case_images: PMC9852344_01
case_images: Preoperative x-ray revealing atlantoaxial instability.
case_images: fsurg-09-1006167-g001.jpg
case_images: PMC9852344_01_fsurg-09-1006167-g001.jpg
case_images: F1
case_images: Cervical flexion and extension radiographs suggested atlantoaxial instability (Figure 1), and a cervical computed tomography (CT) scan demonstrated the existence of a bony continuity that had not been displaced within the odontoid process (Figure 2).
case_images: Sagittal CT view showing os odontoideum ( ).
case_images: fsurg-09-1006167-g002.jpg
case_images: PMC9852344_01_fsurg-09-1006167-g002.jpg
case_images: F2
case_images: Cervical flexion and extension radiographs suggested atlantoaxial instability (Figure 1), and a cervical computed tomography (CT) scan demonstrated the existence of a bony continuity that had not been displaced within the odontoid process (Figure 2).
case_images: Sagittal and axial preoperative magnetic resonance imaging showing os odontoideum ( ) and a compressive retro-odontoid cyst (arrows) with a hyperintense medullary signal.
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case_images: PMC9852344_01_fsurg-09-1006167-g003.jpg
case_images: F3
case_images: T2 hyperintensity and T1 hypointensity. The cyst was exerting pressure on the spinal cord, and the intramedullary T2 hyperintensity signified a spinal cord disorder (Figure 3).
case_images: Preoperative carotid CTA indicated the presence of a high left carotid artery span in the patient.
case_images: fsurg-09-1006167-g004.jpg
case_images: PMC9852344_01_fsurg-09-1006167-g004.jpg
case_images: F4
case_images: Figure 4 indicates the presence of a high left carotid artery span in the patient.
case_images: Postoperative lateral x-ray of cervical spine.
case_images: fsurg-09-1006167-g005.jpg
case_images: PMC9852344_01_fsurg-09-1006167-g005.jpg
case_images: F5
case_images: It was decided to perform a C1-C3 fixation (Figure 5), and, two days after the operation, the MRI results showed that the retro-odontoid cyst was still present and had not changed significantly compared with the preoperative MRI results (Figure 6).
case_images: Sagittal and axial immediate postoperative magnetic resonance imaging showing the continued presence of the retro-odontoid cyst.
case_images: fsurg-09-1006167-g006.jpg
case_images: PMC9852344_01_fsurg-09-1006167-g006.jpg
case_images: F6
case_images: It was decided to perform a C1-C3 fixation (Figure 5), and, two days after the operation, the MRI results showed that the retro-odontoid cyst was still present and had not changed significantly compared with the preoperative MRI results (Figure 6).
case_images: Sagittal and axial 3-month postoperative magnetic resonance imaging showing the complete disappearance of the retro-odontoid cyst.
case_images: fsurg-09-1006167-g007.jpg
case_images: PMC9852344_01_fsurg-09-1006167-g007.jpg
case_images: F7
case_images: The follow-up MRI also showed the complete disappearance of the retro-odontoid cyst and no signs of persistent spinal cord involvement (Figure 7).