Assessing the Temporal Evolution and Utility of Neuromonitoring in Adult Spinal Deformity Corrective Surgery

Thursday, June 1, 2023

8:30 AM – 6:15 PM

Location: Salons 7-8

Co-Author(s)

PT

Peter S. Tretiakov, BS

United States
KM

Kim Mcfarland

Florida, United States
PD

Pooja R. Dave

Miami, Florida, United States
JM

Jamshaid M. Mir, MD

Research Fellow
NYU Langone Health | NY Spine Institute, United States
JL

Jordan Lebovic, MD, MBA

Resident
NYU Langone Orthopedics
New York, New York, United States
SV

Shaleen Vira, MD

Assistant Professor, Orthopaedic Surgery & Neurosurgery
UT Southwestern Medical Center
Dallas, Texas, United States

Presenting Author (Person doing the Podium Present(s)

PP

Peter G. Passias, M.D.

Spine Surgeon
NYU Langone Orthopedic Hospital
New York, New York, United States

View E-Poster

Submitter(s)

PP

Peter G. Passias, M.D.

Spine Surgeon
NYU Langone Orthopedic Hospital
New York, New York, United States

View E-Poster

Disclosure(s):

Peter G. Passias, MD: No relevant disclosure to display

Background: Given the inherent neurological risk of adult spinal deformity surgical correction, numerous intraoperative technologies are utilized to provide real-time monitoring. More recent implementation of robotic screw placement and other navigation technologies may reduce necessity of intraoperative neuromonitoring, though it may be critical in cases of severe deformity carrying increased risk of neurologic complications.

Purpose: To evaluate temporal trends and utility of neuromonitoring for thoracolumbar adult spinal deformity surgery.

Methods: Operative adult spinal deformity patients with available demographics and intraoperative data were included. Date of surgery was recorded as the year only. Intraoperative neuromonitoring reports were reviewed for abnormalities and the lowest signal threshold was recorded. A neuromonitoring event (“NM event”) was defined as any incident of abnormal signal and/or a threshold < 12 mA. Two-tailed T-test assessed differences in mean year of surgery for NM event. Nonparametric testing with Yates’ continuity correction assessed differences in median year of surgery. Date of surgery was then grouped as pre-2016, 2017-2018, and 2019-2022 based on adoption of robotics in 2017 and CAIN + intraoperative 3D CT in 2019. Backstep logistic regression assessed predictive potential of NM in assessing risk of complications while controlling for relevant covariates.

Results: 190 ASD patients (average 58.9±11.5 years old, 48% female, BMI of 31.3±6.6 kg/m2, CCI of 2.8±1.6) were isolated who underwent surgical correction (average 7.2±4.5 levels fused, EBL of 1625±1718 mL, operative time 530.2±165.5 mins, and length of stay 7.1±4.9 days). Surgical date ranged from 2013 to 2022 with median of 2019 and mode of 2021. Overall, 64.7% had at least one NM event with median of 2017 and mode of 2016. Median year of surgery was significantly different in those with NM events (ꭕ2Yates=24.6, p<.001). By surgical year group, rates of any NM event decreased with increasing year group (95.8% vs 80.0% vs 33.3%, p<.001) which was also true for any medial or lateral pedicle screw deviation >3mm (16.7% vs. 0% vs. 0%, p<.001). A logistic regression model controlled for BMI, levels fused, and osteotomies performed found that increasing DOS group was predictive of fewer NM events (OR: 0.248 [0.091-0.677], p=.007). However, when assessing patients with severe deformity by any SRS-Schwab criteria or those requiring 3-column osteotomy, NM alerts were significantly correlated with decreased risk of intra-operative neurological complications (OR: .083 [.011 - .641], p=.017), though not in predicting screw deviation alone (p>.05).

Conclusions: The advancement of intraoperative navigation and screw placement technologies in adult spinal deformity patients has allowed for a decrease in neuromonitoring abnormalities over time. Yet, in patients with severe deformity or those requiring increased correction via 3-column osteotomy, predictive analytics demonstrate that neuromonitoring may be efficacious in preventing intra-operative neurologic complications. Such findings suggest that implementing neuromonitoring protocols may aid surgeons in preventing suboptimal outcomes, though such technologies should continue to be investigated to avoid false-positive events.