Comparison of Atlantoaxial Fusion with Transarticular Screws and C1 Lateral Mass–C2 Screws Using Intraoperative O-Arm Navigation

This study compared the surgical outcomes of atlantoaxial fusion with transarticular screws (TASs) and C1 lateral mass–C2 screws (screw-rod constructs [SRCs]) using the intraoperative O-arm navigation system (O-arm). Among a total of 28 patients who underwent atlantoaxial fixation, 13 underwent TAS fixation and 15 underwent SRC fixation using the O-arm. All patients underwent Brooks procedure with iliac bone graft in addition to screw fixation. TAS fixation was performed for cases without high-riding vertebral artery (hVA). In the SRC group, pars or lamina screws were inserted for the side with a C2 hVA. Operative time, intraoperative bleeding, perioperative complications, screw accuracy, and bone union were evaluated. There were statistically significant differences in mean operative time between the 2 procedures (166 minutes in the TAS group vs. 212 minutes in the SRC group, P < 0.05) and in mean blood loss (80 vs. 185 mL, respectively; P < 0.01). Two patients developed temporary postoperative occipital neuralgia probably related to C2 nerve root in the SRC group. No screws violated the cortex in either group. Complete bone union was observed in all cases. O-arm–assisted TAS fixation had less intraoperative blood loss, shorter operative time, and fewer screw insertion complications than O-arm–assisted SRC fixation. O-arm–assisted TAS fixation is preferable for atlantoaxial fusion in patients without hVA.