Calancie B. J Neurosurg Spine. 2014. doi:10.3171/2014.2.SPINE13648.
Neuromonitoring with pulse-train stimulation was shown to be an accurate method for predicting medially malpositioned thoracic screws.
A prospective, blinded, randomized study included 71 patients in whom 802 screws were implanted between the T-1 and L-1 vertebral levels.
According to the researchers, 32 screws were incorrectly placed, with their threads encroaching on the spinal canal by at least 2 mm. By using pulse-train stimulation within the pedicle track with a ball-tipped probe and electromyography from lower limb muscles, all 32 screws were correctly predicted to be malpositioned.
“This novel neuromonitoring approach accurately predicts medially malpositioned thoracic screws. The approach could be readily implemented within any surgical program that is already using contemporary neuromonitoring methods that include transcranial stimulation for monitoring motor evoked potentials,” the researchers concluded.
Disclosure: This study was supported by a grant from the National Institutes of Health to Calancie. Digitimer Limited designed and provided the authors with a current:voltage adapter for recording voltage pulses calibrated to the intensity of current pulses being delivered. Moquin is a consultant for K2M.
