Spinal Deformity Intraoperative Monitoring.

A multicenter, international prospectively collected patient cohort undergoing high-risk
spinal cord level surgery or spinal osteotomy procedures will be enrolled to establish the
incidence of intraoperative alerts in high-risk spinal cord cases, and explore factors
associated with mitigating injury. Baseline, intraoperative, and postoperative
characteristics, including demographics, radiological features, lower extremity motor score
(LEMS), procedure, anesthetic agents used, and baseline blood pressure will be recorded for
either adult patients or pediatric patients.

If a major change occurs in the intraoperative neuromonitoring, defined as a loss of
amplitude greater than 50% in the MEP or SSEP from baseline or sustained EMG activity, a
separate form (Appendix 3, Intraoperative Alert Form) will be completed in real-time by the
neuromonitoring technician outlining the timing of the alert, blood pressure at the time,
surgical events at the time of the change, intraoperative maneuvers performed to address the
change, and resultant outcome of these maneuvers to address the neuromonitoring change. For
each alert occurring during the procedure, a separate form will be completed.

Once the patient is awake from anesthesia, the treating surgeon will perform a neurological
examination to identify details about the deficit including sidedness, LEMS, sensory deficit,
injury to the nerve root, incomplete spinal cord (ie anterior cord, posterior cord, central
cord, Brown-Sequard), complete spinal cord injury, conus or cauda equina deficit. The
examination is repeated on the day of discharge from hospital, or at day 30, whichever comes
first and documented in the corresponding form.

The objective of this study is to identify the incidence of intraoperative alerts in
high-risk spinal cord cases, correlate significant neuromonitoring changes to intraoperative
events, and identify maneuvers that will restore the neuromonitoring changes to baseline. The
information provided by this study will educate spinal surgeons to recognize a spinal cord at
risk and to perform intraoperative maneuvers that will decrease the incidence of neurological
injuries.

Inclusion Criteria:

- Age >10 years to <80 years

- Neurologically intact spinal cord (with or without radiculopathy)

- Undergoing primary or revision procedure in the spine

- Anterior and/or posterior surgical approach for any of the following:

- Correction of spinal deformity with a major Cobb angle of ≥ 80° in the coronal or
sagittal plane

- Correction of high grade spondylolisthesis (Grades 3- 5)

- Posterior column or 3-column osteotomy

- Requiring multimodal neuromonitoring with EMG, SSEP, and MEP as per standard of care

- Informed consent obtained for patients i.e.:

- Ability to understand the content of the patient information

- Willingness and ability to participate in the clinical investigation according to
the Clinical Investigation Plan (CIP)

- Signed and dated EC/IRB approved written informed consent OR

- Written consent obtained according to defined and IRB/EC approved procedures for
patients who are not able to provide independent written informed consent

Exclusion Criteria: • Neurodegenerative disease

- Upper motor neuron lesion

- Growing rods or growth guidance procedures

- Tether or staple procedures

- Stand-alone cervical deformity correction procedures

- Any not medically managed severe systemic disease

- Recent history of substance abuse (ie recreational drugs, alcohol) that would preclude
reliable assessment

- Pregnancy or women planning to conceive within the study period

- Prisoner

- Participation in any other medical device or medicinal product study that could
influence the results of the present study