Spine Pedicle Screw Placement Clinical Trial
Official title:
Accuracy of Lumbar Pedicle Screw Placement Assisted With Continuous Pulse-train Stimulation During Track Creation and Screw Insertion
The purpose of this study is to establish the accuracy of pedicle positioning using continuous electrical pulse during screwing. Additionally, the investigators evaluate if this maneuver can prevent neurological injury during track creation and screwing in lumbar and thoracic spine instrumentation surgery
Pedicle screw instrumentation as part of spine surgery is a recurrent technique used for most
of spine surgeons. Since its description by Boucher in 1959 and its popularization later by
Roy-Camille, has been considered a technique that demands great anatomy knowledge and some
grade of expertise. Even in experienced hands the misplacement of pedicle screws could have
an incidence of 10-40% (average of 20%). Medially misplacements during track creation and
screw insertion are the most feared complications, because the anatomic relationship between
medial pedicle wall and neural structures. The first attempt to use continuous electrical
stimulation during pedicle track creation and screw insertion was communicated in 1997 by
Welch WC, et al. In that study they used the bone impedance as a direct measurement of
pedicle wall integrity; unfortunately they used inhaled anesthetics and assessed the final
screw position with plain X-rays. They reported a sensibility and specificity of 98% and 99%
respectively. The great limitation for this study is its assessment of screw accuracy
performed by plain X-rays, now a days the best way to do it is with computed tomography (CT).
After the Welch report, a couple of studies more have used similar techniques in the thoracic
spine trying to avoid neurological injuries during pedicle screw insertion, but none
described the use of continuous train pulses during screwing.
The present study pretends to evaluate the final accuracy and trans-operative usefulness of
the pulse train stimulation during track creation and screw insertion using intra venous
anesthetic agents and CT scans to assess the integrity of pedicle walls
;