Anterior transarticular screw fixation for atlantoaxial arthrodesis: A report of two cases
This is a first case of a 34-year-old male patient presented to the orthopedic out-patient clinic with a diagnosis of chronic AAI secondary to an os odontoideum. On presentation, he complained of neck stiffness and denied numbness or weakness. On examination, the patient was neurologically intact and had full range of motion of the cervical spine in flexion, extension, lateral bending and axial rotation. CT and plain radiographs demonstrated significant displacement in flexion and extension, os odontoideum and instability at C1-2 []. MRI of the brain showed cerebellar infarct, with confirmation on CT angiogram of bilateral vertebral artery occlusions between C2 and C3, collateral reconstitution from the right occipital artery and bridging anastomoses on the left. Significant instability at C1-2 warranted surgical fusion and an anterior approach was selected due to anomalous vascular anatomy, which precluded a safe posterior exposure and fixation by C1 LMS-C2PS.\nThe patient was treated with anterior transarticular C1-2 instrumentation and fusion as described by Sen et al.[] Post-operative CT scans confirmed acceptable screw placement in the axial [Figure and ], sagittal [] and coronal [Figure and ] planes. At 16 months follow-up, the patient maintained painless range of motion of the cervical spine with stable fixation and fusion without sensorimotor deficit.