Commentary: Utility of the O-Arm in spinal surgery

Abstract

More studies report the intraoperative benefits vs. risks of utilizing the O-Arm in performing pedicle screw insertion in spinal surgery. Several studies document the utility of CT-guided O-arm placement of pedicle/lateral mass screws. Singh et al. documented the efficacy of CT guided-O Arm placement of pedicle screws and lateral mass screws in the upper cervical spine.[4] Specifically, 10 patients with unstable hangman's fractures (ages 17-80) required 52 screws; C2 pedicle screws (20), C3 lateral mass screws (20), C4 lateral mass screws (12) and one C2 pedicle screw. Of these only 5% were misplaced, and none had new neuorlogical deficits. Kim et al. demonstrated the safety/efficacy of the CT/O-arm in minimally invasive spine surgery (MIS) (posterior percutaneous spinal fusions).[1] Of 290 pedicle screws, 280 (96.6%) were acceptably placed. Kotani et al. compared the placement of 222 pedicle screws (29 patients operated upon with CT-based navigation) vs. 416 screws (32 having surgery using O-arm-based navigation); postoperative CT studies confirmed the accuracy of screw placement, and no significant differences in the frequency of grade 2-3 perforations between the two groups. Nelson et al. analyzed the radiation exposure delivered to the operating room staff utilizing C-arm fluoroscopy (C-arm), portable X-ray (XR) radiography, and portable cone-beam computed tomography (O-arm); the surgeon and assistant were exposed to higher levels of scatter radiation from the C-arm, with a 7.7-fold increase in radiation exposure on the tube vs. detector sides.[3] There are several pros and a few cons (radiation dosage) for the use of the O-arm in spine surgery.