Intraoperative Multimodal Monitoring in Pedicle Subtraction Osteotomies of the Lumbar Spine

Abstract

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. While IOM has the potential to mitigate neurological damage, it also increases operation time and cost; thus, it should only be employed 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 employed 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