Accuracy of Lumbar Pedicle Screw Placement Assisted With Continuous Pulse-train Stimulation

Not Applicable

• Conditions: Spine Pedicle Screw Placement
• Interventions: Procedure: Electric pulse train stimulation

• Registration Number: NCT01342588
• Lead Sponsor: American British Cowdray Medical Center

Brief Summary

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

Detailed Description

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

Study Timeline

• Study Start: 2011-01
• Status Verified: 2011-04
• Study First Submitted: 2011-04-20
• Study First Submitted QC: 2011-04-26
• Last Update Submitted: 2011-04-26
• Study First Posted: 2011-04-27
• Last Update Posted: 2011-04-27
• Primary Completion: 2012-04
• Study Completion: 2012-05

Recruitment & Eligibility

• Status: UNKNOWN
• Sex: All
• Target Recruitment: 60

Inclusion Criteria

• Any patient who needs pedicle screw placement for any spine condition

Exclusion Criteria

• Previous spine surgery
• Pedicle fracture documented before or during surgery.
• Preoperative identified neurological deficit of the nerve roots close to the instrumented levels

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: SINGLE_GROUP

Arm && Interventions

Group	Intervention	Description
Electrical stimulation	Electric pulse train stimulation	Only arm of the study, the experimental

Primary Outcome Measures

Name	Time	Method
Intra operative neurophysiological monitoring (IONM) alert	Participants will be followed for the duration of surgical procedure, an expected average of 3-4 hours	- Continuous electrical stimulation delivered by a wire connected to the surgical instruments only during pedicle track creation and screw placement combined with neurophysiological monitoring will let us identify any IONM alert, defined as nerve irritation or a decrease in voltage and/or amplitude response. This is a single and immediate measurement obtained at surgery during spinal screw placement.

Secondary Outcome Measures

Name	Time	Method
Pedicle screw accuracy	On day 2 after surgery before patient discharge, a CT scan will be performed	On day 2 post surgery, a CT scan with sagittal, coronal and axial reconstructions will be obtained . The same day of the study, two independent observers will assess the accuracy of screws inside lumbar pedicles, recording in millimeters, any pedicle wall violation on sagittal, axial and coronal views for each screw placed. In that way we could have the accuracy of pedicle screws placed with the proposed technique, before patient discharge.

Trial Locations

Locations (1)

American British Cowdray Medical Center; 🇲🇽 Mexico City, Mexico DF, Mexico