Risk Factors for Spinal Cord Monitoring Alerts in Paediatric Patients Undergoing Spinal Deformity Surgery

Intraoperative neurophysiological monitoring (IONM) is a standard practice during spinal deformity surgery, but evidence in paediatric patients is limited. This retrospective study aims to identify factors associated with IONM alerts during paediatric spinal deformity surgery.

Patients ≤18 years old who underwent scoliosis correction surgery in a single institute between 2017 and 2022 were reviewed. Analysed factors included estimated blood loss (EBL), operative time, pre- and postoperative major Cobb angles, and mean corrective rate.

Among 216 cases, eight had significant IONM alerts. These patients had a significantly longer operative time (p = 0.030), preoperative major Cobb angle (p = 0.048) and postoperative major Cobb angle (p = 0.019). Age (p = 0.481), sex (p = 0.416), mean corrective rate (p = 0.799) and EBL (p = 0.062) did not differ significantly. Alerts were found to be primarily triggered by rod application and curve correction (62.5%), screw insertion (25.0%) and corpectomy (12.5%). In the alert group, no patients experienced postoperative neurological deficits, and one operation (12.5%) was aborted. One patient (0.5%) in the non-alert group developed a transient postoperative foot drop but recovered completely nine weeks later.  Conclusion: Greater operative time and preoperative and postoperative major Cobb angles were associated with IONM alerts. Most alerts occur during and after the insertion of instrumentation and curve correction manoeuvres. The triggering event should be reversed immediately, and if signals do not recover, surgery should be aborted and staged to prevent neurological deficit.