Asian Journal of Orthopaedic Research

Purpose:  To evaluate the correlation between perioperative neurology and intraoperative neuromonitoring (IONM), to define IONM's clinical value and its optimal applicability in spine patients.

Overview of Literature: In Malaysia, rising spine surgery rates and a 5.2-12.6% risk of neurological deficits highlight the need for safety measures. IONM can mitigate risks, but its high cost and contentious clinical value create a dilemma for surgeons, balancing medicolegal pressures against proven patient benefits.

Methods: The study employed a retrospective cross-sectional design, analysing a cohort of 114 patients who received spinal surgery with IONM at Hospital Queen Elizabeth over a one-year period (January - December 2024). Through a systematic review of medical records, we collected a defined dataset encompassing demographic profiles, primary spinal diagnoses, serial ASIA Impairment Scale scores (preoperative and at 24h/72h postoperative), patient-reported symptoms, and full intraoperative neurophysiological data (MEP, SSEP, and EMG).

Study Design: Cross Sectional Retrospective Study

Results: In this study of 114 patients, IONM was most frequently used for scoliosis corrective surgeries (56%). Remarkably, the vast majority of its use was for spine surgeries involving the cervical and thoracic regions (95.6%). The majority of spine patients (94.7%) we utilized IONM on are of ASIA A, B and C. A significant association existed between preoperative ASIA scores and baseline IONM signals (p<0.001). MEPs demonstrated superior sensitivity to SSEP for detecting preoperative neurological deficits. Crucially, intraoperative MEP changes strongly predicted postoperative neurological and symptomatic outcomes (p<0.001), unlike SSEPs. Transient EMG bursts were not associated with postoperative radiculopathy.

Conclusion: This study substantiates our institutional protocol mandating IONM for scoliosis corrections, recommending it for cervical/thoracic spine surgeries, complicated lumbar spine surgery/minimally invasive lumbar spine surgery, and patients with preoperative ASIA A, B or C. We found a significant association between preoperative neurological status and baseline IONM signals. Crucially, intraoperative MEP changes proved to be a specific and significant predictor of postoperative neurological function, underscoring MEP's paramount value in preventing deficits and enhancing surgical safety.