Enhanced Safety of Pedicle Subtraction Osteotomy Using Intraoperative Ultrasound

Abstract

Pedicle subtraction osteotomy (PSO) can improve sagittal alignment but carries risks, including iatrogenic spinal cord and nerve root injury. Critically, during the reduction phase of the technique, medullary kinking or neural element compression can lead to neurologic deficits. We describe 3 cases of thoracic PSO and evaluate the feasibility, findings, and utility of intraoperative ultrasound in this setting. Intraoperative ultrasound can provide a visual assessment of spinal cord morphology before and after PSO reduction and influences surgical decision making with regard to the final amount of sagittal plane correction. This modality is particularly useful for confirming ventral decompression of disc-osteophyte complex before reduction and also after reduction maneuvers when there is kinking of the thecal sac but uncertainty about the underlying status of the spinal cord. Intraoperative ultrasound is a reliable modality that fits well into the technical sequence of PSO, adds a minimal amount of operative time, and has few limitations. We propose that intraoperative ultrasound is a useful supplement to standard neuromonitoring modalities for ensuring safe PSO reduction and decompression of neural elements.