neurofibroma was resected by durotomy and intradural neurofibromas were extirpated through O-C6 laminectomy. Anterior fusion with VFG was performed 6 months later, and bone union was confirmed after 4 months. Cervical alignment was maintained with 50° kyphosis 15 years after the operation. The man suffered a subarachnoid hemorrhage 22 years after the operation. Case 2 was a 23-year-old woman with diastematomyelia at C6–T1 who was treated by anterior fusion with VFG at C4–T1. The diastematomyelia septum was resected through a C4–T1 laminectomy with simultaneous posterolateral fusion at C3–T2. Cervical alignment was maintained with 50° kyphosis 18 years later. The left vertebral artery ruptured and was embolized 10 years after the operation. CONCLUSION: Anterior fusion with VFG can achieve good bone union and maintains long-term alignment. However, it is important to watch for vascular events related to NF-1.