MMG vs. EMG for Cortical Breach Detection

Prospective Evaluation of Mechanomyography Versus Triggered Electromyography for Intraoperative Assessment of Cortical Breaches During Instrumented Lumbar Spine Surgery

The purpose of this study is to determine how well mechanomyography (MMG) and electromyography (EMG) prevent cortical bone breaches, or the pinching of a nerve from screw placement, in patients having lower back surgery requiring hardware. Both MMG and EMG are devices approved by the FDA to detect the location of nerves during surgery so they can be avoided. The results from both tests will be compared to one another to determine if one is better at accurately locating nerves than the other.

Study Overview

• Status: Completed
• Conditions: Low Back Disorder
• Intervention / Treatment: Device: Triggered Electromyography; Device: Mechanomyography

• Study Type: Interventional
• Enrollment (Actual): 65
• Phase: Not Applicable

Contacts and Locations

Study Locations

• United States
  • Kentucky
    • Lexington, Kentucky, United States, 40536
      • University Of Kentucky

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 14 years to 76 years (Adult, Older Adult)
• Accepts Healthy Volunteers: Yes

Description

Inclusion Criteria:

• scheduled to undergo a one-, two-, or three-level posterolateral spinal fusion surgery using Depuy Synthes Expedium pedicle screw instrumentation.
• over the age of 18 years old
• unresponsive to conservative care for a minimum of 6 months
• psychosocially, mentally, and physically able to fully consent and comply with this protocol

Exclusion Criteria:

• preexisting medical condition or comorbidity that makes them a poor candidate
• open wound local to the operative area, or rapid joint disease, bone absorption, or osteoporosis
• requires medications that may interfere with bone or soft tissue healing
• active local or systemic infection
• metal sensitivity/foreign body sensitivity
• implanted pacemaker
• morbidly obese, defined as a body mass index (BMI) greater than 45
• osteoporosis
• involved in or planning to engage in litigation or receiving Workers Compensation related to neck or back pain.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Diagnostic
• Allocation: N/A
• Interventional Model: Single Group Assignment
• Masking: None (Open Label)

Number of Arms

1

Arms and Interventions

Participant Group / Arm

Intervention / Treatment

Experimental: Intraoperative MMG vs EMG for cortical breach detection; Participants in this arm will be assessed with both MMG and EMG during their lower spine fusion surgery.

Device: Triggered Electromyography; Triggered electromyography will be used during surgery to detect nerve impingement by pedicle screws used for spinal fusion. Threshold stimulation data from the device will be recorded.; Device: Mechanomyography; SENTIO MMG ball tip probe will be used during surgery to detect nerve impingement by pedicle screws used for spinal fusion. Threshold stimulation data from the device will be recorded, and the accuracy compared to the data from the triggered electromyography.; Other Names: SENTIO MMG

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Success of Pedicle Screw Trajectories	Patients with successful pedicle screw trajectories determined by the percentage of patients with A/B or C/D/E breaches.; Grade A - No cortical breach (0 mm); Grade B - Pedicle cortical breach < 2 mm; Grade C - Pedicle cortical breach = 2 to < 4 mm; Grade D - Pedicle cortical breach = 4 to < 6 mm; Grade E - Pedicle cortical breach = 6 mm	1 hour

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change in the Short-From (SF-36) Health Survey	This survey quantifies how a patient feels about their health, and how well they are able to do common activities. This survey has 9 domains that assess the patients functional ability. The domains are scored as percentages from 0%-100% with 0% being severely limited and 100% being no deficits.	6 weeks and 3 months after surgery
Change From Baseline in the Numeric Rating Scale (NRS) Questionnaire for Pain.	This survey is used to assess pain experienced by the subject and the severity of the pain. Types of pain include numbness, pins and needles, dull aching, burning sensation, muscle cramps, and stabbing pain. Pain severity is rated on a scale of 0-10 where 0 is no pain and 10 is the worst pain imaginable. Pain is assessed in the back and legs. Changes reported as percentages using the formula [(Average measure at 3 months - Average measure at baseline)/Average measure at baseline].	3 months after surgery
Change From Baseline in the Oswestry Disability Index Version 2.1A	This survey is used to quantify disability for low back pain. There are five disability categories ranging from minimally disabled to crippled. The appropriate disability category is determined by the sum of the subjects points divided by the total possible points(50) times 100. This yields a % disabled score and this % determines the appropriate category designation. 0% is equated with no disability and 100% is the maximum disability possible. Changes reported as percentages using the formula [(Average measure at 3 months - Average measure at baseline)/Average measure at baseline]	3 months after surgery
Change From Baseline in the PROMIS Global-10	This questionnaire is a 10 item patient reported tool used to quantify the patients general healthcare related quality of life. It assesses both physical and mental health and is scored as a percentage. Scores closer to 100% report a better quality of life than those who score lower. Changes reported as percentages using the formula [(Average measure at 3 months - Average measure at baseline)/Average measure at baseline]	3 months after surgery
Hospital Readmission at 30 Days	Percent of patients undergoing hospital readmission 30 days following the procedure.	30 days
Hospital Readmission at 90 Days	Percent of patients undergoing hospital readmission 90 days following the procedure.	90 days

Collaborators and Investigators

• Sponsor: Francis Farhadi
• Collaborators: DePuy Synthes
• Investigators: Principal Investigator: H. Francis Farhadi, MD, PhD, University Of Kentucky

Study record dates

Study Major Dates

• Study Start (Actual): August 2, 2022
• Primary Completion (Actual): July 9, 2024
• Study Completion (Actual): November 6, 2024

Study Registration Dates

• First Submitted: April 22, 2022
• First Submitted That Met QC Criteria: April 22, 2022
• First Posted (Actual): April 28, 2022

Study Record Updates

• Last Update Posted (Actual): August 19, 2025
• Last Update Submitted That Met QC Criteria: August 1, 2025
• Last Verified: August 1, 2025

More Information

Terms related to this study

• Keywords: Lumbar fusion; Lower back surgery
• Other Study ID Numbers: 76122

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: Yes
• product manufactured in and exported from the U.S.: Yes