Accuracy of 837 pedicle screw positions in degenerative lumbar spine with conventional open surgery evaluated by computed tomography.

Screw application reached a mean accuracy of 85.7% based on anatomical landmarks supported by fluoroscopy, warranting computer-assisted navigation for increased accuracy. Our results of 24 patients (16.3%) with the breached screws indicate that the direction of the breach may be more important than the absolute deviation in causing new neurologic symptoms.