Intraoperative neurophysiologic monitoring during spinal osteotomies

Intraoperative Multimodal Monitoring in Pedicle Subtraction Osteotomies of the Lumbar Spine: A Narrative Literature Review

The use of intraoperative multimodal monitoring (IOM) in spinal deformity surgeries is well documented. In particular, pedicle subtraction osteotomy (PSO), a corrective procedure for sagittal deformity of the spine, often involves IOM usage. By providing immediate feedback to the operating surgeon, IOM has the potential to eliminate or at least minimize the risk of iatrogenic neurological injury. However, despite the widespread usage of IOM, there is currently no standardization of IOM usage in complex spine surgeries, including lumbar PSOs, and decisions concerning IOM utilization are often driven by surgeon experience and preference. This creates a state of clinical equipoise, which is further complicated by the varying degrees of benefit that IOM has on patient outcomes depending on the operation and spinal levels involved. For instance, while IOM use in thoracic PSOs has been shown to be effective, there is no established consensus on the net impact of IOM use in PSOs of the lumbar spine. Although IOM has the potential to mitigate neurological damage, it also increases operation time and cost; thus, it should only be used in operations where it will have a net positive impact on patient outcomes. The question thus becomes whether PSO of the lumbar spine is one such operation. To address this, we examine the most frequently used IOM modalities and evaluate their current usage and efficacy in lumbar PSOs. Furthermore, we will also examine the utility of IOM for other surgeries of the lumbar spine, including corrective procedures for idiopathic scoliosis and degenerative scoliosis, and routine lumbar procedures, such as discectomies and decompression surgeries for foraminal and canal stenosis.

Ponte Osteotomies Increase the Risk of Neuromonitoring Alerts in Adolescent Idiopathic Scoliosis Correction Surgery

STUDY DESIGN

Observational cohort study of prospective database registry.

OBJECTIVE

To determine the incidence of neurological complications in AIS patients undergoing surgical treatment with PO.

SUMMARY OF BACKGROUND DATA

Despite the widespread use of Ponte Osteotomies (PO) in adolescent idiopathic scoliosis (AIS) correction, outcomes and complications in patients treated with this technique have not been well characterized.

METHODS

A multicenter prospective registry of patients undergoing surgical correction of AIS was queried at 2-year follow-up for patient demographics, surgical data, deformity characteristics, and peri-operative complications. A neurological complication was defined as perioperative nerve root or spinal cord injury as identified by the surgeon. Patients were divided into those who underwent peri-apical PO and those without, and further stratified by Lenke curve classification into 3 groups (I-types 1 and 2, II-types 3, 4, 6, and III-type 5). Patients with- and without neurological complications were compared with respect to baseline demographics, surgical variables, curve types, fusion construct types (screws vs. hybrid), curve magnitude (coronal and sagittal Cobb), apical vertebral translation, and coronal-deformity angular ratios (C-DAR).

RESULTS

Of 2210 patients included in the study, 1611 underwent PO. Peri-operative neurological complications occurred in 7 patients, with 6 in the PO group (0.37%) and 1 in non-PO group (0.17%) though this was not a statistically significant risk factor for peri-operative neurological injury (P = 0.45). Neuromonitoring alerts were recorded in 168 patients (7.6%: 9.3% PO group; 4.2% no-PO group (P < 0.001)). Multivariate logistic regression analysis found PO and curve magnitude to be independent risk factors for intraoperative neuromonitoring alerts (P < 0.01).

CONCLUSION

PO and curve magnitude were independent risk factors for intraoperative neuromonitoring alerts in surgical AIS correction. The effect of Ponte osteotomy on neurological complications remains unknown due to the low incidence of these complications.

LEVEL OF EVIDENCE

3.