Postoperative intracranial migration of a C2 odontoid screw: A case report and literature review.

Surg Neurol Int. 2019 Sep 10;10:173. doi: 10.25259/SNI_245_2019. eCollection 2019.

Ankush Chandra, Seong-Jin Moon, Blake Walker, Emre Yilmaz, Marc Moisi, Robert Johnson

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Abstract

Background: Intracranial migration of odontoid screws is a rare but serious complication of anterior odontoid screw fixation not often reported in literature by neurosurgeons. Here, we describe the second case in literature of intracranial migration of an odontoid screw.

Case description: A 64-year-old neurologically intact patient with a type II odontoid fracture secondary to trauma underwent anterior odontoid screw fixation without any intraoperative complications. He tolerated the procedure well, and postoperative imaging demonstrated near anatomic correction of the fracture with satisfactory placement of the lag screw. Unfortunately, the patient was subsequently lost to follow up and he presented 7 months later for a routine outpatient computed tomography (CT) of the cervical spine, which demonstrated upward migration of the screw into the intracranial cavity abutting the medulla, with CT angiography of the neck also confirming the screw lying between the two vertebral arteries. Magnetic resonance imaging of the cervical spine also demonstrated the odontoid screw lying within close proximity to the ventral cervicomedullary junction, marginating the left vertebral artery. Subsequently, the patient was managed with removal of the odontoid screw and posterior cervical arthrodesis and instrumented fusion.

Conclusion: Our case demonstrates the rare but serious complication of intracranial odontoid screw migration, which we bring to the attention of the neurosurgical community. The recognition of risk factors for this complication and optimized management of this rare occurrence is important for surgeons to recognize.

Keywords: Anterior odontoid screw fixation; C2 odontoid screw; Postoperative intracranial migration.

Copyright: © 2019 Surgical Neurology International.

Figure 1:

Coronal and sagittal computed tomography images of the cervical spine, demonstrating type II odontoid fracture.

Figure 2:

Sagittal immediate post-anterior odontoid screw fixation computed tomography images of the cervical spine, demonstrating near anatomic correction of the patient’s type II odontoid fracture with a lag screw.

Figure 3:

Coronal immediate post-anterior odontoid screw fixation computed tomography images of the cervical spine, demonstrating near anatomic correction of the patient’s type II odontoid fracture with a lag screw.

Figure 4:

Sagittal and coronal computed tomography images of the cervical spine 7 months after anterior odontoid screw fixation demonstrating upward migration of the patient’s odontoid screw.

Figure 5:

Axial computed tomography angiography sequence of the neck 7 months after anterior odontoid screw fixation demonstrating the odontoid screw (thick arrow) marginating the left vertebral artery (thin arrow).

Figure 6:

Sagittal magnetic resonance imaging sequences of the cervical spine demonstrating the odontoid screw lying within the ventral cervicomedullary junction.

Figure 7:

Axial magnetic resonance imaging sequences of the cervical spine demonstrating the odontoid screw lying within the ventral cervicomedullary junction.

Figure 8:

Sagittal computed tomography images of the cervical spine demonstrating subsequent removal of the odontoid screw with C1-4 posterior cervical instrumented fusion.