Correlation: Impedance and Tomography in Implants Insertion in Lumbar Arthrodesis

Abstract

Objective: To define whether the electroneurophysiological stimulation would be a safe method for reducing injuries in nerve roots during surgery of lumbar spine arthrodesis, as well as verify whether there is a direct correlation between the intraoperative impedance values and the distance from the medial cortical pedicle screw. Methods: Randomized retrospective multicenter study of 10 patients who underwent arthrodesis of lumbar spine after conservative treatment failure, with a total of 50 pedicle screws instrumented. Reliable and safe impedance values were measured in order to reduce the risk of injury to nerve roots in the perioperative period, and these values were compared with the distance between the screw and the medial cortical of the pedicle by CT scan, measured in the immediate post-operative period. Results: There is no direct correlation between the intraoperative impedance values and the distance from the screw to the medial cortical of the pedicle. Conclusion: The electroneurostimulation proved to be a reliable quantitative method to reduce the risk of injury to nerve roots during surgery of lumbar spine arthrodesis when the measured values are greater than 10mA.