The purpose of this study is to document the usefulness of an intraoperative neuromonitoring (IONM) system that is already established and approved by the U.S. Food and Drug Administration (FDA). The system is used to monitor nerve health during lateral lumbar interbody fusion (LLIF) surgical procedures. Specifically, the study will record the information that is provided by the neuromonitoring system to the patient’s surgeon and how that information was used. The study may provide information about how such monitoring may help to avoid surgical complications in future patients by identifying patient and surgical factors that might affect neuromonitoring results. Participants will be patients whose surgeons have already determined that lateral lumbar interbody fusion is the best treatment option for their spinal condition. Researchers will capture observational details of otherwise routine and standard-of-care surgical treatment, surgical monitoring, and follow-up.