An interventional study of Document intraoperative Maneuvers in Spinal Deformity, sponsored by AO Foundation, AO Spine. Completed at 24 sites in 14 countries. Open to participants aged 10 Years to 80 Years. Per ClinicalTrials.gov, last updated 2026-10-06.
Sponsored by AO Foundation, AO Spine · Not applicable, Interventional, and Diagnostic
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.
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.
AO Foundation, AO Spine is the lead sponsor of 11 studies on the registry; 4 are open to participants now.
Counted across the registry records on this site, refreshed daily.
Inclusion Criteria:
Anterior and/or posterior surgical approach for any of the following:
obtained for patients i.e.:
Exclusion Criteria: • Neurodegenerative disease
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Informed consent
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
To document intraoperative maneuvers performed in response to alerts
Procedure: Document intraoperative Maneuvers
Monitoring procedure during surgery
Number of Patients Who Had at Least One Intraoperative Neuromonitoring Alert
Number of intraoperative neuromonitoring alert, defined as a major change in neuromonitoring signals: * SSEP: amplitude loss \> 50% * MEP: amplitude loss \> 50% in two of three muscle groups and/or * EMG: sustained activity for \> 10 seconds
Time frame: Intraoperative, on average 6.3 hours
Number of Patients With IONM Alerts by Modality Combination
Count of IONM alerts and modalities affected
Time frame: Intraoperative, on average 6.3 hours
Preceding Events
Data from the safety set was used to analyze the events preceding the alerts.
Time frame: Intraoperative, on average 6.3 hours
De Novo Neurological Deficit
A de novo neurological deficit is defined as: * Postoperative decrease of one point from baseline in the ASIA LEMS * Worsening in sensory function from baseline * Presence of spinal cord syndrome
Time frame: At discharge or 30 days postoperative (which ever occurs first)
Number of Patient With Different Recovery Status of Alerts
Status of alert recovery
Time frame: Intraoperative
| Milestone | Intraoperative Maneuvers |
|---|---|
| Started | 555 |
| Completed | 555 |
| Not completed | 0 |
Number of intraoperative neuromonitoring alert, defined as a major change in neuromonitoring signals: * SSEP: amplitude loss \> 50% * MEP: amplitude loss \> 50% in two of three muscle groups and/or * EMG: sustained activity for \> 10 seconds
| Participants | The Incidence of IONM Alerts |
|---|---|
| No | 471 |
| Yes | 84 |
Count of IONM alerts and modalities affected
| Participants | The Frequency of IONM Alerts by Modality Combination |
|---|---|
| MEP only | 81 |
| SSEP only | 4 |
| MEP and SSEP only | 16 |
| EMG only | 8 |
| MEP and EMG only | 7 |
| SSEP and EMG only | 0 |
| MEP and SSEP and EMG | 1 |
Data from the safety set was used to analyze the events preceding the alerts.
| Preceding event | Preceding Events |
|---|---|
| Systemic | 7 |
| Anesthesia | 14 |
| Technical | 18 |
| Surgical cause | 89 |
A de novo neurological deficit is defined as: * Postoperative decrease of one point from baseline in the ASIA LEMS * Worsening in sensory function from baseline * Presence of spinal cord syndrome
| Participants | Overall Patients |
|---|---|
| De Novo Neurological Deficit | 62 |
Status of alert recovery
| Participants | Alert Recovery |
|---|---|
| Fully recovered | 90 |
| Partially recovered | 8 |
| Not recovered | 19 |
Collected over 0. Non-serious events are listed at a 0% frequency threshold.
| Group | Deaths | Serious | Other |
|---|---|---|---|
| All Patients | — | — | — |
| Age, Categorical(Participants) | Overall Patients |
|---|---|
| <=18 years | 0 |
| Between 18 and 65 years | 459 |
| >=65 years | 96 |
| Age, Continuous(years) | Overall Patients |
|---|---|
| Mean | 33.4 ± 23.17 |
| Sex: Female, Male(Participants) | Overall Patients |
|---|---|
| Female | 389 |
| Male | 166 |
| Race and Ethnicity Not Collected(Participants) | Overall Patients |
|---|
| Height(cm) | Overall Patients |
|---|---|
| Mean | 157.9 ± 13.49 |
| Weight(kg) | Overall Patients |
|---|---|
| Mean | 57.8 ± 17.75 |
| Diagnosis(patients) | Overall Patients |
|---|---|
| Scoliosis | 376 |
| Kyphosis | 127 |
| High-grade spondylolisthesis | 9 |
| Lordosis | 0 |
| Other | 43 |
| Systolic blood pressure(mmHg) | Overall Patients |
|---|---|
| Mean | 118.5 ± 14.92 |
3 further baseline measures are reported on the registry.
PDFs hosted by the registry, ClinicalTrials.gov.
Ran from May 2019 to primary completion in Mar 2022, 34 months.
Results were first posted in Oct 2026, 4 years 6 months after primary completion.
How these figures are worked out, and which studies are left out of them.
From the registry record's own update history. This site started tracking changes on Sep 25, 2026; for anything earlier, see the record history on ClinicalTrials.gov ↗
This study is completed, as verified in Oct 2026. You cannot join it, but the record below documents what was studied.
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AO Foundation, AO Spine