Surgical Results of Intraoperative C-arm Fluoroscopy Versus O-arm in Transarticular Screw Fixation for Atlantoaxial Instability

Abstract

This study compared the surgical results of transarticular screw (TAS) fixation for atlantoaxial instability between C-arm fluoroscopy and O-arm. Of 58 patients who underwent TAS fixation for atlantoaxial instability, 35 underwent C-arm-assisted surgery (C-group) and 23 underwent O-arm-assisted surgery (O-group). In total, 78 TASs were placed: 39 in the C-group and 39 in the O-group. Unilateral and bilateral TAS fixation was performed in 38 and 20 patients, respectively. All patients underwent Brook's procedure with TAS. TAS fixation accuracy on postoperative computed tomography, operative time, intraoperative bleeding, perioperative complications, and bone union were evaluated. Screw accuracy was assessed using Neo's classification: grade (G) 0, no perforation; G1, perforation <2 mm; G2, perforation 2-4 mm; G3, perforation >4 mm. TAS fixation accuracy was greater in the O-group than the C-group: G0: 38, 97.4%; G1: 1, 2.6% (O-group) vs G0: 22, 56.4%; G1: 11, 28.2%; G2: 3, 7.7%; G3: 3, 7.7% (C-group) (P < 0.001). Median operative time and median blood loss were similar between both groups. Bone union rate was greater with bilateral than unilateral TAS fixation (P <0.05). There were no complications regarding screw malposition. Deep wound infection was observed in 1 case in the C-group. O-arm use improved TAS fixation accuracy. Blood loss was equivalent between the groups. O-arm-assisted TAS fixation did not prolong operative timedespite the time required for setting and scanning. The O-arm is safe and useful for TAS fixation in atlantoaxial instability.