Use of intraoperative navigation for reconstruction of the C1 lateral mass after resection of aneurysmal bone cyst

Background Aneurysmal bone cysts (ABCs) are rare blood-filled cystic lesions that are found in the long bones and spine. Here, we present a case of an ABC found in the lateral mass and lamina of C1. Lesions in this area provide a surgical challenge because of its difficulty to access as well as its need for reconstruction. We describe a novel use of intraoperative navigation (ION) to assist in the placement of a C1 lateral mass titanium cage. Case Description An 18-year-old female patient presented with headaches and progressive neck pain. Imaging revealed a large cystic lesion involving the C1 lamina and right lateral mass. The patient underwent ION-assisted aggressive intralesional resection of the ABC and reconstruction of the C1 lateral mass with a static titanium cage, supplemented with posterior fusion from the occiput to C3. At 2-year follow-up, there was no evidence of recurrence and the hardware remained intact. Conclusions ION is a useful aid in assessing the extent of tumor resection and performing cage reconstruction of the C1 lateral mass.